feat(编辑渲染): 完善三维转换，优化编辑渲染压缩

ofdgo_compression_pattern.go

@@ -0,0 +1,164 @@
+// 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 (
+	"crypto/sha256"
+	"reflect"
+	"slices"
+)
+
+const (
+	compressionPatternMinimum = 4096
+	compressionPatternLimit   = 4096
+	compressionPatternUses    = 65536
+)
+
+// compressionPatternPaint 保存可共享的底纹颜色，不修改输入对象
+type compressionPatternPaint struct {
+	fill   *FillColor
+	stroke *StrokeColor
+	count  int
+	id     string
+}
+
+// compressionPatternUse 记录输出快照内需要替换的直接对象
+type compressionPatternUse struct {
+	page, layer, object int
+	paint               *compressionPatternPaint
+}
+
+// compressPatternPaints 将新文档中重复的大底纹颜色提取为绘制参数，仅修改输出快照
+// 返回: error 编码或取消错误
+func (e *Editor) compressPatternPaints() error {
+	if e.output == nil || e.output.options.Mode == CompressionUnchanged || e.output.protected || e.source != nil {
+		return nil
+	}
+	paints := make(map[[32]byte]*compressionPatternPaint)
+	var uses []compressionPatternUse
+	for pi, page := range e.pages {
+		for li, layer := range page.Content.Layer {
+			if layer.DrawParam != "" {
+				continue
+			}
+			for oi, object := range layer.Objects {
+				if err := e.output.ctx.Err(); err != nil {
+					return err
+				}
+				if len(uses) == compressionPatternUses {
+					break
+				}
+				fill, stroke := compressionObjectPattern(object)
+				if fill == nil && stroke == nil {
+					continue
+				}
+				hash := sha256.New()
+				var size int64
+				x := newOFDXML(convertWriter{writer: hash, count: &size, context: e.output.ctx})
+				x.ctx = e.output.ctx
+				x.color("FillColor", fill)
+				x.color("StrokeColor", (*FillColor)(stroke))
+				if err := x.finish(); err != nil {
+					return err
+				}
+				if size < compressionPatternMinimum {
+					continue
+				}
+				key := [32]byte(hash.Sum(nil))
+				paint := paints[key]
+				if paint == nil {
+					if len(paints) == compressionPatternLimit {
+						continue
+					}
+					paint = &compressionPatternPaint{fill: fill, stroke: stroke}
+					paints[key] = paint
+				} else if !reflect.DeepEqual(paint.fill, fill) || !reflect.DeepEqual(paint.stroke, stroke) {
+					continue
+				}
+				paint.count++
+				uses = append(uses, compressionPatternUse{pi, li, oi, paint})
+			}
+		}
+	}
+	var copied bool
+	lastPage, lastLayer := -1, -1
+	for _, use := range uses {
+		if err := e.output.ctx.Err(); err != nil {
+			return err
+		}
+		if use.paint.count < 2 {
+			continue
+		}
+		if !copied {
+			e.pages = slices.Clone(e.pages)
+			e.resources = slices.Clone(e.resources)
+			copied = true
+		}
+		if use.paint.id == "" {
+			id, err := e.addEditorDrawParam(DrawParam{FillColor: use.paint.fill, StrokeColor: use.paint.stroke})
+			if err != nil {
+				return err
+			}
+			use.paint.id = id
+		}
+		if use.page != lastPage {
+			e.pages[use.page].Content.Layer = slices.Clone(e.pages[use.page].Content.Layer)
+			lastPage, lastLayer = use.page, -1
+		}
+		layer := &e.pages[use.page].Content.Layer[use.layer]
+		if use.layer != lastLayer {
+			layer.Objects = slices.Clone(layer.Objects)
+			lastLayer = use.layer
+		}
+		object := &layer.Objects[use.object]
+		if object.Type == "PathObject" {
+			object.PathObject.DrawParam = use.paint.id
+			object.PathObject.FillColor, object.PathObject.StrokeColor = nil, nil
+		} else {
+			object.TextObject.DrawParam = use.paint.id
+			object.TextObject.FillColor, object.TextObject.StrokeColor = nil, nil
+		}
+	}
+	return nil
+}
+
+// compressionObjectPattern 筛选没有原文及绘制参数继承的底纹对象
+// 入参: object 图形对象
+// 返回: *FillColor 填充颜色, *StrokeColor 描边颜色，不适用时均为空
+func compressionObjectPattern(object GraphicObject) (*FillColor, *StrokeColor) {
+	if object.origin != nil {
+		return nil, nil
+	}
+	var fill *FillColor
+	var stroke *StrokeColor
+	switch object.Type {
+	case "PathObject":
+		if object.PathObject.DrawParam != "" {
+			return nil, nil
+		}
+		fill, stroke = object.PathObject.FillColor, object.PathObject.StrokeColor
+	case "TextObject":
+		if object.TextObject.DrawParam != "" {
+			return nil, nil
+		}
+		fill, stroke = object.TextObject.FillColor, object.TextObject.StrokeColor
+	default:
+		return nil, nil
+	}
+	if fill != nil && fill.Pattern != nil || stroke != nil && stroke.Pattern != nil {
+		return fill, stroke
+	}
+	return nil, nil
+}