refactor(重构代码): 拆分代码，提升代码质量

2026-08-30 12:12:40 +08:00 · 2026-07-09 12:17:31 +08:00
parent 9eb9104380
commit 155f5c7299
7 changed files with 1212 additions and 1046 deletions
@@ -0,0 +1,247 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"image/color"
+
+	"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 len(annot.Appearance.Objects) == 0 {
+			continue
+		}
+		box, _ := ParseBox(annot.Appearance.Boundary)
+		ctm := Matrix{a: 1, d: 1, e: box.X, f: box.Y}
+		for _, obj := range annot.Appearance.Objects {
+			r.renderObject(ctx, obj, pageH, nil, nil, 0, &ctm, false)
+		}
+	}
+}
+
+// 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) {
+	var tplPage *TemplatePage
+	for _, tp := range r.Reader.doc.CommonData.TemplatePage {
+		if tp.ID == templateID {
+			tplPage = &tp
+			break
+		}
+	}
+	if tplPage == nil {
+		return
+	}
+	tplContent, err := r.Reader.PageContent(Page{BaseLoc: tplPage.BaseLoc})
+	if err != nil {
+		return
+	}
+	if tplContent.Content.Layer != nil {
+		for _, layer := range tplContent.Content.Layer {
+			r.renderLayer(ctx, layer, pageH, nil, nil, 0, nil)
+		}
+	}
+}
+
+// renderLayer 渲染图层
+// 入参: ctx 画布上下文, layer 图层对象, pageH 页面高度, defaultFill 默认填充色, defaultStroke 默认描边色, defaultLW 默认线宽, parentCTM 父级CTM
+func (r *Renderer) renderLayer(ctx *canvas.Context, layer Layer, pageH float64, defaultFill, defaultStroke color.Color, defaultLW float64, parentCTM *Matrix) {
+	defaultFill, defaultStroke, defaultLW = r.drawParamDefaults(layer.DrawParam, defaultFill, defaultStroke, defaultLW)
+	if len(layer.Objects) > 0 {
+		for _, obj := range layer.Objects {
+			r.renderObject(ctx, obj, pageH, defaultFill, defaultStroke, defaultLW, parentCTM, false)
+		}
+		return
+	}
+	for _, textObj := range layer.TextObject {
+		r.renderText(ctx, textObj, pageH, defaultFill, defaultStroke, parentCTM, false)
+	}
+	for _, pathObj := range layer.PathObject {
+		r.renderPath(ctx, pathObj, pageH, defaultFill, defaultStroke, defaultLW, parentCTM, false)
+	}
+	for _, imgObj := range layer.ImageObject {
+		r.renderImage(ctx, imgObj, pageH, parentCTM, false)
+	}
+	for _, cgu := range layer.CompositeGraphicUnit {
+		r.renderCompositeGraphicUnit(ctx, cgu, pageH, defaultFill, defaultStroke, defaultLW, parentCTM, false)
+	}
+}
+
+// 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, defaultFill 默认填充色, defaultStroke 默认描边色, defaultLW 默认线宽, parentCTM 父级CTM, boundaryInCTM 边界是否参与CTM变换
+func (r *Renderer) renderCompositeGraphicUnit(ctx *canvas.Context, cgu CompositeGraphicUnit, pageH float64, defaultFill, defaultStroke color.Color, defaultLW float64, parentCTM *Matrix, boundaryInCTM bool) {
+	if cgu.Visible != nil && !*cgu.Visible {
+		return
+	}
+	ctx.Push()
+	currentCTM := NewMatrix(cgu.CTM)
+	if parentCTM != nil {
+		currentCTM = parentCTM.Multiply(currentCTM)
+	}
+	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, defaultFill, defaultStroke, defaultLW, &currentCTM, true)
+		}
+	}
+	defaultFill, defaultStroke, defaultLW = r.drawParamDefaults(cgu.DrawParam, defaultFill, defaultStroke, defaultLW)
+	if len(cgu.Objects) > 0 {
+		for _, obj := range cgu.Objects {
+			obj = mergeGraphicObjectAlpha(obj, cgu.Alpha)
+			r.renderObject(ctx, obj, pageH, defaultFill, defaultStroke, defaultLW, &currentCTM, boundaryInCTM)
+		}
+		ctx.Pop()
+		return
+	}
+	for _, imgObj := range cgu.ImageObject {
+		imgObj.Alpha = mergeAlpha(imgObj.Alpha, cgu.Alpha)
+		r.renderImage(ctx, imgObj, pageH, &currentCTM, boundaryInCTM)
+	}
+	for _, pathObj := range cgu.PathObject {
+		pathObj.Alpha = mergeAlpha(pathObj.Alpha, cgu.Alpha)
+		r.renderPath(ctx, pathObj, pageH, defaultFill, defaultStroke, defaultLW, &currentCTM, boundaryInCTM)
+	}
+	for _, textObj := range cgu.TextObject {
+		textObj.Alpha = mergeAlpha(textObj.Alpha, cgu.Alpha)
+		r.renderText(ctx, textObj, pageH, defaultFill, defaultStroke, &currentCTM, boundaryInCTM)
+	}
+	for _, subCgu := range cgu.CompositeGraphicUnit {
+		subCgu.Alpha = mergeAlpha(subCgu.Alpha, cgu.Alpha)
+		r.renderCompositeGraphicUnit(ctx, subCgu, pageH, defaultFill, defaultStroke, defaultLW, &currentCTM, boundaryInCTM)
+	}
+	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, defaultFill 默认填充色, defaultStroke 默认描边色, defaultLW 默认线宽, parentCTM 父级CTM, boundaryInCTM 边界是否参与CTM变换
+func (r *Renderer) renderObject(ctx *canvas.Context, obj GraphicObject, pageH float64, defaultFill, defaultStroke color.Color, defaultLW float64, parentCTM *Matrix, boundaryInCTM bool) {
+	switch obj.Type {
+	case "TextObject":
+		r.renderText(ctx, obj.TextObject, pageH, defaultFill, defaultStroke, parentCTM, boundaryInCTM)
+	case "PathObject":
+		r.renderPath(ctx, obj.PathObject, pageH, defaultFill, defaultStroke, defaultLW, parentCTM, boundaryInCTM)
+	case "ImageObject":
+		r.renderImage(ctx, obj.ImageObject, pageH, parentCTM, boundaryInCTM)
+	case "CompositeGraphicUnit", "CompositeObject":
+		r.renderCompositeGraphicUnit(ctx, obj.CompositeGraphicUnit, pageH, defaultFill, defaultStroke, defaultLW, parentCTM, boundaryInCTM)
+	}
+}
+
+// mergeGraphicObjectAlpha 合并图形对象透明度
+// 入参: obj 图形对象, alpha 父级透明度
+// 返回: GraphicObject 合并后的图形对象
+func mergeGraphicObjectAlpha(obj GraphicObject, alpha *int) GraphicObject {
+	if alpha == nil {
+		return obj
+	}
+	switch obj.Type {
+	case "TextObject":
+		obj.TextObject.Alpha = mergeAlpha(obj.TextObject.Alpha, alpha)
+	case "PathObject":
+		obj.PathObject.Alpha = mergeAlpha(obj.PathObject.Alpha, alpha)
+	case "ImageObject":
+		obj.ImageObject.Alpha = mergeAlpha(obj.ImageObject.Alpha, alpha)
+	case "CompositeGraphicUnit", "CompositeObject":
+		obj.CompositeGraphicUnit.Alpha = mergeAlpha(obj.CompositeGraphicUnit.Alpha, alpha)
+	}
+	return obj
+}
+
+// drawParamDefaults 合并绘制参数默认样式
+// 入参: id 绘制参数ID, defaultFill 默认填充色, defaultStroke 默认描边色, defaultLW 默认线宽
+// 返回: color.Color 默认填充色, color.Color 默认描边色, float64 默认线宽
+func (r *Renderer) drawParamDefaults(id string, defaultFill, defaultStroke color.Color, defaultLW float64) (color.Color, color.Color, float64) {
+	if id == "" {
+		return defaultFill, defaultStroke, defaultLW
+	}
+	dp := r.getDrawParam(id, nil)
+	if dp == nil {
+		return defaultFill, defaultStroke, defaultLW
+	}
+	if dp.LineWidth > 0 {
+		defaultLW = dp.LineWidth
+	}
+	if dp.FillColor != nil {
+		defaultFill = parseFillColor(dp.FillColor)
+	}
+	if dp.StrokeColor != nil {
+		defaultStroke = parseStrokeColor(dp.StrokeColor)
+	}
+	return defaultFill, defaultStroke, defaultLW
+}
+
+// getDrawParam 获取绘制参数逻辑
+// 入参: id 参数ID, visited 访问记录
+// 返回: *DrawParam 绘制参数
+func (r *Renderer) getDrawParam(id string, visited map[string]bool) *DrawParam {
+	if visited == nil {
+		visited = make(map[string]bool)
+	}
+	if visited[id] {
+		return nil
+	}
+	visited[id] = true
+	if dp, ok := r.DrawParams[id]; ok {
+		if dp.Relative != "" {
+			base := r.getDrawParam(dp.Relative, visited)
+			if base == nil {
+				return dp
+			}
+			merged := *base
+			if dp.LineWidth > 0 {
+				merged.LineWidth = dp.LineWidth
+			}
+			if dp.Join != "" {
+				merged.Join = dp.Join
+			}
+			if dp.Cap != "" {
+				merged.Cap = dp.Cap
+			}
+			if dp.DashPattern != "" {
+				merged.DashPattern = dp.DashPattern
+				merged.DashOffset = dp.DashOffset
+			}
+			if dp.MiterLimit > 0 {
+				merged.MiterLimit = dp.MiterLimit
+			}
+			if dp.FillColor != nil {
+				merged.FillColor = dp.FillColor
+			}
+			if dp.StrokeColor != nil {
+				merged.StrokeColor = dp.StrokeColor
+			}
+			if dp.Font != "" {
+				merged.Font = dp.Font
+			}
+			if dp.Size > 0 {
+				merged.Size = dp.Size
+			}
+			if dp.Weight > 0 {
+				merged.Weight = dp.Weight
+			}
+			if dp.Italic {
+				merged.Italic = dp.Italic
+			}
+			return &merged
+		}
+		return dp
+	}
+	return nil
+}