mirror of
https://github.com/xiaoqidun/ofdgo.git
synced 2026-10-29 17:27:08 +08:00
280 lines
9.1 KiB
Go
280 lines
9.1 KiB
Go
// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package ofdgo
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import "github.com/tdewolff/canvas"
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// renderAnnotations 渲染页面注释外观
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// 入参: ctx 画布上下文, pageID 页面ID, pageH 页面高度
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func (r *Renderer) renderAnnotations(ctx *canvas.Context, pageID string, pageH float64) {
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for _, annot := range r.Reader.Annots[pageID] {
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if annot.Visible != nil && !*annot.Visible {
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continue
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}
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box, _ := ParseBox(annot.Appearance.Boundary)
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ctm := Matrix{a: 1, d: 1, e: box.X, f: box.Y}
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for _, obj := range annot.Appearance.Objects {
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r.renderObject(ctx, obj, pageH, nil, &ctm, false, nil)
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}
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}
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}
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// renderTemplate 渲染模板
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// 入参: ctx 画布上下文, templateID 模板ID, pageH 页面高度
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func (r *Renderer) renderTemplate(ctx *canvas.Context, templateID string, pageH float64) {
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tplContent := r.templatePageCache[templateID]
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if tplContent == nil {
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var tplPage *TemplatePage
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for i := range r.Reader.doc.CommonData.TemplatePage {
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if r.Reader.doc.CommonData.TemplatePage[i].ID == templateID {
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tplPage = &r.Reader.doc.CommonData.TemplatePage[i]
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break
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}
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}
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if tplPage == nil {
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return
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}
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var err error
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tplContent, err = r.Reader.PageContent(Page{BaseLoc: tplPage.BaseLoc})
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if err != nil {
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return
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}
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r.templatePageCache[templateID] = tplContent
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}
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for order := range 3 {
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r.renderLayers(ctx, tplContent.Content.Layer, pageH, order)
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}
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}
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// layerOrder 获取图层类型的绘制顺序
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// 入参: kind 图层类型
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// 返回: int 绘制顺序
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func layerOrder(kind string) int {
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switch kind {
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case "Background":
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return 0
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case "Foreground":
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return 2
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}
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return 1
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}
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// renderLayers 按原顺序渲染指定类型的图层
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// 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
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func (r *Renderer) renderLayers(ctx *canvas.Context, layers []Layer, pageH float64, order int) {
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for _, layer := range layers {
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if layerOrder(layer.Type) == order {
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r.renderLayer(ctx, layer, pageH, nil, nil)
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}
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}
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}
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// renderLayer 渲染图层
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// 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
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func (r *Renderer) renderLayer(ctx *canvas.Context, layer Layer, pageH float64, defaults *DrawParam, parentCTM *Matrix) {
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defaults = r.drawParamDefaults(layer.DrawParam, defaults)
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if len(layer.Objects) > 0 {
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for _, obj := range layer.Objects {
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r.renderObject(ctx, obj, pageH, defaults, parentCTM, false, nil)
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}
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return
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}
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for _, textObj := range layer.TextObject {
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r.renderText(ctx, textObj, pageH, defaults, parentCTM, false, nil)
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}
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for _, pathObj := range layer.PathObject {
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r.renderPath(ctx, pathObj, pageH, defaults, parentCTM, false, nil)
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}
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for _, imgObj := range layer.ImageObject {
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r.renderImage(ctx, imgObj, pageH, parentCTM, false, nil)
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}
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for _, cgu := range layer.CompositeGraphicUnit {
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r.renderCompositeGraphicUnit(ctx, cgu, pageH, defaults, parentCTM, false, nil)
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}
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}
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// renderCompositeGraphicUnit 渲染复合图元
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// 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
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func (r *Renderer) renderCompositeGraphicUnit(ctx *canvas.Context, cgu CompositeGraphicUnit, pageH float64, defaults *DrawParam, parentCTM *Matrix, boundaryInCTM bool, parentClip *canvas.Path) {
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if cgu.Visible != nil && !*cgu.Visible {
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return
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}
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ctx.Push()
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box, _ := ParseBox(cgu.Boundary)
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boundaryCTM := TranslationMatrix(box.X, box.Y)
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if parentCTM != nil {
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boundaryCTM = parentCTM.Multiply(boundaryCTM)
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}
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currentCTM := boundaryCTM.Multiply(NewMatrix(cgu.CTM))
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clips, clipCTM := cgu.Clips, currentCTM
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if clips != nil && clips.TransFlag != nil && !*clips.TransFlag {
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// 不参与对象CTM的裁剪仍位于对象边界及父级坐标系中
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clipCopy := *clips
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clipCopy.TransFlag = nil
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clips, clipCTM = &clipCopy, boundaryCTM
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}
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clipPath := intersectClipPath(parentClip, r.buildClipPath(clips, pageH, 0, 0, clipCTM))
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defaults = r.drawParamDefaults(cgu.DrawParam, defaults)
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if cgu.ResourceID != "" {
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if ref, ok := r.CompositeGraphicUnits[cgu.ResourceID]; ok {
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refCopy := *ref
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refCopy.Alpha = mergeAlpha(refCopy.Alpha, cgu.Alpha)
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r.renderCompositeGraphicUnit(ctx, refCopy, pageH, defaults, ¤tCTM, true, clipPath)
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}
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}
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if len(cgu.Objects) > 0 {
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for _, obj := range cgu.Objects {
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obj = mergeGraphicObjectAlpha(obj, cgu.Alpha)
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r.renderObject(ctx, obj, pageH, defaults, ¤tCTM, boundaryInCTM, clipPath)
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}
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ctx.Pop()
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return
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}
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for _, imgObj := range cgu.ImageObject {
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imgObj.Alpha = mergeAlpha(imgObj.Alpha, cgu.Alpha)
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r.renderImage(ctx, imgObj, pageH, ¤tCTM, boundaryInCTM, clipPath)
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}
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for _, pathObj := range cgu.PathObject {
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pathObj.Alpha = mergeAlpha(pathObj.Alpha, cgu.Alpha)
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r.renderPath(ctx, pathObj, pageH, defaults, ¤tCTM, boundaryInCTM, clipPath)
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}
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for _, textObj := range cgu.TextObject {
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textObj.Alpha = mergeAlpha(textObj.Alpha, cgu.Alpha)
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r.renderText(ctx, textObj, pageH, defaults, ¤tCTM, boundaryInCTM, clipPath)
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}
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for _, subCgu := range cgu.CompositeGraphicUnit {
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subCgu.Alpha = mergeAlpha(subCgu.Alpha, cgu.Alpha)
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r.renderCompositeGraphicUnit(ctx, subCgu, pageH, defaults, ¤tCTM, boundaryInCTM, clipPath)
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}
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ctx.Pop()
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}
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// renderObject 渲染图形对象
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// 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
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func (r *Renderer) renderObject(ctx *canvas.Context, obj GraphicObject, pageH float64, defaults *DrawParam, parentCTM *Matrix, boundaryInCTM bool, parentClip *canvas.Path) {
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switch obj.Type {
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case "TextObject":
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r.renderText(ctx, obj.TextObject, pageH, defaults, parentCTM, boundaryInCTM, parentClip)
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case "PathObject":
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r.renderPath(ctx, obj.PathObject, pageH, defaults, parentCTM, boundaryInCTM, parentClip)
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case "ImageObject":
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r.renderImage(ctx, obj.ImageObject, pageH, parentCTM, boundaryInCTM, parentClip)
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case "CompositeGraphicUnit", "CompositeObject":
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r.renderCompositeGraphicUnit(ctx, obj.CompositeGraphicUnit, pageH, defaults, parentCTM, boundaryInCTM, parentClip)
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}
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}
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// mergeGraphicObjectAlpha 合并图形对象透明度
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// 入参: obj 图形对象, alpha 父级透明度
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// 返回: GraphicObject 合并后的图形对象
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func mergeGraphicObjectAlpha(obj GraphicObject, alpha *int) GraphicObject {
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if alpha == nil {
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return obj
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}
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switch obj.Type {
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case "TextObject":
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obj.TextObject.Alpha = mergeAlpha(obj.TextObject.Alpha, alpha)
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case "PathObject":
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obj.PathObject.Alpha = mergeAlpha(obj.PathObject.Alpha, alpha)
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case "ImageObject":
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obj.ImageObject.Alpha = mergeAlpha(obj.ImageObject.Alpha, alpha)
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case "CompositeGraphicUnit", "CompositeObject":
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obj.CompositeGraphicUnit.Alpha = mergeAlpha(obj.CompositeGraphicUnit.Alpha, alpha)
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}
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return obj
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}
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// drawParamDefaults 合并绘制参数默认样式
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// 入参: id 绘制参数ID, defaults 默认绘制参数
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// 返回: *DrawParam 合并后的绘制参数
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func (r *Renderer) drawParamDefaults(id string, defaults *DrawParam) *DrawParam {
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if id == "" {
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return defaults
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}
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dp := r.getDrawParam(id, nil)
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if dp == nil {
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return defaults
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}
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if defaults == nil {
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return dp
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}
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return mergeDrawParam(*defaults, dp)
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}
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// mergeDrawParam 合并绘制参数属性
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// 入参: base 基础绘制参数, dp 覆盖绘制参数
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// 返回: *DrawParam 合并后的绘制参数
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func mergeDrawParam(base DrawParam, dp *DrawParam) *DrawParam {
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if dp.LineWidth > 0 {
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base.LineWidth = dp.LineWidth
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}
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if dp.Join != "" {
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base.Join = dp.Join
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}
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if dp.Cap != "" {
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base.Cap = dp.Cap
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}
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if dp.DashPattern != "" {
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base.DashPattern = dp.DashPattern
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base.DashOffset = dp.DashOffset
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}
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if dp.MiterLimit > 0 {
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base.MiterLimit = dp.MiterLimit
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}
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if dp.FillColor != nil {
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base.FillColor = dp.FillColor
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}
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if dp.StrokeColor != nil {
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base.StrokeColor = dp.StrokeColor
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}
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if dp.Font != "" {
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base.Font = dp.Font
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}
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if dp.Size > 0 {
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base.Size = dp.Size
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}
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if dp.Weight > 0 {
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base.Weight = dp.Weight
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}
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if dp.Italic {
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base.Italic = dp.Italic
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}
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return &base
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}
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// getDrawParam 获取绘制参数逻辑
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// 入参: id 参数ID, visited 访问记录
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// 返回: *DrawParam 绘制参数
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func (r *Renderer) getDrawParam(id string, visited map[string]bool) *DrawParam {
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if visited == nil {
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visited = make(map[string]bool)
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}
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if visited[id] {
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return nil
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}
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visited[id] = true
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if dp, ok := r.DrawParams[id]; ok {
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if dp.Relative != "" {
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base := r.getDrawParam(dp.Relative, visited)
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if base == nil {
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return dp
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}
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return mergeDrawParam(*base, dp)
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}
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return dp
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}
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return nil
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}
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