mirror of
https://github.com/xiaoqidun/ofdgo.git
synced 2026-10-29 14:53:44 +08:00
This commit is contained in:
xiaoqidun committed
1 parent
697a059162
commit
86330dddd7
8 files changed
+606
-12
No files matched your search
+246
@@ -0,0 +1,246 @@
|
||||
// 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 (
|
||||
"context"
|
||||
"fmt"
|
||||
"io"
|
||||
"math"
|
||||
"strconv"
|
||||
"strings"
|
||||
|
||||
"github.com/xiaoqidun/pdfgo"
|
||||
)
|
||||
|
||||
// PDFImportOptions 指定PDF转换的运行时后端与进度通知
|
||||
type PDFImportOptions struct {
|
||||
Backends *RenderBackends
|
||||
Progress func(int) error
|
||||
}
|
||||
|
||||
// PDFImportReport 汇总成功转换的页面和可编辑对象
|
||||
type PDFImportReport struct {
|
||||
Pages int
|
||||
TextObjects int
|
||||
PathObjects int
|
||||
ImageObjects int
|
||||
}
|
||||
|
||||
// pdfImporter 保存单次转换的对象与资源状态
|
||||
type pdfImporter struct {
|
||||
reader *pdfgo.Reader
|
||||
editor *Editor
|
||||
report PDFImportReport
|
||||
matrix pdfgo.Matrix
|
||||
page int
|
||||
fontIDs map[*pdfgo.Font]string
|
||||
fontMetrics map[string]FontMetrics
|
||||
cmykSpace string
|
||||
objects []GraphicObject
|
||||
}
|
||||
|
||||
// ImportPDF 将PDF内容转换为独立OFD编辑文档，失败时不返回部分结果
|
||||
// 入参: ctx 取消上下文, source PDF数据, size 字节数, options 转换选项
|
||||
// 返回: *Editor 编辑文档, PDFImportReport 转换统计, error 错误信息
|
||||
func ImportPDF(ctx context.Context, source io.ReaderAt, size int64, options PDFImportOptions) (*Editor, PDFImportReport, error) {
|
||||
if err := ctx.Err(); err != nil {
|
||||
return nil, PDFImportReport{}, err
|
||||
}
|
||||
reader, err := pdfgo.NewReader(source, size)
|
||||
if err != nil {
|
||||
return nil, PDFImportReport{}, err
|
||||
}
|
||||
editor := NewEditor()
|
||||
if options.Backends != nil {
|
||||
editor.SetRenderBackends(*options.Backends)
|
||||
}
|
||||
importer := pdfImporter{reader: reader, editor: editor, fontIDs: map[*pdfgo.Font]string{}, fontMetrics: map[string]FontMetrics{}}
|
||||
err = reader.WalkPages(ctx, func(index int, page *pdfgo.Page) error {
|
||||
matrix, width, height := pdfPageMatrix(page)
|
||||
importer.matrix = matrix
|
||||
importer.page, err = editor.AddPage(width, height)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
if err := reader.WalkPage(ctx, page, pdfgo.Visitor{Path: importer.path, Text: importer.text, Image: importer.image}); err != nil {
|
||||
return fmt.Errorf("import PDF page %d: %w", index+1, err)
|
||||
}
|
||||
if _, err := editor.CopyObjects(importer.page, importer.objects, 0, 0); err != nil {
|
||||
return fmt.Errorf("import PDF page %d: %w", index+1, err)
|
||||
}
|
||||
importer.objects = nil
|
||||
importer.report.Pages++
|
||||
if options.Progress != nil {
|
||||
return options.Progress(index + 1)
|
||||
}
|
||||
return ctx.Err()
|
||||
})
|
||||
if err != nil {
|
||||
return nil, PDFImportReport{}, err
|
||||
}
|
||||
if importer.report.Pages == 0 {
|
||||
return nil, PDFImportReport{}, fmt.Errorf("PDF contains no pages")
|
||||
}
|
||||
return editor, importer.report, nil
|
||||
}
|
||||
|
||||
// ConvertPDF 将PDF转换并写入OFD，转换阶段失败时不写入目标
|
||||
// 入参: ctx 取消上下文, source PDF数据, size 字节数, output OFD输出, options 转换选项
|
||||
// 返回: PDFImportReport 转换统计, error 错误信息
|
||||
func ConvertPDF(ctx context.Context, source io.ReaderAt, size int64, output io.Writer, options PDFImportOptions) (PDFImportReport, error) {
|
||||
editor, report, err := ImportPDF(ctx, source, size, options)
|
||||
if err != nil {
|
||||
return PDFImportReport{}, err
|
||||
}
|
||||
if err := ctx.Err(); err != nil {
|
||||
return PDFImportReport{}, err
|
||||
}
|
||||
_, err = editor.WriteTo(output)
|
||||
return report, err
|
||||
}
|
||||
|
||||
// pdfPageMatrix 将裁剪框、用户单位及页面旋转转换为OFD毫米坐标
|
||||
func pdfPageMatrix(page *pdfgo.Page) (pdfgo.Matrix, float64, float64) {
|
||||
b := page.CropBox
|
||||
scale := 25.4 / 72 * page.UserUnit
|
||||
width, height := (b.XMax-b.XMin)*scale, (b.YMax-b.YMin)*scale
|
||||
m := pdfgo.Matrix{scale, 0, 0, -scale, -b.XMin * scale, b.YMax * scale}
|
||||
switch page.Rotation {
|
||||
case 90:
|
||||
m = pdfgo.Matrix{0, 1, -1, 0, height, 0}.Mul(m)
|
||||
width, height = height, width
|
||||
case 180:
|
||||
m = pdfgo.Matrix{-1, 0, 0, -1, width, height}.Mul(m)
|
||||
case 270:
|
||||
m = pdfgo.Matrix{0, -1, 1, 0, 0, width}.Mul(m)
|
||||
width, height = height, width
|
||||
}
|
||||
return m, width, height
|
||||
}
|
||||
|
||||
// pdfNumbers 按OFD数值格式序列化坐标
|
||||
func pdfNumbers(values ...float64) string {
|
||||
parts := make([]string, len(values))
|
||||
for n, v := range values {
|
||||
parts[n] = strconv.FormatFloat(v, 'g', -1, 64)
|
||||
}
|
||||
return strings.Join(parts, " ")
|
||||
}
|
||||
|
||||
// pdfBoundary 序列化对象边界
|
||||
func pdfBoundary(b Box) string { return pdfNumbers(b.X, b.Y, b.W, b.H) }
|
||||
|
||||
// pdfBounds 计算点集合的包围框
|
||||
func pdfBounds(points []pdfgo.Point) Box {
|
||||
if len(points) == 0 {
|
||||
return Box{}
|
||||
}
|
||||
minX, minY, maxX, maxY := points[0].X, points[0].Y, points[0].X, points[0].Y
|
||||
for _, p := range points {
|
||||
minX = math.Min(minX, p.X)
|
||||
minY = math.Min(minY, p.Y)
|
||||
maxX = math.Max(maxX, p.X)
|
||||
maxY = math.Max(maxY, p.Y)
|
||||
}
|
||||
return Box{minX, minY, math.Max(maxX-minX, 1e-6), math.Max(maxY-minY, 1e-6)}
|
||||
}
|
||||
|
||||
// color 保留设备色彩分量并复用文档颜色空间
|
||||
func (p *pdfImporter) color(paint pdfgo.Paint) *FillColor {
|
||||
alpha := int(math.Round(paint.Alpha * 255))
|
||||
if paint.CMYK != nil {
|
||||
if p.cmykSpace == "" {
|
||||
p.cmykSpace = p.editor.nextID()
|
||||
p.editor.resources = append(p.editor.resources, editorResource{space: &ColorSpace{ID: p.cmykSpace, Type: "CMYK", BitsPerComponent: 16}})
|
||||
}
|
||||
v := paint.CMYK
|
||||
return &FillColor{ColorSpace: p.cmykSpace, Value: pdfNumbers(math.Round(v[0]*65535), math.Round(v[1]*65535), math.Round(v[2]*65535), math.Round(v[3]*65535)), Alpha: &alpha}
|
||||
}
|
||||
return &FillColor{Value: pdfNumbers(math.Round(paint.RGB[0]*255), math.Round(paint.RGB[1]*255), math.Round(paint.RGB[2]*255)), Alpha: &alpha}
|
||||
}
|
||||
|
||||
// pathData 将PDF路径转换为相对对象边界的OFD路径
|
||||
func (p *pdfImporter) pathData(path pdfgo.Path, origin Box) string {
|
||||
var parts []string
|
||||
for _, segment := range path.Segments {
|
||||
parts = append(parts, segment.Operator)
|
||||
for _, point := range segment.Points {
|
||||
point = p.matrix.Apply(point)
|
||||
parts = append(parts, pdfNumbers(point.X-origin.X, point.Y-origin.Y))
|
||||
}
|
||||
}
|
||||
return strings.Join(parts, " ")
|
||||
}
|
||||
|
||||
// clips 保持裁剪路径的交集，不随对象CTM重复变换
|
||||
func (p *pdfImporter) clips(paths []pdfgo.Path, origin Box) *Clips {
|
||||
if len(paths) == 0 {
|
||||
return nil
|
||||
}
|
||||
flag := false
|
||||
clips := &Clips{TransFlag: &flag}
|
||||
for _, path := range paths {
|
||||
var points []pdfgo.Point
|
||||
for _, segment := range path.Segments {
|
||||
for _, point := range segment.Points {
|
||||
points = append(points, p.matrix.Apply(point))
|
||||
}
|
||||
}
|
||||
box := pdfBounds(points)
|
||||
rule := "NonZero"
|
||||
if path.EvenOdd {
|
||||
rule = "Even-Odd"
|
||||
}
|
||||
clips.Clip = append(clips.Clip, Clip{Area: []ClipArea{{Path: []PathObject{{Boundary: pdfBoundary(Box{box.X - origin.X, box.Y - origin.Y, box.W, box.H}), AbbreviatedData: p.pathData(path, box), Rule: rule}}}}})
|
||||
}
|
||||
return clips
|
||||
}
|
||||
|
||||
// path 添加独立可编辑路径
|
||||
func (p *pdfImporter) path(mark pdfgo.PathMark) error {
|
||||
var points []pdfgo.Point
|
||||
for _, segment := range mark.Path.Segments {
|
||||
for _, point := range segment.Points {
|
||||
points = append(points, p.matrix.Apply(point))
|
||||
}
|
||||
}
|
||||
if len(points) == 0 {
|
||||
return fmt.Errorf("empty PDF painted path")
|
||||
}
|
||||
box := pdfBounds(points)
|
||||
scale := math.Hypot(p.matrix[0], p.matrix[1])
|
||||
if mark.Stroke {
|
||||
margin := mark.Style.LineWidth * scale / 2 * math.Max(1, mark.Style.MiterLimit)
|
||||
box = Box{box.X - margin, box.Y - margin, box.W + 2*margin, box.H + 2*margin}
|
||||
}
|
||||
strokeColor := StrokeColor(*p.color(mark.Style.Stroke))
|
||||
object := PathObject{Boundary: pdfBoundary(box), AbbreviatedData: p.pathData(mark.Path, box), Fill: &mark.Fill, Stroke: &mark.Stroke, FillColor: p.color(mark.Style.Fill), StrokeColor: &strokeColor, LineWidth: mark.Style.LineWidth * scale, Cap: []string{"Butt", "Round", "Square"}[mark.Style.Cap], Join: []string{"Miter", "Round", "Bevel"}[mark.Style.Join], MiterLimit: mark.Style.MiterLimit, Clips: p.clips(mark.Style.Clips, box)}
|
||||
if mark.Path.EvenOdd {
|
||||
object.Rule = "Even-Odd"
|
||||
}
|
||||
if len(mark.Style.Dash) > 0 {
|
||||
values := make([]float64, len(mark.Style.Dash))
|
||||
for n, v := range mark.Style.Dash {
|
||||
values[n] = v * scale
|
||||
}
|
||||
object.DashPattern = pdfNumbers(values...)
|
||||
phase := mark.Style.DashPhase * scale
|
||||
object.DashOffset = &phase
|
||||
}
|
||||
p.objects = append(p.objects, GraphicObject{Type: "PathObject", PathObject: object})
|
||||
p.report.PathObjects++
|
||||
return nil
|
||||
}
|
||||
Reference in new issue
Block a user