feat(后端结构): 完善多后端解耦，清理遗留代码

2026-10-29 16:44:23 +08:00 · 2026-09-23 17:20:25 +08:00
1 parent 77ffbe6a72
commit c15547f0d2
@@ -16,159 +16,101 @@ package ofdgo

 import "github.com/tdewolff/canvas"

-// renderAnnotations 渲染页面注释外观
-// 入参: ctx 画布上下文, pageID 页面ID, pageH 页面高度
-func (r *Renderer) renderAnnotations(ctx *canvas.Context, pageID string, pageH float64) {
-	for _, annot := range r.Reader.Annots[pageID] {
-		if annot.Visible != nil && !*annot.Visible {
-			continue
-		}
-		groups, grouped := ctx.Renderer.(interface {
-			beginAnnotation(string) bool
-			endObject()
-		})
-		grouped = grouped && groups.beginAnnotation(annot.ID)
-		box, _ := ParseBox(annot.Appearance.Boundary)
-		ctm := Matrix{a: 1, d: 1, e: box.X, f: box.Y}
-		for i := range annot.Appearance.Objects {
-			r.renderObject(ctx, &annot.Appearance.Objects[i], pageH, nil, &ctm, false, nil)
-		}
-		if grouped {
-			groups.endObject()
-		}
-	}
+// canvasPageVisitor 将公共页面遍历结果交给Canvas解释器
+type canvasPageVisitor struct {
+	renderer *Renderer
+	context  *canvas.Context
+	height   float64
 }

-// renderTemplate 渲染模板
-// 入参: ctx 画布上下文, templateID 模板ID, pageH 页面高度
-func (r *Renderer) renderTemplate(ctx *canvas.Context, templateID string, pageH float64) {
-	tplContent := r.loadTemplate(templateID)
-	if tplContent == nil {
-		return
+// DrawObject 绘制叶子对象，转换页面坐标裁剪
+// 入参: object 源对象, state 继承状态
+// 返回: error 绘制错误
+func (v *canvasPageVisitor) DrawObject(object *GraphicObject, state RenderState) error {
+	clip, err := geometryToCanvasPath(state.Clip)
+	if err != nil {
+		return err
 	}
-	for order := range 3 {
-		r.renderLayers(ctx, tplContent.Content.Layer, pageH, order)
+	if clip != nil {
+		clip = clip.Translate(0, v.height)
 	}
+	switch object.Type {
+	case "TextObject":
+		v.renderer.renderText(v.context, object.TextObject, v.height, state.Defaults, state.Parent, state.BoundaryInCTM, clip)
+	case "PathObject":
+		v.renderer.renderPath(v.context, object.PathObject, v.height, state.Defaults, state.Parent, state.BoundaryInCTM, clip)
+	case "ImageObject":
+		v.renderer.renderImage(v.context, object.ImageObject, v.height, state.Parent, state.BoundaryInCTM, clip)
+	}
+	return v.renderer.renderError
 }

-// renderLayers 按原顺序渲染指定类型的图层
-// 入参: ctx 画布上下文, layers 图层列表, pageH 页面高度, order 图层类型顺序
-func (r *Renderer) renderLayers(ctx *canvas.Context, layers []Layer, pageH float64, order int) {
-	for _, layer := range layers {
-		if layerOrder(layer.Type) == order {
-			r.renderLayer(ctx, layer, pageH, nil, nil)
-		}
-	}
+// DrawStamp 绘制签章外观
+// 入参: stamp 签章
+// 返回: error 绘制错误
+func (v *canvasPageVisitor) DrawStamp(stamp Stamp) error {
+	v.renderer.renderStamp(v.context, stamp, v.height)
+	return v.renderer.renderError
 }

-// renderLayer 渲染图层
-// 入参: ctx 画布上下文, layer 图层对象, pageH 页面高度, defaults 默认绘制参数, parentCTM 父级CTM
-func (r *Renderer) renderLayer(ctx *canvas.Context, layer Layer, pageH float64, defaults *DrawParam, parentCTM *Matrix) {
-	defaults = r.drawParamDefaults(layer.DrawParam, defaults)
-	if len(layer.Objects) > 0 {
-		for i := range layer.Objects {
-			r.renderObject(ctx, &layer.Objects[i], pageH, defaults, parentCTM, false, nil)
-		}
-		return
-	}
-	for _, textObj := range layer.TextObject {
-		r.renderText(ctx, textObj, pageH, defaults, parentCTM, false, nil)
-	}
-	for _, pathObj := range layer.PathObject {
-		r.renderPath(ctx, pathObj, pageH, defaults, parentCTM, false, nil)
-	}
-	for _, imgObj := range layer.ImageObject {
-		r.renderImage(ctx, imgObj, pageH, parentCTM, false, nil)
-	}
-	for _, cgu := range layer.CompositeGraphicUnit {
-		r.renderCompositeGraphicUnit(ctx, cgu, pageH, defaults, parentCTM, false, nil)
-	}
-}
-
-// renderCompositeGraphicUnit 渲染复合图元
-// 入参: ctx 画布上下文, cgu 复合图元对象, pageH 页面高度, defaults 默认绘制参数, parentCTM 父级CTM, boundaryInCTM 边界是否参与CTM变换, parentClip 父级裁剪路径
-func (r *Renderer) renderCompositeGraphicUnit(ctx *canvas.Context, cgu CompositeGraphicUnit, pageH float64, defaults *DrawParam, parentCTM *Matrix, boundaryInCTM bool, parentClip *canvas.Path) {
-	if cgu.Visible != nil && !*cgu.Visible {
-		if groups, ok := ctx.Renderer.(interface{ skipObjects(int) }); ok {
-			count, ref, seen := len(cgu.Objects), cgu.ResourceID, make(map[string]bool)
-			for ref != "" && !seen[ref] {
-				seen[ref] = true
-				unit := r.CompositeGraphicUnits[ref]
-				if unit == nil {
-					break
-				}
-				count, ref = count+len(unit.Objects), unit.ResourceID
-			}
-			groups.skipObjects(count)
-		}
-		return
-	}
-	ctx.Push()
-	box, _ := ParseBox(cgu.Boundary)
-	boundaryCTM := TranslationMatrix(box.X, box.Y)
-	if parentCTM != nil {
-		boundaryCTM = parentCTM.Multiply(boundaryCTM)
-	}
-	currentCTM := boundaryCTM.Multiply(NewMatrix(cgu.CTM))
-	clips, clipCTM := cgu.Clips, currentCTM
-	if clips != nil && clips.TransFlag != nil && !*clips.TransFlag {
-		clipCopy := *clips
-		clipCopy.TransFlag = nil
-		clips, clipCTM = &clipCopy, boundaryCTM
-	}
-	clipPath := intersectClipPath(parentClip, r.buildClipPath(clips, pageH, 0, 0, clipCTM))
-	defaults = r.drawParamDefaults(cgu.DrawParam, defaults)
-	if cgu.ResourceID != "" {
-		if ref, ok := r.CompositeGraphicUnits[cgu.ResourceID]; ok {
-			refCopy := *ref
-			refCopy.Alpha = mergeAlpha(refCopy.Alpha, cgu.Alpha)
-			r.renderCompositeGraphicUnit(ctx, refCopy, pageH, defaults, &currentCTM, true, clipPath)
-		}
-	}
-	if len(cgu.Objects) > 0 {
-		for _, obj := range cgu.Objects {
-			obj = mergeGraphicObjectAlpha(obj, cgu.Alpha)
-			r.renderObject(ctx, &obj, pageH, defaults, &currentCTM, boundaryInCTM, clipPath)
-		}
-		ctx.Pop()
-		return
-	}
-	for _, imgObj := range cgu.ImageObject {
-		imgObj.Alpha = mergeAlpha(imgObj.Alpha, cgu.Alpha)
-		r.renderImage(ctx, imgObj, pageH, &currentCTM, boundaryInCTM, clipPath)
-	}
-	for _, pathObj := range cgu.PathObject {
-		pathObj.Alpha = mergeAlpha(pathObj.Alpha, cgu.Alpha)
-		r.renderPath(ctx, pathObj, pageH, defaults, &currentCTM, boundaryInCTM, clipPath)
-	}
-	for _, textObj := range cgu.TextObject {
-		textObj.Alpha = mergeAlpha(textObj.Alpha, cgu.Alpha)
-		r.renderText(ctx, textObj, pageH, defaults, &currentCTM, boundaryInCTM, clipPath)
-	}
-	for _, subCgu := range cgu.CompositeGraphicUnit {
-		subCgu.Alpha = mergeAlpha(subCgu.Alpha, cgu.Alpha)
-		r.renderCompositeGraphicUnit(ctx, subCgu, pageH, defaults, &currentCTM, boundaryInCTM, clipPath)
-	}
-	ctx.Pop()
-}
-
-// renderObject 渲染图形对象
-// 入参: ctx 画布上下文, obj 图形对象, pageH 页面高度, defaults 默认绘制参数, parentCTM 父级CTM, boundaryInCTM 边界是否参与CTM变换, parentClip 父级裁剪路径
-func (r *Renderer) renderObject(ctx *canvas.Context, obj *GraphicObject, pageH float64, defaults *DrawParam, parentCTM *Matrix, boundaryInCTM bool, parentClip *canvas.Path) {
-	if groups, ok := ctx.Renderer.(interface {
+// BeginObject 开始可编辑对象分组
+// 入参: object 源对象
+// 返回: bool 是否建立分组
+func (v *canvasPageVisitor) BeginObject(object *GraphicObject) bool {
+	groups, ok := v.context.Renderer.(interface {
 		beginObject(*GraphicObject) bool
 		endObject()
-	}); ok && groups.beginObject(obj) {
-		defer groups.endObject()
+	})
+	return ok && groups.beginObject(object)
+}
+
+// BeginAnnotation 开始注解分组
+// 入参: id 注解标识
+// 返回: bool 是否建立分组
+func (v *canvasPageVisitor) BeginAnnotation(id string) bool {
+	groups, ok := v.context.Renderer.(interface {
+		beginAnnotation(string) bool
+		endObject()
+	})
+	return ok && groups.beginAnnotation(id)
+}
+
+// EndObject 结束对象或注解分组
+func (v *canvasPageVisitor) EndObject() {
+	v.context.Renderer.(interface{ endObject() }).endObject()
+}
+
+// SkipObjects 保留不可见对象的编号
+// 入参: count 对象数量
+func (v *canvasPageVisitor) SkipObjects(count int) {
+	if groups, ok := v.context.Renderer.(interface{ skipObjects(int) }); ok {
+		groups.skipObjects(count)
 	}
-	switch obj.Type {
-	case "TextObject":
-		r.renderText(ctx, obj.TextObject, pageH, defaults, parentCTM, boundaryInCTM, parentClip)
-	case "PathObject":
-		r.renderPath(ctx, obj.PathObject, pageH, defaults, parentCTM, boundaryInCTM, parentClip)
-	case "ImageObject":
-		r.renderImage(ctx, obj.ImageObject, pageH, parentCTM, boundaryInCTM, parentClip)
-	case "CompositeGraphicUnit", "CompositeObject":
-		r.renderCompositeGraphicUnit(ctx, obj.CompositeGraphicUnit, pageH, defaults, parentCTM, boundaryInCTM, parentClip)
+}
+
+// canvasRenderState 将Canvas裁剪转换为公共页面状态
+// 入参: pageH 页面高度, defaults 默认样式, parentCTM 父变换, boundaryInCTM 边界是否参与变换, parentClip 父裁剪
+// 返回: RenderState 公共页面状态
+func canvasRenderState(pageH float64, defaults *DrawParam, parentCTM *Matrix, boundaryInCTM bool, parentClip *canvas.Path) RenderState {
+	var clip *GeometryPath
+	if parentClip != nil {
+		clip = geometryFromCanvasPath(parentClip.Copy().Translate(0, -pageH))
+	}
+	return RenderState{Defaults: defaults, Parent: parentCTM, BoundaryInCTM: boundaryInCTM, Clip: clip}
+}
+
+// renderCompositeGraphicUnit 通过公共遍历绘制复合图元
+// 入参: ctx 画布上下文, cgu 复合图元, pageH 页面高度, defaults 默认样式, parentCTM 父变换, boundaryInCTM 边界是否参与变换, parentClip 父裁剪
+func (r *Renderer) renderCompositeGraphicUnit(ctx *canvas.Context, cgu CompositeGraphicUnit, pageH float64, defaults *DrawParam, parentCTM *Matrix, boundaryInCTM bool, parentClip *canvas.Path) {
+	if err := r.walkComposite(cgu, canvasRenderState(pageH, defaults, parentCTM, boundaryInCTM, parentClip), &canvasPageVisitor{r, ctx, pageH}, nil); err != nil {
+		r.renderError = err
+	}
+}
+
+// renderObject 通过公共遍历绘制图形对象
+// 入参: ctx 画布上下文, obj 图形对象, pageH 页面高度, defaults 默认样式, parentCTM 父变换, boundaryInCTM 边界是否参与变换, parentClip 父裁剪
+func (r *Renderer) renderObject(ctx *canvas.Context, obj *GraphicObject, pageH float64, defaults *DrawParam, parentCTM *Matrix, boundaryInCTM bool, parentClip *canvas.Path) {
+	if err := r.WalkObject(obj, canvasRenderState(pageH, defaults, parentCTM, boundaryInCTM, parentClip), &canvasPageVisitor{r, ctx, pageH}); err != nil {
+		r.renderError = err
 	}
 }