feat: support mulit y axis

bar_chart.go

@@ -37,7 +37,7 @@ func barChartRender(opt ChartOption, result *basicRenderResult) (*Draw, error) {
 	if err != nil {
 		return nil, err
 	}
-	yRange := result.yRange
+	// yRange := result.yRange
 	xRange := result.xRange
 	x0, x1 := xRange.GetRange(0)
 	width := int(x1 - x0)
@@ -50,7 +50,7 @@ func barChartRender(opt ChartOption, result *basicRenderResult) (*Draw, error) {
 	// 总的宽度-两个margin-(总数-1)的barMargin
 	barWidth := (width - 2*margin - barMargin*(seriesCount-1)) / len(opt.SeriesList)
 
-	barMaxHeight := yRange.Size
+	barMaxHeight := result.getYRange(0).Size
 	theme := NewTheme(opt.Theme)
 
 	seriesNames := opt.Legend.Data
@@ -58,6 +58,9 @@ func barChartRender(opt ChartOption, result *basicRenderResult) (*Draw, error) {
 	r := d.Render
 
 	for i, series := range opt.SeriesList {
+		yRange := result.getYRange(series.YAxisIndex)
+		points := make([]Point, len(series.Data))
+		seriesColor := theme.GetSeriesColor(i)
 		for j, item := range series.Data {
 			x0, _ := xRange.GetRange(j)
 			x := int(x0)
@@ -67,26 +70,32 @@ func barChartRender(opt ChartOption, result *basicRenderResult) (*Draw, error) {
 			}
 
 			h := int(yRange.getHeight(item.Value))
-			fillColor := theme.GetSeriesColor(i)
+			fillColor := seriesColor
 			if !item.Style.FillColor.IsZero() {
 				fillColor = item.Style.FillColor
 			}
-
+			top := barMaxHeight - h
 			d.Bar(chart.Box{
-				Top:    barMaxHeight - h,
+				Top:    top,
 				Left:   x,
 				Right:  x + barWidth,
 				Bottom: barMaxHeight - 1,
 			}, BarStyle{
 				FillColor: fillColor,
 			})
+			// 用于生成marker point
+			points[j] = Point{
+				// 居中的位置
+				X: x + barWidth>>1,
+				Y: top,
+			}
 			if !series.Label.Show {
 				continue
 			}
 			text := NewValueLabelFormater(seriesNames, series.Label.Formatter)(i, item.Value, -1)
 			labelStyle := chart.Style{
 				FontColor: theme.GetTextColor(),
-				FontSize:  10,
+				FontSize:  labelFontSize,
 				Font:      opt.Font,
 			}
 			if !series.Label.Color.IsZero() {
@@ -96,6 +105,12 @@ func barChartRender(opt ChartOption, result *basicRenderResult) (*Draw, error) {
 			textBox := r.MeasureText(text)
 			d.text(text, x+(barWidth-textBox.Width())>>1, barMaxHeight-h-5)
 		}
+		markPointRender(d, markPointRenderOption{
+			FillColor: seriesColor,
+			Font:      opt.Font,
+			Points:    points,
+			Series:    &series,
+		})
 	}
 
 	return result.d, nil