feat(文件归并): 归并同类文件清理辅助代码

ofdgo_renderer_page_canvas.go

@@ -18,6 +18,13 @@ import (
 	"github.com/tdewolff/canvas"
 )
 
+// 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
+}
+
 // renderCanvasPage 渲染特定页面内容
 // 入参: page 页面内容
 // 返回: *canvas.Canvas 画布实例, error 错误信息
@@ -74,3 +81,98 @@ func (r *Renderer) renderCanvasPageToContext(ctx *canvas.Context, page *PageCont
 	}
 	return nil
 }
+
+// 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 {
+	if state.Hidden {
+		return nil
+	}
+	clip, err := geometryToCanvasPath(state.Clip)
+	if err != nil {
+		return err
+	}
+	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
+}
+
+// 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
+}
+
+// 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()
+	})
+	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)
+	}
+}
+
+// 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
+	}
+}