feat(渲染能力): 修复轴向渐变延伸与裁剪异常，统一文字渐变渲染效果

2026-10-29 08:46:55 +08:00 · 2026-09-09 11:45:33 +08:00
1 parent 62456ce44d
commit 8d26471b1e
@@ -16,6 +16,7 @@ package ofdgo

 import (
 	"image/color"
+	"math"
 	"strconv"
 	"strings"

@@ -154,19 +155,19 @@ func parseFillColor(fillColor *FillColor) color.Color {
 }

 // parseFillPaint 解析填充画刷
-// 入参: fillColor 填充颜色节点, x X坐标, y Y坐标, pageH 页面高度, originX 原点X坐标, originY 原点Y坐标
+// 入参: fillColor 填充颜色节点, x X坐标, y Y坐标, pageH 页面高度
 // 返回: any 填充画刷
-func parseFillPaint(fillColor *FillColor, x, y, pageH, originX, originY float64) any {
+func parseFillPaint(fillColor *FillColor, x, y, pageH float64) any {
 	if fillColor == nil {
 		return nil
 	}
 	if fillColor.Pattern != nil {
 		return nil
 	}
-	if gradient := parseAxialShdGradient(fillColor.AxialShd, fillColor.Alpha, x, y, pageH, originX, originY); gradient != nil {
+	if gradient := parseAxialShdGradient(fillColor.AxialShd, fillColor.Alpha, x, y, pageH); gradient != nil {
 		return gradient
 	}
-	if gradient := parseRadialShdGradient(fillColor.RadialShd, fillColor.Alpha, x, y, pageH, originX, originY); gradient != nil {
+	if gradient := parseRadialShdGradient(fillColor.RadialShd, fillColor.Alpha, x, y, pageH); gradient != nil {
 		return gradient
 	}
 	if fillColor.AxialShd != nil {
@@ -201,16 +202,16 @@ func parseStrokeColor(strokeColor *StrokeColor) color.Color {
 }

 // parseStrokePaint 解析勾边画刷
-// 入参: strokeColor 勾边颜色节点, x X坐标, y Y坐标, pageH 页面高度, originX 原点X坐标, originY 原点Y坐标
+// 入参: strokeColor 勾边颜色节点, x X坐标, y Y坐标, pageH 页面高度
 // 返回: any 勾边画刷
-func parseStrokePaint(strokeColor *StrokeColor, x, y, pageH, originX, originY float64) any {
+func parseStrokePaint(strokeColor *StrokeColor, x, y, pageH float64) any {
 	if strokeColor == nil {
 		return nil
 	}
-	if gradient := parseAxialShdGradient(strokeColor.AxialShd, strokeColor.Alpha, x, y, pageH, originX, originY); gradient != nil {
+	if gradient := parseAxialShdGradient(strokeColor.AxialShd, strokeColor.Alpha, x, y, pageH); gradient != nil {
 		return gradient
 	}
-	if gradient := parseRadialShdGradient(strokeColor.RadialShd, strokeColor.Alpha, x, y, pageH, originX, originY); gradient != nil {
+	if gradient := parseRadialShdGradient(strokeColor.RadialShd, strokeColor.Alpha, x, y, pageH); gradient != nil {
 		return gradient
 	}
 	if strokeColor.AxialShd != nil {
@@ -287,9 +288,9 @@ func parseShdSegments(segments []ShdSegment, alpha *int) canvas.Grad {
 }

 // parseAxialShdGradient 解析轴向渐变
-// 入参: axialShd 轴向渐变节点, alpha 透明度, x X坐标, y Y坐标, pageH 页面高度, originX 原点X坐标, originY 原点Y坐标
+// 入参: axialShd 轴向渐变节点, alpha 透明度, x X坐标, y Y坐标, pageH 页面高度
 // 返回: canvas.Gradient 渐变对象
-func parseAxialShdGradient(axialShd *AxialShd, alpha *int, x, y, pageH, originX, originY float64) canvas.Gradient {
+func parseAxialShdGradient(axialShd *AxialShd, alpha *int, x, y, pageH float64) canvas.Gradient {
 	if axialShd == nil {
 		return nil
 	}
@@ -302,18 +303,51 @@ func parseAxialShdGradient(axialShd *AxialShd, alpha *int, x, y, pageH, originX,
 	if gradient == nil {
 		return nil
 	}
-	startPoint := canvas.Point{X: x + start[0] - originX, Y: pageH - (y + start[1]) - originY}
-	endPoint := canvas.Point{X: x + end[0] - originX, Y: pageH - (y + end[1]) - originY}
+	startPoint := canvas.Point{X: x + start[0], Y: pageH - (y + start[1])}
+	endPoint := canvas.Point{X: x + end[0], Y: pageH - (y + end[1])}
 	if startPoint.Equals(endPoint) {
 		return nil
 	}
 	return gradient.ToLinear(startPoint, endPoint)
 }

+// axialShdClip 获取轴向渐变的延伸裁剪区域
+// 入参: ctx 画布上下文, paint 画刷, shading 轴向渐变节点
+// 返回: *canvas.Path 裁剪区域
+func axialShdClip(ctx *canvas.Context, paint any, shading *AxialShd) *canvas.Path {
+	gradient, ok := paint.(*canvas.LinearGradient)
+	if !ok || shading == nil {
+		return nil
+	}
+	extend, _ := strconv.Atoi(shading.Extend)
+	if extend == 3 {
+		return nil
+	}
+	d := gradient.End.Sub(gradient.Start)
+	axis := canvas.Matrix{{d.X, -d.Y, gradient.Start.X}, {d.Y, d.X, gradient.Start.Y}}
+	origin := ctx.CoordView().Dot(canvas.Point{})
+	view := ctx.CoordSystemView().Mul(ctx.View()).Translate(origin.X, origin.Y).Mul(axis)
+	if view.Det() == 0 {
+		return &canvas.Path{}
+	}
+	width, height := ctx.Size()
+	area := (canvas.Rect{X1: width, Y1: height}).Transform(view.Inv())
+	if extend&1 == 0 {
+		area.X0 = math.Max(area.X0, 0)
+	}
+	if extend&2 == 0 {
+		area.X1 = math.Min(area.X1, 1)
+	}
+	if area.X1 <= area.X0 {
+		return &canvas.Path{}
+	}
+	return area.ToPath().Transform(axis)
+}
+
 // parseRadialShdGradient 解析径向渐变
-// 入参: radialShd 径向渐变节点, alpha 透明度, x X坐标, y Y坐标, pageH 页面高度, originX 原点X坐标, originY 原点Y坐标
+// 入参: radialShd 径向渐变节点, alpha 透明度, x X坐标, y Y坐标, pageH 页面高度
 // 返回: canvas.Gradient 渐变对象
-func parseRadialShdGradient(radialShd *RadialShd, alpha *int, x, y, pageH, originX, originY float64) canvas.Gradient {
+func parseRadialShdGradient(radialShd *RadialShd, alpha *int, x, y, pageH float64) canvas.Gradient {
 	if radialShd == nil || radialShd.EndRadius <= 0 {
 		return nil
 	}
@@ -326,8 +360,8 @@ func parseRadialShdGradient(radialShd *RadialShd, alpha *int, x, y, pageH, origi
 	if gradient == nil {
 		return nil
 	}
-	startPoint := canvas.Point{X: x + start[0] - originX, Y: pageH - (y + start[1]) - originY}
-	endPoint := canvas.Point{X: x + end[0] - originX, Y: pageH - (y + end[1]) - originY}
+	startPoint := canvas.Point{X: x + start[0], Y: pageH - (y + start[1])}
+	endPoint := canvas.Point{X: x + end[0], Y: pageH - (y + end[1])}
 	return gradient.ToRadial(startPoint, radialShd.StartRadius, endPoint, radialShd.EndRadius)
 }

@@ -30,6 +30,8 @@ type pathStyle struct {
 	strokeColor      color.Color
 	fillPaint        any
 	strokePaint      any
+	fillAxialShd     *AxialShd
+	strokeAxialShd   *AxialShd
 	fillPattern      *Pattern
 	fillPatternColor color.Color
 	lineWidth        float64
@@ -65,7 +67,8 @@ func (s *pathStyle) applyFillColor(fill *FillColor, bx, by, pageH float64, alpha
 	s.fillPattern = fillColorNode.Pattern
 	s.fillPatternColor = patternColor(fillColorNode)
 	s.fillColor = parseFillColor(fillColorNode)
-	s.fillPaint = parseFillPaint(fillColorNode, bx, by, pageH, 0, 0)
+	s.fillPaint = parseFillPaint(fillColorNode, bx, by, pageH)
+	s.fillAxialShd = fillColorNode.AxialShd
 }

 // applyStrokeColor 应用描边颜色
@@ -73,7 +76,8 @@ func (s *pathStyle) applyFillColor(fill *FillColor, bx, by, pageH float64, alpha
 func (s *pathStyle) applyStrokeColor(stroke *StrokeColor, bx, by, pageH float64, alpha *int) {
 	strokeColorNode := withStrokeAlpha(stroke, alpha)
 	s.strokeColor = parseStrokeColor(strokeColorNode)
-	s.strokePaint = parseStrokePaint(strokeColorNode, bx, by, pageH, 0, 0)
+	s.strokePaint = parseStrokePaint(strokeColorNode, bx, by, pageH)
+	s.strokeAxialShd = strokeColorNode.AxialShd
 }

 // pathLineCap 转换线帽样式
@@ -211,18 +215,19 @@ func (r *Renderer) renderPath(ctx *canvas.Context, obj PathObject, pageH float64
 		style.fillPaint = style.fillColor
 	}
 	if shouldFill {
+		fillClip := intersectClipPath(clipPath, axialShdClip(ctx, style.fillPaint, style.fillAxialShd))
 		fp := p
 		fillRule := canvas.NonZero
 		if obj.Rule == "Even-Odd" {
 			fillRule = canvas.EvenOdd
-			if clipPath != nil || style.fillPattern != nil {
+			if fillClip != nil || style.fillPattern != nil {
 				fp = fp.Settle(fillRule)
 			}
 		}
-		if clipPath != nil {
+		if fillClip != nil {
 			fp = fp.Copy()
 			fp.Close()
-			fp = applyClipPath(fp, clipPath)
+			fp = applyClipPath(fp, fillClip)
 		}
 		if style.fillPattern != nil {
 			r.renderPattern(ctx, style.fillPattern, style.fillPatternColor, pageH, fp, ctm, bx, by)
@@ -253,13 +258,14 @@ func (r *Renderer) renderPath(ctx *canvas.Context, obj PathObject, pageH float64
 		if len(style.dashPattern) > 0 {
 			ctx.SetDashes(style.dashOffset, style.dashPattern...)
 		}
-		if clipPath != nil {
+		strokeClip := intersectClipPath(clipPath, axialShdClip(ctx, style.strokePaint, style.strokeAxialShd))
+		if strokeClip != nil {
 			sp := p.Copy()
 			if len(style.dashPattern) > 0 {
 				sp = sp.Dash(style.dashOffset, style.dashPattern...)
 			}
 			sp = sp.Stroke(style.lineWidth, style.lineCap, style.lineJoin, canvas.Tolerance)
-			sp = applyClipPath(sp, clipPath)
+			sp = applyClipPath(sp, strokeClip)
 			ctx.SetFill(style.strokePaint)
 			ctx.SetStrokeColor(canvas.Transparent)
 			ctx.DrawPath(0, 0, sp)
@@ -543,7 +549,6 @@ func applyClipPath(path, clip *canvas.Path) *canvas.Path {
 		if pathRect, ok := rectangularPath(path); ok {
 			return pathRect.And(rect).ToPath()
 		}
-		return path.Flatten(canvas.Tolerance).Clip(rect.X0, rect.Y0, rect.X1, rect.Y1)
 	}
 	return path.And(clip)
 }
@@ -80,17 +80,22 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 	if dp != nil && dp.FillColor != nil {
 		fillColorNode = withFillAlpha(dp.FillColor, obj.Alpha)
 		fillColor = parseFillColor(fillColorNode)
-		fillPaint = parseFillPaint(fillColorNode, bx, by, pageH, 0, 0)
+		fillPaint = parseFillPaint(fillColorNode, bx, by, pageH)
 	}
 	if obj.FillColor != nil {
 		fillColorNode = withFillAlpha(obj.FillColor, obj.Alpha)
 		fillColor = parseFillColor(fillColorNode)
-		fillPaint = parseFillPaint(fillColorNode, bx, by, pageH, 0, 0)
+		fillPaint = parseFillPaint(fillColorNode, bx, by, pageH)
 	}
 	if fillPaint == nil {
 		fillPaint = fillColor
 	}
+	fillClip := clipPath
+	if fillColorNode != nil {
+		fillClip = intersectClipPath(fillClip, axialShdClip(ctx, fillPaint, fillColorNode.AxialShd))
+	}
 	strokeStyle := newPathStyle(nil, defaultStroke, 0, obj.Alpha)
+	strokeClip := clipPath
 	if shouldStroke {
 		if dp != nil {
 			strokeStyle.applyDrawParam(dp, bx, by, pageH, obj.Alpha)
@@ -105,6 +110,7 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 			strokeStyle.strokePaint = colorWithAlpha(canvas.Black, obj.Alpha)
 		}
 		strokeStyle.scale(ctm)
+		strokeClip = intersectClipPath(strokeClip, axialShdClip(ctx, strokeStyle.strokePaint, strokeStyle.strokeAxialShd))
 	}
 	fontStyle := canvas.FontRegular
 	weight := obj.Weight
@@ -144,7 +150,7 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 	face := ff.Face(sizePt, fillPaint, fontStyle, canvas.FontNormal)
 	glyphTransforms := r.textObjectGlyphTransforms(fontID, obj)
 	hasUnderline := strings.Contains(obj.Decoration, "Underline")
-	useGlyphFillPaint := fillColorNode != nil && fillColorNode.AxialShd != nil
+	_, axialFill := fillPaint.(*canvas.LinearGradient)
 	verticalAdvance := (obj.ReadDirection-obj.CharDirection)%180 != 0
 	advanceX, advanceY := 1.0, 0.0
 	switch obj.ReadDirection {
@@ -168,7 +174,7 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 		}
 		dxs, dys := parseFloats(tc.DeltaX), parseFloats(tc.DeltaY)
 		xs, ys := parseFloats(tc.X), parseFloats(tc.Y)
-		drawAsPath := embeddedFont || textCodePositioned(tc, xs, ys) || clipPath != nil || shouldStroke
+		drawAsPath := embeddedFont || textCodePositioned(tc, xs, ys) || fillClip != nil || axialFill || shouldStroke
 		cx, cy := 0.0, 0.0
 		previousAdvance := 0.0
 		if len(xs) > 0 {
@@ -219,10 +225,6 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 				canvasX, canvasY = tx+bx, pageH-(ty+by)
 			}
 			textWidth := glyphWidth * hScale
-			glyphFillPaint := fillPaint
-			if useGlyphFillPaint {
-				glyphFillPaint = parseFillPaint(fillColorNode, bx, by, pageH, canvasX, canvasY)
-			}
 			advanceLimit := 0.0
 			if obj.CharDirection == 0 {
 				advanceLimit = textGlyphAdvanceLimit(dxs, dys, xs, i, len(glyphs), cx)
@@ -237,10 +239,10 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 					transform = transform.Mul(glyphMatrix)
 				}
 				path := glyphPath.Copy().Transform(transform.Scale(scaleX, 1))
-				if shouldFill && glyphFillPaint != nil {
-					ctx.SetFill(glyphFillPaint)
+				if shouldFill && fillPaint != nil {
+					ctx.SetFill(fillPaint)
 					ctx.SetStrokeColor(canvas.Transparent)
-					ctx.DrawPath(0, 0, applyClipPath(path.Copy(), clipPath))
+					ctx.DrawPath(0, 0, applyClipPath(path.Copy(), fillClip))
 				}
 				if len(strokeStyle.dashPattern) > 0 {
 					path = path.Dash(strokeStyle.dashOffset, strokeStyle.dashPattern...)
@@ -248,7 +250,7 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 				path = path.Stroke(strokeStyle.lineWidth, strokeStyle.lineCap, strokeStyle.lineJoin, canvas.Tolerance)
 				ctx.SetFill(strokeStyle.strokePaint)
 				ctx.SetStrokeColor(canvas.Transparent)
-				ctx.DrawPath(0, 0, applyClipPath(path, clipPath))
+				ctx.DrawPath(0, 0, applyClipPath(path, strokeClip))
 				if hasUnderline {
 					underline := &canvas.Path{}
 					underline.MoveTo(0, -sizeMM*0.1)
@@ -261,9 +263,9 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 				}
 				continue
 			}
-			if glyphFillPaint != nil {
-				ctx.SetFill(glyphFillPaint)
-				if clipPath != nil {
+			if fillPaint != nil {
+				ctx.SetFill(fillPaint)
+				if fillClip != nil || axialFill {
 					scaleX := hScale
 					if advanceLimit > 0 && glyphWidth*scaleX > advanceLimit {
 						scaleX = advanceLimit / glyphWidth
@@ -273,7 +275,7 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 					if useTextMatrix {
 						textTransform = textTransform.Mul(glyphMatrix)
 					}
-					glyphPath = applyClipPath(glyphPath.Copy().Transform(textTransform.Scale(scaleX, 1)), clipPath)
+					glyphPath = applyClipPath(glyphPath.Copy().Transform(textTransform.Scale(scaleX, 1)), fillClip)
 					ctx.DrawPath(0, 0, glyphPath)
 					if hasUnderline {
 						uw := sizeMM * 0.05
@@ -313,11 +315,7 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 							ctx.Scale(hScale, 1)
 							x, y = 0, 0
 						}
-						textFace := face
-						if useGlyphFillPaint {
-							textFace = ff.Face(sizePt, glyphFillPaint, fontStyle, canvas.FontNormal)
-						}
-						text := canvas.NewTextLine(textFace, str, canvas.Left)
+						text := canvas.NewTextLine(face, str, canvas.Left)
 						ctx.DrawText(x, y, text)
 						if scaled {
 							ctx.Pop()