diff --git a/pie_chart.go b/pie_chart.go
index b4714ac..bbf7814 100644
--- a/pie_chart.go
+++ b/pie_chart.go
@@ -63,6 +63,96 @@ func NewPieChart(p *Painter, opt PieChartOption) *pieChart {
}
}
+type sector struct {
+ value float64
+ percent float64
+ cx int
+ cy int
+ rx float64
+ ry float64
+ start float64
+ delta float64
+ offset int
+ quadrant int
+ lineStartX int
+ lineStartY int
+ lineBranchX int
+ lineBranchY int
+ lineEndX int
+ lineEndY int
+ showLabel bool
+ label string
+ series Series
+ color Color
+}
+
+func NewSector(cx int, cy int, radius float64, labelRadius float64, value float64, currentValue float64, totalValue float64, labelLineLength int, label string, series Series, color Color) sector {
+ s := sector{}
+ s.value = value
+ s.percent = value / totalValue
+ s.cx = cx
+ s.cy = cy
+ s.rx = radius
+ s.ry = radius
+ p := currentValue / totalValue
+ if p < 0.25 {
+ s.quadrant = 1
+ } else if p < 0.5 {
+ s.quadrant = 4
+ } else if p < 0.75 {
+ s.quadrant = 3
+ } else {
+ s.quadrant = 2
+ }
+ s.start = chart.PercentToRadians(currentValue/totalValue) - math.Pi/2 // Bogenmaß
+ s.delta = chart.PercentToRadians(value / totalValue)
+ angle := s.start + s.delta/2
+ s.lineStartX = cx + int(radius*math.Cos(angle))
+ s.lineStartY = cy + int(radius*math.Sin(angle))
+ s.lineBranchX = cx + int(labelRadius*math.Cos(angle))
+ s.lineBranchY = cy + int(labelRadius*math.Sin(angle))
+ s.offset = labelLineLength
+ if s.lineBranchX <= cx {
+ s.offset *= -1
+ }
+ s.lineEndX = s.lineBranchX + s.offset
+ s.lineEndY = s.lineBranchY
+ s.series = series
+ s.color = color
+ s.showLabel = series.Label.Show
+ s.label = NewPieLabelFormatter([]string{label}, series.Label.Formatter)(0, s.value, s.percent)
+ return s
+}
+
+func (s *sector) calculateY(prevY int) int {
+ for i := 0; i <= s.cy; i++ {
+ if s.quadrant <= 2 {
+ if (prevY - s.lineBranchY) > labelFontSize+5 {
+ break
+ }
+ s.lineBranchY -= 1
+ } else {
+ if (s.lineBranchY - prevY) > labelFontSize+5 {
+ break
+ }
+ s.lineBranchY += 1
+ }
+ }
+ s.lineEndY = s.lineBranchY
+ return s.lineBranchY
+}
+
+func (s *sector) calculateTextXY(textBox Box) (x int, y int) {
+ textMargin := 3
+ x = s.lineEndX + textMargin
+ y = s.lineEndY + textBox.Height()>>1 - 1
+ if s.offset < 0 {
+ textWidth := textBox.Width()
+ x = s.lineEndX - textWidth - textMargin
+ }
+ return
+}
+
func (p *pieChart) render(result *defaultRenderResult, seriesList SeriesList) (Box, error) {
opt := p.opt
values := make([]float64, len(seriesList))
@@ -101,98 +191,91 @@ func (p *pieChart) render(result *defaultRenderResult, seriesList SeriesList) (B
theme := opt.Theme
currentValue := float64(0)
- prevPoints := make([]Point, 0)
- isOverride := func(x, y int) bool {
- for _, p := range prevPoints {
- if math.Abs(float64(p.Y-y)) > labelFontSize {
- continue
- }
- // label可能较多内容，不好计算横向占用空间
- // 因此x的位置需要中间位置两侧，否则认为override
- if (p.X <= cx && x <= cx) ||
- (p.X > cx && x > cx) {
- return true
+ var quadrant1, quadrant2, quadrant3, quadrant4 []sector
+ for index, v := range values {
+ series := seriesList[index]
+ color := theme.GetSeriesColor(index)
+ if index == len(values)-1 {
+ if color == theme.GetSeriesColor(0) {
+ color = theme.GetSeriesColor(1)
}
}
- return false
+ s := NewSector(cx, cy, radius, labelRadius, v, currentValue, total, labelLineWidth, seriesNames[index], series, color)
+ switch quadrant := s.quadrant; quadrant {
+ case 1:
+ quadrant1 = append([]sector{s}, quadrant1...)
+ case 2:
+ quadrant2 = append(quadrant2, s)
+ case 3:
+ quadrant3 = append([]sector{s}, quadrant3...)
+ case 4:
+ quadrant4 = append(quadrant4, s)
+ }
+ currentValue += v
}
+ sectors := append(quadrant1, quadrant4...)
+ sectors = append(sectors, quadrant3...)
+ sectors = append(sectors, quadrant2...)
- for index, v := range values {
+ currentQuadrant := 0
+ prevY := 0
+ maxY := 0
+ minY := 0
+ for _, s := range sectors {
seriesPainter.OverrideDrawingStyle(Style{
StrokeWidth: 1,
- StrokeColor: theme.GetSeriesColor(index),
- FillColor: theme.GetSeriesColor(index),
+ StrokeColor: s.color,
+ FillColor: s.color,
})
- seriesPainter.MoveTo(cx, cy)
- start := chart.PercentToRadians(currentValue/total) - math.Pi/2
- currentValue += v
- percent := (v / total)
- delta := chart.PercentToRadians(percent)
- seriesPainter.ArcTo(cx, cy, radius, radius, start, delta).
- LineTo(cx, cy).
- Close().
- FillStroke()
-
- series := seriesList[index]
- // 是否显示label
- showLabel := series.Label.Show
- if !showLabel {
+ seriesPainter.MoveTo(s.cx, s.cy)
+ seriesPainter.ArcTo(s.cx, s.cy, s.rx, s.ry, s.start, s.delta).LineTo(s.cx, s.cy).Close().FillStroke()
+ if !s.showLabel {
continue
}
-
- // label的角度为饼块中间
- angle := start + delta/2
- startx := cx + int(radius*math.Cos(angle))
- starty := cy + int(radius*math.Sin(angle))
-
- endx := cx + int(labelRadius*math.Cos(angle))
- endy := cy + int(labelRadius*math.Sin(angle))
- // 计算是否有重叠，如果有则调整y坐标位置
- // 最多只尝试5次
- for i := 0; i < 5; i++ {
- if !isOverride(endx, endy) {
- break
+ if currentQuadrant != s.quadrant {
+ currentQuadrant = s.quadrant
+ if s.quadrant == 1 {
+ minY = cy * 2
+ maxY = 0
+ prevY = cy * 2
+ }
+ if s.quadrant == 2 {
+ prevY = minY
+ }
+ if s.quadrant == 3 {
+ minY = cy * 2
+ maxY = 0
+ prevY = 0
+ }
+ if s.quadrant == 4 {
+ prevY = maxY
}
- endy -= (labelFontSize << 1)
}
- prevPoints = append(prevPoints, Point{
- X: endx,
- Y: endy,
- })
-
- seriesPainter.MoveTo(startx, starty)
- seriesPainter.LineTo(endx, endy)
- offset := labelLineWidth
- if endx < cx {
- offset *= -1
+ prevY = s.calculateY(prevY)
+ if prevY > maxY {
+ maxY = prevY
}
- seriesPainter.MoveTo(endx, endy)
- endx += offset
- seriesPainter.LineTo(endx, endy)
+ if prevY < minY {
+ minY = prevY
+ }
+ seriesPainter.MoveTo(s.lineStartX, s.lineStartY)
+ seriesPainter.LineTo(s.lineBranchX, s.lineBranchY)
+ seriesPainter.MoveTo(s.lineBranchX, s.lineBranchY)
+ seriesPainter.LineTo(s.lineEndX, s.lineEndY)
seriesPainter.Stroke()
-
textStyle := Style{
FontColor: theme.GetTextColor(),
FontSize: labelFontSize,
Font: opt.Font,
}
- if !series.Label.Color.IsZero() {
- textStyle.FontColor = series.Label.Color
+ if !s.series.Label.Color.IsZero() {
+ textStyle.FontColor = s.series.Label.Color
}
seriesPainter.OverrideTextStyle(textStyle)
- text := NewPieLabelFormatter(seriesNames, series.Label.Formatter)(index, v, percent)
- textBox := seriesPainter.MeasureText(text)
- textMargin := 3
- x := endx + textMargin
- y := endy + textBox.Height()>>1 - 1
- if offset < 0 {
- textWidth := textBox.Width()
- x = endx - textWidth - textMargin
- }
- seriesPainter.Text(text, x, y)
+ x, y := s.calculateTextXY(seriesPainter.MeasureText(s.label))
+ seriesPainter.Text(s.label, x, y)
}
-
return p.p.box, nil
}
diff --git a/pie_chart_test.go b/pie_chart_test.go
index c373a7e..0b8f798 100644
--- a/pie_chart_test.go
+++ b/pie_chart_test.go
@@ -23,6 +23,7 @@
package charts
import (
+ "strconv"
"testing"
"github.com/stretchr/testify/assert"
@@ -98,3 +99,296 @@ func TestPieChart(t *testing.T) {
assert.Equal(tt.result, string(data))
}
}
+
+func TestPieChartWithLabelsValuesSortedDescending(t *testing.T) {
+ assert := assert.New(t)
+
+ tests := []struct {
+ render func(*Painter) ([]byte, error)
+ result string
+ }{
+ {
+ render: func(p *Painter) ([]byte, error) {
+ values := []float64{
+ 84358845,
+ 68070697,
+ 58850717,
+ 48059777,
+ 36753736,
+ 19051562,
+ 17947406,
+ 11754004,
+ 10827529,
+ 10521556,
+ 10467366,
+ 10394055,
+ 9597085,
+ 9104772,
+ 6447710,
+ 5932654,
+ 5563970,
+ 5428792,
+ 5194336,
+ 3850894,
+ 2857279,
+ 2116792,
+ 1883008,
+ 1373101,
+ 920701,
+ 660809,
+ 542051,
+ }
+ _, err := NewPieChart(p, PieChartOption{
+ SeriesList: NewPieSeriesList(values, PieSeriesOption{
+ Label: SeriesLabel{
+ Show: true,
+ Formatter: "{b} ({c} ≅ {d})",
+ },
+ Radius: "200",
+ }),
+ Title: TitleOption{
+ Text: "European Union member states by population",
+ Left: PositionRight,
+ },
+ Padding: Box{
+ Top: 20,
+ Right: 20,
+ Bottom: 20,
+ Left: 20,
+ },
+ Legend: LegendOption{
+ Data: []string{
+ "Germany",
+ "France",
+ "Italy",
+ "Spain",
+ "Poland",
+ "Romania",
+ "Netherlands",
+ "Belgium",
+ "Czech Republic",
+ "Sweden",
+ "Portugal",
+ "Greece",
+ "Hungary",
+ "Austria",
+ "Bulgaria",
+ "Denmark",
+ "Finland",
+ "Slovakia",
+ "Ireland",
+ "Croatia",
+ "Lithuania",
+ "Slovenia",
+ "Latvia",
+ "Estonia",
+ "Cyprus",
+ "Luxembourg",
+ "Malta",
+ },
+ Show: FalseFlag(),
+ },
+ }).Render()
+ if err != nil {
+ return nil, err
+ }
+ return p.Bytes()
+ },
+ result: "",
+ },
+ }
+ for _, tt := range tests {
+ p, err := NewPainter(PainterOptions{
+ Type: ChartOutputSVG,
+ Width: 1000,
+ Height: 800,
+ }, PainterThemeOption(defaultTheme))
+ assert.Nil(err)
+ data, err := tt.render(p.Child(PainterPaddingOption(Box{
+ Left: 20,
+ Top: 20,
+ Right: 20,
+ Bottom: 20,
+ })))
+ assert.Nil(err)
+ assert.Equal(tt.result, string(data))
+ }
+}
+
+func TestPieChartWithLabelsValuesUnsorted(t *testing.T) {
+ assert := assert.New(t)
+
+ tests := []struct {
+ render func(*Painter) ([]byte, error)
+ result string
+ }{
+ {
+ render: func(p *Painter) ([]byte, error) {
+ values := []float64{
+ 9104772,
+ 11754004,
+ 6447710,
+ 3850894,
+ 920701,
+ 10827529,
+ 5932654,
+ 1373101,
+ 5563970,
+ 68070697,
+ 84358845,
+ 10394055,
+ 9597085,
+ 5194336,
+ 58850717,
+ 1883008,
+ 2857279,
+ 660809,
+ 542051,
+ 17947406,
+ 36753736,
+ 10467366,
+ 19051562,
+ 5428792,
+ 2116792,
+ 48059777,
+ 10521556,
+ }
+ _, err := NewPieChart(p, PieChartOption{
+ SeriesList: NewPieSeriesList(values, PieSeriesOption{
+ Label: SeriesLabel{
+ Show: true,
+ Formatter: "{b} ({c} ≅ {d})",
+ },
+ Radius: "200",
+ }),
+ Title: TitleOption{
+ Text: "European Union member states by population",
+ Left: PositionRight,
+ },
+ Padding: Box{
+ Top: 20,
+ Right: 20,
+ Bottom: 20,
+ Left: 20,
+ },
+ Legend: LegendOption{
+ Data: []string{
+ "Austria",
+ "Belgium",
+ "Bulgaria",
+ "Croatia",
+ "Cyprus",
+ "Czech Republic",
+ "Denmark",
+ "Estonia",
+ "Finland",
+ "France",
+ "Germany",
+ "Greece",
+ "Hungary",
+ "Ireland",
+ "Italy",
+ "Latvia",
+ "Lithuania",
+ "Luxembourg",
+ "Malta",
+ "Netherlands",
+ "Poland",
+ "Portugal",
+ "Romania",
+ "Slovakia",
+ "Slovenia",
+ "Spain",
+ "Sweden",
+ },
+ Show: FalseFlag(),
+ },
+ }).Render()
+ if err != nil {
+ return nil, err
+ }
+ return p.Bytes()
+ },
+ result: "",
+ },
+ }
+ for _, tt := range tests {
+ p, err := NewPainter(PainterOptions{
+ Type: ChartOutputSVG,
+ Width: 1000,
+ Height: 800,
+ }, PainterThemeOption(defaultTheme))
+ assert.Nil(err)
+ data, err := tt.render(p.Child(PainterPaddingOption(Box{
+ Left: 20,
+ Top: 20,
+ Right: 20,
+ Bottom: 20,
+ })))
+ assert.Nil(err)
+ assert.Equal(tt.result, string(data))
+ }
+}
+
+func TestPieChartWith100Labels(t *testing.T) {
+ assert := assert.New(t)
+
+ tests := []struct {
+ render func(*Painter) ([]byte, error)
+ result string
+ }{
+ {
+ render: func(p *Painter) ([]byte, error) {
+ var values []float64
+ var labels []string
+ for i := 1; i <= 100; i++ {
+ values = append(values, float64(1))
+ labels = append(labels, "Label "+strconv.Itoa(i))
+ }
+ _, err := NewPieChart(p, PieChartOption{
+ SeriesList: NewPieSeriesList(values, PieSeriesOption{
+ Label: SeriesLabel{
+ Show: true,
+ },
+ Radius: "200",
+ }),
+ Title: TitleOption{
+ Text: "Test with 100 labels",
+ Left: PositionRight,
+ },
+ Padding: Box{
+ Top: 20,
+ Right: 20,
+ Bottom: 20,
+ Left: 20,
+ },
+ Legend: LegendOption{
+ Data: labels,
+ Show: FalseFlag(),
+ },
+ }).Render()
+ if err != nil {
+ return nil, err
+ }
+ return p.Bytes()
+ },
+ result: "",
+ },
+ }
+ for _, tt := range tests {
+ p, err := NewPainter(PainterOptions{
+ Type: ChartOutputSVG,
+ Width: 1000,
+ Height: 900,
+ }, PainterThemeOption(defaultTheme))
+ assert.Nil(err)
+ data, err := tt.render(p.Child(PainterPaddingOption(Box{
+ Left: 20,
+ Top: 20,
+ Right: 20,
+ Bottom: 20,
+ })))
+ assert.Nil(err)
+ assert.Equal(tt.result, string(data))
+ }
+}