diff --git a/pie_chart.go b/pie_chart.go index 0075ffc..b4714ac 100644 --- a/pie_chart.go +++ b/pie_chart.go @@ -101,8 +101,23 @@ func (p *pieChart) render(result *defaultRenderResult, seriesList SeriesList) (B theme := opt.Theme currentValue := float64(0) - prevEndX := 0 - prevEndY := 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 + } + } + return false + } + for index, v := range values { seriesPainter.OverrideDrawingStyle(Style{ StrokeWidth: 1, @@ -134,13 +149,17 @@ func (p *pieChart) render(result *defaultRenderResult, seriesList SeriesList) (B 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 - if index != 0 && - math.Abs(float64(endx-prevEndX)) < labelFontSize && - math.Abs(float64(endy-prevEndY)) < labelFontSize { + // 最多只尝试5次 + for i := 0; i < 5; i++ { + if !isOverride(endx, endy) { + break + } endy -= (labelFontSize << 1) } - prevEndX = endx - prevEndY = endy + prevPoints = append(prevPoints, Point{ + X: endx, + Y: endy, + }) seriesPainter.MoveTo(startx, starty) seriesPainter.LineTo(endx, endy)