feat(增强渲染): 支持Pattern

ofdgo_geom.go

@@ -86,6 +86,30 @@ func (m Matrix) Transform(x, y float64) (float64, float64) {
 	return nx, ny
 }
 
+// Invert 求逆矩阵
+// 返回: Matrix 逆矩阵, bool 是否可逆
+func (m Matrix) Invert() (Matrix, bool) {
+	det := m.a*m.d - m.b*m.c
+	if math.Abs(det) < 1e-9 {
+		return IdentityMatrix, false
+	}
+	return Matrix{
+		a: m.d / det,
+		b: -m.b / det,
+		c: -m.c / det,
+		d: m.a / det,
+		e: (m.c*m.f - m.d*m.e) / det,
+		f: (m.b*m.e - m.a*m.f) / det,
+	}, true
+}
+
+// TranslationMatrix 构造平移矩阵
+// 入参: x X轴偏移, y Y轴偏移
+// 返回: Matrix 平移矩阵
+func TranslationMatrix(x, y float64) Matrix {
+	return Matrix{a: 1, d: 1, e: x, f: y}
+}
+
 // YScale 获取Y轴缩放比例
 // 返回: float64 缩放比例
 func (m Matrix) YScale() float64 {

ofdgo_object.go

@@ -302,6 +302,92 @@ func (a *Appearance) decodePageBlock(d *xml.Decoder, start xml.StartElement) err
 	}
 }
 
+// UnmarshalXML 解析图案单元内容并保留对象顺序
+// 入参: d XML解码器, start 起始节点
+// 返回: error 错误信息
+func (p *PatternContent) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
+	*p = PatternContent{}
+	for {
+		tok, err := d.Token()
+		if err != nil {
+			return err
+		}
+		switch node := tok.(type) {
+		case xml.StartElement:
+			if err := p.decodeObject(d, node); err != nil {
+				return err
+			}
+		case xml.EndElement:
+			if node.Name.Local == start.Name.Local {
+				return nil
+			}
+		}
+	}
+}
+
+// decodeObject 解析图案单元内容子对象
+// 入参: d XML解码器, start 起始节点
+// 返回: error 错误信息
+func (p *PatternContent) decodeObject(d *xml.Decoder, start xml.StartElement) error {
+	switch start.Name.Local {
+	case "TextObject":
+		var obj TextObject
+		if err := d.DecodeElement(&obj, &start); err != nil {
+			return err
+		}
+		p.TextObject = append(p.TextObject, obj)
+		p.Objects = append(p.Objects, GraphicObject{Type: start.Name.Local, TextObject: obj})
+	case "PathObject":
+		var obj PathObject
+		if err := d.DecodeElement(&obj, &start); err != nil {
+			return err
+		}
+		p.PathObject = append(p.PathObject, obj)
+		p.Objects = append(p.Objects, GraphicObject{Type: start.Name.Local, PathObject: obj})
+	case "ImageObject":
+		var obj ImageObject
+		if err := d.DecodeElement(&obj, &start); err != nil {
+			return err
+		}
+		p.ImageObject = append(p.ImageObject, obj)
+		p.Objects = append(p.Objects, GraphicObject{Type: start.Name.Local, ImageObject: obj})
+	case "CompositeGraphicUnit", "CompositeObject":
+		var obj CompositeGraphicUnit
+		if err := d.DecodeElement(&obj, &start); err != nil {
+			return err
+		}
+		p.CompositeGraphicUnit = append(p.CompositeGraphicUnit, obj)
+		p.Objects = append(p.Objects, GraphicObject{Type: start.Name.Local, CompositeGraphicUnit: obj})
+	case "PageBlock":
+		return p.decodePageBlock(d, start)
+	default:
+		return d.Skip()
+	}
+	return nil
+}
+
+// decodePageBlock 解析图案单元内容页块子对象
+// 入参: d XML解码器, start 起始节点
+// 返回: error 错误信息
+func (p *PatternContent) decodePageBlock(d *xml.Decoder, start xml.StartElement) error {
+	for {
+		tok, err := d.Token()
+		if err != nil {
+			return err
+		}
+		switch node := tok.(type) {
+		case xml.StartElement:
+			if err := p.decodeObject(d, node); err != nil {
+				return err
+			}
+		case xml.EndElement:
+			if node.Name.Local == start.Name.Local {
+				return nil
+			}
+		}
+	}
+}
+
 // 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

@@ -103,10 +103,30 @@ type TextObject struct {
 type FillColor struct {
 	Value     string     `xml:"Value,attr"`
 	Alpha     *int       `xml:"Alpha,attr"`
+	Pattern   *Pattern   `xml:"Pattern"`
 	AxialShd  *AxialShd  `xml:"AxialShd"`
 	RadialShd *RadialShd `xml:"RadialShd"`
 }
 
+// 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"`
+}
+
+// PatternContent 图案单元内容
+type PatternContent struct {
+	Objects              []GraphicObject        `xml:"-"`
+	TextObject           []TextObject           `xml:"TextObject"`
+	PathObject           []PathObject           `xml:"PathObject"`
+	ImageObject          []ImageObject          `xml:"ImageObject"`
+	CompositeGraphicUnit []CompositeGraphicUnit `xml:"CompositeGraphicUnit"`
+}
+
 // TextCode 文本内容节点
 type TextCode struct {
 	X      string `xml:"X,attr"`

ofdgo_renderer.go

@@ -551,6 +551,8 @@ func (r *Renderer) renderPath(ctx *canvas.Context, obj PathObject, pageH float64
 	fillColor, strokeColor := colorWithAlpha(defaultFill, obj.Alpha), colorWithAlpha(defaultStroke, obj.Alpha)
 	var fillPaint any = fillColor
 	var strokePaint any = strokeColor
+	var fillPattern *Pattern
+	var fillPatternColor color.Color
 	lineWidth := defaultLW
 	if lineWidth == 0 {
 		lineWidth = 0.353
@@ -566,6 +568,8 @@ func (r *Renderer) renderPath(ctx *canvas.Context, obj PathObject, pageH float64
 			}
 			if dp.FillColor != nil {
 				fillColorNode := withFillAlpha(dp.FillColor, obj.Alpha)
+				fillPattern = fillColorNode.Pattern
+				fillPatternColor = patternColor(fillColorNode)
 				fillColor = parseFillColor(fillColorNode)
 				fillPaint = parseFillPaint(fillColorNode, bx, by, pageH, 0, 0)
 			}
@@ -595,6 +599,8 @@ func (r *Renderer) renderPath(ctx *canvas.Context, obj PathObject, pageH float64
 	}
 	if obj.FillColor != nil {
 		fillColorNode := withFillAlpha(obj.FillColor, obj.Alpha)
+		fillPattern = fillColorNode.Pattern
+		fillPatternColor = patternColor(fillColorNode)
 		fillColor = parseFillColor(fillColorNode)
 		fillPaint = parseFillPaint(fillColorNode, bx, by, pageH, 0, 0)
 	}
@@ -644,7 +650,15 @@ func (r *Renderer) renderPath(ctx *canvas.Context, obj PathObject, pageH float64
 	if fillPaint == nil {
 		fillPaint = fillColor
 	}
-	if shouldFill && fillPaint != nil {
+	if shouldFill && fillPattern != nil {
+		fp := p
+		if clipPath != nil {
+			fp = p.Copy()
+			fp.Close()
+			fp = fp.And(clipPath)
+		}
+		r.renderPattern(ctx, fillPattern, fillPatternColor, pageH, fp, ctm)
+	} else if shouldFill && fillPaint != nil {
 		ctx.SetFill(fillPaint)
 		ctx.SetStrokeColor(canvas.Transparent)
 		fp := p
@@ -691,6 +705,72 @@ func (r *Renderer) renderPath(ctx *canvas.Context, obj PathObject, pageH float64
 	ctx.Pop()
 }
 
+// renderPattern 渲染图案填充
+// 入参: ctx 画布上下文, pattern 图案对象, defaultColor 默认颜色, pageH 页面高度, clip 填充区域, parentCTM 父级CTM
+func (r *Renderer) renderPattern(ctx *canvas.Context, pattern *Pattern, defaultColor color.Color, pageH float64, clip *canvas.Path, parentCTM Matrix) {
+	if pattern == nil || clip == nil || len(pattern.CellContent.Objects) == 0 {
+		return
+	}
+	xStep, yStep := pattern.XStep, pattern.YStep
+	if xStep == 0 {
+		xStep = pattern.Width
+	}
+	if yStep == 0 {
+		yStep = pattern.Height
+	}
+	if xStep <= 0 || yStep <= 0 {
+		return
+	}
+	patternCTM := parentCTM.Multiply(NewMatrix(pattern.CTM))
+	invCTM, ok := patternCTM.Invert()
+	if !ok {
+		return
+	}
+	bounds := clip.FastBounds()
+	points := [][2]float64{
+		{bounds.X0, pageH - bounds.Y0},
+		{bounds.X1, pageH - bounds.Y0},
+		{bounds.X1, pageH - bounds.Y1},
+		{bounds.X0, pageH - bounds.Y1},
+	}
+	minX, maxX := 0.0, 0.0
+	minY, maxY := 0.0, 0.0
+	for i, point := range points {
+		x, y := invCTM.Transform(point[0], point[1])
+		if i == 0 {
+			minX, maxX = x, x
+			minY, maxY = y, y
+			continue
+		}
+		minX = math.Min(minX, x)
+		maxX = math.Max(maxX, x)
+		minY = math.Min(minY, y)
+		maxY = math.Max(maxY, y)
+	}
+	startX := int(math.Floor(minX/xStep)) - 1
+	endX := int(math.Ceil(maxX/xStep)) + 1
+	startY := int(math.Floor(minY/yStep)) - 1
+	endY := int(math.Ceil(maxY/yStep)) + 1
+	for ix := startX; ix <= endX; ix++ {
+		for iy := startY; iy <= endY; iy++ {
+			tileCTM := patternCTM.Multiply(TranslationMatrix(float64(ix)*xStep, float64(iy)*yStep))
+			for _, obj := range pattern.CellContent.Objects {
+				r.renderObject(ctx, obj, pageH, defaultColor, defaultColor, 0, &tileCTM)
+			}
+		}
+	}
+}
+
+// patternColor 获取图案单元默认颜色
+// 入参: fillColor 填充颜色节点
+// 返回: color.Color 默认颜色
+func patternColor(fillColor *FillColor) color.Color {
+	if fillColor == nil || strings.TrimSpace(fillColor.Value) == "" {
+		return nil
+	}
+	return parseColorWithAlpha(fillColor.Value, fillColor.Alpha)
+}
+
 // renderText 渲染文本
 // 入参: ctx 画布上下文, obj 文本对象, pageH 页面高度, defaultFill 默认填充色, defaultStroke 默认描边色, parentCTM 父级CTM
 func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64, defaultFill, defaultStroke color.Color, parentCTM *Matrix) {

ofdgo_text.go

@@ -132,6 +132,9 @@ func parseFillColor(fillColor *FillColor) color.Color {
 	if fillColor == nil {
 		return nil
 	}
+	if fillColor.Pattern != nil {
+		return nil
+	}
 	if strings.TrimSpace(fillColor.Value) != "" {
 		return parseColorWithAlpha(fillColor.Value, fillColor.Alpha)
 	}
@@ -148,6 +151,9 @@ func parseFillPaint(fillColor *FillColor, x, y, pageH, originX, originY float64)
 	if fillColor == nil {
 		return nil
 	}
+	if fillColor.Pattern != nil {
+		return nil
+	}
 	if strings.TrimSpace(fillColor.Value) != "" {
 		return parseColorWithAlpha(fillColor.Value, fillColor.Alpha)
 	}