feat(正式发布): 实现了OFD渲染和导出为PDF、图片、矢量图等

ofdgo_geom.go

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+// Copyright 2025 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 首款原生、全平台兼容的纯 Go 语言 OFD 渲染库
+package ofdgo
+
+import (
+	"math"
+	"strconv"
+	"strings"
+)
+
+// Box 矩形区域
+type Box struct {
+	X, Y, W, H float64
+}
+
+// ParseBox 解析Box字符串
+// 入参: s 字符串
+// 返回: Box 矩形对象, error 错误信息
+func ParseBox(s string) (Box, error) {
+	parts := strings.Fields(s)
+	if len(parts) < 4 {
+		return Box{}, nil
+	}
+	x, _ := strconv.ParseFloat(parts[0], 64)
+	y, _ := strconv.ParseFloat(parts[1], 64)
+	w, _ := strconv.ParseFloat(parts[2], 64)
+	h, _ := strconv.ParseFloat(parts[3], 64)
+	return Box{X: x, Y: y, W: w, H: h}, nil
+}
+
+// Matrix 2D仿射变换矩阵
+type Matrix struct {
+	a, b, c, d, e, f float64
+}
+
+// IdentityMatrix 单位矩阵
+var IdentityMatrix = Matrix{1, 0, 0, 1, 0, 0}
+
+// NewMatrix 解析CTM字符串
+// 入参: s 字符串
+// 返回: Matrix 矩阵对象
+func NewMatrix(s string) Matrix {
+	floats := parseFloats(s)
+	if len(floats) != 6 {
+		return IdentityMatrix
+	}
+	return Matrix{
+		a: floats[0], b: floats[1],
+		c: floats[2], d: floats[3],
+		e: floats[4], f: floats[5],
+	}
+}
+
+// Transform 应用变换矩阵
+// 入参: x X坐标, y Y坐标
+// 返回: float64 变换后X, float64 变换后Y
+func (m Matrix) Transform(x, y float64) (float64, float64) {
+	nx := m.a*x + m.c*y + m.e
+	ny := m.b*x + m.d*y + m.f
+	return nx, ny
+}
+
+// YScale 获取Y轴缩放比例
+// 返回: float64 缩放比例
+func (m Matrix) YScale() float64 {
+	return math.Sqrt(m.c*m.c + m.d*m.d)
+}
+
+// parseFloats 解析浮点数数组
+// 入参: s 字符串
+// 返回: []float64 浮点数数组
+func parseFloats(s string) []float64 {
+	if s == "" {
+		return nil
+	}
+	if strings.Contains(s, "g") {
+		return parseFloatsWithG(s)
+	}
+	s = strings.ReplaceAll(s, ",", " ")
+	parts := strings.Fields(s)
+	result := make([]float64, 0, len(parts))
+	for _, p := range parts {
+		if v, err := strconv.ParseFloat(p, 64); err == nil {
+			result = append(result, v)
+		}
+	}
+	return result
+}
+
+// parseFloatsWithG 解析带g的压缩浮点数数组
+// 入参: s 字符串
+// 返回: []float64 浮点数数组
+func parseFloatsWithG(s string) []float64 {
+	parts := strings.Fields(s)
+	var result []float64
+	gFlag := false
+	gCount := 0
+	for _, p := range parts {
+		if p == "g" {
+			gFlag = true
+			continue
+		}
+		if gFlag {
+			gCount, _ = strconv.Atoi(p)
+			gFlag = false
+			continue
+		}
+		if gCount > 0 {
+			v, _ := strconv.ParseFloat(p, 64)
+			for j := 0; j < gCount; j++ {
+				result = append(result, v)
+			}
+			gCount = 0
+		} else {
+			if v, err := strconv.ParseFloat(p, 64); err == nil {
+				result = append(result, v)
+			}
+		}
+	}
+	return result
+}