feat(渲染能力): 修正渐变色标位置，完善底纹翻转与边界变换

ofdgo_object.go

@@ -237,6 +237,15 @@ func (p *PatternContent) decodeObject(d *xml.Decoder, start xml.StartElement) er
 	return d.Skip()
 }
 
+// UnmarshalXML 解析渐变分段并保留位置的缺省状态
+// 入参: d XML解码器, start 起始节点
+// 返回: error 错误信息
+func (s *ShdSegment) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
+	type segment ShdSegment
+	*s = ShdSegment{positionMissing: attrValue(start, "Position") == ""}
+	return d.DecodeElement((*segment)(s), &start)
+}
+
 // attrValue 获取XML属性值
 // 入参: start 起始节点, name 属性名
 // 返回: string 属性值

ofdgo_page.go

@@ -114,12 +114,13 @@ type FillColor struct {
 
 // Pattern 图案填充
 type Pattern struct {
-	Width       float64        `xml:"Width,attr"`
-	Height      float64        `xml:"Height,attr"`
-	XStep       float64        `xml:"XStep,attr"`
-	YStep       float64        `xml:"YStep,attr"`
-	CTM         string         `xml:"CTM,attr"`
-	CellContent PatternContent `xml:"CellContent"`
+	Width         float64        `xml:"Width,attr"`
+	Height        float64        `xml:"Height,attr"`
+	XStep         float64        `xml:"XStep,attr"`
+	YStep         float64        `xml:"YStep,attr"`
+	ReflectMethod string         `xml:"ReflectMethod,attr"`
+	CTM           string         `xml:"CTM,attr"`
+	CellContent   PatternContent `xml:"CellContent"`
 }
 
 // PatternContent 图案单元内容
@@ -201,8 +202,9 @@ type RadialShd struct {
 
 // ShdSegment 渐变分段
 type ShdSegment struct {
-	Position float64  `xml:"Position,attr"`
-	Color    ShdColor `xml:"Color"`
+	Position        float64  `xml:"Position,attr"`
+	Color           ShdColor `xml:"Color"`
+	positionMissing bool
 }
 
 // ShdColor 渐变颜色

ofdgo_paint.go

@@ -257,7 +257,26 @@ func parseShdColor(segments []ShdSegment, alpha *int) color.Color {
 // 返回: canvas.Grad 渐变分段
 func parseShdSegments(segments []ShdSegment, alpha *int) canvas.Grad {
 	gradient := canvas.NewGradient()
-	for _, segment := range segments {
+	position, step := 0.0, 0.0
+	for i, segment := range segments {
+		if !segment.positionMissing {
+			position = segment.Position
+		} else if i == len(segments)-1 {
+			position = 1
+		}
+		if i == 0 || !segment.positionMissing {
+			next := i + 1
+			for next < len(segments)-1 && segments[next].positionMissing {
+				next++
+			}
+			end := 1.0
+			if next < len(segments) && !segments[next].positionMissing {
+				end = segments[next].Position
+			}
+			step = (end - position) / float64(next-i)
+		}
+		offset := position
+		position += step
 		if strings.TrimSpace(segment.Color.Value) == "" {
 			continue
 		}
@@ -265,7 +284,7 @@ func parseShdSegments(segments []ShdSegment, alpha *int) canvas.Grad {
 		if segmentAlpha == nil {
 			segmentAlpha = segment.Color.Alpha
 		}
-		gradient.Add(segment.Position, colorToRGBA(parseColorWithAlpha(segment.Color.Value, segmentAlpha)))
+		gradient.Add(offset, colorToRGBA(parseColorWithAlpha(segment.Color.Value, segmentAlpha)))
 	}
 	if len(gradient) == 0 {
 		return nil

ofdgo_renderer_path.go

@@ -188,10 +188,20 @@ func (r *Renderer) renderPath(ctx *canvas.Context, obj PathObject, pageH float64
 	}
 	style.applyPathObject(obj, bx, by, pageH)
 	style.scale(ctm)
-	p := r.buildPath(obj, pageH, ctm, boundaryInCTM)
-	if rectPath := r.buildTinyFillRectPath(obj, pageH, ctm, bx, by); rectPath != nil {
+	pathCTM := ctm
+	if boundaryInCTM {
+		pathCTM = localCTM
+	}
+	p := r.buildPath(obj, pageH, pathCTM, false)
+	if rectPath := r.buildTinyFillRectPath(obj, pageH, pathCTM, bx, by); rectPath != nil {
 		p = rectPath
 	}
+	if boundaryInCTM && parentCTM != nil {
+		p = p.Transform(canvas.Matrix{
+			{parentCTM.a, -parentCTM.c, parentCTM.c*pageH + parentCTM.e},
+			{-parentCTM.b, parentCTM.d, pageH*(1-parentCTM.d) - parentCTM.f},
+		})
+	}
 	clipPath := intersectClipPath(parentClip, r.buildObjectClipPath(obj.Clips, pageH, bx, by, localCTM, parentCTM, boundaryInCTM))
 	shouldFill := false
 	if obj.Fill != nil {
@@ -309,8 +319,14 @@ func (r *Renderer) renderPattern(ctx *canvas.Context, pattern *Pattern, defaultC
 	for ix := startX; ix <= endX; ix++ {
 		for iy := startY; iy <= endY; iy++ {
 			tileCTM := patternCTM.Multiply(TranslationMatrix(float64(ix)*xStep, float64(iy)*yStep))
+			if ix%2 != 0 && (pattern.ReflectMethod == "Column" || pattern.ReflectMethod == "RowAndColumn") {
+				tileCTM = tileCTM.Multiply(Matrix{a: -1, d: 1, e: pattern.Width})
+			}
+			if iy%2 != 0 && (pattern.ReflectMethod == "Row" || pattern.ReflectMethod == "RowAndColumn") {
+				tileCTM = tileCTM.Multiply(Matrix{a: 1, d: -1, f: pattern.Height})
+			}
 			for _, obj := range pattern.CellContent.Objects {
-				r.renderObject(ctx, obj, pageH, defaultColor, defaultColor, 0, &tileCTM, false, clip)
+				r.renderObject(ctx, obj, pageH, defaultColor, defaultColor, 0, &tileCTM, true, clip)
 			}
 		}
 	}