feat: support text rotation for series label, #38

axis.go

@@ -75,6 +75,10 @@ type AxisOption struct {
 	SplitLineShow bool
 	// The color of split line
 	SplitLineColor Color
+	// The text rotation of label
+	TextRotation float64
+	// The offset of label
+	LabelOffset Box
 	Unit        int
 }
 
@@ -153,7 +157,15 @@ func (a *axisPainter) Render() (Box, error) {
 	}
 	top.SetDrawingStyle(style).OverrideTextStyle(style)
 
+	isTextRotation := opt.TextRotation != 0
+
+	if isTextRotation {
+		top.SetTextRotation(opt.TextRotation)
+	}
 	textMaxWidth, textMaxHeight := top.MeasureTextMaxWidthHeight(data)
+	if isTextRotation {
+		top.ClearTextRotation()
+	}
 
 	// 增加30px来计算文本展示区域
 	textFillWidth := float64(textMaxWidth + 20)
@@ -266,6 +278,8 @@ func (a *axisPainter) Render() (Box, error) {
 		Orient:       orient,
 		Unit:         unit,
 		Position:     labelPosition,
+		TextRotation: opt.TextRotation,
+		Offset:       opt.LabelOffset,
 	})
 	// 显示辅助线
 	if opt.SplitLineShow {

painter.go

@@ -71,6 +71,9 @@ type MultiTextOption struct {
 	Unit     int
 	Position string
 	Align    string
+	// The text rotation of label
+	TextRotation float64
+	Offset       Box
 }
 
 type GridOption struct {
@@ -682,10 +685,13 @@ func (p *Painter) MultiText(opt MultiTextOption) *Painter {
 	} else {
 		values = autoDivide(width, count)
 	}
+	offset := opt.Offset
 	for index, text := range opt.TextList {
 		if opt.Unit != 0 && index%opt.Unit != showIndex {
 			continue
 		}
+		p.ClearTextRotation()
+		p.SetTextRotation(opt.TextRotation)
 		box := p.MeasureText(text)
 		start := values[index]
 		if positionCenter {
@@ -706,8 +712,11 @@ func (p *Painter) MultiText(opt MultiTextOption) *Painter {
 		} else {
 			x = start - box.Width()>>1
 		}
+		x += offset.Left
+		y += offset.Top
 		p.Text(text, x, y)
 	}
+	p.ClearTextRotation()
 	return p
 }
 

xaxis.go

@@ -48,6 +48,10 @@ type XAxisOption struct {
 	StrokeColor Color
 	// The color of label
 	FontColor Color
+	// The text rotation of label
+	TextRotation float64
+	// The offset of label
+	LabelOffset Box
 	isValueAxis bool
 }
 
@@ -81,6 +85,8 @@ func (opt *XAxisOption) ToAxisOption() AxisOption {
 		FontColor:      opt.FontColor,
 		Show:           opt.Show,
 		SplitLineColor: opt.Theme.GetAxisSplitLineColor(),
+		TextRotation:   opt.TextRotation,
+		LabelOffset:    opt.LabelOffset,
 	}
 	if opt.isValueAxis {
 		axisOpt.SplitLineShow = true