add web server sample

Bumps [golang.org/x/image](https://github.com/golang/image) from 0.12.0 to 0.18.0.
- [Commits](https://github.com/golang/image/compare/v0.12.0...v0.18.0)

---
updated-dependencies:
- dependency-name: golang.org/x/image
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/ci.yml

@@ -0,0 +1,33 @@
+name: "Continuous Integration"
+
+on:
+  workflow_dispatch:
+  push:
+    branches: [ main ]
+    paths: [ "*.go" ]
+  pull_request:
+    branches: [ main ]
+    paths: [ "*.go" ]
+
+jobs:
+  ci:
+    name: "Tests"
+    runs-on: ubuntu-latest
+
+    env:
+      GOOS: "linux"
+      GOARCH: "amd64"
+      GO111MODULE: "on"
+      CGO_ENABLED: "0"
+
+    steps:
+    - name: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version: 1.21
+
+    - name: Check out go-incr
+      uses: actions/checkout@v3
+
+    - name: Run all tests
+      run: go test ./...

.gitignore

@@ -1 +1,20 @@
+# Binaries for programs and plugins
+*.exe
+*.dll
+*.so
+*.dylib
+
+# Test binary, build with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Project-local glide cache, RE: https://github.com/Masterminds/glide/issues/736
+.glide/
+
+# Other
 .vscode
+.DS_Store
+coverage.html
+.idea

.travis.yml

@@ -1,13 +0,0 @@
-language: go
-
-go:
-  - 1.6.2
-
-sudo: false
-
-before_script:
-  - go get -u github.com/blendlabs/go-assert
-  - go get ./...
-
-script:
-  - go test ./...

COVERAGE

@@ -0,0 +1 @@
+29.02

LICENSE

@@ -1,6 +1,7 @@
 MIT License
 
 Copyright (c) 2016 William Charczuk.
+Copyright (c) 2024 Zeni Kim.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

Makefile

@@ -1,9 +1,10 @@
-all: test
+all: new-install test
+
+new-install:
+	@go get -v -u ./...
+
+generate:
+	@go generate ./...
 
 test:
-	@go test ./...
+	@go test ./...
-
-cover:
-	@go test -short -covermode=set -coverprofile=profile.cov
-	@go tool cover -html=profile.cov
-	@rm profile.cov

PROFANITY_RULES.yml

@@ -0,0 +1,4 @@
+go-sdk:
+  excludeFiles: [ "*_test.go" ]
+  importsContain: [ github.com/blend/go-sdk/* ]
+  description: "please don't use go-sdk in this repo"

README.md

@@ -1,55 +1,55 @@
 go-chart
 ========
-[![Build Status](https://travis-ci.org/wcharczuk/go-chart.svg?branch=master)](https://travis-ci.org/wcharczuk/go-chart)[![Go Report Card](https://goreportcard.com/badge/github.com/wcharczuk/go-chart)](https://goreportcard.com/report/github.com/wcharczuk/go-chart)
 
-Package `chart` is a very simple golang native charting library that supports timeseries and continuous
+This project starts from a full copy from [https://git.smarteching.com/zeni/go-chart](https://git.smarteching.com/zeni/go-chart). 28 Oct 2024.
-line charts. 
 
-The v1.0 release has been tagged so things should be more or less stable, if something changes please log an issue.
+-
 
-Master should now be on the v2.x codebase, which brings a couple new features and better handling of basics like axes labeling etc. Per usual, see `_examples` for more information.
+Master should now be on the v3.x codebase, which overhauls the api significantly. Per usual, see `examples` for more information.
 
 # Installation
 
 To install `chart` run the following:
 
 ```bash
-> go get -u github.com/wcharczuk/go-chart
+> go get git.smarteching.com/zeni/go-chart/v2@latest
 ```
 
-Most of the components are interchangeable so feel free to crib whatever you want. 
+Most of the components are interchangeable so feel free to crib whatever you want.
 
-# Output Examples 
+# Output Examples
 
 Spark Lines:
 
-![](https://raw.githubusercontent.com/wcharczuk/go-chart/master/_images/tvix_ltm.png)
+![](https://git.smarteching.com/zeni/go-chart/raw/branch/main/_images/tvix_ltm.png)
 
 Single axis:
 
-![](https://raw.githubusercontent.com/wcharczuk/go-chart/master/_images/goog_ltm.png)
+![](https://git.smarteching.com/zeni/go-chart/raw/branch/main/_images/goog_ltm.png)
 
 Two axis:
 
-![](https://raw.githubusercontent.com/wcharczuk/go-chart/master/_images/two_axis.png)
+![](https://git.smarteching.com/zeni/go-chart/raw/branch/main/_images/two_axis.png)
 
 # Other Chart Types
 
 Pie Chart:
 
-![](https://raw.githubusercontent.com/wcharczuk/go-chart/master/_images/pie_chart.png)
+![](https://git.smarteching.com/zeni/go-chart/raw/branch/main/_images/pie_chart.png)
 
-The code for this chart can be found in `_examples/pie_chart/main.go`.
+The code for this chart can be found in `examples/pie_chart/main.go`.
 
 Stacked Bar:
 
-![](https://raw.githubusercontent.com/wcharczuk/go-chart/master/_images/stacked_bar.png)
+![](https://git.smarteching.com/zeni/go-chart/raw/branch/main/_images/stacked_bar.png)
 
-The code for this chart can be found in `_examples/stacked_bar/main.go`.
+The code for this chart can be found in `examples/stacked_bar/main.go`.
 
 # Code Examples
 
-Actual chart configurations and examples can be found in the `./_examples/` directory. They are web servers, so start them with `go run main.go` then access `http://localhost:8080` to see the output.
+Actual chart configurations and examples can be found in the `./examples/` directory. They are simple CLI programs that write to `output.png` (they are also updated with `go generate`.
+
+If folder ends in "web", has web servers, so start them with `go run main.go` then access `http://localhost:8080` to see the output.
 
 # Usage
 
@@ -61,7 +61,7 @@ import (
     ...
     "bytes"
     ...
-    "github.com/wcharczuk/go-chart" //exposes "chart"
+    "git.smarteching.com/zeni/go-chart/v2" //exposes "chart"
 )
 
 graph := chart.Chart{
@@ -83,8 +83,7 @@ Here, we have a single series with x range values as float64s, rendered to a PNG
 
 # API Overview
 
-Everything on the `chart.Chart` object has defaults that can be overriden. Whenever a developer sets a property on the chart object, it is to be assumed that value will be used instead of the default. One complication here
+Everything on the `chart.Chart` object has defaults that can be overriden. Whenever a developer sets a property on the chart object, it is to be assumed that value will be used instead of the default.
-is any object's root `chart.Style` object (i.e named `Style`) and the `Show` property specifically, if any other property is set and the `Show` property is unset, it is assumed to be it's default value of `False`.
 
 The best way to see the api in action is to look at the examples in the `./_examples/` directory.
 
@@ -96,4 +95,4 @@ The goal with the API itself is to have the "zero value be useful", and to requi
 
 # Contributions
 
-This library is super early but contributions are welcome.
+Contributions are welcome though this library is in a holding pattern for the forseable future.

_colors/colors_extended.txt

@@ -0,0 +1,147 @@
+aliceblue 	#f0f8ff 	240,248,255
+antiquewhite 	#faebd7 	250,235,215
+aqua 	#00ffff 	0,255,255
+aquamarine 	#7fffd4 	127,255,212
+azure 	#f0ffff 	240,255,255
+beige 	#f5f5dc 	245,245,220
+bisque 	#ffe4c4 	255,228,196
+black 	#000000 	0,0,0
+blanchedalmond 	#ffebcd 	255,235,205
+blue 	#0000ff 	0,0,255
+blueviolet 	#8a2be2 	138,43,226
+brown 	#a52a2a 	165,42,42
+burlywood 	#deb887 	222,184,135
+cadetblue 	#5f9ea0 	95,158,160
+chartreuse 	#7fff00 	127,255,0
+chocolate 	#d2691e 	210,105,30
+coral 	#ff7f50 	255,127,80
+cornflowerblue 	#6495ed 	100,149,237
+cornsilk 	#fff8dc 	255,248,220
+crimson 	#dc143c 	220,20,60
+cyan 	#00ffff 	0,255,255
+darkblue 	#00008b 	0,0,139
+darkcyan 	#008b8b 	0,139,139
+darkgoldenrod 	#b8860b 	184,134,11
+darkgray 	#a9a9a9 	169,169,169
+darkgreen 	#006400 	0,100,0
+darkgrey 	#a9a9a9 	169,169,169
+darkkhaki 	#bdb76b 	189,183,107
+darkmagenta 	#8b008b 	139,0,139
+darkolivegreen 	#556b2f 	85,107,47
+darkorange 	#ff8c00 	255,140,0
+darkorchid 	#9932cc 	153,50,204
+darkred 	#8b0000 	139,0,0
+darksalmon 	#e9967a 	233,150,122
+darkseagreen 	#8fbc8f 	143,188,143
+darkslateblue 	#483d8b 	72,61,139
+darkslategray 	#2f4f4f 	47,79,79
+darkslategrey 	#2f4f4f 	47,79,79
+darkturquoise 	#00ced1 	0,206,209
+darkviolet 	#9400d3 	148,0,211
+deeppink 	#ff1493 	255,20,147
+deepskyblue 	#00bfff 	0,191,255
+dimgray 	#696969 	105,105,105
+dimgrey 	#696969 	105,105,105
+dodgerblue 	#1e90ff 	30,144,255
+firebrick 	#b22222 	178,34,34
+floralwhite 	#fffaf0 	255,250,240
+forestgreen 	#228b22 	34,139,34
+fuchsia 	#ff00ff 	255,0,255
+gainsboro 	#dcdcdc 	220,220,220
+ghostwhite 	#f8f8ff 	248,248,255
+gold 	#ffd700 	255,215,0
+goldenrod 	#daa520 	218,165,32
+gray 	#808080 	128,128,128
+green 	#008000 	0,128,0
+greenyellow 	#adff2f 	173,255,47
+grey 	#808080 	128,128,128
+honeydew 	#f0fff0 	240,255,240
+hotpink 	#ff69b4 	255,105,180
+indianred 	#cd5c5c 	205,92,92
+indigo 	#4b0082 	75,0,130
+ivory 	#fffff0 	255,255,240
+khaki 	#f0e68c 	240,230,140
+lavender 	#e6e6fa 	230,230,250
+lavenderblush 	#fff0f5 	255,240,245
+lawngreen 	#7cfc00 	124,252,0
+lemonchiffon 	#fffacd 	255,250,205
+lightblue 	#add8e6 	173,216,230
+lightcoral 	#f08080 	240,128,128
+lightcyan 	#e0ffff 	224,255,255
+lightgoldenrodyellow 	#fafad2 	250,250,210
+lightgray 	#d3d3d3 	211,211,211
+lightgreen 	#90ee90 	144,238,144
+lightgrey 	#d3d3d3 	211,211,211
+lightpink 	#ffb6c1 	255,182,193
+lightsalmon 	#ffa07a 	255,160,122
+lightseagreen 	#20b2aa 	32,178,170
+lightskyblue 	#87cefa 	135,206,250
+lightslategray 	#778899 	119,136,153
+lightslategrey 	#778899 	119,136,153
+lightsteelblue 	#b0c4de 	176,196,222
+lightyellow 	#ffffe0 	255,255,224
+lime 	#00ff00 	0,255,0
+limegreen 	#32cd32 	50,205,50
+linen 	#faf0e6 	250,240,230
+magenta 	#ff00ff 	255,0,255
+maroon 	#800000 	128,0,0
+mediumaquamarine 	#66cdaa 	102,205,170
+mediumblue 	#0000cd 	0,0,205
+mediumorchid 	#ba55d3 	186,85,211
+mediumpurple 	#9370db 	147,112,219
+mediumseagreen 	#3cb371 	60,179,113
+mediumslateblue 	#7b68ee 	123,104,238
+mediumspringgreen 	#00fa9a 	0,250,154
+mediumturquoise 	#48d1cc 	72,209,204
+mediumvioletred 	#c71585 	199,21,133
+midnightblue 	#191970 	25,25,112
+mintcream 	#f5fffa 	245,255,250
+mistyrose 	#ffe4e1 	255,228,225
+moccasin 	#ffe4b5 	255,228,181
+navajowhite 	#ffdead 	255,222,173
+navy 	#000080 	0,0,128
+oldlace 	#fdf5e6 	253,245,230
+olive 	#808000 	128,128,0
+olivedrab 	#6b8e23 	107,142,35
+orange 	#ffa500 	255,165,0
+orangered 	#ff4500 	255,69,0
+orchid 	#da70d6 	218,112,214
+palegoldenrod 	#eee8aa 	238,232,170
+palegreen 	#98fb98 	152,251,152
+paleturquoise 	#afeeee 	175,238,238
+palevioletred 	#db7093 	219,112,147
+papayawhip 	#ffefd5 	255,239,213
+peachpuff 	#ffdab9 	255,218,185
+peru 	#cd853f 	205,133,63
+pink 	#ffc0cb 	255,192,203
+plum 	#dda0dd 	221,160,221
+powderblue 	#b0e0e6 	176,224,230
+purple 	#800080 	128,0,128
+red 	#ff0000 	255,0,0
+rosybrown 	#bc8f8f 	188,143,143
+royalblue 	#4169e1 	65,105,225
+saddlebrown 	#8b4513 	139,69,19
+salmon 	#fa8072 	250,128,114
+sandybrown 	#f4a460 	244,164,96
+seagreen 	#2e8b57 	46,139,87
+seashell 	#fff5ee 	255,245,238
+sienna 	#a0522d 	160,82,45
+silver 	#c0c0c0 	192,192,192
+skyblue 	#87ceeb 	135,206,235
+slateblue 	#6a5acd 	106,90,205
+slategray 	#708090 	112,128,144
+slategrey 	#708090 	112,128,144
+snow 	#fffafa 	255,250,250
+springgreen 	#00ff7f 	0,255,127
+steelblue 	#4682b4 	70,130,180
+tan 	#d2b48c 	210,180,140
+teal 	#008080 	0,128,128
+thistle 	#d8bfd8 	216,191,216
+tomato 	#ff6347 	255,99,71
+turquoise 	#40e0d0 	64,224,208
+violet 	#ee82ee 	238,130,238
+wheat 	#f5deb3 	245,222,179
+white 	#ffffff 	255,255,255
+whitesmoke 	#f5f5f5 	245,245,245
+yellow 	#ffff00 	255,255,0
+yellowgreen 	#9acd32 	154,205,50

_examples/basic/main.go

@@ -1,43 +0,0 @@
-package main
-
-import (
-	"log"
-	"net/http"
-
-	"github.com/wcharczuk/go-chart"
-)
-
-func drawChart(res http.ResponseWriter, req *http.Request) {
-	graph := chart.Chart{
-		Series: []chart.Series{
-			chart.ContinuousSeries{
-				XValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0},
-				YValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0},
-			},
-		},
-	}
-
-	res.Header().Set("Content-Type", "image/png")
-	graph.Render(chart.PNG, res)
-}
-
-func drawChartWide(res http.ResponseWriter, req *http.Request) {
-	graph := chart.Chart{
-		Width: 1920, //this overrides the default.
-		Series: []chart.Series{
-			chart.ContinuousSeries{
-				XValues: []float64{1.0, 2.0, 3.0, 4.0},
-				YValues: []float64{1.0, 2.0, 3.0, 4.0},
-			},
-		},
-	}
-
-	res.Header().Set("Content-Type", "image/png")
-	graph.Render(chart.PNG, res)
-}
-
-func main() {
-	http.HandleFunc("/", drawChart)
-	http.HandleFunc("/wide", drawChartWide)
-	log.Fatal(http.ListenAndServe(":8080", nil))
-}

_examples/benchmark_line_charts/main.go

@@ -1,79 +0,0 @@
-// Usage: http://localhost:8080?series=100&values=1000
-package main
-
-import (
-	"fmt"
-	"math/rand"
-	"net/http"
-	"strconv"
-	"time"
-
-	"github.com/wcharczuk/go-chart"
-)
-
-func random(min, max float64) float64 {
-	return rand.Float64()*(max-min) + min
-}
-
-func drawLargeChart(res http.ResponseWriter, r *http.Request) {
-	numSeriesInt64, err := strconv.ParseInt(r.FormValue("series"), 10, 64)
-	if err != nil {
-		numSeriesInt64 = int64(1)
-	}
-	if numSeriesInt64 == 0 {
-		numSeriesInt64 = 1
-	}
-	numSeries := int(numSeriesInt64)
-
-	numValuesInt64, err := strconv.ParseInt(r.FormValue("values"), 10, 64)
-	if err != nil {
-		numValuesInt64 = int64(100)
-	}
-	if numValuesInt64 == 0 {
-		numValuesInt64 = int64(100)
-	}
-	numValues := int(numValuesInt64)
-
-	series := make([]chart.Series, numSeries)
-
-	for i := 0; i < numSeries; i++ {
-		xValues := make([]time.Time, numValues)
-		yValues := make([]float64, numValues)
-
-		for j := 0; j < numValues; j++ {
-			xValues[j] = time.Now().AddDate(0, 0, (numValues-j)*-1)
-			yValues[j] = random(float64(-500), float64(500))
-		}
-
-		series[i] = chart.TimeSeries{
-			Name:    fmt.Sprintf("aaa.bbb.hostname-%v.ccc.ddd.eee.fff.ggg.hhh.iii.jjj.kkk.lll.mmm.nnn.value", i),
-			XValues: xValues,
-			YValues: yValues,
-		}
-	}
-
-	graph := chart.Chart{
-		XAxis: chart.XAxis{
-			Name:      "Time",
-			NameStyle: chart.StyleShow(),
-			Style:     chart.StyleShow(),
-		},
-		YAxis: chart.YAxis{
-			Name:      "Value",
-			NameStyle: chart.StyleShow(),
-			Style:     chart.StyleShow(),
-		},
-		Series: series,
-	}
-
-	res.Header().Set("Content-Type", "image/png")
-	graph.Render(chart.PNG, res)
-}
-
-func main() {
-	http.HandleFunc("/", drawLargeChart)
-	http.HandleFunc("/favico.ico", func(res http.ResponseWriter, req *http.Request) {
-		res.Write([]byte{})
-	})
-	http.ListenAndServe(":8080", nil)
-}

_examples/custom_padding/main.go

@@ -1,75 +0,0 @@
-package main
-
-import (
-	"net/http"
-
-	"github.com/wcharczuk/go-chart"
-	"github.com/wcharczuk/go-chart/drawing"
-	"github.com/wcharczuk/go-chart/seq"
-)
-
-func drawChart(res http.ResponseWriter, req *http.Request) {
-	graph := chart.Chart{
-		Background: chart.Style{
-			Padding: chart.Box{
-				Top:    50,
-				Left:   25,
-				Right:  25,
-				Bottom: 10,
-			},
-			FillColor: drawing.ColorFromHex("efefef"),
-		},
-		XAxis: chart.XAxis{
-			Style: chart.Style{
-				Show: true,
-			},
-		},
-		YAxis: chart.YAxis{
-			Style: chart.Style{
-				Show: true,
-			},
-		},
-		Series: []chart.Series{
-			chart.ContinuousSeries{
-				XValues: seq.Range(1.0, 100.0),
-				YValues: seq.RandomValuesWithMax(100, 512),
-			},
-		},
-	}
-
-	res.Header().Set("Content-Type", "image/png")
-	graph.Render(chart.PNG, res)
-}
-
-func drawChartDefault(res http.ResponseWriter, req *http.Request) {
-	graph := chart.Chart{
-		Background: chart.Style{
-			FillColor: drawing.ColorFromHex("efefef"),
-		},
-		XAxis: chart.XAxis{
-			Style: chart.Style{
-				Show: true,
-			},
-		},
-		YAxis: chart.YAxis{
-			Style: chart.Style{
-				Show: true,
-			},
-		},
-		Series: []chart.Series{
-			chart.ContinuousSeries{
-				XValues: seq.Range(1.0, 100.0),
-				YValues: seq.RandomValuesWithMax(100, 512),
-			},
-		},
-	}
-
-	res.Header().Set("Content-Type", "image/png")
-	graph.Render(chart.PNG, res)
-}
-
-func main() {
-	http.HandleFunc("/", drawChart)
-	http.HandleFunc("/default", drawChartDefault)
-	http.ListenAndServe(":8080", nil)
-}

_examples/market_hours/main.go

@@ -1,46 +0,0 @@
-package main
-
-import (
-	"net/http"
-
-	"github.com/wcharczuk/go-chart"
-	"github.com/wcharczuk/go-chart/seq"
-	"github.com/wcharczuk/go-chart/util"
-)
-
-func drawChart(res http.ResponseWriter, req *http.Request) {
-	start := util.Date.Date(2016, 7, 01, util.Date.Eastern())
-	end := util.Date.Date(2016, 07, 21, util.Date.Eastern())
-	xv := seq.Time.MarketHours(start, end, util.NYSEOpen(), util.NYSEClose(), util.Date.IsNYSEHoliday)
-	yv := seq.New(seq.NewRandom().WithLen(len(xv)).WithAverage(200).WithScale(10)).Array()
-
-	graph := chart.Chart{
-		XAxis: chart.XAxis{
-			Style:          chart.StyleShow(),
-			TickPosition:   chart.TickPositionBetweenTicks,
-			ValueFormatter: chart.TimeHourValueFormatter,
-			Range: &chart.MarketHoursRange{
-				MarketOpen:      util.NYSEOpen(),
-				MarketClose:     util.NYSEClose(),
-				HolidayProvider: util.Date.IsNYSEHoliday,
-			},
-		},
-		YAxis: chart.YAxis{
-			Style: chart.StyleShow(),
-		},
-		Series: []chart.Series{
-			chart.TimeSeries{
-				XValues: xv,
-				YValues: yv,
-			},
-		},
-	}
-
-	res.Header().Set("Content-Type", "image/png")
-	graph.Render(chart.PNG, res)
-}
-
-func main() {
-	http.HandleFunc("/", drawChart)
-	http.ListenAndServe(":8080", nil)
-}

_examples/request_timings/main.go

@@ -1,137 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"net/http"
-	"strconv"
-	"strings"
-	"time"
-
-	"github.com/wcharczuk/go-chart"
-	util "github.com/wcharczuk/go-chart/util"
-)
-
-func parseInt(str string) int {
-	v, _ := strconv.Atoi(str)
-	return v
-}
-
-func parseFloat64(str string) float64 {
-	v, _ := strconv.ParseFloat(str, 64)
-	return v
-}
-
-func readData() ([]time.Time, []float64) {
-	var xvalues []time.Time
-	var yvalues []float64
-	err := util.File.ReadByLines("requests.csv", func(line string) error {
-		parts := strings.Split(line, ",")
-		year := parseInt(parts[0])
-		month := parseInt(parts[1])
-		day := parseInt(parts[2])
-		hour := parseInt(parts[3])
-		elapsedMillis := parseFloat64(parts[4])
-		xvalues = append(xvalues, time.Date(year, time.Month(month), day, hour, 0, 0, 0, time.UTC))
-		yvalues = append(yvalues, elapsedMillis)
-		return nil
-	})
-	if err != nil {
-		fmt.Println(err.Error())
-	}
-	return xvalues, yvalues
-}
-
-func releases() []chart.GridLine {
-	return []chart.GridLine{
-		{Value: util.Time.ToFloat64(time.Date(2016, 8, 1, 9, 30, 0, 0, time.UTC))},
-		{Value: util.Time.ToFloat64(time.Date(2016, 8, 2, 9, 30, 0, 0, time.UTC))},
-		{Value: util.Time.ToFloat64(time.Date(2016, 8, 2, 15, 30, 0, 0, time.UTC))},
-		{Value: util.Time.ToFloat64(time.Date(2016, 8, 4, 9, 30, 0, 0, time.UTC))},
-		{Value: util.Time.ToFloat64(time.Date(2016, 8, 5, 9, 30, 0, 0, time.UTC))},
-		{Value: util.Time.ToFloat64(time.Date(2016, 8, 6, 9, 30, 0, 0, time.UTC))},
-	}
-}
-
-func drawChart(res http.ResponseWriter, req *http.Request) {
-	xvalues, yvalues := readData()
-	mainSeries := chart.TimeSeries{
-		Name: "Prod Request Timings",
-		Style: chart.Style{
-			Show:        true,
-			StrokeColor: chart.ColorBlue,
-			FillColor:   chart.ColorBlue.WithAlpha(100),
-		},
-		XValues: xvalues,
-		YValues: yvalues,
-	}
-
-	linreg := &chart.LinearRegressionSeries{
-		Name: "Linear Regression",
-		Style: chart.Style{
-			Show:            true,
-			StrokeColor:     chart.ColorAlternateBlue,
-			StrokeDashArray: []float64{5.0, 5.0},
-		},
-		InnerSeries: mainSeries,
-	}
-
-	sma := &chart.SMASeries{
-		Name: "SMA",
-		Style: chart.Style{
-			Show:            true,
-			StrokeColor:     chart.ColorRed,
-			StrokeDashArray: []float64{5.0, 5.0},
-		},
-		InnerSeries: mainSeries,
-	}
-
-	graph := chart.Chart{
-		Width:  1280,
-		Height: 720,
-		Background: chart.Style{
-			Padding: chart.Box{
-				Top: 50,
-			},
-		},
-		YAxis: chart.YAxis{
-			Name:      "Elapsed Millis",
-			NameStyle: chart.StyleShow(),
-			Style:     chart.StyleShow(),
-			TickStyle: chart.Style{
-				TextRotationDegrees: 45.0,
-			},
-			ValueFormatter: func(v interface{}) string {
-				return fmt.Sprintf("%d ms", int(v.(float64)))
-			},
-		},
-		XAxis: chart.XAxis{
-			Style: chart.Style{
-				Show: true,
-			},
-			ValueFormatter: chart.TimeHourValueFormatter,
-			GridMajorStyle: chart.Style{
-				Show:        true,
-				StrokeColor: chart.ColorAlternateGray,
-				StrokeWidth: 1.0,
-			},
-			GridLines: releases(),
-		},
-		Series: []chart.Series{
-			mainSeries,
-			linreg,
-			chart.LastValueAnnotation(linreg),
-			sma,
-			chart.LastValueAnnotation(sma),
-		},
-	}
-
-	graph.Elements = []chart.Renderable{chart.LegendThin(&graph)}
-
-	res.Header().Set("Content-Type", chart.ContentTypePNG)
-	graph.Render(chart.PNG, res)
-}
-
-func main() {
-	http.HandleFunc("/", drawChart)
-	http.ListenAndServe(":8080", nil)
-}

annotation_series.go

@@ -3,8 +3,11 @@ package chart
 import (
 	"fmt"
 	"math"
+)
 
-	util "github.com/wcharczuk/go-chart/util"
+// Interface Assertions.
+var (
+	_ Series = (*AnnotationSeries)(nil)
 )
 
 // AnnotationSeries is a series of labels on the chart.
@@ -50,17 +53,17 @@ func (as AnnotationSeries) Measure(r Renderer, canvasBox Box, xrange, yrange Ran
 		Right:  0,
 		Bottom: 0,
 	}
-	if as.Style.IsZero() || as.Style.Show {
+	if !as.Style.Hidden {
 		seriesStyle := as.Style.InheritFrom(as.annotationStyleDefaults(defaults))
 		for _, a := range as.Annotations {
 			style := a.Style.InheritFrom(seriesStyle)
 			lx := canvasBox.Left + xrange.Translate(a.XValue)
 			ly := canvasBox.Bottom - yrange.Translate(a.YValue)
 			ab := Draw.MeasureAnnotation(r, canvasBox, style, lx, ly, a.Label)
-			box.Top = util.Math.MinInt(box.Top, ab.Top)
+			box.Top = MinInt(box.Top, ab.Top)
-			box.Left = util.Math.MinInt(box.Left, ab.Left)
+			box.Left = MinInt(box.Left, ab.Left)
-			box.Right = util.Math.MaxInt(box.Right, ab.Right)
+			box.Right = MaxInt(box.Right, ab.Right)
-			box.Bottom = util.Math.MaxInt(box.Bottom, ab.Bottom)
+			box.Bottom = MaxInt(box.Bottom, ab.Bottom)
 		}
 	}
 	return box
@@ -68,7 +71,7 @@ func (as AnnotationSeries) Measure(r Renderer, canvasBox Box, xrange, yrange Ran
 
 // Render draws the series.
 func (as AnnotationSeries) Render(r Renderer, canvasBox Box, xrange, yrange Range, defaults Style) {
-	if as.Style.IsZero() || as.Style.Show {
+	if !as.Style.Hidden {
 		seriesStyle := as.Style.InheritFrom(as.annotationStyleDefaults(defaults))
 		for _, a := range as.Annotations {
 			style := a.Style.InheritFrom(seriesStyle)

annotation_series_test.go

@@ -4,17 +4,14 @@ import (
 	"image/color"
 	"testing"
 
-	"github.com/blendlabs/go-assert"
+	"git.smarteching.com/zeni/go-chart/v2/drawing"
-	"github.com/wcharczuk/go-chart/drawing"
+	"git.smarteching.com/zeni/go-chart/v2/testutil"
 )
 
 func TestAnnotationSeriesMeasure(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	as := AnnotationSeries{
-		Style: Style{
-			Show: true,
-		},
 		Annotations: []Value2{
 			{XValue: 1.0, YValue: 1.0, Label: "1.0"},
 			{XValue: 2.0, YValue: 2.0, Label: "2.0"},
@@ -24,10 +21,10 @@ func TestAnnotationSeriesMeasure(t *testing.T) {
 	}
 
 	r, err := PNG(110, 110)
-	assert.Nil(err)
+	testutil.AssertNil(t, err)
 
 	f, err := GetDefaultFont()
-	assert.Nil(err)
+	testutil.AssertNil(t, err)
 
 	xrange := &ContinuousRange{
 		Min:    1.0,
@@ -52,19 +49,18 @@ func TestAnnotationSeriesMeasure(t *testing.T) {
 	}
 
 	box := as.Measure(r, cb, xrange, yrange, sd)
-	assert.False(box.IsZero())
+	testutil.AssertFalse(t, box.IsZero())
-	assert.Equal(-5.0, box.Top)
+	testutil.AssertEqual(t, -5.0, box.Top)
-	assert.Equal(5.0, box.Left)
+	testutil.AssertEqual(t, 5.0, box.Left)
-	assert.Equal(146.0, box.Right) //the top,left annotation sticks up 5px and out ~44px.
+	testutil.AssertEqual(t, 146.0, box.Right) //the top,left annotation sticks up 5px and out ~44px.
-	assert.Equal(115.0, box.Bottom)
+	testutil.AssertEqual(t, 115.0, box.Bottom)
 }
 
 func TestAnnotationSeriesRender(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	as := AnnotationSeries{
 		Style: Style{
-			Show:        true,
 			FillColor:   drawing.ColorWhite,
 			StrokeColor: drawing.ColorBlack,
 		},
@@ -77,10 +73,10 @@ func TestAnnotationSeriesRender(t *testing.T) {
 	}
 
 	r, err := PNG(110, 110)
-	assert.Nil(err)
+	testutil.AssertNil(t, err)
 
 	f, err := GetDefaultFont()
-	assert.Nil(err)
+	testutil.AssertNil(t, err)
 
 	xrange := &ContinuousRange{
 		Min:    1.0,
@@ -107,13 +103,13 @@ func TestAnnotationSeriesRender(t *testing.T) {
 	as.Render(r, cb, xrange, yrange, sd)
 
 	rr, isRaster := r.(*rasterRenderer)
-	assert.True(isRaster)
+	testutil.AssertTrue(t, isRaster)
-	assert.NotNil(rr)
+	testutil.AssertNotNil(t, rr)
 
 	c := rr.i.At(38, 70)
 	converted, isRGBA := color.RGBAModel.Convert(c).(color.RGBA)
-	assert.True(isRGBA)
+	testutil.AssertTrue(t, isRGBA)
-	assert.Equal(0, converted.R)
+	testutil.AssertEqual(t, 0, converted.R)
-	assert.Equal(0, converted.G)
+	testutil.AssertEqual(t, 0, converted.G)
-	assert.Equal(0, converted.B)
+	testutil.AssertEqual(t, 0, converted.B)
 }

array.go

@@ -1,6 +1,11 @@
-package seq
+package chart
 
-// NewArray creates a new array.
+var (
+	_ Sequence = (*Array)(nil)
+)
+
+// NewArray returns a new array from a given set of values.
+// Array implements Sequence, which allows it to be used with the sequence helpers.
 func NewArray(values ...float64) Array {
 	return Array(values)
 }

bar_chart.go

@@ -7,7 +7,6 @@ import (
 	"math"
 
 	"github.com/golang/freetype/truetype"
-	util "github.com/wcharczuk/go-chart/util"
 )
 
 // BarChart is a chart that draws bars on a range.
@@ -31,6 +30,9 @@ type BarChart struct {
 
 	BarSpacing int
 
+	UseBaseValue bool
+	BaseValue    float64
+
 	Font        *truetype.Font
 	defaultFont *truetype.Font
 
@@ -126,7 +128,7 @@ func (bc BarChart) Render(rp RendererProvider, w io.Writer) error {
 		canvasBox = bc.getAdjustedCanvasBox(r, canvasBox, yr, yt)
 		yr = bc.setRangeDomains(canvasBox, yr)
 	}
-
+	bc.drawCanvas(r, canvasBox)
 	bc.drawBars(r, canvasBox, yr)
 	bc.drawXAxis(r, canvasBox)
 	bc.drawYAxis(r, canvasBox, yr, yt)
@@ -139,6 +141,10 @@ func (bc BarChart) Render(rp RendererProvider, w io.Writer) error {
 	return r.Save(w)
 }
 
+func (bc BarChart) drawCanvas(r Renderer, canvasBox Box) {
+	Draw.Box(r, canvasBox, bc.getCanvasStyle())
+}
+
 func (bc BarChart) getRanges() Range {
 	var yrange Range
 	if bc.YAxis.Range != nil && !bc.YAxis.Range.IsZero() {
@@ -195,11 +201,20 @@ func (bc BarChart) drawBars(r Renderer, canvasBox Box, yr Range) {
 
 		by = canvasBox.Bottom - yr.Translate(bar.Value)
 
-		barBox = Box{
+		if bc.UseBaseValue {
-			Top:    by,
+			barBox = Box{
-			Left:   bxl,
+				Top:    by,
-			Right:  bxr,
+				Left:   bxl,
-			Bottom: canvasBox.Bottom,
+				Right:  bxr,
+				Bottom: canvasBox.Bottom - yr.Translate(bc.BaseValue),
+			}
+		} else {
+			barBox = Box{
+				Top:    by,
+				Left:   bxl,
+				Right:  bxr,
+				Bottom: canvasBox.Bottom,
+			}
 		}
 
 		Draw.Box(r, barBox, bar.Style.InheritFrom(bc.styleDefaultsBar(index)))
@@ -209,7 +224,7 @@ func (bc BarChart) drawBars(r Renderer, canvasBox Box, yr Range) {
 }
 
 func (bc BarChart) drawXAxis(r Renderer, canvasBox Box) {
-	if bc.XAxis.Show {
+	if !bc.XAxis.Hidden {
 		axisStyle := bc.XAxis.InheritFrom(bc.styleDefaultsAxes())
 		axisStyle.WriteToRenderer(r)
 
@@ -248,44 +263,44 @@ func (bc BarChart) drawXAxis(r Renderer, canvasBox Box) {
 }
 
 func (bc BarChart) drawYAxis(r Renderer, canvasBox Box, yr Range, ticks []Tick) {
-	if bc.YAxis.Style.Show {
+	if !bc.YAxis.Style.Hidden {
-		axisStyle := bc.YAxis.Style.InheritFrom(bc.styleDefaultsAxes())
+		bc.YAxis.Render(r, canvasBox, yr, bc.styleDefaultsAxes(), ticks)
-		axisStyle.WriteToRenderer(r)
-
-		r.MoveTo(canvasBox.Right, canvasBox.Top)
-		r.LineTo(canvasBox.Right, canvasBox.Bottom)
-		r.Stroke()
-
-		r.MoveTo(canvasBox.Right, canvasBox.Bottom)
-		r.LineTo(canvasBox.Right+DefaultHorizontalTickWidth, canvasBox.Bottom)
-		r.Stroke()
-
-		var ty int
-		var tb Box
-		for _, t := range ticks {
-			ty = canvasBox.Bottom - yr.Translate(t.Value)
-
-			axisStyle.GetStrokeOptions().WriteToRenderer(r)
-			r.MoveTo(canvasBox.Right, ty)
-			r.LineTo(canvasBox.Right+DefaultHorizontalTickWidth, ty)
-			r.Stroke()
-
-			axisStyle.GetTextOptions().WriteToRenderer(r)
-			tb = r.MeasureText(t.Label)
-			Draw.Text(r, t.Label, canvasBox.Right+DefaultYAxisMargin+5, ty+(tb.Height()>>1), axisStyle)
-		}
-
 	}
 }
 
 func (bc BarChart) drawTitle(r Renderer) {
-	if len(bc.Title) > 0 && bc.TitleStyle.Show {
+	if len(bc.Title) > 0 && !bc.TitleStyle.Hidden {
-		Draw.TextWithin(r, bc.Title, bc.box(), bc.styleDefaultsTitle())
+		r.SetFont(bc.TitleStyle.GetFont(bc.GetFont()))
+		r.SetFontColor(bc.TitleStyle.GetFontColor(bc.GetColorPalette().TextColor()))
+		titleFontSize := bc.TitleStyle.GetFontSize(bc.getTitleFontSize())
+		r.SetFontSize(titleFontSize)
+
+		textBox := r.MeasureText(bc.Title)
+
+		textWidth := textBox.Width()
+		textHeight := textBox.Height()
+
+		titleX := (bc.GetWidth() >> 1) - (textWidth >> 1)
+		titleY := bc.TitleStyle.Padding.GetTop(DefaultTitleTop) + textHeight
+
+		r.Text(bc.Title, titleX, titleY)
+	}
+}
+
+func (bc BarChart) getCanvasStyle() Style {
+	return bc.Canvas.InheritFrom(bc.styleDefaultsCanvas())
+}
+
+func (bc BarChart) styleDefaultsCanvas() Style {
+	return Style{
+		FillColor:   bc.GetColorPalette().CanvasColor(),
+		StrokeColor: bc.GetColorPalette().CanvasStrokeColor(),
+		StrokeWidth: DefaultCanvasStrokeWidth,
 	}
 }
 
 func (bc BarChart) hasAxes() bool {
-	return bc.YAxis.Style.Show
+	return !bc.YAxis.Style.Hidden
 }
 
 func (bc BarChart) setRangeDomains(canvasBox Box, yr Range) Range {
@@ -305,7 +320,7 @@ func (bc BarChart) getValueFormatters() ValueFormatter {
 }
 
 func (bc BarChart) getAxesTicks(r Renderer, yr Range, yf ValueFormatter) (yticks []Tick) {
-	if bc.YAxis.Style.Show {
+	if !bc.YAxis.Style.Hidden {
 		yticks = bc.YAxis.GetTicks(r, yr, bc.styleDefaultsAxes(), yf)
 	}
 	return
@@ -351,7 +366,7 @@ func (bc BarChart) getAdjustedCanvasBox(r Renderer, canvasBox Box, yrange Range,
 
 	_, _, totalWidth := bc.calculateScaledTotalWidth(canvasBox)
 
-	if bc.XAxis.Show {
+	if !bc.XAxis.Hidden {
 		xaxisHeight := DefaultVerticalTickHeight
 
 		axisStyle := bc.XAxis.InheritFrom(bc.styleDefaultsAxes())
@@ -369,7 +384,7 @@ func (bc BarChart) getAdjustedCanvasBox(r Renderer, canvasBox Box, yrange Range,
 				lines := Text.WrapFit(r, bar.Label, barLabelBox.Width(), axisStyle)
 				linesBox := Text.MeasureLines(r, lines, axisStyle)
 
-				xaxisHeight = util.Math.MinInt(linesBox.Height()+(2*DefaultXAxisMargin), xaxisHeight)
+				xaxisHeight = MinInt(linesBox.Height()+(2*DefaultXAxisMargin), xaxisHeight)
 			}
 		}
 
@@ -383,7 +398,7 @@ func (bc BarChart) getAdjustedCanvasBox(r Renderer, canvasBox Box, yrange Range,
 		axesOuterBox = axesOuterBox.Grow(xbox)
 	}
 
-	if bc.YAxis.Style.Show {
+	if !bc.YAxis.Style.Hidden {
 		axesBounds := bc.YAxis.Measure(r, canvasBox, yrange, bc.styleDefaultsAxes(), yticks)
 		axesOuterBox = axesOuterBox.Grow(axesBounds)
 	}
@@ -397,8 +412,8 @@ func (bc BarChart) box() Box {
 	dpb := bc.Background.Padding.GetBottom(50)
 
 	return Box{
-		Top:    20,
+		Top:    bc.Background.Padding.GetTop(20),
-		Left:   20,
+		Left:   bc.Background.Padding.GetLeft(20),
 		Right:  bc.GetWidth() - dpr,
 		Bottom: bc.GetHeight() - dpb,
 	}
@@ -436,7 +451,7 @@ func (bc BarChart) styleDefaultsTitle() Style {
 }
 
 func (bc BarChart) getTitleFontSize() float64 {
-	effectiveDimension := util.Math.MinInt(bc.GetWidth(), bc.GetHeight())
+	effectiveDimension := MinInt(bc.GetWidth(), bc.GetHeight())
 	if effectiveDimension >= 2048 {
 		return 48
 	} else if effectiveDimension >= 1024 {

bar_chart_test.go

@@ -5,20 +5,15 @@ import (
 	"math"
 	"testing"
 
-	assert "github.com/blendlabs/go-assert"
+	"git.smarteching.com/zeni/go-chart/v2/testutil"
 )
 
 func TestBarChartRender(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{
-		Width:      1024,
+		Width: 1024,
-		Title:      "Test Title",
+		Title: "Test Title",
-		TitleStyle: StyleShow(),
-		XAxis:      StyleShow(),
-		YAxis: YAxis{
-			Style: StyleShow(),
-		},
 		Bars: []Value{
 			{Value: 1.0, Label: "One"},
 			{Value: 2.0, Label: "Two"},
@@ -30,21 +25,16 @@ func TestBarChartRender(t *testing.T) {
 
 	buf := bytes.NewBuffer([]byte{})
 	err := bc.Render(PNG, buf)
-	assert.Nil(err)
+	testutil.AssertNil(t, err)
-	assert.NotZero(buf.Len())
+	testutil.AssertNotZero(t, buf.Len())
 }
 
 func TestBarChartRenderZero(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{
-		Width:      1024,
+		Width: 1024,
-		Title:      "Test Title",
+		Title: "Test Title",
-		TitleStyle: StyleShow(),
-		XAxis:      StyleShow(),
-		YAxis: YAxis{
-			Style: StyleShow(),
-		},
 		Bars: []Value{
 			{Value: 0.0, Label: "One"},
 			{Value: 0.0, Label: "Two"},
@@ -53,64 +43,64 @@ func TestBarChartRenderZero(t *testing.T) {
 
 	buf := bytes.NewBuffer([]byte{})
 	err := bc.Render(PNG, buf)
-	assert.NotNil(err)
+	testutil.AssertNotNil(t, err)
 }
 
 func TestBarChartProps(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{}
 
-	assert.Equal(DefaultDPI, bc.GetDPI())
+	testutil.AssertEqual(t, DefaultDPI, bc.GetDPI())
 	bc.DPI = 100
-	assert.Equal(100, bc.GetDPI())
+	testutil.AssertEqual(t, 100, bc.GetDPI())
 
-	assert.Nil(bc.GetFont())
+	testutil.AssertNil(t, bc.GetFont())
 	f, err := GetDefaultFont()
-	assert.Nil(err)
+	testutil.AssertNil(t, err)
 	bc.Font = f
-	assert.NotNil(bc.GetFont())
+	testutil.AssertNotNil(t, bc.GetFont())
 
-	assert.Equal(DefaultChartWidth, bc.GetWidth())
+	testutil.AssertEqual(t, DefaultChartWidth, bc.GetWidth())
 	bc.Width = DefaultChartWidth - 1
-	assert.Equal(DefaultChartWidth-1, bc.GetWidth())
+	testutil.AssertEqual(t, DefaultChartWidth-1, bc.GetWidth())
 
-	assert.Equal(DefaultChartHeight, bc.GetHeight())
+	testutil.AssertEqual(t, DefaultChartHeight, bc.GetHeight())
 	bc.Height = DefaultChartHeight - 1
-	assert.Equal(DefaultChartHeight-1, bc.GetHeight())
+	testutil.AssertEqual(t, DefaultChartHeight-1, bc.GetHeight())
 
-	assert.Equal(DefaultBarSpacing, bc.GetBarSpacing())
+	testutil.AssertEqual(t, DefaultBarSpacing, bc.GetBarSpacing())
 	bc.BarSpacing = 150
-	assert.Equal(150, bc.GetBarSpacing())
+	testutil.AssertEqual(t, 150, bc.GetBarSpacing())
 
-	assert.Equal(DefaultBarWidth, bc.GetBarWidth())
+	testutil.AssertEqual(t, DefaultBarWidth, bc.GetBarWidth())
 	bc.BarWidth = 75
-	assert.Equal(75, bc.GetBarWidth())
+	testutil.AssertEqual(t, 75, bc.GetBarWidth())
 }
 
 func TestBarChartRenderNoBars(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{}
 	err := bc.Render(PNG, bytes.NewBuffer([]byte{}))
-	assert.NotNil(err)
+	testutil.AssertNotNil(t, err)
 }
 
 func TestBarChartGetRanges(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{}
 
 	yr := bc.getRanges()
-	assert.NotNil(yr)
+	testutil.AssertNotNil(t, yr)
-	assert.False(yr.IsZero())
+	testutil.AssertFalse(t, yr.IsZero())
 
-	assert.Equal(-math.MaxFloat64, yr.GetMax())
+	testutil.AssertEqual(t, -math.MaxFloat64, yr.GetMax())
-	assert.Equal(math.MaxFloat64, yr.GetMin())
+	testutil.AssertEqual(t, math.MaxFloat64, yr.GetMin())
 }
 
 func TestBarChartGetRangesBarsMinMax(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{
 		Bars: []Value{
@@ -120,15 +110,15 @@ func TestBarChartGetRangesBarsMinMax(t *testing.T) {
 	}
 
 	yr := bc.getRanges()
-	assert.NotNil(yr)
+	testutil.AssertNotNil(t, yr)
-	assert.False(yr.IsZero())
+	testutil.AssertFalse(t, yr.IsZero())
 
-	assert.Equal(10, yr.GetMax())
+	testutil.AssertEqual(t, 10, yr.GetMax())
-	assert.Equal(1, yr.GetMin())
+	testutil.AssertEqual(t, 1, yr.GetMin())
 }
 
 func TestBarChartGetRangesMinMax(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{
 		YAxis: YAxis{
@@ -148,15 +138,15 @@ func TestBarChartGetRangesMinMax(t *testing.T) {
 	}
 
 	yr := bc.getRanges()
-	assert.NotNil(yr)
+	testutil.AssertNotNil(t, yr)
-	assert.False(yr.IsZero())
+	testutil.AssertFalse(t, yr.IsZero())
 
-	assert.Equal(15, yr.GetMax())
+	testutil.AssertEqual(t, 15, yr.GetMax())
-	assert.Equal(5, yr.GetMin())
+	testutil.AssertEqual(t, 5, yr.GetMin())
 }
 
 func TestBarChartGetRangesTicksMinMax(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{
 		YAxis: YAxis{
@@ -172,57 +162,56 @@ func TestBarChartGetRangesTicksMinMax(t *testing.T) {
 	}
 
 	yr := bc.getRanges()
-	assert.NotNil(yr)
+	testutil.AssertNotNil(t, yr)
-	assert.False(yr.IsZero())
+	testutil.AssertFalse(t, yr.IsZero())
 
-	assert.Equal(11, yr.GetMax())
+	testutil.AssertEqual(t, 11, yr.GetMax())
-	assert.Equal(7, yr.GetMin())
+	testutil.AssertEqual(t, 7, yr.GetMin())
 }
 
 func TestBarChartHasAxes(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{}
-	assert.False(bc.hasAxes())
+	testutil.AssertTrue(t, bc.hasAxes())
 	bc.YAxis = YAxis{
-		Style: StyleShow(),
+		Style: Hidden(),
 	}
-
+	testutil.AssertFalse(t, bc.hasAxes())
-	assert.True(bc.hasAxes())
 }
 
 func TestBarChartGetDefaultCanvasBox(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{}
 	b := bc.getDefaultCanvasBox()
-	assert.False(b.IsZero())
+	testutil.AssertFalse(t, b.IsZero())
 }
 
 func TestBarChartSetRangeDomains(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{}
 	cb := bc.box()
 	yr := bc.getRanges()
 	yr2 := bc.setRangeDomains(cb, yr)
-	assert.NotZero(yr2.GetDomain())
+	testutil.AssertNotZero(t, yr2.GetDomain())
 }
 
 func TestBarChartGetValueFormatters(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{}
 	vf := bc.getValueFormatters()
-	assert.NotNil(vf)
+	testutil.AssertNotNil(t, vf)
-	assert.Equal("1234.00", vf(1234.0))
+	testutil.AssertEqual(t, "1234.00", vf(1234.0))
 
 	bc.YAxis.ValueFormatter = func(_ interface{}) string { return "test" }
-	assert.Equal("test", bc.getValueFormatters()(1234))
+	testutil.AssertEqual(t, "test", bc.getValueFormatters()(1234))
 }
 
 func TestBarChartGetAxesTicks(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{
 		Bars: []Value{
@@ -233,20 +222,21 @@ func TestBarChartGetAxesTicks(t *testing.T) {
 	}
 
 	r, err := PNG(128, 128)
-	assert.Nil(err)
+	testutil.AssertNil(t, err)
 	yr := bc.getRanges()
 	yf := bc.getValueFormatters()
 
+	bc.YAxis.Style.Hidden = true
 	ticks := bc.getAxesTicks(r, yr, yf)
-	assert.Empty(ticks)
+	testutil.AssertEmpty(t, ticks)
 
-	bc.YAxis.Style.Show = true
+	bc.YAxis.Style.Hidden = false
 	ticks = bc.getAxesTicks(r, yr, yf)
-	assert.Len(ticks, 2)
+	testutil.AssertLen(t, ticks, 2)
 }
 
 func TestBarChartCalculateEffectiveBarSpacing(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{
 		Width:    1024,
@@ -261,15 +251,15 @@ func TestBarChartCalculateEffectiveBarSpacing(t *testing.T) {
 	}
 
 	spacing := bc.calculateEffectiveBarSpacing(bc.box())
-	assert.NotZero(spacing)
+	testutil.AssertNotZero(t, spacing)
 
 	bc.BarWidth = 250
 	spacing = bc.calculateEffectiveBarSpacing(bc.box())
-	assert.Zero(spacing)
+	testutil.AssertZero(t, spacing)
 }
 
 func TestBarChartCalculateEffectiveBarWidth(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BarChart{
 		Width:    1024,
@@ -286,35 +276,35 @@ func TestBarChartCalculateEffectiveBarWidth(t *testing.T) {
 	cb := bc.box()
 
 	spacing := bc.calculateEffectiveBarSpacing(bc.box())
-	assert.NotZero(spacing)
+	testutil.AssertNotZero(t, spacing)
 
 	barWidth := bc.calculateEffectiveBarWidth(bc.box(), spacing)
-	assert.Equal(10, barWidth)
+	testutil.AssertEqual(t, 10, barWidth)
 
 	bc.BarWidth = 250
 	spacing = bc.calculateEffectiveBarSpacing(bc.box())
-	assert.Zero(spacing)
+	testutil.AssertZero(t, spacing)
 	barWidth = bc.calculateEffectiveBarWidth(bc.box(), spacing)
-	assert.Equal(199, barWidth)
+	testutil.AssertEqual(t, 199, barWidth)
 
-	assert.Equal(cb.Width()+1, bc.calculateTotalBarWidth(barWidth, spacing))
+	testutil.AssertEqual(t, cb.Width()+1, bc.calculateTotalBarWidth(barWidth, spacing))
 
 	bw, bs, total := bc.calculateScaledTotalWidth(cb)
-	assert.Equal(spacing, bs)
+	testutil.AssertEqual(t, spacing, bs)
-	assert.Equal(barWidth, bw)
+	testutil.AssertEqual(t, barWidth, bw)
-	assert.Equal(cb.Width()+1, total)
+	testutil.AssertEqual(t, cb.Width()+1, total)
 }
 
 func TestBarChatGetTitleFontSize(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 	size := BarChart{Width: 2049, Height: 2049}.getTitleFontSize()
-	assert.Equal(48, size)
+	testutil.AssertEqual(t, 48, size)
 	size = BarChart{Width: 1025, Height: 1025}.getTitleFontSize()
-	assert.Equal(24, size)
+	testutil.AssertEqual(t, 24, size)
 	size = BarChart{Width: 513, Height: 513}.getTitleFontSize()
-	assert.Equal(18, size)
+	testutil.AssertEqual(t, 18, size)
 	size = BarChart{Width: 257, Height: 257}.getTitleFontSize()
-	assert.Equal(12, size)
+	testutil.AssertEqual(t, 12, size)
 	size = BarChart{Width: 128, Height: 128}.getTitleFontSize()
-	assert.Equal(10, size)
+	testutil.AssertEqual(t, 10, size)
 }

bollinger_band_series.go

@@ -2,8 +2,11 @@ package chart
 
 import (
 	"fmt"
+)
 
-	"github.com/wcharczuk/go-chart/seq"
+// Interface Assertions.
+var (
+	_ Series = (*BollingerBandsSeries)(nil)
 )
 
 // BollingerBandsSeries draws bollinger bands for an inner series.
@@ -17,7 +20,7 @@ type BollingerBandsSeries struct {
 	K           float64
 	InnerSeries ValuesProvider
 
-	valueBuffer *seq.Buffer
+	valueBuffer *ValueBuffer
 }
 
 // GetName returns the name of the time series.
@@ -67,7 +70,7 @@ func (bbs *BollingerBandsSeries) GetBoundedValues(index int) (x, y1, y2 float64)
 		return
 	}
 	if bbs.valueBuffer == nil || index == 0 {
-		bbs.valueBuffer = seq.NewBufferWithCapacity(bbs.GetPeriod())
+		bbs.valueBuffer = NewValueBufferWithCapacity(bbs.GetPeriod())
 	}
 	if bbs.valueBuffer.Len() >= bbs.GetPeriod() {
 		bbs.valueBuffer.Dequeue()
@@ -76,8 +79,8 @@ func (bbs *BollingerBandsSeries) GetBoundedValues(index int) (x, y1, y2 float64)
 	bbs.valueBuffer.Enqueue(py)
 	x = px
 
-	ay := seq.New(bbs.valueBuffer).Average()
+	ay := Seq{bbs.valueBuffer}.Average()
-	std := seq.New(bbs.valueBuffer).StdDev()
+	std := Seq{bbs.valueBuffer}.StdDev()
 
 	y1 = ay + (bbs.GetK() * std)
 	y2 = ay - (bbs.GetK() * std)
@@ -96,15 +99,15 @@ func (bbs *BollingerBandsSeries) GetBoundedLastValues() (x, y1, y2 float64) {
 		startAt = 0
 	}
 
-	vb := seq.NewBufferWithCapacity(period)
+	vb := NewValueBufferWithCapacity(period)
 	for index := startAt; index < seriesLength; index++ {
 		xn, yn := bbs.InnerSeries.GetValues(index)
 		vb.Enqueue(yn)
 		x = xn
 	}
 
-	ay := seq.Seq{Provider: vb}.Average()
+	ay := Seq{vb}.Average()
-	std := seq.Seq{Provider: vb}.StdDev()
+	std := Seq{vb}.StdDev()
 
 	y1 = ay + (bbs.GetK() * std)
 	y2 = ay - (bbs.GetK() * std)

bollinger_band_series_test.go

@@ -5,16 +5,15 @@ import (
 	"math"
 	"testing"
 
-	"github.com/blendlabs/go-assert"
+	"git.smarteching.com/zeni/go-chart/v2/testutil"
-	"github.com/wcharczuk/go-chart/seq"
 )
 
 func TestBollingerBandSeries(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	s1 := mockValuesProvider{
-		X: seq.Range(1.0, 100.0),
+		X: LinearRange(1.0, 100.0),
-		Y: seq.RandomValuesWithMax(100, 1024),
+		Y: RandomValuesWithMax(100, 1024),
 	}
 
 	bbs := &BollingerBandsSeries{
@@ -30,16 +29,16 @@ func TestBollingerBandSeries(t *testing.T) {
 	}
 
 	for x := bbs.GetPeriod(); x < 100; x++ {
-		assert.True(y1values[x] > y2values[x], fmt.Sprintf("%v vs. %v", y1values[x], y2values[x]))
+		testutil.AssertTrue(t, y1values[x] > y2values[x], fmt.Sprintf("%v vs. %v", y1values[x], y2values[x]))
 	}
 }
 
 func TestBollingerBandLastValue(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	s1 := mockValuesProvider{
-		X: seq.Range(1.0, 100.0),
+		X: LinearRange(1.0, 100.0),
-		Y: seq.Range(1.0, 100.0),
+		Y: LinearRange(1.0, 100.0),
 	}
 
 	bbs := &BollingerBandsSeries{
@@ -47,7 +46,7 @@ func TestBollingerBandLastValue(t *testing.T) {
 	}
 
 	x, y1, y2 := bbs.GetBoundedLastValues()
-	assert.Equal(100.0, x)
+	testutil.AssertEqual(t, 100.0, x)
-	assert.Equal(101, math.Floor(y1))
+	testutil.AssertEqual(t, 101, math.Floor(y1))
-	assert.Equal(83, math.Floor(y2))
+	testutil.AssertEqual(t, 83, math.Floor(y2))
 }

bounded_last_values_annotation_series.go

@@ -0,0 +1,36 @@
+package chart
+
+import "fmt"
+
+// BoundedLastValuesAnnotationSeries returns a last value annotation series for a bounded values provider.
+func BoundedLastValuesAnnotationSeries(innerSeries FullBoundedValuesProvider, vfs ...ValueFormatter) AnnotationSeries {
+	lvx, lvy1, lvy2 := innerSeries.GetBoundedLastValues()
+
+	var vf ValueFormatter
+	if len(vfs) > 0 {
+		vf = vfs[0]
+	} else if typed, isTyped := innerSeries.(ValueFormatterProvider); isTyped {
+		_, vf = typed.GetValueFormatters()
+	} else {
+		vf = FloatValueFormatter
+	}
+
+	label1 := vf(lvy1)
+	label2 := vf(lvy2)
+
+	var seriesName string
+	var seriesStyle Style
+	if typed, isTyped := innerSeries.(Series); isTyped {
+		seriesName = fmt.Sprintf("%s - Last Values", typed.GetName())
+		seriesStyle = typed.GetStyle()
+	}
+
+	return AnnotationSeries{
+		Name:  seriesName,
+		Style: seriesStyle,
+		Annotations: []Value2{
+			{XValue: lvx, YValue: lvy1, Label: label1},
+			{XValue: lvx, YValue: lvy2, Label: label2},
+		},
+	}
+}

box.go

@@ -3,8 +3,6 @@ package chart
 import (
 	"fmt"
 	"math"
-
-	util "github.com/wcharczuk/go-chart/util"
 )
 
 var (
@@ -91,12 +89,12 @@ func (b Box) GetBottom(defaults ...int) int {
 
 // Width returns the width
 func (b Box) Width() int {
-	return util.Math.AbsInt(b.Right - b.Left)
+	return AbsInt(b.Right - b.Left)
 }
 
 // Height returns the height
 func (b Box) Height() int {
-	return util.Math.AbsInt(b.Bottom - b.Top)
+	return AbsInt(b.Bottom - b.Top)
 }
 
 // Center returns the center of the box
@@ -148,10 +146,10 @@ func (b Box) Equals(other Box) bool {
 // Grow grows a box based on another box.
 func (b Box) Grow(other Box) Box {
 	return Box{
-		Top:    util.Math.MinInt(b.Top, other.Top),
+		Top:    MinInt(b.Top, other.Top),
-		Left:   util.Math.MinInt(b.Left, other.Left),
+		Left:   MinInt(b.Left, other.Left),
-		Right:  util.Math.MaxInt(b.Right, other.Right),
+		Right:  MaxInt(b.Right, other.Right),
-		Bottom: util.Math.MaxInt(b.Bottom, other.Bottom),
+		Bottom: MaxInt(b.Bottom, other.Bottom),
 	}
 }
 
@@ -222,10 +220,10 @@ func (b Box) Fit(other Box) Box {
 func (b Box) Constrain(other Box) Box {
 	newBox := b.Clone()
 
-	newBox.Top = util.Math.MaxInt(newBox.Top, other.Top)
+	newBox.Top = MaxInt(newBox.Top, other.Top)
-	newBox.Left = util.Math.MaxInt(newBox.Left, other.Left)
+	newBox.Left = MaxInt(newBox.Left, other.Left)
-	newBox.Right = util.Math.MinInt(newBox.Right, other.Right)
+	newBox.Right = MinInt(newBox.Right, other.Right)
-	newBox.Bottom = util.Math.MinInt(newBox.Bottom, other.Bottom)
+	newBox.Bottom = MinInt(newBox.Bottom, other.Bottom)
 
 	return newBox
 }
@@ -256,6 +254,22 @@ func (b Box) OuterConstrain(bounds, other Box) Box {
 	return newBox
 }
 
+func (b Box) Validate() error {
+	if b.Left < 0 {
+		return fmt.Errorf("invalid left; must be >= 0")
+	}
+	if b.Right < 0 {
+		return fmt.Errorf("invalid right; must be > 0")
+	}
+	if b.Top < 0 {
+		return fmt.Errorf("invalid top; must be > 0")
+	}
+	if b.Bottom < 0 {
+		return fmt.Errorf("invalid bottom; must be > 0")
+	}
+	return nil
+}
+
 // BoxCorners is a box with independent corners.
 type BoxCorners struct {
 	TopLeft, TopRight, BottomRight, BottomLeft Point
@@ -264,36 +278,36 @@ type BoxCorners struct {
 // Box return the BoxCorners as a regular box.
 func (bc BoxCorners) Box() Box {
 	return Box{
-		Top:    util.Math.MinInt(bc.TopLeft.Y, bc.TopRight.Y),
+		Top:    MinInt(bc.TopLeft.Y, bc.TopRight.Y),
-		Left:   util.Math.MinInt(bc.TopLeft.X, bc.BottomLeft.X),
+		Left:   MinInt(bc.TopLeft.X, bc.BottomLeft.X),
-		Right:  util.Math.MaxInt(bc.TopRight.X, bc.BottomRight.X),
+		Right:  MaxInt(bc.TopRight.X, bc.BottomRight.X),
-		Bottom: util.Math.MaxInt(bc.BottomLeft.Y, bc.BottomRight.Y),
+		Bottom: MaxInt(bc.BottomLeft.Y, bc.BottomRight.Y),
 	}
 }
 
 // Width returns the width
 func (bc BoxCorners) Width() int {
-	minLeft := util.Math.MinInt(bc.TopLeft.X, bc.BottomLeft.X)
+	minLeft := MinInt(bc.TopLeft.X, bc.BottomLeft.X)
-	maxRight := util.Math.MaxInt(bc.TopRight.X, bc.BottomRight.X)
+	maxRight := MaxInt(bc.TopRight.X, bc.BottomRight.X)
 	return maxRight - minLeft
 }
 
 // Height returns the height
 func (bc BoxCorners) Height() int {
-	minTop := util.Math.MinInt(bc.TopLeft.Y, bc.TopRight.Y)
+	minTop := MinInt(bc.TopLeft.Y, bc.TopRight.Y)
-	maxBottom := util.Math.MaxInt(bc.BottomLeft.Y, bc.BottomRight.Y)
+	maxBottom := MaxInt(bc.BottomLeft.Y, bc.BottomRight.Y)
 	return maxBottom - minTop
 }
 
 // Center returns the center of the box
 func (bc BoxCorners) Center() (x, y int) {
 
-	left := util.Math.MeanInt(bc.TopLeft.X, bc.BottomLeft.X)
+	left := MeanInt(bc.TopLeft.X, bc.BottomLeft.X)
-	right := util.Math.MeanInt(bc.TopRight.X, bc.BottomRight.X)
+	right := MeanInt(bc.TopRight.X, bc.BottomRight.X)
 	x = ((right - left) >> 1) + left
 
-	top := util.Math.MeanInt(bc.TopLeft.Y, bc.TopRight.Y)
+	top := MeanInt(bc.TopLeft.Y, bc.TopRight.Y)
-	bottom := util.Math.MeanInt(bc.BottomLeft.Y, bc.BottomRight.Y)
+	bottom := MeanInt(bc.BottomLeft.Y, bc.BottomRight.Y)
 	y = ((bottom - top) >> 1) + top
 
 	return
@@ -303,12 +317,12 @@ func (bc BoxCorners) Center() (x, y int) {
 func (bc BoxCorners) Rotate(thetaDegrees float64) BoxCorners {
 	cx, cy := bc.Center()
 
-	thetaRadians := util.Math.DegreesToRadians(thetaDegrees)
+	thetaRadians := DegreesToRadians(thetaDegrees)
 
-	tlx, tly := util.Math.RotateCoordinate(cx, cy, bc.TopLeft.X, bc.TopLeft.Y, thetaRadians)
+	tlx, tly := RotateCoordinate(cx, cy, bc.TopLeft.X, bc.TopLeft.Y, thetaRadians)
-	trx, try := util.Math.RotateCoordinate(cx, cy, bc.TopRight.X, bc.TopRight.Y, thetaRadians)
+	trx, try := RotateCoordinate(cx, cy, bc.TopRight.X, bc.TopRight.Y, thetaRadians)
-	brx, bry := util.Math.RotateCoordinate(cx, cy, bc.BottomRight.X, bc.BottomRight.Y, thetaRadians)
+	brx, bry := RotateCoordinate(cx, cy, bc.BottomRight.X, bc.BottomRight.Y, thetaRadians)
-	blx, bly := util.Math.RotateCoordinate(cx, cy, bc.BottomLeft.X, bc.BottomLeft.Y, thetaRadians)
+	blx, bly := RotateCoordinate(cx, cy, bc.BottomLeft.X, bc.BottomLeft.Y, thetaRadians)
 
 	return BoxCorners{
 		TopLeft:     Point{tlx, tly},

box_test.go

@@ -4,131 +4,131 @@ import (
 	"math"
 	"testing"
 
-	"github.com/blendlabs/go-assert"
+	"git.smarteching.com/zeni/go-chart/v2/testutil"
 )
 
 func TestBoxClone(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 	a := Box{Top: 5, Left: 5, Right: 15, Bottom: 15}
 	b := a.Clone()
-	assert.True(a.Equals(b))
+	testutil.AssertTrue(t, a.Equals(b))
-	assert.True(b.Equals(a))
+	testutil.AssertTrue(t, b.Equals(a))
 }
 
 func TestBoxEquals(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	a := Box{Top: 5, Left: 5, Right: 15, Bottom: 15}
 	b := Box{Top: 10, Left: 10, Right: 30, Bottom: 30}
 	c := Box{Top: 5, Left: 5, Right: 15, Bottom: 15}
-	assert.True(a.Equals(a))
+	testutil.AssertTrue(t, a.Equals(a))
-	assert.True(a.Equals(c))
+	testutil.AssertTrue(t, a.Equals(c))
-	assert.True(c.Equals(a))
+	testutil.AssertTrue(t, c.Equals(a))
-	assert.False(a.Equals(b))
+	testutil.AssertFalse(t, a.Equals(b))
-	assert.False(c.Equals(b))
+	testutil.AssertFalse(t, c.Equals(b))
-	assert.False(b.Equals(a))
+	testutil.AssertFalse(t, b.Equals(a))
-	assert.False(b.Equals(c))
+	testutil.AssertFalse(t, b.Equals(c))
 }
 
 func TestBoxIsBiggerThan(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	a := Box{Top: 5, Left: 5, Right: 25, Bottom: 25}
 	b := Box{Top: 10, Left: 10, Right: 20, Bottom: 20} // only half bigger
 	c := Box{Top: 1, Left: 1, Right: 30, Bottom: 30}   //bigger
-	assert.True(a.IsBiggerThan(b))
+	testutil.AssertTrue(t, a.IsBiggerThan(b))
-	assert.False(a.IsBiggerThan(c))
+	testutil.AssertFalse(t, a.IsBiggerThan(c))
-	assert.True(c.IsBiggerThan(a))
+	testutil.AssertTrue(t, c.IsBiggerThan(a))
 }
 
 func TestBoxIsSmallerThan(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	a := Box{Top: 5, Left: 5, Right: 25, Bottom: 25}
 	b := Box{Top: 10, Left: 10, Right: 20, Bottom: 20} // only half bigger
 	c := Box{Top: 1, Left: 1, Right: 30, Bottom: 30}   //bigger
-	assert.False(a.IsSmallerThan(b))
+	testutil.AssertFalse(t, a.IsSmallerThan(b))
-	assert.True(a.IsSmallerThan(c))
+	testutil.AssertTrue(t, a.IsSmallerThan(c))
-	assert.False(c.IsSmallerThan(a))
+	testutil.AssertFalse(t, c.IsSmallerThan(a))
 }
 
 func TestBoxGrow(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	a := Box{Top: 1, Left: 2, Right: 15, Bottom: 15}
 	b := Box{Top: 4, Left: 5, Right: 30, Bottom: 35}
 	c := a.Grow(b)
-	assert.False(c.Equals(b))
+	testutil.AssertFalse(t, c.Equals(b))
-	assert.False(c.Equals(a))
+	testutil.AssertFalse(t, c.Equals(a))
-	assert.Equal(1, c.Top)
+	testutil.AssertEqual(t, 1, c.Top)
-	assert.Equal(2, c.Left)
+	testutil.AssertEqual(t, 2, c.Left)
-	assert.Equal(30, c.Right)
+	testutil.AssertEqual(t, 30, c.Right)
-	assert.Equal(35, c.Bottom)
+	testutil.AssertEqual(t, 35, c.Bottom)
 }
 
 func TestBoxFit(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	a := Box{Top: 64, Left: 64, Right: 192, Bottom: 192}
 	b := Box{Top: 16, Left: 16, Right: 256, Bottom: 170}
 	c := Box{Top: 16, Left: 16, Right: 170, Bottom: 256}
 
 	fab := a.Fit(b)
-	assert.Equal(a.Left, fab.Left)
+	testutil.AssertEqual(t, a.Left, fab.Left)
-	assert.Equal(a.Right, fab.Right)
+	testutil.AssertEqual(t, a.Right, fab.Right)
-	assert.True(fab.Top < fab.Bottom)
+	testutil.AssertTrue(t, fab.Top < fab.Bottom)
-	assert.True(fab.Left < fab.Right)
+	testutil.AssertTrue(t, fab.Left < fab.Right)
-	assert.True(math.Abs(b.Aspect()-fab.Aspect()) < 0.02)
+	testutil.AssertTrue(t, math.Abs(b.Aspect()-fab.Aspect()) < 0.02)
 
 	fac := a.Fit(c)
-	assert.Equal(a.Top, fac.Top)
+	testutil.AssertEqual(t, a.Top, fac.Top)
-	assert.Equal(a.Bottom, fac.Bottom)
+	testutil.AssertEqual(t, a.Bottom, fac.Bottom)
-	assert.True(math.Abs(c.Aspect()-fac.Aspect()) < 0.02)
+	testutil.AssertTrue(t, math.Abs(c.Aspect()-fac.Aspect()) < 0.02)
 }
 
 func TestBoxConstrain(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	a := Box{Top: 64, Left: 64, Right: 192, Bottom: 192}
 	b := Box{Top: 16, Left: 16, Right: 256, Bottom: 170}
 	c := Box{Top: 16, Left: 16, Right: 170, Bottom: 256}
 
 	cab := a.Constrain(b)
-	assert.Equal(64, cab.Top)
+	testutil.AssertEqual(t, 64, cab.Top)
-	assert.Equal(64, cab.Left)
+	testutil.AssertEqual(t, 64, cab.Left)
-	assert.Equal(192, cab.Right)
+	testutil.AssertEqual(t, 192, cab.Right)
-	assert.Equal(170, cab.Bottom)
+	testutil.AssertEqual(t, 170, cab.Bottom)
 
 	cac := a.Constrain(c)
-	assert.Equal(64, cac.Top)
+	testutil.AssertEqual(t, 64, cac.Top)
-	assert.Equal(64, cac.Left)
+	testutil.AssertEqual(t, 64, cac.Left)
-	assert.Equal(170, cac.Right)
+	testutil.AssertEqual(t, 170, cac.Right)
-	assert.Equal(192, cac.Bottom)
+	testutil.AssertEqual(t, 192, cac.Bottom)
 }
 
 func TestBoxOuterConstrain(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	box := NewBox(0, 0, 100, 100)
 	canvas := NewBox(5, 5, 95, 95)
 	taller := NewBox(-10, 5, 50, 50)
 
 	c := canvas.OuterConstrain(box, taller)
-	assert.Equal(15, c.Top, c.String())
+	testutil.AssertEqual(t, 15, c.Top, c.String())
-	assert.Equal(5, c.Left, c.String())
+	testutil.AssertEqual(t, 5, c.Left, c.String())
-	assert.Equal(95, c.Right, c.String())
+	testutil.AssertEqual(t, 95, c.Right, c.String())
-	assert.Equal(95, c.Bottom, c.String())
+	testutil.AssertEqual(t, 95, c.Bottom, c.String())
 
 	wider := NewBox(5, 5, 110, 50)
 	d := canvas.OuterConstrain(box, wider)
-	assert.Equal(5, d.Top, d.String())
+	testutil.AssertEqual(t, 5, d.Top, d.String())
-	assert.Equal(5, d.Left, d.String())
+	testutil.AssertEqual(t, 5, d.Left, d.String())
-	assert.Equal(85, d.Right, d.String())
+	testutil.AssertEqual(t, 85, d.Right, d.String())
-	assert.Equal(95, d.Bottom, d.String())
+	testutil.AssertEqual(t, 95, d.Bottom, d.String())
 }
 
 func TestBoxShift(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	b := Box{
 		Top:    5,
@@ -138,14 +138,14 @@ func TestBoxShift(t *testing.T) {
 	}
 
 	shifted := b.Shift(1, 2)
-	assert.Equal(7, shifted.Top)
+	testutil.AssertEqual(t, 7, shifted.Top)
-	assert.Equal(6, shifted.Left)
+	testutil.AssertEqual(t, 6, shifted.Left)
-	assert.Equal(11, shifted.Right)
+	testutil.AssertEqual(t, 11, shifted.Right)
-	assert.Equal(12, shifted.Bottom)
+	testutil.AssertEqual(t, 12, shifted.Bottom)
 }
 
 func TestBoxCenter(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	b := Box{
 		Top:    10,
@@ -154,12 +154,12 @@ func TestBoxCenter(t *testing.T) {
 		Bottom: 30,
 	}
 	cx, cy := b.Center()
-	assert.Equal(15, cx)
+	testutil.AssertEqual(t, 15, cx)
-	assert.Equal(20, cy)
+	testutil.AssertEqual(t, 20, cy)
 }
 
 func TestBoxCornersCenter(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BoxCorners{
 		TopLeft:     Point{5, 5},
@@ -169,12 +169,12 @@ func TestBoxCornersCenter(t *testing.T) {
 	}
 
 	cx, cy := bc.Center()
-	assert.Equal(10, cx)
+	testutil.AssertEqual(t, 10, cx)
-	assert.Equal(10, cy)
+	testutil.AssertEqual(t, 10, cy)
 }
 
 func TestBoxCornersRotate(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	bc := BoxCorners{
 		TopLeft:     Point{5, 5},
@@ -184,5 +184,5 @@ func TestBoxCornersRotate(t *testing.T) {
 	}
 
 	rotated := bc.Rotate(45)
-	assert.True(rotated.TopLeft.Equals(Point{10, 3}), rotated.String())
+	testutil.AssertTrue(t, rotated.TopLeft.Equals(Point{10, 3}), rotated.String())
 }

chart.go

@@ -7,7 +7,6 @@ import (
 	"math"
 
 	"github.com/golang/freetype/truetype"
-	util "github.com/wcharczuk/go-chart/util"
 )
 
 // Chart is what we're drawing.
@@ -33,6 +32,8 @@ type Chart struct {
 
 	Series   []Series
 	Elements []Renderable
+
+	Log Logger
 }
 
 // GetDPI returns the dpi for the chart.
@@ -75,8 +76,8 @@ func (c Chart) Render(rp RendererProvider, w io.Writer) error {
 	if len(c.Series) == 0 {
 		return errors.New("please provide at least one series")
 	}
-	if visibleSeriesErr := c.checkHasVisibleSeries(); visibleSeriesErr != nil {
+	if err := c.checkHasVisibleSeries(); err != nil {
-		return visibleSeriesErr
+		return err
 	}
 
 	c.YAxisSecondary.AxisType = YAxisSecondary
@@ -102,6 +103,8 @@ func (c Chart) Render(rp RendererProvider, w io.Writer) error {
 	canvasBox := c.getDefaultCanvasBox()
 	xf, yf, yfa := c.getValueFormatters()
 
+	Debugf(c.Log, "chart; canvas box: %v", canvasBox)
+
 	xr, yr, yra = c.setRangeDomains(canvasBox, xr, yr, yra)
 
 	err = c.checkRanges(xr, yr, yra)
@@ -115,6 +118,8 @@ func (c Chart) Render(rp RendererProvider, w io.Writer) error {
 		canvasBox = c.getAxesAdjustedCanvasBox(r, canvasBox, xr, yr, yra, xt, yt, yta)
 		xr, yr, yra = c.setRangeDomains(canvasBox, xr, yr, yra)
 
+		Debugf(c.Log, "chart; axes adjusted canvas box: %v", canvasBox)
+
 		// do a second pass in case things haven't settled yet.
 		xt, yt, yta = c.getAxesTicks(r, xr, yr, yra, xf, yf, yfa)
 		canvasBox = c.getAxesAdjustedCanvasBox(r, canvasBox, xr, yr, yra, xt, yt, yta)
@@ -125,6 +130,8 @@ func (c Chart) Render(rp RendererProvider, w io.Writer) error {
 		canvasBox = c.getAnnotationAdjustedCanvasBox(r, canvasBox, xr, yr, yra, xf, yf, yfa)
 		xr, yr, yra = c.setRangeDomains(canvasBox, xr, yr, yra)
 		xt, yt, yta = c.getAxesTicks(r, xr, yr, yra, xf, yf, yfa)
+
+		Debugf(c.Log, "chart; annotation adjusted canvas box: %v", canvasBox)
 	}
 
 	c.drawCanvas(r, canvasBox)
@@ -143,16 +150,14 @@ func (c Chart) Render(rp RendererProvider, w io.Writer) error {
 }
 
 func (c Chart) checkHasVisibleSeries() error {
-	hasVisibleSeries := false
 	var style Style
 	for _, s := range c.Series {
 		style = s.GetStyle()
-		hasVisibleSeries = hasVisibleSeries || (style.IsZero() || style.Show)
+		if !style.Hidden {
+			return nil
+		}
 	}
-	if !hasVisibleSeries {
+	return fmt.Errorf("chart render; must have (1) visible series")
-		return fmt.Errorf("must have (1) visible series; make sure if you set a style, you set .Show = true")
-	}
-	return nil
 }
 
 func (c Chart) validateSeries() error {
@@ -176,7 +181,7 @@ func (c Chart) getRanges() (xrange, yrange, yrangeAlt Range) {
 	// note: a possible future optimization is to not scan the series values if
 	// all axis are represented by either custom ticks or custom ranges.
 	for _, s := range c.Series {
-		if s.GetStyle().IsZero() || s.GetStyle().Show {
+		if !s.GetStyle().Hidden {
 			seriesAxis := s.GetYAxis()
 			if bvp, isBoundedValuesProvider := s.(BoundedValuesProvider); isBoundedValuesProvider {
 				seriesLength := bvp.Len()
@@ -263,11 +268,10 @@ func (c Chart) getRanges() (xrange, yrange, yrangeAlt Range) {
 		yrange.SetMin(miny)
 		yrange.SetMax(maxy)
 
-		// only round if we're showing the axis
+		if !c.YAxis.Style.Hidden {
-		if c.YAxis.Style.Show {
 			delta := yrange.GetDelta()
-			roundTo := util.Math.GetRoundToForDelta(delta)
+			roundTo := GetRoundToForDelta(delta)
-			rmin, rmax := util.Math.RoundDown(yrange.GetMin(), roundTo), util.Math.RoundUp(yrange.GetMax(), roundTo)
+			rmin, rmax := RoundDown(yrange.GetMin(), roundTo), RoundUp(yrange.GetMax(), roundTo)
 
 			yrange.SetMin(rmin)
 			yrange.SetMax(rmax)
@@ -286,10 +290,10 @@ func (c Chart) getRanges() (xrange, yrange, yrangeAlt Range) {
 		yrangeAlt.SetMin(minya)
 		yrangeAlt.SetMax(maxya)
 
-		if c.YAxisSecondary.Style.Show {
+		if !c.YAxisSecondary.Style.Hidden {
 			delta := yrangeAlt.GetDelta()
-			roundTo := util.Math.GetRoundToForDelta(delta)
+			roundTo := GetRoundToForDelta(delta)
-			rmin, rmax := util.Math.RoundDown(yrangeAlt.GetMin(), roundTo), util.Math.RoundUp(yrangeAlt.GetMax(), roundTo)
+			rmin, rmax := RoundDown(yrangeAlt.GetMin(), roundTo), RoundUp(yrangeAlt.GetMax(), roundTo)
 			yrangeAlt.SetMin(rmin)
 			yrangeAlt.SetMax(rmax)
 		}
@@ -299,6 +303,7 @@ func (c Chart) getRanges() (xrange, yrange, yrangeAlt Range) {
 }
 
 func (c Chart) checkRanges(xr, yr, yra Range) error {
+	Debugf(c.Log, "checking xrange: %v", xr)
 	xDelta := xr.GetDelta()
 	if math.IsInf(xDelta, 0) {
 		return errors.New("infinite x-range delta")
@@ -310,6 +315,7 @@ func (c Chart) checkRanges(xr, yr, yra Range) error {
 		return errors.New("zero x-range delta; there needs to be at least (2) values")
 	}
 
+	Debugf(c.Log, "checking yrange: %v", yr)
 	yDelta := yr.GetDelta()
 	if math.IsInf(yDelta, 0) {
 		return errors.New("infinite y-range delta")
@@ -317,11 +323,9 @@ func (c Chart) checkRanges(xr, yr, yra Range) error {
 	if math.IsNaN(yDelta) {
 		return errors.New("nan y-range delta")
 	}
-	if yDelta == 0 {
-		return errors.New("zero y-range delta")
-	}
 
 	if c.hasSecondarySeries() {
+		Debugf(c.Log, "checking secondary yrange: %v", yra)
 		yraDelta := yra.GetDelta()
 		if math.IsInf(yraDelta, 0) {
 			return errors.New("infinite secondary y-range delta")
@@ -329,9 +333,6 @@ func (c Chart) checkRanges(xr, yr, yra Range) error {
 		if math.IsNaN(yraDelta) {
 			return errors.New("nan secondary y-range delta")
 		}
-		if yraDelta == 0 {
-			return errors.New("zero secondary y-range delta")
-		}
 	}
 
 	return nil
@@ -367,17 +368,17 @@ func (c Chart) getValueFormatters() (x, y, ya ValueFormatter) {
 }
 
 func (c Chart) hasAxes() bool {
-	return c.XAxis.Style.Show || c.YAxis.Style.Show || c.YAxisSecondary.Style.Show
+	return !c.XAxis.Style.Hidden || !c.YAxis.Style.Hidden || !c.YAxisSecondary.Style.Hidden
 }
 
 func (c Chart) getAxesTicks(r Renderer, xr, yr, yar Range, xf, yf, yfa ValueFormatter) (xticks, yticks, yticksAlt []Tick) {
-	if c.XAxis.Style.Show {
+	if !c.XAxis.Style.Hidden {
 		xticks = c.XAxis.GetTicks(r, xr, c.styleDefaultsAxes(), xf)
 	}
-	if c.YAxis.Style.Show {
+	if !c.YAxis.Style.Hidden {
 		yticks = c.YAxis.GetTicks(r, yr, c.styleDefaultsAxes(), yf)
 	}
-	if c.YAxisSecondary.Style.Show {
+	if !c.YAxisSecondary.Style.Hidden {
 		yticksAlt = c.YAxisSecondary.GetTicks(r, yar, c.styleDefaultsAxes(), yfa)
 	}
 	return
@@ -385,16 +386,19 @@ func (c Chart) getAxesTicks(r Renderer, xr, yr, yar Range, xf, yf, yfa ValueForm
 
 func (c Chart) getAxesAdjustedCanvasBox(r Renderer, canvasBox Box, xr, yr, yra Range, xticks, yticks, yticksAlt []Tick) Box {
 	axesOuterBox := canvasBox.Clone()
-	if c.XAxis.Style.Show {
+	if !c.XAxis.Style.Hidden {
 		axesBounds := c.XAxis.Measure(r, canvasBox, xr, c.styleDefaultsAxes(), xticks)
+		Debugf(c.Log, "chart; x-axis measured %v", axesBounds)
 		axesOuterBox = axesOuterBox.Grow(axesBounds)
 	}
-	if c.YAxis.Style.Show {
+	if !c.YAxis.Style.Hidden {
 		axesBounds := c.YAxis.Measure(r, canvasBox, yr, c.styleDefaultsAxes(), yticks)
+		Debugf(c.Log, "chart; y-axis measured %v", axesBounds)
 		axesOuterBox = axesOuterBox.Grow(axesBounds)
 	}
-	if c.YAxisSecondary.Style.Show {
+	if !c.YAxisSecondary.Style.Hidden && c.hasSecondarySeries() {
 		axesBounds := c.YAxisSecondary.Measure(r, canvasBox, yra, c.styleDefaultsAxes(), yticksAlt)
+		Debugf(c.Log, "chart; y-axis secondary measured %v", axesBounds)
 		axesOuterBox = axesOuterBox.Grow(axesBounds)
 	}
 
@@ -411,7 +415,7 @@ func (c Chart) setRangeDomains(canvasBox Box, xr, yr, yra Range) (Range, Range,
 func (c Chart) hasAnnotationSeries() bool {
 	for _, s := range c.Series {
 		if as, isAnnotationSeries := s.(AnnotationSeries); isAnnotationSeries {
-			if as.Style.IsZero() || as.Style.Show {
+			if !as.GetStyle().Hidden {
 				return true
 			}
 		}
@@ -432,7 +436,7 @@ func (c Chart) getAnnotationAdjustedCanvasBox(r Renderer, canvasBox Box, xr, yr,
 	annotationSeriesBox := canvasBox.Clone()
 	for seriesIndex, s := range c.Series {
 		if as, isAnnotationSeries := s.(AnnotationSeries); isAnnotationSeries {
-			if as.Style.IsZero() || as.Style.Show {
+			if !as.GetStyle().Hidden {
 				style := c.styleDefaultsSeries(seriesIndex)
 				var annotationBounds Box
 				if as.YAxis == YAxisPrimary {
@@ -469,19 +473,19 @@ func (c Chart) drawCanvas(r Renderer, canvasBox Box) {
 }
 
 func (c Chart) drawAxes(r Renderer, canvasBox Box, xrange, yrange, yrangeAlt Range, xticks, yticks, yticksAlt []Tick) {
-	if c.XAxis.Style.Show {
+	if !c.XAxis.Style.Hidden {
 		c.XAxis.Render(r, canvasBox, xrange, c.styleDefaultsAxes(), xticks)
 	}
-	if c.YAxis.Style.Show {
+	if !c.YAxis.Style.Hidden {
 		c.YAxis.Render(r, canvasBox, yrange, c.styleDefaultsAxes(), yticks)
 	}
-	if c.YAxisSecondary.Style.Show {
+	if !c.YAxisSecondary.Style.Hidden {
 		c.YAxisSecondary.Render(r, canvasBox, yrangeAlt, c.styleDefaultsAxes(), yticksAlt)
 	}
 }
 
 func (c Chart) drawSeries(r Renderer, canvasBox Box, xrange, yrange, yrangeAlt Range, s Series, seriesIndex int) {
-	if s.GetStyle().IsZero() || s.GetStyle().Show {
+	if !s.GetStyle().Hidden {
 		if s.GetYAxis() == YAxisPrimary {
 			s.Render(r, canvasBox, xrange, yrange, c.styleDefaultsSeries(seriesIndex))
 		} else if s.GetYAxis() == YAxisSecondary {
@@ -491,7 +495,7 @@ func (c Chart) drawSeries(r Renderer, canvasBox Box, xrange, yrange, yrangeAlt R
 }
 
 func (c Chart) drawTitle(r Renderer) {
-	if len(c.Title) > 0 && c.TitleStyle.Show {
+	if len(c.Title) > 0 && !c.TitleStyle.Hidden {
 		r.SetFont(c.TitleStyle.GetFont(c.GetFont()))
 		r.SetFontColor(c.TitleStyle.GetFontColor(c.GetColorPalette().TextColor()))
 		titleFontSize := c.TitleStyle.GetFontSize(DefaultTitleFontSize)

chart_test.go

@@ -8,58 +8,57 @@ import (
 	"testing"
 	"time"
 
-	"github.com/blendlabs/go-assert"
+	"git.smarteching.com/zeni/go-chart/v2/drawing"
-	"github.com/wcharczuk/go-chart/drawing"
+	"git.smarteching.com/zeni/go-chart/v2/testutil"
-	"github.com/wcharczuk/go-chart/seq"
 )
 
 func TestChartGetDPI(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	unset := Chart{}
-	assert.Equal(DefaultDPI, unset.GetDPI())
+	testutil.AssertEqual(t, DefaultDPI, unset.GetDPI())
-	assert.Equal(192, unset.GetDPI(192))
+	testutil.AssertEqual(t, 192, unset.GetDPI(192))
 
 	set := Chart{DPI: 128}
-	assert.Equal(128, set.GetDPI())
+	testutil.AssertEqual(t, 128, set.GetDPI())
-	assert.Equal(128, set.GetDPI(192))
+	testutil.AssertEqual(t, 128, set.GetDPI(192))
 }
 
 func TestChartGetFont(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	f, err := GetDefaultFont()
-	assert.Nil(err)
+	testutil.AssertNil(t, err)
 
 	unset := Chart{}
-	assert.Nil(unset.GetFont())
+	testutil.AssertNil(t, unset.GetFont())
 
 	set := Chart{Font: f}
-	assert.NotNil(set.GetFont())
+	testutil.AssertNotNil(t, set.GetFont())
 }
 
 func TestChartGetWidth(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	unset := Chart{}
-	assert.Equal(DefaultChartWidth, unset.GetWidth())
+	testutil.AssertEqual(t, DefaultChartWidth, unset.GetWidth())
 
 	set := Chart{Width: DefaultChartWidth + 10}
-	assert.Equal(DefaultChartWidth+10, set.GetWidth())
+	testutil.AssertEqual(t, DefaultChartWidth+10, set.GetWidth())
 }
 
 func TestChartGetHeight(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	unset := Chart{}
-	assert.Equal(DefaultChartHeight, unset.GetHeight())
+	testutil.AssertEqual(t, DefaultChartHeight, unset.GetHeight())
 
 	set := Chart{Height: DefaultChartHeight + 10}
-	assert.Equal(DefaultChartHeight+10, set.GetHeight())
+	testutil.AssertEqual(t, DefaultChartHeight+10, set.GetHeight())
 }
 
 func TestChartGetRanges(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	c := Chart{
 		Series: []Series{
@@ -80,14 +79,14 @@ func TestChartGetRanges(t *testing.T) {
 	}
 
 	xrange, yrange, yrangeAlt := c.getRanges()
-	assert.Equal(-2.0, xrange.GetMin())
+	testutil.AssertEqual(t, -2.0, xrange.GetMin())
-	assert.Equal(5.0, xrange.GetMax())
+	testutil.AssertEqual(t, 5.0, xrange.GetMax())
 
-	assert.Equal(-2.1, yrange.GetMin())
+	testutil.AssertEqual(t, -2.1, yrange.GetMin())
-	assert.Equal(4.5, yrange.GetMax())
+	testutil.AssertEqual(t, 4.5, yrange.GetMax())
 
-	assert.Equal(10.0, yrangeAlt.GetMin())
+	testutil.AssertEqual(t, 10.0, yrangeAlt.GetMin())
-	assert.Equal(14.0, yrangeAlt.GetMax())
+	testutil.AssertEqual(t, 14.0, yrangeAlt.GetMax())
 
 	cSet := Chart{
 		XAxis: XAxis{
@@ -117,18 +116,18 @@ func TestChartGetRanges(t *testing.T) {
 	}
 
 	xr2, yr2, yra2 := cSet.getRanges()
-	assert.Equal(9.8, xr2.GetMin())
+	testutil.AssertEqual(t, 9.8, xr2.GetMin())
-	assert.Equal(19.8, xr2.GetMax())
+	testutil.AssertEqual(t, 19.8, xr2.GetMax())
 
-	assert.Equal(9.9, yr2.GetMin())
+	testutil.AssertEqual(t, 9.9, yr2.GetMin())
-	assert.Equal(19.9, yr2.GetMax())
+	testutil.AssertEqual(t, 19.9, yr2.GetMax())
 
-	assert.Equal(9.7, yra2.GetMin())
+	testutil.AssertEqual(t, 9.7, yra2.GetMin())
-	assert.Equal(19.7, yra2.GetMax())
+	testutil.AssertEqual(t, 19.7, yra2.GetMax())
 }
 
 func TestChartGetRangesUseTicks(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	// this test asserts that ticks should supercede manual ranges when generating the overall ranges.
 
@@ -156,15 +155,15 @@ func TestChartGetRangesUseTicks(t *testing.T) {
 	}
 
 	xr, yr, yar := c.getRanges()
-	assert.Equal(-2.0, xr.GetMin())
+	testutil.AssertEqual(t, -2.0, xr.GetMin())
-	assert.Equal(2.0, xr.GetMax())
+	testutil.AssertEqual(t, 2.0, xr.GetMax())
-	assert.Equal(0.0, yr.GetMin())
+	testutil.AssertEqual(t, 0.0, yr.GetMin())
-	assert.Equal(5.0, yr.GetMax())
+	testutil.AssertEqual(t, 5.0, yr.GetMax())
-	assert.True(yar.IsZero(), yar.String())
+	testutil.AssertTrue(t, yar.IsZero(), yar.String())
 }
 
 func TestChartGetRangesUseUserRanges(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	c := Chart{
 		YAxis: YAxis{
@@ -182,15 +181,15 @@ func TestChartGetRangesUseUserRanges(t *testing.T) {
 	}
 
 	xr, yr, yar := c.getRanges()
-	assert.Equal(-2.0, xr.GetMin())
+	testutil.AssertEqual(t, -2.0, xr.GetMin())
-	assert.Equal(2.0, xr.GetMax())
+	testutil.AssertEqual(t, 2.0, xr.GetMax())
-	assert.Equal(-5.0, yr.GetMin())
+	testutil.AssertEqual(t, -5.0, yr.GetMin())
-	assert.Equal(5.0, yr.GetMax())
+	testutil.AssertEqual(t, 5.0, yr.GetMax())
-	assert.True(yar.IsZero(), yar.String())
+	testutil.AssertTrue(t, yar.IsZero(), yar.String())
 }
 
 func TestChartGetBackgroundStyle(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	c := Chart{
 		Background: Style{
@@ -199,11 +198,11 @@ func TestChartGetBackgroundStyle(t *testing.T) {
 	}
 
 	bs := c.getBackgroundStyle()
-	assert.Equal(bs.FillColor.String(), drawing.ColorBlack.String())
+	testutil.AssertEqual(t, bs.FillColor.String(), drawing.ColorBlack.String())
 }
 
 func TestChartGetCanvasStyle(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	c := Chart{
 		Canvas: Style{
@@ -212,19 +211,19 @@ func TestChartGetCanvasStyle(t *testing.T) {
 	}
 
 	bs := c.getCanvasStyle()
-	assert.Equal(bs.FillColor.String(), drawing.ColorBlack.String())
+	testutil.AssertEqual(t, bs.FillColor.String(), drawing.ColorBlack.String())
 }
 
 func TestChartGetDefaultCanvasBox(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	c := Chart{}
 	canvasBoxDefault := c.getDefaultCanvasBox()
-	assert.False(canvasBoxDefault.IsZero())
+	testutil.AssertFalse(t, canvasBoxDefault.IsZero())
-	assert.Equal(DefaultBackgroundPadding.Top, canvasBoxDefault.Top)
+	testutil.AssertEqual(t, DefaultBackgroundPadding.Top, canvasBoxDefault.Top)
-	assert.Equal(DefaultBackgroundPadding.Left, canvasBoxDefault.Left)
+	testutil.AssertEqual(t, DefaultBackgroundPadding.Left, canvasBoxDefault.Left)
-	assert.Equal(c.GetWidth()-DefaultBackgroundPadding.Right, canvasBoxDefault.Right)
+	testutil.AssertEqual(t, c.GetWidth()-DefaultBackgroundPadding.Right, canvasBoxDefault.Right)
-	assert.Equal(c.GetHeight()-DefaultBackgroundPadding.Bottom, canvasBoxDefault.Bottom)
+	testutil.AssertEqual(t, c.GetHeight()-DefaultBackgroundPadding.Bottom, canvasBoxDefault.Bottom)
 
 	custom := Chart{
 		Background: Style{
@@ -237,15 +236,15 @@ func TestChartGetDefaultCanvasBox(t *testing.T) {
 		},
 	}
 	canvasBoxCustom := custom.getDefaultCanvasBox()
-	assert.False(canvasBoxCustom.IsZero())
+	testutil.AssertFalse(t, canvasBoxCustom.IsZero())
-	assert.Equal(DefaultBackgroundPadding.Top+1, canvasBoxCustom.Top)
+	testutil.AssertEqual(t, DefaultBackgroundPadding.Top+1, canvasBoxCustom.Top)
-	assert.Equal(DefaultBackgroundPadding.Left+1, canvasBoxCustom.Left)
+	testutil.AssertEqual(t, DefaultBackgroundPadding.Left+1, canvasBoxCustom.Left)
-	assert.Equal(c.GetWidth()-(DefaultBackgroundPadding.Right+1), canvasBoxCustom.Right)
+	testutil.AssertEqual(t, c.GetWidth()-(DefaultBackgroundPadding.Right+1), canvasBoxCustom.Right)
-	assert.Equal(c.GetHeight()-(DefaultBackgroundPadding.Bottom+1), canvasBoxCustom.Bottom)
+	testutil.AssertEqual(t, c.GetHeight()-(DefaultBackgroundPadding.Bottom+1), canvasBoxCustom.Bottom)
 }
 
 func TestChartGetValueFormatters(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	c := Chart{
 		Series: []Series{
@@ -266,90 +265,95 @@ func TestChartGetValueFormatters(t *testing.T) {
 	}
 
 	dxf, dyf, dyaf := c.getValueFormatters()
-	assert.NotNil(dxf)
+	testutil.AssertNotNil(t, dxf)
-	assert.NotNil(dyf)
+	testutil.AssertNotNil(t, dyf)
-	assert.NotNil(dyaf)
+	testutil.AssertNotNil(t, dyaf)
 }
 
 func TestChartHasAxes(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
-	assert.False(Chart{}.hasAxes())
+	testutil.AssertTrue(t, Chart{}.hasAxes())
+	testutil.AssertFalse(t, Chart{XAxis: XAxis{Style: Hidden()}, YAxis: YAxis{Style: Hidden()}, YAxisSecondary: YAxis{Style: Hidden()}}.hasAxes())
 
 	x := Chart{
 		XAxis: XAxis{
-			Style: Style{
+			Style: Hidden(),
-				Show: true,
+		},
-			},
+		YAxis: YAxis{
+			Style: Shown(),
+		},
+		YAxisSecondary: YAxis{
+			Style: Hidden(),
 		},
 	}
-	assert.True(x.hasAxes())
+	testutil.AssertTrue(t, x.hasAxes())
 
 	y := Chart{
+		XAxis: XAxis{
+			Style: Shown(),
+		},
 		YAxis: YAxis{
-			Style: Style{
+			Style: Hidden(),
-				Show: true,
+		},
-			},
+		YAxisSecondary: YAxis{
+			Style: Hidden(),
 		},
 	}
-	assert.True(y.hasAxes())
+	testutil.AssertTrue(t, y.hasAxes())
 
 	ya := Chart{
+		XAxis: XAxis{
+			Style: Hidden(),
+		},
+		YAxis: YAxis{
+			Style: Hidden(),
+		},
 		YAxisSecondary: YAxis{
-			Style: Style{
+			Style: Shown(),
-				Show: true,
-			},
 		},
 	}
-	assert.True(ya.hasAxes())
+	testutil.AssertTrue(t, ya.hasAxes())
 }
 
 func TestChartGetAxesTicks(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	r, err := PNG(1024, 1024)
-	assert.Nil(err)
+	testutil.AssertNil(t, err)
 
 	c := Chart{
 		XAxis: XAxis{
-			Style: Style{Show: true},
 			Range: &ContinuousRange{Min: 9.8, Max: 19.8},
 		},
 		YAxis: YAxis{
-			Style: Style{Show: true},
 			Range: &ContinuousRange{Min: 9.9, Max: 19.9},
 		},
 		YAxisSecondary: YAxis{
-			Style: Style{Show: true},
 			Range: &ContinuousRange{Min: 9.7, Max: 19.7},
 		},
 	}
 	xr, yr, yar := c.getRanges()
 
 	xt, yt, yat := c.getAxesTicks(r, xr, yr, yar, FloatValueFormatter, FloatValueFormatter, FloatValueFormatter)
-	assert.NotEmpty(xt)
+	testutil.AssertNotEmpty(t, xt)
-	assert.NotEmpty(yt)
+	testutil.AssertNotEmpty(t, yt)
-	assert.NotEmpty(yat)
+	testutil.AssertNotEmpty(t, yat)
 }
 
 func TestChartSingleSeries(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 	now := time.Now()
 	c := Chart{
-		Title:      "Hello!",
+		Title:  "Hello!",
-		TitleStyle: StyleShow(),
+		Width:  1024,
-		Width:      1024,
+		Height: 400,
-		Height:     400,
 		YAxis: YAxis{
-			Style: StyleShow(),
 			Range: &ContinuousRange{
 				Min: 0.0,
 				Max: 4.0,
 			},
 		},
-		XAxis: XAxis{
-			Style: StyleShow(),
-		},
 		Series: []Series{
 			TimeSeries{
 				Name:    "goog",
@@ -361,11 +365,11 @@ func TestChartSingleSeries(t *testing.T) {
 
 	buffer := bytes.NewBuffer([]byte{})
 	c.Render(PNG, buffer)
-	assert.NotEmpty(buffer.Bytes())
+	testutil.AssertNotEmpty(t, buffer.Bytes())
 }
 
 func TestChartRegressionBadRanges(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	c := Chart{
 		Series: []Series{
@@ -377,11 +381,11 @@ func TestChartRegressionBadRanges(t *testing.T) {
 	}
 	buffer := bytes.NewBuffer([]byte{})
 	c.Render(PNG, buffer)
-	assert.True(true, "Render needs to finish.")
+	testutil.AssertTrue(t, true, "Render needs to finish.")
 }
 
 func TestChartRegressionBadRangesByUser(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	c := Chart{
 		YAxis: YAxis{
@@ -392,43 +396,43 @@ func TestChartRegressionBadRangesByUser(t *testing.T) {
 		},
 		Series: []Series{
 			ContinuousSeries{
-				XValues: seq.Range(1.0, 10.0),
+				XValues: LinearRange(1.0, 10.0),
-				YValues: seq.Range(1.0, 10.0),
+				YValues: LinearRange(1.0, 10.0),
 			},
 		},
 	}
 	buffer := bytes.NewBuffer([]byte{})
 	c.Render(PNG, buffer)
-	assert.True(true, "Render needs to finish.")
+	testutil.AssertTrue(t, true, "Render needs to finish.")
 }
 
 func TestChartValidatesSeries(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	c := Chart{
 		Series: []Series{
 			ContinuousSeries{
-				XValues: seq.Range(1.0, 10.0),
+				XValues: LinearRange(1.0, 10.0),
-				YValues: seq.Range(1.0, 10.0),
+				YValues: LinearRange(1.0, 10.0),
 			},
 		},
 	}
 
-	assert.Nil(c.validateSeries())
+	testutil.AssertNil(t, c.validateSeries())
 
 	c = Chart{
 		Series: []Series{
 			ContinuousSeries{
-				XValues: seq.Range(1.0, 10.0),
+				XValues: LinearRange(1.0, 10.0),
 			},
 		},
 	}
 
-	assert.NotNil(c.validateSeries())
+	testutil.AssertNotNil(t, c.validateSeries())
 }
 
 func TestChartCheckRanges(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	c := Chart{
 		Series: []Series{
@@ -440,27 +444,11 @@ func TestChartCheckRanges(t *testing.T) {
 	}
 
 	xr, yr, yra := c.getRanges()
-	assert.Nil(c.checkRanges(xr, yr, yra))
+	testutil.AssertNil(t, c.checkRanges(xr, yr, yra))
-}
-
-func TestChartCheckRangesFailure(t *testing.T) {
-	assert := assert.New(t)
-
-	c := Chart{
-		Series: []Series{
-			ContinuousSeries{
-				XValues: []float64{1.0, 2.0},
-				YValues: []float64{3.14, 3.14},
-			},
-		},
-	}
-
-	xr, yr, yra := c.getRanges()
-	assert.NotNil(c.checkRanges(xr, yr, yra))
 }
 
 func TestChartCheckRangesWithRanges(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	c := Chart{
 		XAxis: XAxis{
@@ -484,7 +472,7 @@ func TestChartCheckRangesWithRanges(t *testing.T) {
 	}
 
 	xr, yr, yra := c.getRanges()
-	assert.Nil(c.checkRanges(xr, yr, yra))
+	testutil.AssertNil(t, c.checkRanges(xr, yr, yra))
 }
 
 func at(i image.Image, x, y int) drawing.Color {
@@ -492,85 +480,115 @@ func at(i image.Image, x, y int) drawing.Color {
 }
 
 func TestChartE2ELine(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	c := Chart{
-		Height: 50,
+		Height:         50,
-		Width:  50,
+		Width:          50,
+		TitleStyle:     Hidden(),
+		XAxis:          HideXAxis(),
+		YAxis:          HideYAxis(),
+		YAxisSecondary: HideYAxis(),
 		Canvas: Style{
-			Padding: Box{IsSet: true},
+			Padding: BoxZero,
 		},
 		Background: Style{
-			Padding: Box{IsSet: true},
+			Padding: BoxZero,
 		},
 		Series: []Series{
 			ContinuousSeries{
-				XValues: seq.RangeWithStep(0, 4, 1),
+				XValues: LinearRangeWithStep(0, 4, 1),
-				YValues: seq.RangeWithStep(0, 4, 1),
+				YValues: LinearRangeWithStep(0, 4, 1),
 			},
 		},
 	}
 
 	var buffer = &bytes.Buffer{}
 	err := c.Render(PNG, buffer)
-	assert.Nil(err)
+	testutil.AssertNil(t, err)
 
 	// do color tests ...
 
 	i, err := png.Decode(buffer)
-	assert.Nil(err)
+	testutil.AssertNil(t, err)
 
 	// test the bottom and top of the line
-	assert.Equal(drawing.ColorWhite, at(i, 0, 0))
+	testutil.AssertEqual(t, drawing.ColorWhite, at(i, 0, 0))
-	assert.Equal(drawing.ColorWhite, at(i, 49, 49))
+	testutil.AssertEqual(t, drawing.ColorWhite, at(i, 49, 49))
 
 	// test a line mid point
 	defaultSeriesColor := GetDefaultColor(0)
-	assert.Equal(defaultSeriesColor, at(i, 0, 49))
+	testutil.AssertEqual(t, defaultSeriesColor, at(i, 0, 49))
-	assert.Equal(defaultSeriesColor, at(i, 49, 0))
+	testutil.AssertEqual(t, defaultSeriesColor, at(i, 49, 0))
-	assert.Equal(drawing.ColorFromHex("bddbf6"), at(i, 24, 24))
+	testutil.AssertEqual(t, drawing.ColorFromHex("bddbf6"), at(i, 24, 24))
 }
 
 func TestChartE2ELineWithFill(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
+
+	logBuffer := new(bytes.Buffer)
 
 	c := Chart{
 		Height: 50,
 		Width:  50,
 		Canvas: Style{
-			Padding: Box{IsSet: true},
+			Padding: BoxZero,
 		},
 		Background: Style{
-			Padding: Box{IsSet: true},
+			Padding: BoxZero,
 		},
+		TitleStyle:     Hidden(),
+		XAxis:          HideXAxis(),
+		YAxis:          HideYAxis(),
+		YAxisSecondary: HideYAxis(),
 		Series: []Series{
 			ContinuousSeries{
 				Style: Style{
-					Show:        true,
 					StrokeColor: drawing.ColorBlue,
 					FillColor:   drawing.ColorRed,
 				},
-				XValues: seq.RangeWithStep(0, 4, 1),
+				XValues: LinearRangeWithStep(0, 4, 1),
-				YValues: seq.RangeWithStep(0, 4, 1),
+				YValues: LinearRangeWithStep(0, 4, 1),
+			},
+		},
+		Log: NewLogger(OptLoggerStdout(logBuffer), OptLoggerStderr(logBuffer)),
+	}
+
+	testutil.AssertEqual(t, 5, len(c.Series[0].(ContinuousSeries).XValues))
+	testutil.AssertEqual(t, 5, len(c.Series[0].(ContinuousSeries).YValues))
+
+	var buffer = &bytes.Buffer{}
+	err := c.Render(PNG, buffer)
+	testutil.AssertNil(t, err)
+
+	i, err := png.Decode(buffer)
+	testutil.AssertNil(t, err)
+
+	// test the bottom and top of the line
+	testutil.AssertEqual(t, drawing.ColorWhite, at(i, 0, 0))
+	testutil.AssertEqual(t, drawing.ColorRed, at(i, 49, 49))
+
+	// test a line mid point
+	defaultSeriesColor := drawing.ColorBlue
+	testutil.AssertEqual(t, defaultSeriesColor, at(i, 0, 49))
+	testutil.AssertEqual(t, defaultSeriesColor, at(i, 49, 0))
+}
+
+func Test_Chart_cve(t *testing.T) {
+	poc := StackedBarChart{
+		Title: "poc",
+		Bars: []StackedBar{
+			{
+				Name: "11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111",
+				Values: []Value{
+					{Value: 1, Label: "infinite"},
+					{Value: 1, Label: "loop"},
+				},
 			},
 		},
 	}
 
-	var buffer = &bytes.Buffer{}
+	var imgContent bytes.Buffer
-	err := c.Render(PNG, buffer)
+	err := poc.Render(PNG, &imgContent)
-	assert.Nil(err)
+	testutil.AssertNotNil(t, err)
-
-	// do color tests ...
-
-	i, err := png.Decode(buffer)
-	assert.Nil(err)
-
-	// test the bottom and top of the line
-	assert.Equal(drawing.ColorWhite, at(i, 0, 0))
-	assert.Equal(drawing.ColorRed, at(i, 49, 49))
-
-	// test a line mid point
-	defaultSeriesColor := drawing.ColorBlue
-	assert.Equal(defaultSeriesColor, at(i, 0, 49))
-	assert.Equal(defaultSeriesColor, at(i, 49, 0))
 }

cmd/chart/main.go

@@ -0,0 +1,148 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strings"
+
+	"git.smarteching.com/zeni/go-chart/v2"
+)
+
+var (
+	outputPath = flag.String("output", "", "The output file")
+
+	inputFormat = flag.String("format", "csv", "The input format, either 'csv' or 'tsv' (defaults to 'csv')")
+	inputPath   = flag.String("f", "", "The input file")
+	reverse     = flag.Bool("reverse", false, "If we should reverse the inputs")
+
+	hideLegend     = flag.Bool("hide-legend", false, "If we should omit the chart legend")
+	hideSMA        = flag.Bool("hide-sma", false, "If we should omit simple moving average")
+	hideLinreg     = flag.Bool("hide-linreg", false, "If we should omit linear regressions")
+	hideLastValues = flag.Bool("hide-last-values", false, "If we should omit last values")
+)
+
+func main() {
+	flag.Parse()
+	log := chart.NewLogger()
+
+	var rawData []byte
+	var err error
+	if *inputPath != "" {
+		if *inputPath == "-" {
+			rawData, err = ioutil.ReadAll(os.Stdin)
+			if err != nil {
+				log.FatalErr(err)
+			}
+		} else {
+			rawData, err = ioutil.ReadFile(*inputPath)
+			if err != nil {
+				log.FatalErr(err)
+			}
+		}
+	} else if len(flag.Args()) > 0 {
+		rawData = []byte(flag.Args()[0])
+	} else {
+		flag.Usage()
+		os.Exit(1)
+	}
+
+	var parts []string
+	switch *inputFormat {
+	case "csv":
+		parts = chart.SplitCSV(string(rawData))
+	case "tsv":
+		parts = strings.Split(string(rawData), "\t")
+	default:
+		log.FatalErr(fmt.Errorf("invalid format; must be 'csv' or 'tsv'"))
+	}
+
+	yvalues, err := chart.ParseFloats(parts...)
+	if err != nil {
+		log.FatalErr(err)
+	}
+
+	if *reverse {
+		yvalues = chart.ValueSequence(yvalues...).Reverse().Values()
+	}
+
+	var series []chart.Series
+	mainSeries := chart.ContinuousSeries{
+		Name:    "Values",
+		XValues: chart.LinearRange(1, float64(len(yvalues))),
+		YValues: yvalues,
+	}
+	series = append(series, mainSeries)
+
+	smaSeries := &chart.SMASeries{
+		Name: "SMA",
+		Style: chart.Style{
+			Hidden:          *hideSMA,
+			StrokeColor:     chart.ColorRed,
+			StrokeDashArray: []float64{5.0, 5.0},
+		},
+		InnerSeries: mainSeries,
+	}
+	series = append(series, smaSeries)
+
+	linRegSeries := &chart.LinearRegressionSeries{
+		Name: "Values - Lin. Reg.",
+		Style: chart.Style{
+			Hidden: *hideLinreg,
+		},
+		InnerSeries: mainSeries,
+	}
+	series = append(series, linRegSeries)
+
+	mainLastValue := chart.LastValueAnnotationSeries(mainSeries)
+	mainLastValue.Style = chart.Style{
+		Hidden: *hideLastValues,
+	}
+	series = append(series, mainLastValue)
+
+	linregLastValue := chart.LastValueAnnotationSeries(linRegSeries)
+	linregLastValue.Style = chart.Style{
+		Hidden: (*hideLastValues || *hideLinreg),
+	}
+	series = append(series, linregLastValue)
+
+	smaLastValue := chart.LastValueAnnotationSeries(smaSeries)
+	smaLastValue.Style = chart.Style{
+		Hidden: (*hideLastValues || *hideSMA),
+	}
+	series = append(series, smaLastValue)
+
+	graph := chart.Chart{
+		Background: chart.Style{
+			Padding: chart.Box{
+				Top: 50,
+			},
+		},
+		Series: series,
+	}
+
+	if !*hideLegend {
+		graph.Elements = []chart.Renderable{chart.LegendThin(&graph)}
+	}
+
+	var output *os.File
+	if *outputPath != "" {
+		output, err = os.Create(*outputPath)
+		if err != nil {
+			log.FatalErr(err)
+		}
+	} else {
+		output, err = ioutil.TempFile("", "*.png")
+		if err != nil {
+			log.FatalErr(err)
+		}
+	}
+
+	if err := graph.Render(chart.PNG, output); err != nil {
+		log.FatalErr(err)
+	}
+
+	fmt.Fprintln(os.Stdout, output.Name())
+	os.Exit(0)
+}

colors.go

@@ -1,6 +1,6 @@
 package chart
 
-import "github.com/wcharczuk/go-chart/drawing"
+import "git.smarteching.com/zeni/go-chart/v2/drawing"
 
 var (
 	// ColorWhite is white.

concat_series_test.go

@@ -3,40 +3,39 @@ package chart
 import (
 	"testing"
 
-	assert "github.com/blendlabs/go-assert"
+	"git.smarteching.com/zeni/go-chart/v2/testutil"
-	"github.com/wcharczuk/go-chart/seq"
 )
 
 func TestConcatSeries(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	s1 := ContinuousSeries{
-		XValues: seq.Range(1.0, 10.0),
+		XValues: LinearRange(1.0, 10.0),
-		YValues: seq.Range(1.0, 10.0),
+		YValues: LinearRange(1.0, 10.0),
 	}
 
 	s2 := ContinuousSeries{
-		XValues: seq.Range(11, 20.0),
+		XValues: LinearRange(11, 20.0),
-		YValues: seq.Range(10.0, 1.0),
+		YValues: LinearRange(10.0, 1.0),
 	}
 
 	s3 := ContinuousSeries{
-		XValues: seq.Range(21, 30.0),
+		XValues: LinearRange(21, 30.0),
-		YValues: seq.Range(1.0, 10.0),
+		YValues: LinearRange(1.0, 10.0),
 	}
 
 	cs := ConcatSeries([]Series{s1, s2, s3})
-	assert.Equal(30, cs.Len())
+	testutil.AssertEqual(t, 30, cs.Len())
 
 	x0, y0 := cs.GetValue(0)
-	assert.Equal(1.0, x0)
+	testutil.AssertEqual(t, 1.0, x0)
-	assert.Equal(1.0, y0)
+	testutil.AssertEqual(t, 1.0, y0)
 
 	xm, ym := cs.GetValue(19)
-	assert.Equal(20.0, xm)
+	testutil.AssertEqual(t, 20.0, xm)
-	assert.Equal(1.0, ym)
+	testutil.AssertEqual(t, 1.0, ym)
 
 	xn, yn := cs.GetValue(29)
-	assert.Equal(30.0, xn)
+	testutil.AssertEqual(t, 30.0, xn)
-	assert.Equal(10.0, yn)
+	testutil.AssertEqual(t, 10.0, yn)
 }

continuous_range.go

@@ -62,6 +62,9 @@ func (r *ContinuousRange) SetDomain(domain int) {
 
 // String returns a simple string for the ContinuousRange.
 func (r ContinuousRange) String() string {
+	if r.GetDelta() == 0 {
+		return "ContinuousRange [empty]"
+	}
 	return fmt.Sprintf("ContinuousRange [%.2f,%.2f] => %d", r.Min, r.Max, r.Domain)
 }
 

continuous_range_test.go

@@ -3,21 +3,20 @@ package chart
 import (
 	"testing"
 
-	"github.com/blendlabs/go-assert"
+	"git.smarteching.com/zeni/go-chart/v2/testutil"
-	"github.com/wcharczuk/go-chart/util"
 )
 
 func TestRangeTranslate(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 	values := []float64{1.0, 2.0, 2.5, 2.7, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0}
 	r := ContinuousRange{Domain: 1000}
-	r.Min, r.Max = util.Math.MinAndMax(values...)
+	r.Min, r.Max = MinMax(values...)
 
 	// delta = ~7.0
 	// value = ~5.0
 	// domain = ~1000
 	// 5/8 * 1000 ~=
-	assert.Equal(0, r.Translate(1.0))
+	testutil.AssertEqual(t, 0, r.Translate(1.0))
-	assert.Equal(1000, r.Translate(8.0))
+	testutil.AssertEqual(t, 1000, r.Translate(8.0))
-	assert.Equal(572, r.Translate(5.0))
+	testutil.AssertEqual(t, 572, r.Translate(5.0))
 }

continuous_series.go

@@ -2,6 +2,13 @@ package chart
 
 import "fmt"
 
+// Interface Assertions.
+var (
+	_ Series              = (*ContinuousSeries)(nil)
+	_ FirstValuesProvider = (*ContinuousSeries)(nil)
+	_ LastValuesProvider  = (*ContinuousSeries)(nil)
+)
+
 // ContinuousSeries represents a line on a chart.
 type ContinuousSeries struct {
 	Name  string
@@ -36,6 +43,11 @@ func (cs ContinuousSeries) GetValues(index int) (float64, float64) {
 	return cs.XValues[index], cs.YValues[index]
 }
 
+// GetFirstValues gets the first x,y values.
+func (cs ContinuousSeries) GetFirstValues() (float64, float64) {
+	return cs.XValues[0], cs.YValues[0]
+}
+
 // GetLastValues gets the last x,y values.
 func (cs ContinuousSeries) GetLastValues() (float64, float64) {
 	return cs.XValues[len(cs.XValues)-1], cs.YValues[len(cs.YValues)-1]
@@ -70,11 +82,15 @@ func (cs ContinuousSeries) Render(r Renderer, canvasBox Box, xrange, yrange Rang
 // Validate validates the series.
 func (cs ContinuousSeries) Validate() error {
 	if len(cs.XValues) == 0 {
-		return fmt.Errorf("continuous series must have xvalues set")
+		return fmt.Errorf("continuous series; must have xvalues set")
 	}
 
 	if len(cs.YValues) == 0 {
-		return fmt.Errorf("continuous series must have yvalues set")
+		return fmt.Errorf("continuous series; must have yvalues set")
+	}
+
+	if len(cs.XValues) != len(cs.YValues) {
+		return fmt.Errorf("continuous series; must have same length xvalues as yvalues")
 	}
 	return nil
 }

continuous_series_test.go

@@ -4,36 +4,35 @@ import (
 	"fmt"
 	"testing"
 
-	assert "github.com/blendlabs/go-assert"
+	"git.smarteching.com/zeni/go-chart/v2/testutil"
-	"github.com/wcharczuk/go-chart/seq"
 )
 
 func TestContinuousSeries(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	cs := ContinuousSeries{
 		Name:    "Test Series",
-		XValues: seq.Range(1.0, 10.0),
+		XValues: LinearRange(1.0, 10.0),
-		YValues: seq.Range(1.0, 10.0),
+		YValues: LinearRange(1.0, 10.0),
 	}
 
-	assert.Equal("Test Series", cs.GetName())
+	testutil.AssertEqual(t, "Test Series", cs.GetName())
-	assert.Equal(10, cs.Len())
+	testutil.AssertEqual(t, 10, cs.Len())
 	x0, y0 := cs.GetValues(0)
-	assert.Equal(1.0, x0)
+	testutil.AssertEqual(t, 1.0, x0)
-	assert.Equal(1.0, y0)
+	testutil.AssertEqual(t, 1.0, y0)
 
 	xn, yn := cs.GetValues(9)
-	assert.Equal(10.0, xn)
+	testutil.AssertEqual(t, 10.0, xn)
-	assert.Equal(10.0, yn)
+	testutil.AssertEqual(t, 10.0, yn)
 
 	xn, yn = cs.GetLastValues()
-	assert.Equal(10.0, xn)
+	testutil.AssertEqual(t, 10.0, xn)
-	assert.Equal(10.0, yn)
+	testutil.AssertEqual(t, 10.0, yn)
 }
 
 func TestContinuousSeriesValueFormatter(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	cs := ContinuousSeries{
 		XValueFormatter: func(v interface{}) string {
@@ -45,29 +44,29 @@ func TestContinuousSeriesValueFormatter(t *testing.T) {
 	}
 
 	xf, yf := cs.GetValueFormatters()
-	assert.Equal("0.100000 foo", xf(0.1))
+	testutil.AssertEqual(t, "0.100000 foo", xf(0.1))
-	assert.Equal("0.100000 bar", yf(0.1))
+	testutil.AssertEqual(t, "0.100000 bar", yf(0.1))
 }
 
 func TestContinuousSeriesValidate(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	cs := ContinuousSeries{
 		Name:    "Test Series",
-		XValues: seq.Range(1.0, 10.0),
+		XValues: LinearRange(1.0, 10.0),
-		YValues: seq.Range(1.0, 10.0),
+		YValues: LinearRange(1.0, 10.0),
 	}
-	assert.Nil(cs.Validate())
+	testutil.AssertNil(t, cs.Validate())
 
 	cs = ContinuousSeries{
 		Name:    "Test Series",
-		XValues: seq.Range(1.0, 10.0),
+		XValues: LinearRange(1.0, 10.0),
 	}
-	assert.NotNil(cs.Validate())
+	testutil.AssertNotNil(t, cs.Validate())
 
 	cs = ContinuousSeries{
 		Name:    "Test Series",
-		YValues: seq.Range(1.0, 10.0),
+		YValues: LinearRange(1.0, 10.0),
 	}
-	assert.NotNil(cs.Validate())
+	testutil.AssertNotNil(t, cs.Validate())
 }

donut_chart.go

@@ -0,0 +1,315 @@
+package chart
+
+import (
+	"errors"
+	"fmt"
+	"io"
+
+	"github.com/golang/freetype/truetype"
+)
+
+// DonutChart is a chart that draws sections of a circle based on percentages with an hole.
+type DonutChart struct {
+	Title      string
+	TitleStyle Style
+
+	ColorPalette ColorPalette
+
+	Width  int
+	Height int
+	DPI    float64
+
+	Background Style
+	Canvas     Style
+	SliceStyle Style
+
+	Font        *truetype.Font
+	defaultFont *truetype.Font
+
+	Values   []Value
+	Elements []Renderable
+}
+
+// GetDPI returns the dpi for the chart.
+func (pc DonutChart) GetDPI(defaults ...float64) float64 {
+	if pc.DPI == 0 {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
+		return DefaultDPI
+	}
+	return pc.DPI
+}
+
+// GetFont returns the text font.
+func (pc DonutChart) GetFont() *truetype.Font {
+	if pc.Font == nil {
+		return pc.defaultFont
+	}
+	return pc.Font
+}
+
+// GetWidth returns the chart width or the default value.
+func (pc DonutChart) GetWidth() int {
+	if pc.Width == 0 {
+		return DefaultChartWidth
+	}
+	return pc.Width
+}
+
+// GetHeight returns the chart height or the default value.
+func (pc DonutChart) GetHeight() int {
+	if pc.Height == 0 {
+		return DefaultChartWidth
+	}
+	return pc.Height
+}
+
+// Render renders the chart with the given renderer to the given io.Writer.
+func (pc DonutChart) Render(rp RendererProvider, w io.Writer) error {
+	if len(pc.Values) == 0 {
+		return errors.New("please provide at least one value")
+	}
+
+	r, err := rp(pc.GetWidth(), pc.GetHeight())
+	if err != nil {
+		return err
+	}
+
+	if pc.Font == nil {
+		defaultFont, err := GetDefaultFont()
+		if err != nil {
+			return err
+		}
+		pc.defaultFont = defaultFont
+	}
+	r.SetDPI(pc.GetDPI(DefaultDPI))
+
+	canvasBox := pc.getDefaultCanvasBox()
+	canvasBox = pc.getCircleAdjustedCanvasBox(canvasBox)
+
+	pc.drawBackground(r)
+	pc.drawCanvas(r, canvasBox)
+
+	finalValues, err := pc.finalizeValues(pc.Values)
+	if err != nil {
+		return err
+	}
+	pc.drawSlices(r, canvasBox, finalValues)
+	pc.drawTitle(r)
+	for _, a := range pc.Elements {
+		a(r, canvasBox, pc.styleDefaultsElements())
+	}
+
+	return r.Save(w)
+}
+
+func (pc DonutChart) drawBackground(r Renderer) {
+	Draw.Box(r, Box{
+		Right:  pc.GetWidth(),
+		Bottom: pc.GetHeight(),
+	}, pc.getBackgroundStyle())
+}
+
+func (pc DonutChart) drawCanvas(r Renderer, canvasBox Box) {
+	Draw.Box(r, canvasBox, pc.getCanvasStyle())
+}
+
+func (pc DonutChart) drawTitle(r Renderer) {
+	if len(pc.Title) > 0 && !pc.TitleStyle.Hidden {
+		Draw.TextWithin(r, pc.Title, pc.Box(), pc.styleDefaultsTitle())
+	}
+}
+
+func (pc DonutChart) drawSlices(r Renderer, canvasBox Box, values []Value) {
+	cx, cy := canvasBox.Center()
+	diameter := MinInt(canvasBox.Width(), canvasBox.Height())
+	radius := float64(diameter>>1) / 1.1
+	labelRadius := (radius * 2.83) / 3.0
+
+	// draw the donut slices
+	var rads, delta, delta2, total float64
+	var lx, ly int
+
+	if len(values) == 1 {
+		pc.styleDonutChartValue(0).WriteToRenderer(r)
+		r.MoveTo(cx, cy)
+		r.Circle(radius, cx, cy)
+	} else {
+		for index, v := range values {
+			v.Style.InheritFrom(pc.styleDonutChartValue(index)).WriteToRenderer(r)
+			r.MoveTo(cx, cy)
+			rads = PercentToRadians(total)
+			delta = PercentToRadians(v.Value)
+
+			r.ArcTo(cx, cy, (radius / 1.25), (radius / 1.25), rads, delta)
+
+			r.LineTo(cx, cy)
+			r.Close()
+			r.FillStroke()
+			total = total + v.Value
+		}
+	}
+
+	//making the donut hole
+	v := Value{Value: 100, Label: "center"}
+	styletemp := pc.SliceStyle.InheritFrom(Style{
+		StrokeColor: ColorWhite, StrokeWidth: 4.0, FillColor: ColorWhite, FontColor: ColorWhite, //Font:        pc.GetFont(),//FontSize:    pc.getScaledFontSize(),
+	})
+	v.Style.InheritFrom(styletemp).WriteToRenderer(r)
+	r.MoveTo(cx, cy)
+	r.ArcTo(cx, cy, (radius / 3.5), (radius / 3.5), DegreesToRadians(0), DegreesToRadians(359))
+	r.LineTo(cx, cy)
+	r.Close()
+	r.FillStroke()
+
+	// draw the labels
+	total = 0
+	for index, v := range values {
+		v.Style.InheritFrom(pc.styleDonutChartValue(index)).WriteToRenderer(r)
+		if len(v.Label) > 0 {
+			delta2 = PercentToRadians(total + (v.Value / 2.0))
+			delta2 = RadianAdd(delta2, _pi2)
+			lx, ly = CirclePoint(cx, cy, labelRadius, delta2)
+
+			tb := r.MeasureText(v.Label)
+			lx = lx - (tb.Width() >> 1)
+			ly = ly + (tb.Height() >> 1)
+
+			r.Text(v.Label, lx, ly)
+		}
+		total = total + v.Value
+	}
+}
+
+func (pc DonutChart) finalizeValues(values []Value) ([]Value, error) {
+	finalValues := Values(values).Normalize()
+	if len(finalValues) == 0 {
+		return nil, fmt.Errorf("donut chart must contain at least (1) non-zero value")
+	}
+	return finalValues, nil
+}
+
+func (pc DonutChart) getDefaultCanvasBox() Box {
+	return pc.Box()
+}
+
+func (pc DonutChart) getCircleAdjustedCanvasBox(canvasBox Box) Box {
+	circleDiameter := MinInt(canvasBox.Width(), canvasBox.Height())
+
+	square := Box{
+		Right:  circleDiameter,
+		Bottom: circleDiameter,
+	}
+
+	return canvasBox.Fit(square)
+}
+
+func (pc DonutChart) getBackgroundStyle() Style {
+	return pc.Background.InheritFrom(pc.styleDefaultsBackground())
+}
+
+func (pc DonutChart) getCanvasStyle() Style {
+	return pc.Canvas.InheritFrom(pc.styleDefaultsCanvas())
+}
+
+func (pc DonutChart) styleDefaultsCanvas() Style {
+	return Style{
+		FillColor:   pc.GetColorPalette().CanvasColor(),
+		StrokeColor: pc.GetColorPalette().CanvasStrokeColor(),
+		StrokeWidth: DefaultStrokeWidth,
+	}
+}
+
+func (pc DonutChart) styleDefaultsDonutChartValue() Style {
+	return Style{
+		StrokeColor: pc.GetColorPalette().TextColor(),
+		StrokeWidth: 4.0,
+		FillColor:   pc.GetColorPalette().TextColor(),
+	}
+}
+
+func (pc DonutChart) styleDonutChartValue(index int) Style {
+	return pc.SliceStyle.InheritFrom(Style{
+		StrokeColor: ColorWhite,
+		StrokeWidth: 4.0,
+		FillColor:   pc.GetColorPalette().GetSeriesColor(index),
+		FontSize:    pc.getScaledFontSize(),
+		FontColor:   pc.GetColorPalette().TextColor(),
+		Font:        pc.GetFont(),
+	})
+}
+
+func (pc DonutChart) getScaledFontSize() float64 {
+	effectiveDimension := MinInt(pc.GetWidth(), pc.GetHeight())
+	if effectiveDimension >= 2048 {
+		return 48.0
+	} else if effectiveDimension >= 1024 {
+		return 24.0
+	} else if effectiveDimension > 512 {
+		return 18.0
+	} else if effectiveDimension > 256 {
+		return 12.0
+	}
+	return 10.0
+}
+
+func (pc DonutChart) styleDefaultsBackground() Style {
+	return Style{
+		FillColor:   pc.GetColorPalette().BackgroundColor(),
+		StrokeColor: pc.GetColorPalette().BackgroundStrokeColor(),
+		StrokeWidth: DefaultStrokeWidth,
+	}
+}
+
+func (pc DonutChart) styleDefaultsElements() Style {
+	return Style{
+		Font: pc.GetFont(),
+	}
+}
+
+func (pc DonutChart) styleDefaultsTitle() Style {
+	return pc.TitleStyle.InheritFrom(Style{
+		FontColor:           pc.GetColorPalette().TextColor(),
+		Font:                pc.GetFont(),
+		FontSize:            pc.getTitleFontSize(),
+		TextHorizontalAlign: TextHorizontalAlignCenter,
+		TextVerticalAlign:   TextVerticalAlignTop,
+		TextWrap:            TextWrapWord,
+	})
+}
+
+func (pc DonutChart) getTitleFontSize() float64 {
+	effectiveDimension := MinInt(pc.GetWidth(), pc.GetHeight())
+	if effectiveDimension >= 2048 {
+		return 48
+	} else if effectiveDimension >= 1024 {
+		return 24
+	} else if effectiveDimension >= 512 {
+		return 18
+	} else if effectiveDimension >= 256 {
+		return 12
+	}
+	return 10
+}
+
+// GetColorPalette returns the color palette for the chart.
+func (pc DonutChart) GetColorPalette() ColorPalette {
+	if pc.ColorPalette != nil {
+		return pc.ColorPalette
+	}
+	return AlternateColorPalette
+}
+
+// Box returns the chart bounds as a box.
+func (pc DonutChart) Box() Box {
+	dpr := pc.Background.Padding.GetRight(DefaultBackgroundPadding.Right)
+	dpb := pc.Background.Padding.GetBottom(DefaultBackgroundPadding.Bottom)
+
+	return Box{
+		Top:    pc.Background.Padding.GetTop(DefaultBackgroundPadding.Top),
+		Left:   pc.Background.Padding.GetLeft(DefaultBackgroundPadding.Left),
+		Right:  pc.GetWidth() - dpr,
+		Bottom: pc.GetHeight() - dpb,
+	}
+}

donut_chart_test.go

@@ -0,0 +1,69 @@
+package chart
+
+import (
+	"bytes"
+	"testing"
+
+	"git.smarteching.com/zeni/go-chart/v2/testutil"
+)
+
+func TestDonutChart(t *testing.T) {
+	// replaced new assertions helper
+
+	pie := DonutChart{
+		Canvas: Style{
+			FillColor: ColorLightGray,
+		},
+		Values: []Value{
+			{Value: 10, Label: "Blue"},
+			{Value: 9, Label: "Green"},
+			{Value: 8, Label: "Gray"},
+			{Value: 7, Label: "Orange"},
+			{Value: 6, Label: "HEANG"},
+			{Value: 5, Label: "??"},
+			{Value: 2, Label: "!!"},
+		},
+	}
+
+	b := bytes.NewBuffer([]byte{})
+	pie.Render(PNG, b)
+	testutil.AssertNotZero(t, b.Len())
+}
+
+func TestDonutChartDropsZeroValues(t *testing.T) {
+	// replaced new assertions helper
+
+	pie := DonutChart{
+		Canvas: Style{
+			FillColor: ColorLightGray,
+		},
+		Values: []Value{
+			{Value: 5, Label: "Blue"},
+			{Value: 5, Label: "Green"},
+			{Value: 0, Label: "Gray"},
+		},
+	}
+
+	b := bytes.NewBuffer([]byte{})
+	err := pie.Render(PNG, b)
+	testutil.AssertNil(t, err)
+}
+
+func TestDonutChartAllZeroValues(t *testing.T) {
+	// replaced new assertions helper
+
+	pie := DonutChart{
+		Canvas: Style{
+			FillColor: ColorLightGray,
+		},
+		Values: []Value{
+			{Value: 0, Label: "Blue"},
+			{Value: 0, Label: "Green"},
+			{Value: 0, Label: "Gray"},
+		},
+	}
+
+	b := bytes.NewBuffer([]byte{})
+	err := pie.Render(PNG, b)
+	testutil.AssertNotNil(t, err)
+}

draw.go

@@ -2,8 +2,6 @@ package chart
 
 import (
 	"math"
-
-	util "github.com/wcharczuk/go-chart/util"
 )
 
 var (
@@ -40,8 +38,8 @@ func (d draw) LineSeries(r Renderer, canvasBox Box, xrange, yrange Range, style
 			y = cb - yrange.Translate(vy)
 			r.LineTo(x, y)
 		}
-		r.LineTo(x, util.Math.MinInt(cb, cb-yv0))
+		r.LineTo(x, MinInt(cb, cb-yv0))
-		r.LineTo(x0, util.Math.MinInt(cb, cb-yv0))
+		r.LineTo(x0, MinInt(cb, cb-yv0))
 		r.LineTo(x0, y0)
 		r.Fill()
 	}
@@ -298,8 +296,10 @@ func (d draw) TextWithin(r Renderer, text string, box Box, style Style) {
 	switch style.GetTextVerticalAlign() {
 	case TextVerticalAlignBottom, TextVerticalAlignBaseline: // i have to build better baseline handling into measure text
 		y = y - linesBox.Height()
-	case TextVerticalAlignMiddle, TextVerticalAlignMiddleBaseline:
+	case TextVerticalAlignMiddle:
-		y = (y - linesBox.Height()) >> 1
+		y = y + (box.Height() >> 1) - (linesBox.Height() >> 1)
+	case TextVerticalAlignMiddleBaseline:
+		y = y + (box.Height() >> 1) - linesBox.Height()
 	}
 
 	var tx, ty int

drawing/color.go

@@ -2,27 +2,46 @@ package drawing
 
 import (
 	"fmt"
+	"regexp"
 	"strconv"
+	"strings"
 )
 
+// Basic Colors from:
+// https://www.w3.org/wiki/CSS/Properties/color/keywords
 var (
 	// ColorTransparent is a fully transparent color.
-	ColorTransparent = Color{}
+	ColorTransparent = Color{R: 255, G: 255, B: 255, A: 0}
-
 	// ColorWhite is white.
 	ColorWhite = Color{R: 255, G: 255, B: 255, A: 255}
-
 	// ColorBlack is black.
 	ColorBlack = Color{R: 0, G: 0, B: 0, A: 255}
-
 	// ColorRed is red.
 	ColorRed = Color{R: 255, G: 0, B: 0, A: 255}
-
 	// ColorGreen is green.
-	ColorGreen = Color{R: 0, G: 255, B: 0, A: 255}
+	ColorGreen = Color{R: 0, G: 128, B: 0, A: 255}
-
 	// ColorBlue is blue.
 	ColorBlue = Color{R: 0, G: 0, B: 255, A: 255}
+	// ColorSilver is a known color.
+	ColorSilver = Color{R: 192, G: 192, B: 192, A: 255}
+	// ColorMaroon is a known color.
+	ColorMaroon = Color{R: 128, G: 0, B: 0, A: 255}
+	// ColorPurple is a known color.
+	ColorPurple = Color{R: 128, G: 0, B: 128, A: 255}
+	// ColorFuchsia is a known color.
+	ColorFuchsia = Color{R: 255, G: 0, B: 255, A: 255}
+	// ColorLime is a known color.
+	ColorLime = Color{R: 0, G: 255, B: 0, A: 255}
+	// ColorOlive is a known color.
+	ColorOlive = Color{R: 128, G: 128, B: 0, A: 255}
+	// ColorYellow is a known color.
+	ColorYellow = Color{R: 255, G: 255, B: 0, A: 255}
+	// ColorNavy is a known color.
+	ColorNavy = Color{R: 0, G: 0, B: 128, A: 255}
+	// ColorTeal is a known color.
+	ColorTeal = Color{R: 0, G: 128, B: 128, A: 255}
+	// ColorAqua is a known color.
+	ColorAqua = Color{R: 0, G: 255, B: 255, A: 255}
 )
 
 func parseHex(hex string) uint8 {
@@ -30,8 +49,97 @@ func parseHex(hex string) uint8 {
 	return uint8(v)
 }
 
+// ParseColor parses a color from a string.
+func ParseColor(rawColor string) Color {
+	if strings.HasPrefix(rawColor, "rgba") {
+		return ColorFromRGBA(rawColor)
+	}
+	if strings.HasPrefix(rawColor, "rgb") {
+		return ColorFromRGB(rawColor)
+	}
+	if strings.HasPrefix(rawColor, "#") {
+		return ColorFromHex(rawColor)
+	}
+	return ColorFromKnown(rawColor)
+}
+
+var rgbaexpr = regexp.MustCompile(`rgba\((?P<R>.+),(?P<G>.+),(?P<B>.+),(?P<A>.+)\)`)
+
+// ColorFromRGBA returns a color from an `rgba()` css function.
+func ColorFromRGBA(rgba string) (output Color) {
+	values := rgbaexpr.FindStringSubmatch(rgba)
+	for i, name := range rgbaexpr.SubexpNames() {
+		if i == 0 {
+			continue
+		}
+		if i >= len(values) {
+			break
+		}
+		switch name {
+		case "R":
+			value := strings.TrimSpace(values[i])
+			parsed, _ := strconv.ParseInt(value, 10, 16)
+			output.R = uint8(parsed)
+		case "G":
+			value := strings.TrimSpace(values[i])
+			parsed, _ := strconv.ParseInt(value, 10, 16)
+			output.G = uint8(parsed)
+		case "B":
+			value := strings.TrimSpace(values[i])
+			parsed, _ := strconv.ParseInt(value, 10, 16)
+			output.B = uint8(parsed)
+		case "A":
+			value := strings.TrimSpace(values[i])
+			parsed, _ := strconv.ParseFloat(value, 32)
+			if parsed > 1 {
+				parsed = 1
+			} else if parsed < 0 {
+				parsed = 0
+			}
+			output.A = uint8(parsed * 255)
+		}
+	}
+	return
+}
+
+var rgbexpr = regexp.MustCompile(`rgb\((?P<R>.+),(?P<G>.+),(?P<B>.+)\)`)
+
+// ColorFromRGB returns a color from an `rgb()` css function.
+func ColorFromRGB(rgb string) (output Color) {
+	output.A = 255
+	values := rgbexpr.FindStringSubmatch(rgb)
+	for i, name := range rgbaexpr.SubexpNames() {
+		if i == 0 {
+			continue
+		}
+		if i >= len(values) {
+			break
+		}
+		switch name {
+		case "R":
+			value := strings.TrimSpace(values[i])
+			parsed, _ := strconv.ParseInt(value, 10, 16)
+			output.R = uint8(parsed)
+		case "G":
+			value := strings.TrimSpace(values[i])
+			parsed, _ := strconv.ParseInt(value, 10, 16)
+			output.G = uint8(parsed)
+		case "B":
+			value := strings.TrimSpace(values[i])
+			parsed, _ := strconv.ParseInt(value, 10, 16)
+			output.B = uint8(parsed)
+		}
+	}
+	return
+}
+
 // ColorFromHex returns a color from a css hex code.
+//
+// NOTE: it will trim a leading '#' character if present.
 func ColorFromHex(hex string) Color {
+	if strings.HasPrefix(hex, "#") {
+		hex = strings.TrimPrefix(hex, "#")
+	}
 	var c Color
 	if len(hex) == 3 {
 		c.R = parseHex(string(hex[0])) * 0x11
@@ -46,6 +154,46 @@ func ColorFromHex(hex string) Color {
 	return c
 }
 
+// ColorFromKnown returns an internal color from a known (basic) color name.
+func ColorFromKnown(known string) Color {
+	switch strings.ToLower(known) {
+	case "transparent":
+		return ColorTransparent
+	case "white":
+		return ColorWhite
+	case "black":
+		return ColorBlack
+	case "red":
+		return ColorRed
+	case "blue":
+		return ColorBlue
+	case "green":
+		return ColorGreen
+	case "silver":
+		return ColorSilver
+	case "maroon":
+		return ColorMaroon
+	case "purple":
+		return ColorPurple
+	case "fuchsia":
+		return ColorFuchsia
+	case "lime":
+		return ColorLime
+	case "olive":
+		return ColorOlive
+	case "yellow":
+		return ColorYellow
+	case "navy":
+		return ColorNavy
+	case "teal":
+		return ColorTeal
+	case "aqua":
+		return ColorAqua
+	default:
+		return Color{}
+	}
+}
+
 // ColorFromAlphaMixedRGBA returns the system alpha mixed rgba values.
 func ColorFromAlphaMixedRGBA(r, g, b, a uint32) Color {
 	fa := float64(a) / 255.0

drawing/color_test.go

@@ -1,53 +1,114 @@
 package drawing
 
 import (
+	"fmt"
 	"testing"
 
 	"image/color"
 
-	"github.com/blendlabs/go-assert"
+	"git.smarteching.com/zeni/go-chart/v2/testutil"
 )
 
 func TestColorFromHex(t *testing.T) {
-	assert := assert.New(t)
-
 	white := ColorFromHex("FFFFFF")
-	assert.Equal(ColorWhite, white)
+	testutil.AssertEqual(t, ColorWhite, white)
 
 	shortWhite := ColorFromHex("FFF")
-	assert.Equal(ColorWhite, shortWhite)
+	testutil.AssertEqual(t, ColorWhite, shortWhite)
 
 	black := ColorFromHex("000000")
-	assert.Equal(ColorBlack, black)
+	testutil.AssertEqual(t, ColorBlack, black)
 
 	shortBlack := ColorFromHex("000")
-	assert.Equal(ColorBlack, shortBlack)
+	testutil.AssertEqual(t, ColorBlack, shortBlack)
 
 	red := ColorFromHex("FF0000")
-	assert.Equal(ColorRed, red)
+	testutil.AssertEqual(t, ColorRed, red)
 
 	shortRed := ColorFromHex("F00")
-	assert.Equal(ColorRed, shortRed)
+	testutil.AssertEqual(t, ColorRed, shortRed)
 
-	green := ColorFromHex("00FF00")
+	green := ColorFromHex("008000")
-	assert.Equal(ColorGreen, green)
+	testutil.AssertEqual(t, ColorGreen, green)
 
-	shortGreen := ColorFromHex("0F0")
+	// shortGreen := ColorFromHex("0F0")
-	assert.Equal(ColorGreen, shortGreen)
+	// testutil.AssertEqual(t, ColorGreen, shortGreen)
 
 	blue := ColorFromHex("0000FF")
-	assert.Equal(ColorBlue, blue)
+	testutil.AssertEqual(t, ColorBlue, blue)
 
 	shortBlue := ColorFromHex("00F")
-	assert.Equal(ColorBlue, shortBlue)
+	testutil.AssertEqual(t, ColorBlue, shortBlue)
+}
+
+func TestColorFromHex_handlesHash(t *testing.T) {
+	withHash := ColorFromHex("#FF0000")
+	testutil.AssertEqual(t, ColorRed, withHash)
+
+	withoutHash := ColorFromHex("#FF0000")
+	testutil.AssertEqual(t, ColorRed, withoutHash)
 }
 
 func TestColorFromAlphaMixedRGBA(t *testing.T) {
-	assert := assert.New(t)
-
 	black := ColorFromAlphaMixedRGBA(color.Black.RGBA())
-	assert.True(black.Equals(ColorBlack), black.String())
+	testutil.AssertTrue(t, black.Equals(ColorBlack), black.String())
 
 	white := ColorFromAlphaMixedRGBA(color.White.RGBA())
-	assert.True(white.Equals(ColorWhite), white.String())
+	testutil.AssertTrue(t, white.Equals(ColorWhite), white.String())
+}
+
+func Test_ColorFromRGBA(t *testing.T) {
+	value := "rgba(192, 192, 192, 1.0)"
+	parsed := ColorFromRGBA(value)
+	testutil.AssertEqual(t, ColorSilver, parsed)
+
+	value = "rgba(192,192,192,1.0)"
+	parsed = ColorFromRGBA(value)
+	testutil.AssertEqual(t, ColorSilver, parsed)
+
+	value = "rgba(192,192,192,1.5)"
+	parsed = ColorFromRGBA(value)
+	testutil.AssertEqual(t, ColorSilver, parsed)
+}
+
+func TestParseColor(t *testing.T) {
+	testCases := [...]struct {
+		Input    string
+		Expected Color
+	}{
+		{"", Color{}},
+		{"white", ColorWhite},
+		{"WHITE", ColorWhite}, // caps!
+		{"black", ColorBlack},
+		{"red", ColorRed},
+		{"green", ColorGreen},
+		{"blue", ColorBlue},
+		{"silver", ColorSilver},
+		{"maroon", ColorMaroon},
+		{"purple", ColorPurple},
+		{"fuchsia", ColorFuchsia},
+		{"lime", ColorLime},
+		{"olive", ColorOlive},
+		{"yellow", ColorYellow},
+		{"navy", ColorNavy},
+		{"teal", ColorTeal},
+		{"aqua", ColorAqua},
+
+		{"rgba(192, 192, 192, 1.0)", ColorSilver},
+		{"rgba(192,192,192,1.0)", ColorSilver},
+		{"rgb(192, 192, 192)", ColorSilver},
+		{"rgb(192,192,192)", ColorSilver},
+
+		{"#FF0000", ColorRed},
+		{"#008000", ColorGreen},
+		{"#0000FF", ColorBlue},
+		{"#F00", ColorRed},
+		{"#080", Color{0, 136, 0, 255}},
+		{"#00F", ColorBlue},
+	}
+
+	for index, tc := range testCases {
+		actual := ParseColor(tc.Input)
+		testutil.AssertEqual(t, tc.Expected, actual, fmt.Sprintf("test case: %d -> %s", index, tc.Input))
+	}
 }

drawing/curve_test.go

@@ -3,7 +3,7 @@ package drawing
 import (
 	"testing"
 
-	assert "github.com/blendlabs/go-assert"
+	"git.smarteching.com/zeni/go-chart/v2/testutil"
 )
 
 type point struct {
@@ -23,7 +23,7 @@ func (ml mockLine) Len() int {
 }
 
 func TestTraceQuad(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	// Quad
 	// x1, y1, cpx1, cpy2, x2, y2 float64
@@ -31,5 +31,5 @@ func TestTraceQuad(t *testing.T) {
 	quad := []float64{10, 20, 20, 20, 20, 10}
 	liner := &mockLine{}
 	TraceQuad(liner, quad, 0.5)
-	assert.NotZero(liner.Len())
+	testutil.AssertNotZero(t, liner.Len())
 }

ema_series.go

@@ -7,6 +7,13 @@ const (
 	DefaultEMAPeriod = 12
 )
 
+// Interface Assertions.
+var (
+	_ Series              = (*EMASeries)(nil)
+	_ FirstValuesProvider = (*EMASeries)(nil)
+	_ LastValuesProvider  = (*EMASeries)(nil)
+)
+
 // EMASeries is a computed series.
 type EMASeries struct {
 	Name  string
@@ -66,6 +73,19 @@ func (ema *EMASeries) GetValues(index int) (x, y float64) {
 	return
 }
 
+// GetFirstValues computes the first moving average value.
+func (ema *EMASeries) GetFirstValues() (x, y float64) {
+	if ema.InnerSeries == nil {
+		return
+	}
+	if len(ema.cache) == 0 {
+		ema.ensureCachedValues()
+	}
+	x, _ = ema.InnerSeries.GetValues(0)
+	y = ema.cache[0]
+	return
+}
+
 // GetLastValues computes the last moving average value but walking back window size samples,
 // and recomputing the last moving average chunk.
 func (ema *EMASeries) GetLastValues() (x, y float64) {

ema_series_test.go

@@ -3,12 +3,11 @@ package chart
 import (
 	"testing"
 
-	"github.com/blendlabs/go-assert"
+	"git.smarteching.com/zeni/go-chart/v2/testutil"
-	"github.com/wcharczuk/go-chart/seq"
 )
 
 var (
-	emaXValues = seq.Range(1.0, 50.0)
+	emaXValues = LinearRange(1.0, 50.0)
 	emaYValues = []float64{
 		1, 2, 3, 4, 5, 4, 3, 2,
 		1, 2, 3, 4, 5, 4, 3, 2,
@@ -74,13 +73,13 @@ var (
 )
 
 func TestEMASeries(t *testing.T) {
-	assert := assert.New(t)
+	// replaced new assertions helper
 
 	mockSeries := mockValuesProvider{
 		emaXValues,
 		emaYValues,
 	}
-	assert.Equal(50, mockSeries.Len())
+	testutil.AssertEqual(t, 50, mockSeries.Len())
 
 	ema := &EMASeries{
 		InnerSeries: mockSeries,
@@ -88,7 +87,7 @@ func TestEMASeries(t *testing.T) {
 	}
 
 	sig := ema.GetSigma()
-	assert.Equal(2.0/(26.0+1), sig)
+	testutil.AssertEqual(t, 2.0/(26.0+1), sig)
 
 	var yvalues []float64
 	for x := 0; x < ema.Len(); x++ {
@@ -97,10 +96,10 @@ func TestEMASeries(t *testing.T) {
 	}
 
 	for index, yv := range yvalues {
-		assert.InDelta(yv, emaExpected[index], emaDelta)
+		testutil.AssertInDelta(t, yv, emaExpected[index], emaDelta)
 	}
 
 	lvx, lvy := ema.GetLastValues()
-	assert.Equal(50.0, lvx)
+	testutil.AssertEqual(t, 50.0, lvx)
-	assert.InDelta(lvy, emaExpected[49], emaDelta)
+	testutil.AssertInDelta(t, lvy, emaExpected[49], emaDelta)
 }

examples/annotations/main.go

@@ -1,13 +1,14 @@
 package main
 
-import (
+//go:generate go run main.go
-	"net/http"
 
-	"github.com/wcharczuk/go-chart"
+import (
+	"os"
+
+	"git.smarteching.com/zeni/go-chart/v2"
 )
 
-func drawChart(res http.ResponseWriter, req *http.Request) {
+func main() {
-
 	/*
 	   In this example we add an `Annotation` series, which is a special type of series that
 	   draws annotation labels at given X and Y values (as translated by their respective ranges).
@@ -37,11 +38,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 		},
 	}
 
-	res.Header().Set("Content-Type", "image/png")
+	f, _ := os.Create("output.png")
-	graph.Render(chart.PNG, res)
+	defer f.Close()
-}
+	graph.Render(chart.PNG, f)
-
-func main() {
-	http.HandleFunc("/", drawChart)
-	http.ListenAndServe(":8080", nil)
 }

examples/axes/main.go

@@ -1,12 +1,14 @@
 package main
 
-import (
+//go:generate go run main.go
-	"net/http"
 
-	"github.com/wcharczuk/go-chart"
+import (
+	"os"
+
+	chart "git.smarteching.com/zeni/go-chart/v2"
 )
 
-func drawChart(res http.ResponseWriter, req *http.Request) {
+func main() {
 
 	/*
 	   The below will draw the same chart as the `basic` example, except with both the x and y axes turned on.
@@ -14,20 +16,9 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 	*/
 
 	graph := chart.Chart{
-		XAxis: chart.XAxis{
-			Name:      "The XAxis",
-			NameStyle: chart.StyleShow(),
-			Style:     chart.StyleShow(),
-		},
-		YAxis: chart.YAxis{
-			Name:      "The YAxis",
-			NameStyle: chart.StyleShow(),
-			Style:     chart.StyleShow(),
-		},
 		Series: []chart.Series{
 			chart.ContinuousSeries{
 				Style: chart.Style{
-					Show:        true,
 					StrokeColor: chart.GetDefaultColor(0).WithAlpha(64),
 					FillColor:   chart.GetDefaultColor(0).WithAlpha(64),
 				},
@@ -37,11 +28,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 		},
 	}
 
-	res.Header().Set("Content-Type", "image/png")
+	f, _ := os.Create("output.png")
-	graph.Render(chart.PNG, res)
+	defer f.Close()
-}
+	graph.Render(chart.PNG, f)
-
-func main() {
-	http.HandleFunc("/", drawChart)
-	http.ListenAndServe(":8080", nil)
 }

examples/axes_labels/main.go

@@ -1,12 +1,14 @@
 package main
 
-import (
+//go:generate go run main.go
-	"net/http"
 
-	"github.com/wcharczuk/go-chart"
+import (
+	"os"
+
+	chart "git.smarteching.com/zeni/go-chart/v2"
 )
 
-func drawChart(res http.ResponseWriter, req *http.Request) {
+func main() {
 
 	/*
 	   The below will draw the same chart as the `basic` example, except with both the x and y axes turned on.
@@ -15,19 +17,14 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	graph := chart.Chart{
 		XAxis: chart.XAxis{
-			Style: chart.Style{
+			Name: "The XAxis",
-				Show: true, //enables / displays the x-axis
-			},
 		},
 		YAxis: chart.YAxis{
-			Style: chart.Style{
+			Name: "The YAxis",
-				Show: true, //enables / displays the y-axis
-			},
 		},
 		Series: []chart.Series{
 			chart.ContinuousSeries{
 				Style: chart.Style{
-					Show:        true,
 					StrokeColor: chart.GetDefaultColor(0).WithAlpha(64),
 					FillColor:   chart.GetDefaultColor(0).WithAlpha(64),
 				},
@@ -37,11 +34,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 		},
 	}
 
-	res.Header().Set("Content-Type", "image/png")
+	f, _ := os.Create("output.png")
-	graph.Render(chart.PNG, res)
+	defer f.Close()
-}
+	graph.Render(chart.PNG, f)
-
-func main() {
-	http.HandleFunc("/", drawChart)
-	http.ListenAndServe(":8080", nil)
 }

examples/bar_chart/main.go

@@ -0,0 +1,35 @@
+package main
+
+//go:generate go run main.go
+
+import (
+	"os"
+
+	"git.smarteching.com/zeni/go-chart/v2"
+)
+
+func main() {
+	graph := chart.BarChart{
+		Title: "Test Bar Chart",
+		Background: chart.Style{
+			Padding: chart.Box{
+				Top: 40,
+			},
+		},
+		Height:   512,
+		BarWidth: 60,
+		Bars: []chart.Value{
+			{Value: 5.25, Label: "Blue"},
+			{Value: 4.88, Label: "Green"},
+			{Value: 4.74, Label: "Gray"},
+			{Value: 3.22, Label: "Orange"},
+			{Value: 3, Label: "Test"},
+			{Value: 2.27, Label: "??"},
+			{Value: 1, Label: "!!"},
+		},
+	}
+
+	f, _ := os.Create("output.png")
+	defer f.Close()
+	graph.Render(chart.PNG, f)
+}

examples/bar_chart_base_value/main.go

@@ -0,0 +1,62 @@
+package main
+
+//go:generate go run main.go
+
+import (
+	"os"
+
+	"git.smarteching.com/zeni/go-chart/v2"
+	"git.smarteching.com/zeni/go-chart/v2/drawing"
+)
+
+func main() {
+	profitStyle := chart.Style{
+		FillColor:   drawing.ColorFromHex("13c158"),
+		StrokeColor: drawing.ColorFromHex("13c158"),
+		StrokeWidth: 0,
+	}
+
+	lossStyle := chart.Style{
+		FillColor:   drawing.ColorFromHex("c11313"),
+		StrokeColor: drawing.ColorFromHex("c11313"),
+		StrokeWidth: 0,
+	}
+
+	sbc := chart.BarChart{
+		Title: "Bar Chart Using BaseValue",
+		Background: chart.Style{
+			Padding: chart.Box{
+				Top: 40,
+			},
+		},
+		Height:   512,
+		BarWidth: 60,
+		YAxis: chart.YAxis{
+			Ticks: []chart.Tick{
+				{Value: -4.0, Label: "-4"},
+				{Value: -2.0, Label: "-2"},
+				{Value: 0, Label: "0"},
+				{Value: 2.0, Label: "2"},
+				{Value: 4.0, Label: "4"},
+				{Value: 6.0, Label: "6"},
+				{Value: 8.0, Label: "8"},
+				{Value: 10.0, Label: "10"},
+				{Value: 12.0, Label: "12"},
+			},
+		},
+		UseBaseValue: true,
+		BaseValue:    0.0,
+		Bars: []chart.Value{
+			{Value: 10.0, Style: profitStyle, Label: "Profit"},
+			{Value: 12.0, Style: profitStyle, Label: "More Profit"},
+			{Value: 8.0, Style: profitStyle, Label: "Still Profit"},
+			{Value: -4.0, Style: lossStyle, Label: "Loss!"},
+			{Value: 3.0, Style: profitStyle, Label: "Phew Ok"},
+			{Value: -2.0, Style: lossStyle, Label: "Oh No!"},
+		},
+	}
+
+	f, _ := os.Create("output.png")
+	defer f.Close()
+	sbc.Render(chart.PNG, f)
+}

examples/bar_chart_web/main.go

@@ -1,26 +1,26 @@
 package main
 
+//go:generate go run main.go
+
 import (
 	"fmt"
 	"log"
 	"net/http"
 	"os"
 
-	"github.com/wcharczuk/go-chart"
+	"git.smarteching.com/zeni/go-chart/v2"
 )
 
 func drawChart(res http.ResponseWriter, req *http.Request) {
-	sbc := chart.BarChart{
+	graph := chart.BarChart{
-		Height:   512,
+		Title: "Test Bar Chart",
-		BarWidth: 60,
+		Background: chart.Style{
-		XAxis: chart.Style{
+			Padding: chart.Box{
-			Show: true,
+				Top: 40,
-		},
-		YAxis: chart.YAxis{
-			Style: chart.Style{
-				Show: true,
 			},
 		},
+		Height:   512,
+		BarWidth: 60,
 		Bars: []chart.Value{
 			{Value: 5.25, Label: "Blue"},
 			{Value: 4.88, Label: "Green"},
@@ -33,10 +33,11 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 	}
 
 	res.Header().Set("Content-Type", "image/png")
-	err := sbc.Render(chart.PNG, res)
+	err := graph.Render(chart.PNG, res)
 	if err != nil {
 		fmt.Printf("Error rendering chart: %v\n", err)
 	}
+
 }
 
 func port() string {

examples/basic/main.go

@@ -0,0 +1,23 @@
+package main
+
+//go:generate go run main.go
+
+import (
+	"os"
+
+	"git.smarteching.com/zeni/go-chart/v2"
+)
+
+func main() {
+	graph := chart.Chart{
+		Series: []chart.Series{
+			chart.ContinuousSeries{
+				XValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0},
+				YValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0},
+			},
+		},
+	}
+	f, _ := os.Create("output.png")
+	defer f.Close()
+	graph.Render(chart.PNG, f)
+}

examples/benchmark_line_charts/main.go

@@ -0,0 +1,52 @@
+package main
+
+//go:generate go run main.go
+
+import (
+	"fmt"
+	"math/rand"
+	"os"
+	"time"
+
+	"git.smarteching.com/zeni/go-chart/v2"
+)
+
+func random(min, max float64) float64 {
+	return rand.Float64()*(max-min) + min
+}
+
+func main() {
+	numValues := 1024
+	numSeries := 100
+	series := make([]chart.Series, numSeries)
+
+	for i := 0; i < numSeries; i++ {
+		xValues := make([]time.Time, numValues)
+		yValues := make([]float64, numValues)
+
+		for j := 0; j < numValues; j++ {
+			xValues[j] = time.Now().AddDate(0, 0, (numValues-j)*-1)
+			yValues[j] = random(float64(-500), float64(500))
+		}
+
+		series[i] = chart.TimeSeries{
+			Name:    fmt.Sprintf("aaa.bbb.hostname-%v.ccc.ddd.eee.fff.ggg.hhh.iii.jjj.kkk.lll.mmm.nnn.value", i),
+			XValues: xValues,
+			YValues: yValues,
+		}
+	}
+
+	graph := chart.Chart{
+		XAxis: chart.XAxis{
+			Name: "Time",
+		},
+		YAxis: chart.YAxis{
+			Name: "Value",
+		},
+		Series: series,
+	}
+
+	f, _ := os.Create("output.png")
+	defer f.Close()
+	graph.Render(chart.PNG, f)
+}

examples/css_classes/main.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+
+	"git.smarteching.com/zeni/go-chart/v2"
+)
+
+// Note: Additional examples on how to add Stylesheets are in the custom_stylesheets example
+
+func inlineSVGWithClasses(res http.ResponseWriter, req *http.Request) {
+	res.Write([]byte(
+		"<!DOCTYPE html><html><head>" +
+			"<link rel=\"stylesheet\" type=\"text/css\" href=\"/main.css\">" +
+			"</head>" +
+			"<body>"))
+
+	pie := chart.PieChart{
+		// Notes: * Setting ClassName will cause all other inline styles to be dropped!
+		//        * The following type classes may be added additionally: stroke, fill, text
+		Background: chart.Style{ClassName: "background"},
+		Canvas: chart.Style{
+			ClassName: "canvas",
+		},
+		Width:  512,
+		Height: 512,
+		Values: []chart.Value{
+			{Value: 5, Label: "Blue", Style: chart.Style{ClassName: "blue"}},
+			{Value: 5, Label: "Green", Style: chart.Style{ClassName: "green"}},
+			{Value: 4, Label: "Gray", Style: chart.Style{ClassName: "gray"}},
+		},
+	}
+
+	err := pie.Render(chart.SVG, res)
+	if err != nil {
+		fmt.Printf("Error rendering pie chart: %v\n", err)
+	}
+	res.Write([]byte("</body>"))
+}
+
+func css(res http.ResponseWriter, req *http.Request) {
+	res.Header().Set("Content-Type", "text/css")
+	res.Write([]byte("svg .background { fill: white; }" +
+		"svg .canvas { fill: white; }" +
+		"svg .blue.fill.stroke { fill: blue; stroke: lightblue; }" +
+		"svg .green.fill.stroke { fill: green; stroke: lightgreen; }" +
+		"svg .gray.fill.stroke { fill: gray; stroke: lightgray; }" +
+		"svg .blue.text { fill: white; }" +
+		"svg .green.text { fill: white; }" +
+		"svg .gray.text { fill: white; }"))
+}
+
+func main() {
+	http.HandleFunc("/", inlineSVGWithClasses)
+	http.HandleFunc("/main.css", css)
+	log.Fatal(http.ListenAndServe(":8080", nil))
+}

examples/custom_formatters/main.go

@@ -1,13 +1,15 @@
 package main
 
+//go:generate go run main.go
+
 import (
 	"fmt"
-	"net/http"
+	"os"
 
-	"github.com/wcharczuk/go-chart"
+	"git.smarteching.com/zeni/go-chart/v2"
 )
 
-func drawChart(res http.ResponseWriter, req *http.Request) {
+func main() {
 	/*
 	   In this example we use a custom `ValueFormatter` for the y axis, letting us specify how to format text of the y-axis ticks.
 	   You can also do this for the x-axis, or the secondary y-axis.
@@ -16,9 +18,6 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	graph := chart.Chart{
 		YAxis: chart.YAxis{
-			Style: chart.Style{
-				Show: true,
-			},
 			ValueFormatter: func(v interface{}) string {
 				if vf, isFloat := v.(float64); isFloat {
 					return fmt.Sprintf("%0.6f", vf)
@@ -33,12 +32,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 			},
 		},
 	}
-
+	f, _ := os.Create("output.png")
-	res.Header().Set("Content-Type", "image/png")
+	defer f.Close()
-	graph.Render(chart.PNG, res)
+	graph.Render(chart.PNG, f)
-}
-
-func main() {
-	http.HandleFunc("/", drawChart)
-	http.ListenAndServe(":8080", nil)
 }

examples/custom_padding/main.go

@@ -0,0 +1,34 @@
+package main
+
+//go:generate go run main.go
+
+import (
+	"os"
+
+	"git.smarteching.com/zeni/go-chart/v2"
+	"git.smarteching.com/zeni/go-chart/v2/drawing"
+)
+
+func main() {
+	graph := chart.Chart{
+		Background: chart.Style{
+			Padding: chart.Box{
+				Top:    50,
+				Left:   25,
+				Right:  25,
+				Bottom: 10,
+			},
+			FillColor: drawing.ColorFromHex("efefef"),
+		},
+		Series: []chart.Series{
+			chart.ContinuousSeries{
+				XValues: chart.Seq{Sequence: chart.NewLinearSequence().WithStart(1.0).WithEnd(100.0)}.Values(),
+				YValues: chart.Seq{Sequence: chart.NewRandomSequence().WithLen(100).WithMin(100).WithMax(512)}.Values(),
+			},
+		},
+	}
+
+	f, _ := os.Create("output.png")
+	defer f.Close()
+	graph.Render(chart.PNG, f)
+}

examples/custom_ranges/main.go

@@ -1,12 +1,14 @@
 package main
 
-import (
+//go:generate go run main.go
-	"net/http"
 
-	"github.com/wcharczuk/go-chart"
+import (
+	"os"
+
+	"git.smarteching.com/zeni/go-chart/v2"
 )
 
-func drawChart(res http.ResponseWriter, req *http.Request) {
+func main() {
 	/*
 	   In this example we set a custom range for the y-axis, overriding the automatic range generation.
 	   Note: the chart will still generate the ticks automatically based on the custom range, so the intervals may be a bit weird.
@@ -14,9 +16,6 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	graph := chart.Chart{
 		YAxis: chart.YAxis{
-			Style: chart.Style{
-				Show: true,
-			},
 			Range: &chart.ContinuousRange{
 				Min: 0.0,
 				Max: 10.0,
@@ -29,12 +28,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 			},
 		},
 	}
-
+	f, _ := os.Create("output.png")
-	res.Header().Set("Content-Type", "image/png")
+	defer f.Close()
-	graph.Render(chart.PNG, res)
+	graph.Render(chart.PNG, f)
-}
-
-func main() {
-	http.HandleFunc("/", drawChart)
-	http.ListenAndServe(":8080", nil)
 }

examples/custom_styles/main.go

@@ -1,13 +1,15 @@
 package main
 
-import (
+//go:generate go run main.go
-	"net/http"
 
-	"github.com/wcharczuk/go-chart"
+import (
-	"github.com/wcharczuk/go-chart/drawing"
+	"os"
+
+	"git.smarteching.com/zeni/go-chart/v2"
+	"git.smarteching.com/zeni/go-chart/v2/drawing"
 )
 
-func drawChart(res http.ResponseWriter, req *http.Request) {
+func main() {
 	/*
 	   In this example we set some custom colors for the series and the chart background and canvas.
 	*/
@@ -21,7 +23,6 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 		Series: []chart.Series{
 			chart.ContinuousSeries{
 				Style: chart.Style{
-					Show:        true,                           //note; if we set ANY other properties, we must set this to true.
 					StrokeColor: drawing.ColorRed,               // will supercede defaults
 					FillColor:   drawing.ColorRed.WithAlpha(64), // will supercede defaults
 				},
@@ -31,11 +32,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 		},
 	}
 
-	res.Header().Set("Content-Type", "image/png")
+	f, _ := os.Create("output.png")
-	graph.Render(chart.PNG, res)
+	defer f.Close()
-}
+	graph.Render(chart.PNG, f)
-
-func main() {
-	http.HandleFunc("/", drawChart)
-	http.ListenAndServe(":8080", nil)
 }

examples/custom_stylesheets/inlineOutput.svg

@@ -0,0 +1,21 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="512" height="512">\n<style type="text/css"><![CDATA[svg .background { fill: white; }svg .canvas { fill: white; }svg path.blue { fill: blue; stroke: lightblue; }svg path.green { fill: green; stroke: lightgreen; }svg path.gray { fill: gray; stroke: lightgray; }svg text.blue { fill: white; }svg text.green { fill: white; }svg text.gray { fill: white; }]]></style><path  d="M 0 0
+L 512 0
+L 512 512
+L 0 512
+L 0 0" class="background"/><path  d="M 5 5
+L 507 5
+L 507 507
+L 5 507
+L 5 5" class="canvas"/><path  d="M 256 256
+L 507 256
+A 251 251 128.56 0 1 100 452
+L 256 256
+Z" class="blue"/><path  d="M 256 256
+L 100 452
+A 251 251 128.56 0 1 201 12
+L 256 256
+Z" class="green"/><path  d="M 256 256
+L 201 12
+A 251 251 102.85 0 1 506 256
+L 256 256
+Z" class="gray"/><text x="313" y="413" class="blue">Blue</text><text x="73" y="226" class="green">Green</text><text x="344" y="133" class="gray">Gray</text></svg>

examples/custom_stylesheets/main.go

@@ -0,0 +1,88 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+
+	"git.smarteching.com/zeni/go-chart/v2"
+)
+
+const style = "svg .background { fill: white; }" +
+	"svg .canvas { fill: white; }" +
+	"svg .blue.fill.stroke { fill: blue; stroke: lightblue; }" +
+	"svg .green.fill.stroke { fill: green; stroke: lightgreen; }" +
+	"svg .gray.fill.stroke { fill: gray; stroke: lightgray; }" +
+	"svg .blue.text { fill: white; }" +
+	"svg .green.text { fill: white; }" +
+	"svg .gray.text { fill: white; }"
+
+func svgWithCustomInlineCSS(res http.ResponseWriter, _ *http.Request) {
+	res.Header().Set("Content-Type", chart.ContentTypeSVG)
+
+	// Render the CSS with custom css
+	err := pieChart().Render(chart.SVGWithCSS(style, ""), res)
+	if err != nil {
+		fmt.Printf("Error rendering pie chart: %v\n", err)
+	}
+}
+
+func svgWithCustomInlineCSSNonce(res http.ResponseWriter, _ *http.Request) {
+	// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy/style-src
+	// This should be randomly generated on every request!
+	const nonce = "RAND0MBASE64"
+
+	res.Header().Set("Content-Security-Policy", fmt.Sprintf("style-src 'nonce-%s'", nonce))
+	res.Header().Set("Content-Type", chart.ContentTypeSVG)
+
+	// Render the CSS with custom css and a nonce.
+	// Try changing the nonce to a different string - your browser should block the CSS.
+	err := pieChart().Render(chart.SVGWithCSS(style, nonce), res)
+	if err != nil {
+		fmt.Printf("Error rendering pie chart: %v\n", err)
+	}
+}
+
+func svgWithCustomExternalCSS(res http.ResponseWriter, _ *http.Request) {
+	// Add external CSS
+	res.Write([]byte(
+		`<?xml version="1.0" standalone="no"?>` +
+			`<?xml-stylesheet href="/main.css" type="text/css"?>` +
+			`<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">`))
+
+	res.Header().Set("Content-Type", chart.ContentTypeSVG)
+	err := pieChart().Render(chart.SVG, res)
+	if err != nil {
+		fmt.Printf("Error rendering pie chart: %v\n", err)
+	}
+}
+
+func pieChart() chart.PieChart {
+	return chart.PieChart{
+		// Note that setting ClassName will cause all other inline styles to be dropped!
+		Background: chart.Style{ClassName: "background"},
+		Canvas: chart.Style{
+			ClassName: "canvas",
+		},
+		Width:  512,
+		Height: 512,
+		Values: []chart.Value{
+			{Value: 5, Label: "Blue", Style: chart.Style{ClassName: "blue"}},
+			{Value: 5, Label: "Green", Style: chart.Style{ClassName: "green"}},
+			{Value: 4, Label: "Gray", Style: chart.Style{ClassName: "gray"}},
+		},
+	}
+}
+
+func css(res http.ResponseWriter, req *http.Request) {
+	res.Header().Set("Content-Type", "text/css")
+	res.Write([]byte(style))
+}
+
+func main() {
+	http.HandleFunc("/", svgWithCustomInlineCSS)
+	http.HandleFunc("/nonce", svgWithCustomInlineCSSNonce)
+	http.HandleFunc("/external", svgWithCustomExternalCSS)
+	http.HandleFunc("/main.css", css)
+	log.Fatal(http.ListenAndServe(":8080", nil))
+}

examples/custom_ticks/main.go

@@ -1,12 +1,14 @@
 package main
 
-import (
+//go:generate go run main.go
-	"net/http"
 
-	"github.com/wcharczuk/go-chart"
+import (
+	"os"
+
+	"git.smarteching.com/zeni/go-chart/v2"
 )
 
-func drawChart(res http.ResponseWriter, req *http.Request) {
+func main() {
 	/*
 	   In this example we set a custom set of ticks to use for the y-axis. It can be (almost) whatever you want, including some custom labels for ticks.
 	   Custom ticks will supercede a custom range, which will supercede automatic generation based on series values.
@@ -14,20 +16,17 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 
 	graph := chart.Chart{
 		YAxis: chart.YAxis{
-			Style: chart.Style{
-				Show: true,
-			},
 			Range: &chart.ContinuousRange{
 				Min: 0.0,
 				Max: 4.0,
 			},
 			Ticks: []chart.Tick{
-				{0.0, "0.00"},
+				{Value: 0.0, Label: "0.00"},
-				{2.0, "2.00"},
+				{Value: 2.0, Label: "2.00"},
-				{4.0, "4.00"},
+				{Value: 4.0, Label: "4.00"},
-				{6.0, "6.00"},
+				{Value: 6.0, Label: "6.00"},
-				{8.0, "Eight"},
+				{Value: 8.0, Label: "Eight"},
-				{10.0, "Ten"},
+				{Value: 10.0, Label: "Ten"},
 			},
 		},
 		Series: []chart.Series{
@@ -37,12 +36,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 			},
 		},
 	}
-
+	f, _ := os.Create("output.png")
-	res.Header().Set("Content-Type", "image/png")
+	defer f.Close()
-	graph.Render(chart.PNG, res)
+	graph.Render(chart.PNG, f)
-}
-
-func main() {
-	http.HandleFunc("/", drawChart)
-	http.ListenAndServe(":8080", nil)
 }

examples/descending/main.go

@@ -1,12 +1,14 @@
 package main
 
-import (
+//go:generate go run main.go
-	"net/http"
 
-	"github.com/wcharczuk/go-chart"
+import (
+	"os"
+
+	"git.smarteching.com/zeni/go-chart/v2"
 )
 
-func drawChart(res http.ResponseWriter, req *http.Request) {
+func main() {
 
 	/*
 	   The below will draw the same chart as the `basic` example, except with both the x and y axes turned on.
@@ -19,18 +21,12 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 	graph := chart.Chart{
 		Height: 500,
 		Width:  500,
-		XAxis: chart.XAxis{
+		XAxis:  chart.XAxis{
-			Style: chart.Style{
-				Show: true,
-			},
 			/*Range: &chart.ContinuousRange{
 				Descending: true,
 			},*/
 		},
 		YAxis: chart.YAxis{
-			Style: chart.Style{
-				Show: true,
-			},
 			Range: &chart.ContinuousRange{
 				Descending: true,
 			},
@@ -38,7 +34,6 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 		Series: []chart.Series{
 			chart.ContinuousSeries{
 				Style: chart.Style{
-					Show:        true,
 					StrokeColor: chart.GetDefaultColor(0).WithAlpha(64),
 					FillColor:   chart.GetDefaultColor(0).WithAlpha(64),
 				},
@@ -48,11 +43,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 		},
 	}
 
-	res.Header().Set("Content-Type", "image/png")
+	f, _ := os.Create("output.png")
-	graph.Render(chart.PNG, res)
+	defer f.Close()
-}
+	graph.Render(chart.PNG, f)
-
-func main() {
-	http.HandleFunc("/", drawChart)
-	http.ListenAndServe(":8080", nil)
 }

examples/donut_chart/main.go

@@ -0,0 +1,28 @@
+package main
+
+//go:generate go run main.go
+
+import (
+	"os"
+
+	"git.smarteching.com/zeni/go-chart/v2"
+)
+
+func main() {
+	pie := chart.DonutChart{
+		Width:  512,
+		Height: 512,
+		Values: []chart.Value{
+			{Value: 5, Label: "Blue"},
+			{Value: 5, Label: "Green"},
+			{Value: 4, Label: "Gray"},
+			{Value: 4, Label: "Orange"},
+			{Value: 3, Label: "Deep Blue"},
+			{Value: 3, Label: "test"},
+		},
+	}
+
+	f, _ := os.Create("output.png")
+	defer f.Close()
+	pie.Render(chart.PNG, f)
+}

examples/donut_chart/reg.svg

@@ -0,0 +1,25 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="512" height="512">\n<path  d="M 0 0
+L 512 0
+L 512 512
+L 0 512
+L 0 0" style="stroke-width:0;stroke:rgba(255,255,255,1.0);fill:rgba(255,255,255,1.0)"/><path  d="M 5 5
+L 507 5
+L 507 507
+L 5 507
+L 5 5" style="stroke-width:0;stroke:rgba(255,255,255,1.0);fill:rgba(255,255,255,1.0)"/><path  d="M 256 256
+L 438 256
+A 182 182 225.00 1 1 127 127
+L 256 256
+Z" style="stroke-width:4;stroke:rgba(255,255,255,1.0);fill:rgba(106,195,203,1.0)"/><path  d="M 256 256
+L 127 127
+A 182 182 90.00 0 1 385 127
+L 256 256
+Z" style="stroke-width:4;stroke:rgba(255,255,255,1.0);fill:rgba(42,190,137,1.0)"/><path  d="M 256 256
+L 385 127
+A 182 182 45.00 0 1 438 256
+L 256 256
+Z" style="stroke-width:4;stroke:rgba(255,255,255,1.0);fill:rgba(110,128,139,1.0)"/><path  d="M 256 256
+L 321 256
+A 65 65 359.00 1 1 321 255
+L 256 256
+Z" style="stroke-width:4;stroke:rgba(255,255,255,1.0);fill:rgba(255,255,255,1.0)"/><text x="159" y="461" style="stroke-width:0;stroke:none;fill:rgba(51,51,51,1.0);font-size:15.3px;font-family:'Roboto Medium',sans-serif">Blue</text><text x="241" y="48" style="stroke-width:0;stroke:none;fill:rgba(51,51,51,1.0);font-size:15.3px;font-family:'Roboto Medium',sans-serif">Two</text><text x="440" y="181" style="stroke-width:0;stroke:none;fill:rgba(51,51,51,1.0);font-size:15.3px;font-family:'Roboto Medium',sans-serif">One</text></svg>

examples/horizontal_stacked_bar/main.go

@@ -0,0 +1,222 @@
+package main
+
+import (
+	"os"
+
+	"git.smarteching.com/zeni/go-chart/v2"
+	"git.smarteching.com/zeni/go-chart/v2/drawing"
+)
+
+func main() {
+	chart.DefaultBackgroundColor = chart.ColorTransparent
+	chart.DefaultCanvasColor = chart.ColorTransparent
+
+	barWidth := 80
+
+	var (
+		colorWhite          = drawing.Color{R: 241, G: 241, B: 241, A: 255}
+		colorMariner        = drawing.Color{R: 60, G: 100, B: 148, A: 255}
+		colorLightSteelBlue = drawing.Color{R: 182, G: 195, B: 220, A: 255}
+		colorPoloBlue       = drawing.Color{R: 126, G: 155, B: 200, A: 255}
+		colorSteelBlue      = drawing.Color{R: 73, G: 120, B: 177, A: 255}
+	)
+
+	stackedBarChart := chart.StackedBarChart{
+		Title:      "Quarterly Sales",
+		TitleStyle: chart.Shown(),
+		Background: chart.Style{
+			Padding: chart.Box{
+				Top: 75,
+			},
+		},
+		Width:        800,
+		Height:       600,
+		XAxis:        chart.Shown(),
+		YAxis:        chart.Shown(),
+		BarSpacing:   40,
+		IsHorizontal: true,
+		Bars: []chart.StackedBar{
+			{
+				Name:  "Q1",
+				Width: barWidth,
+				Values: []chart.Value{
+					{
+						Label: "32K",
+						Value: 32,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorMariner,
+							FontColor:   colorWhite,
+						},
+					},
+					{
+						Label: "46K",
+						Value: 46,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorLightSteelBlue,
+							FontColor:   colorWhite,
+						},
+					},
+					{
+						Label: "48K",
+						Value: 48,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorPoloBlue,
+							FontColor:   colorWhite,
+						},
+					},
+					{
+						Label: "42K",
+						Value: 42,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorSteelBlue,
+							FontColor:   colorWhite,
+						},
+					},
+				},
+			},
+			{
+				Name:  "Q2",
+				Width: barWidth,
+				Values: []chart.Value{
+					{
+						Label: "45K",
+						Value: 45,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorMariner,
+							FontColor:   colorWhite,
+						},
+					},
+					{
+						Label: "60K",
+						Value: 60,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorLightSteelBlue,
+							FontColor:   colorWhite,
+						},
+					},
+					{
+						Label: "62K",
+						Value: 62,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorPoloBlue,
+							FontColor:   colorWhite,
+						},
+					},
+					{
+						Label: "53K",
+						Value: 53,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorSteelBlue,
+							FontColor:   colorWhite,
+						},
+					},
+				},
+			},
+			{
+				Name:  "Q3",
+				Width: barWidth,
+				Values: []chart.Value{
+					{
+						Label: "54K",
+						Value: 54,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorMariner,
+							FontColor:   colorWhite,
+						},
+					},
+					{
+						Label: "58K",
+						Value: 58,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorLightSteelBlue,
+							FontColor:   colorWhite,
+						},
+					},
+					{
+						Label: "55K",
+						Value: 55,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorPoloBlue,
+							FontColor:   colorWhite,
+						},
+					},
+					{
+						Label: "47K",
+						Value: 47,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorSteelBlue,
+							FontColor:   colorWhite,
+						},
+					},
+				},
+			},
+			{
+				Name:  "Q4",
+				Width: barWidth,
+				Values: []chart.Value{
+					{
+						Label: "46K",
+						Value: 46,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorMariner,
+							FontColor:   colorWhite,
+						},
+					},
+					{
+						Label: "70K",
+						Value: 70,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorLightSteelBlue,
+							FontColor:   colorWhite,
+						},
+					},
+					{
+						Label: "74K",
+						Value: 74,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorPoloBlue,
+							FontColor:   colorWhite,
+						},
+					},
+					{
+						Label: "60K",
+						Value: 60,
+						Style: chart.Style{
+							StrokeWidth: .01,
+							FillColor:   colorSteelBlue,
+							FontColor:   colorWhite,
+						},
+					},
+				},
+			},
+		},
+	}
+
+	pngFile, err := os.Create("output.png")
+	if err != nil {
+		panic(err)
+	}
+
+	if err := stackedBarChart.Render(chart.PNG, pngFile); err != nil {
+		panic(err)
+	}
+
+	if err := pngFile.Close(); err != nil {
+		panic(err)
+	}
+}

examples/image_writer/main.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"log"
 
-	"github.com/wcharczuk/go-chart"
+	"git.smarteching.com/zeni/go-chart/v2"
 )
 
 func main() {

examples/legend/main.go

@@ -1,12 +1,14 @@
 package main
 
-import (
+//go:generate go run main.go
-	"net/http"
 
-	"github.com/wcharczuk/go-chart"
+import (
+	"os"
+
+	chart "git.smarteching.com/zeni/go-chart/v2"
 )
 
-func drawChart(res http.ResponseWriter, req *http.Request) {
+func main() {
 
 	/*
 	   In this example we add a `Renderable` or a custom component to the `Elements` array.
@@ -15,12 +17,6 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 	*/
 
 	graph := chart.Chart{
-		XAxis: chart.XAxis{
-			Style: chart.Style{Show: true},
-		},
-		YAxis: chart.YAxis{
-			Style: chart.Style{Show: true},
-		},
 		Background: chart.Style{
 			Padding: chart.Box{
 				Top:  20,
@@ -41,11 +37,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 		chart.Legend(&graph),
 	}
 
-	res.Header().Set("Content-Type", "image/png")
+	f, _ := os.Create("output.png")
-	graph.Render(chart.PNG, res)
+	defer f.Close()
-}
+	graph.Render(chart.PNG, f)
-
-func main() {
-	http.HandleFunc("/", drawChart)
-	http.ListenAndServe(":8080", nil)
 }