feat(渲染编辑): 完善渲染编辑，优化版本压缩

ofdgo_text_lines.go

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+// 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 (
+	"math"
+	"strconv"
+	"strings"
+)
+
+// textLineScanner 顺序判断文本段换行，复用继承坐标和字符到字形的变换
+type textLineScanner struct {
+	size       float64
+	enabled    bool
+	started    bool
+	firstX     string
+	previous   TextCode
+	offset     int
+	pending    []CGTransform
+	transforms map[int][2]int
+}
+
+// newTextLineScanner 创建独立的换行扫描器，不修改文字对象
+// 入参: obj 定位文字
+// 返回: textLineScanner 扫描状态
+func newTextLineScanner(obj TextObject) textLineScanner {
+	return textLineScanner{size: obj.Size, enabled: len(obj.TextCode) > 1 && obj.ReadDirection == 0 && obj.CharDirection == 0, previous: TextCode{X: "0", Y: "0"}, pending: obj.CGTransform}
+}
+
+// glyphCount 首次需要字形范围时解析变换，后续文本段复用结果
+// 入参: code 文本段, offset 对象内字符起点
+// 返回: int 字形数量
+func (s *textLineScanner) glyphCount(code TextCode, offset int) int {
+	if len(s.pending) != 0 {
+		s.transforms = make(map[int][2]int, len(s.pending))
+	}
+	for _, transform := range s.pending {
+		if transform.CodePosition < 0 {
+			continue
+		}
+		glyphs := len(parseInts(transform.Glyphs))
+		if transform.GlyphCount > 0 {
+			glyphs = min(glyphs, transform.GlyphCount)
+		}
+		if glyphs > 0 {
+			s.transforms[transform.CodePosition] = [2]int{max(1, transform.CodeCount), glyphs}
+		}
+	}
+	s.pending = nil
+	return textCodeGlyphCount(code, offset, s.transforms)
+}
+
+// next 继承文本段原点并根据实际字形范围判断是否换行
+// 入参: code 按文档顺序传入的文本段
+// 返回: bool 当前段前是否换行
+func (s *textLineScanner) next(code TextCode) bool {
+	if !s.enabled {
+		return false
+	}
+	previous, offset := s.previous, s.offset
+	if s.started && (len(s.pending) != 0 || len(s.transforms) != 0) {
+		s.offset += textCodeRuneCount(previous.Value)
+	}
+	if code.X == "" {
+		code.X = previous.X
+	}
+	if code.Y == "" {
+		code.Y = previous.Y
+	}
+	s.previous = code
+	if !s.started {
+		s.started, s.firstX = true, code.X
+		return false
+	}
+	x, ex := strconv.ParseFloat(code.X, 64)
+	start, es := strconv.ParseFloat(s.firstX, 64)
+	y, ey := strconv.ParseFloat(code.Y, 64)
+	prev, ep := strconv.ParseFloat(previous.Y, 64)
+	if ex != nil || es != nil || ey != nil || ep != nil {
+		return false
+	}
+	if x == start && y != prev {
+		return true
+	}
+	left, err := strconv.ParseFloat(previous.X, 64)
+	if err != nil || s.size <= 0 || y-prev < s.size/2 || previous.DeltaY != "" || code.DeltaY != "" {
+		return false
+	}
+	count := s.glyphCount(previous, offset)
+	if count == 0 {
+		return false
+	}
+	right := left + s.size
+	positioner := NewTextPositioner(previous)
+	for range count {
+		right = math.Max(right, positioner.Next().X+s.size)
+	}
+	return x <= right
+}
+
+// textCodeGlyphCount 按文本段的字符起点统计实际字形数量
+// 入参: code 文本段, offset 对象内字符起点, transforms 已解析的字符到字形变换
+// 返回: int 字形数量
+func textCodeGlyphCount(code TextCode, offset int, transforms map[int][2]int) int {
+	if code.Index != "" {
+		count := 0
+		for _, field := range strings.Fields(code.Index) {
+			first, last, interval := strings.Cut(field, "-")
+			start, err := strconv.ParseUint(first, 10, 16)
+			if err != nil {
+				continue
+			}
+			if !interval {
+				count++
+				continue
+			}
+			end, err := strconv.ParseUint(last, 10, 16)
+			if err == nil && end >= start {
+				count += int(end-start) + 1
+			}
+		}
+		return count
+	}
+	count := textCodeRuneCount(code.Value)
+	if len(transforms) == 0 || count == 0 {
+		return count
+	}
+	glyphs := 0
+	for i := 0; i < count; {
+		if transform, ok := transforms[offset+i]; ok && transform[0] <= count-i {
+			i += transform[0]
+			glyphs += transform[1]
+		} else {
+			i++
+			glyphs++
+		}
+	}
+	return glyphs
+}