feat(渲染编辑): 完善渲染编辑验签并优化性能

ofdgo_pdf_text_path.go

@@ -0,0 +1,53 @@
+// 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 (
+	"fmt"
+
+	"github.com/xiaoqidun/pdfgo"
+)
+
+// pdfGlyphPath 将字形轮廓变换到PDF页面坐标，二次曲线精确转换为三次曲线
+// 入参: outline 字形轮廓, matrix 字形到页面的变换
+// 返回: pdfgo.Path 页面路径, error 非字体轮廓指令
+func pdfGlyphPath(outline GeometryPath, matrix pdfgo.Matrix) (pdfgo.Path, error) {
+	path := pdfgo.Path{Segments: make([]pdfgo.Segment, 0, len(outline))}
+	var current, start Point
+	point := func(p Point) pdfgo.Point { return matrix.Apply(pdfgo.Point{X: p.X, Y: p.Y}) }
+	for _, segment := range outline {
+		switch segment.Verb {
+		case GeometryMove:
+			start = segment.End
+			path.Segments = append(path.Segments, pdfgo.Segment{Operator: "M", Points: []pdfgo.Point{point(segment.End)}})
+		case GeometryLine:
+			path.Segments = append(path.Segments, pdfgo.Segment{Operator: "L", Points: []pdfgo.Point{point(segment.End)}})
+		case GeometryQuad:
+			c1 := Point{current.X + (segment.Control1.X-current.X)*2/3, current.Y + (segment.Control1.Y-current.Y)*2/3}
+			c2 := Point{segment.End.X + (segment.Control1.X-segment.End.X)*2/3, segment.End.Y + (segment.Control1.Y-segment.End.Y)*2/3}
+			path.Segments = append(path.Segments, pdfgo.Segment{Operator: "B", Points: []pdfgo.Point{point(c1), point(c2), point(segment.End)}})
+		case GeometryCubic:
+			path.Segments = append(path.Segments, pdfgo.Segment{Operator: "B", Points: []pdfgo.Point{point(segment.Control1), point(segment.Control2), point(segment.End)}})
+		case GeometryClose:
+			path.Segments = append(path.Segments, pdfgo.Segment{Operator: "C"})
+			current = start
+			continue
+		default:
+			return pdfgo.Path{}, fmt.Errorf("unsupported PDF glyph geometry verb %d", segment.Verb)
+		}
+		current = segment.End
+	}
+	return path, nil
+}