feat: support pie, radar and funnel chart

funnel_chart.go

@@ -0,0 +1,172 @@
+// MIT License
+
+// Copyright (c) 2022 Tree Xie
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package charts
+
+import (
+	"fmt"
+
+	"github.com/dustin/go-humanize"
+	"github.com/golang/freetype/truetype"
+)
+
+type funnelChart struct {
+	p   *Painter
+	opt *FunnelChartOption
+}
+
+func NewFunnelChart(p *Painter, opt FunnelChartOption) *funnelChart {
+	if opt.Theme == nil {
+		opt.Theme = NewTheme("")
+	}
+	return &funnelChart{
+		p:   p,
+		opt: &opt,
+	}
+}
+
+type FunnelChartOption struct {
+	Theme ColorPalette
+	// The font size
+	Font *truetype.Font
+	// The data series list
+	SeriesList SeriesList
+	// The padding of line chart
+	Padding Box
+	// The option of title
+	Title TitleOption
+	// The legend option
+	Legend LegendOption
+}
+
+func (f *funnelChart) render(result *defaultRenderResult, seriesList SeriesList) (Box, error) {
+	opt := f.opt
+	seriesPainter := result.seriesPainter
+	max := seriesList[0].Data[0].Value
+	min := float64(0)
+	for _, item := range seriesList {
+		if item.Max != nil {
+			max = *item.Max
+		}
+		if item.Min != nil {
+			min = *item.Min
+		}
+	}
+	theme := opt.Theme
+	gap := 2
+	height := seriesPainter.Height()
+	width := seriesPainter.Width()
+	count := len(seriesList)
+
+	h := (height - gap*(count-1)) / count
+
+	y := 0
+	widthList := make([]int, len(seriesList))
+	textList := make([]string, len(seriesList))
+	for index, item := range seriesList {
+		value := item.Data[0].Value
+		widthPercent := (value - min) / (max - min)
+		w := int(widthPercent * float64(width))
+		widthList[index] = w
+		p := humanize.CommafWithDigits(value/max*100, 2) + "%"
+		textList[index] = fmt.Sprintf("%s(%s)", item.Name, p)
+	}
+
+	for index, w := range widthList {
+		series := seriesList[index]
+		nextWidth := 0
+		if index+1 < len(widthList) {
+			nextWidth = widthList[index+1]
+		}
+		topStartX := (width - w) >> 1
+		topEndX := topStartX + w
+		bottomStartX := (width - nextWidth) >> 1
+		bottomEndX := bottomStartX + nextWidth
+		points := []Point{
+			{
+				X: topStartX,
+				Y: y,
+			},
+			{
+				X: topEndX,
+				Y: y,
+			},
+			{
+				X: bottomEndX,
+				Y: y + h,
+			},
+			{
+				X: bottomStartX,
+				Y: y + h,
+			},
+			{
+				X: topStartX,
+				Y: y,
+			},
+		}
+		color := theme.GetSeriesColor(series.index)
+
+		seriesPainter.OverrideDrawingStyle(Style{
+			FillColor: color,
+		}).FillArea(points)
+
+		// 文本
+		text := textList[index]
+		seriesPainter.OverrideTextStyle(Style{
+			FontColor: theme.GetTextColor(),
+			FontSize:  labelFontSize,
+			Font:      opt.Font,
+		})
+		textBox := seriesPainter.MeasureText(text)
+		textX := width>>1 - textBox.Width()>>1
+		textY := y + h>>1
+		seriesPainter.Text(text, textX, textY)
+		y += (h + gap)
+	}
+
+	return f.p.box, nil
+}
+
+func (f *funnelChart) Render() (Box, error) {
+	p := f.p
+	opt := f.opt
+	renderResult, err := defaultRender(p, defaultRenderOption{
+		Theme:      opt.Theme,
+		Padding:    opt.Padding,
+		SeriesList: opt.SeriesList,
+		XAxis: XAxisOption{
+			Show: FalseFlag(),
+		},
+		YAxisOptions: []YAxisOption{
+			{
+				Show: FalseFlag(),
+			},
+		},
+		TitleOption:  opt.Title,
+		LegendOption: opt.Legend,
+	})
+	if err != nil {
+		return BoxZero, err
+	}
+	seriesList := opt.SeriesList.Filter(ChartTypeFunnel)
+	return f.render(renderResult, seriesList)
+}