feat: support radar chart

radar_chart.go

@@ -0,0 +1,183 @@
+// 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 (
+	"errors"
+
+	"github.com/golang/freetype/truetype"
+	"github.com/wcharczuk/go-chart/v2"
+	"github.com/wcharczuk/go-chart/v2/drawing"
+)
+
+// 线 E0E6F1
+// 填充 rgb(210,219,238) fill-opacity="0.2"
+
+type RadarIndicator struct {
+	Name string
+	Max  float64
+}
+
+type radarChartOption struct {
+	Theme      string
+	Font       *truetype.Font
+	SeriesList SeriesList
+	Indicators []RadarIndicator
+}
+
+func radarChartRender(opt radarChartOption, result *basicRenderResult) error {
+	sides := len(opt.Indicators)
+	if sides < 3 {
+		return errors.New("The count of indicator should be >= 3")
+	}
+	for _, indicator := range opt.Indicators {
+		if indicator.Max <= 0 {
+			return errors.New("The max of indicator should be > 0")
+		}
+	}
+	d, err := NewDraw(DrawOption{
+		Parent: result.d,
+	}, PaddingOption(chart.Box{
+		Top: result.titleBox.Height(),
+	}))
+	if err != nil {
+		return err
+	}
+	radiusValue := ""
+	for _, series := range opt.SeriesList {
+		if len(series.Radius) != 0 {
+			radiusValue = series.Radius
+		}
+	}
+
+	box := d.Box
+	cx := box.Width() >> 1
+	cy := box.Height() >> 1
+	diameter := chart.MinInt(box.Width(), box.Height())
+	radius := getRadius(float64(diameter), radiusValue)
+
+	theme := NewTheme(opt.Theme)
+
+	divideCount := 5
+	divideRadius := float64(int(radius / float64(divideCount)))
+	radius = divideRadius * float64(divideCount)
+
+	style := chart.Style{
+		StrokeColor: theme.GetAxisSplitLineColor(),
+		StrokeWidth: 1,
+	}
+	r := d.Render
+	style.WriteToRenderer(r)
+	center := Point{
+		X: cx,
+		Y: cy,
+	}
+	for i := 0; i < divideCount; i++ {
+		d.polygon(center, divideRadius*float64(i+1), sides)
+	}
+	points := getPolygonPoints(center, radius, sides)
+	for _, p := range points {
+		d.moveTo(center.X, center.Y)
+		d.lineTo(p.X, p.Y)
+		d.Render.Stroke()
+	}
+	// 文本
+	textStyle := chart.Style{
+		FontColor: theme.GetTextColor(),
+		FontSize:  labelFontSize,
+		Font:      opt.Font,
+	}
+	textStyle.GetTextOptions().WriteToRenderer(r)
+	offset := 5
+	// 文本生成
+	for index, p := range points {
+		name := opt.Indicators[index].Name
+		b := r.MeasureText(name)
+		isXCenter := p.X == center.X
+		isYCenter := p.Y == center.Y
+		isRight := p.X > center.X
+		isLeft := p.X < center.X
+		isTop := p.Y < center.Y
+		isBottom := p.Y > center.Y
+		x := p.X
+		y := p.Y
+		if isXCenter {
+			x -= b.Width() >> 1
+			if isTop {
+				y -= b.Height()
+			} else {
+				y += b.Height()
+			}
+		}
+		if isYCenter {
+			y += b.Height() >> 1
+		}
+		if isTop {
+			y += offset
+		}
+		if isBottom {
+			y += offset
+		}
+		if isRight {
+			x += offset
+		}
+		if isLeft {
+			x -= (b.Width() + offset)
+		}
+		d.text(name, x, y)
+	}
+
+	// 雷达图
+	angles := getPolygonPointAngles(sides)
+	maxCount := len(opt.Indicators)
+	for i, series := range opt.SeriesList {
+		linePoints := make([]Point, 0, maxCount)
+		for j, item := range series.Data {
+			if j >= maxCount {
+				continue
+			}
+			percent := item.Value / opt.Indicators[j].Max
+			r := percent * radius
+			p := getPolygonPoint(center, r, angles[j])
+			linePoints = append(linePoints, p)
+		}
+		color := theme.GetSeriesColor(i)
+		dotFillColor := drawing.ColorWhite
+		if theme.IsDark() {
+			dotFillColor = color
+		}
+		linePoints = append(linePoints, linePoints[0])
+		s := LineStyle{
+			StrokeColor:  color,
+			StrokeWidth:  defaultStrokeWidth,
+			DotWidth:     defaultDotWidth,
+			DotColor:     color,
+			DotFillColor: dotFillColor,
+			FillColor:    color.WithAlpha(20),
+		}
+		d.lineStroke(linePoints, s)
+		d.lineFill(linePoints, s)
+		d.lineDot(linePoints[0:len(linePoints)-1], s)
+	}
+	return nil
+}