mirror of
https://github.com/xiaoqidun/ofdgo.git
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103 lines
3.6 KiB
Go
103 lines
3.6 KiB
Go
// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package pdf
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import (
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"math"
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"reflect"
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"github.com/xiaoqidun/pdfgo"
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)
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// MergeReplacement 统一同一替换区段内的坐标原点，不重新塑形或调整字距
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// 入参: marks 连续文字图元, replacement 整段原文
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// 返回: *pdfgo.TextMark 合并文字, bool 是否可等价合并
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func MergeReplacement(marks []*pdfgo.TextMark, replacement *pdfgo.ReplacementText) (*pdfgo.TextMark, bool) {
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first := marks[0]
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style := first.Style
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paint := style.Fill
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if first.Font == nil || len(first.Font.Program) == 0 || first.Mode != 0 || first.Size <= 0 || first.HorizontalScale <= 0 || first.Clip != nil || style.SoftMask != nil || style.Transfer != nil || style.AlphaIsShape || style.FillOverprint || paint.Alpha != 1 || !NormalBlend(style.BlendMode) || paint.Tiling != nil || paint.Axial != nil || paint.Radial != nil || paint.Mesh != nil || paint.Function != nil {
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return nil, false
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}
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inverse, ok := first.Matrix.Inverse()
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if !ok {
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return nil, false
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}
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count := 0
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sequence := first.Sequence
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for _, mark := range marks {
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if mark.Font != first.Font || mark.Size != first.Size || mark.HorizontalScale != first.HorizontalScale || mark.Mode != first.Mode || mark.Clip != nil || len(mark.Glyphs) != len(mark.Positions) || !reflect.DeepEqual(mark.Style, style) {
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return nil, false
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}
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if mark.Matrix[0] != first.Matrix[0] || mark.Matrix[1] != first.Matrix[1] || mark.Matrix[2] != first.Matrix[2] || mark.Matrix[3] != first.Matrix[3] {
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return nil, false
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}
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count += len(mark.Glyphs)
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sequence = CommonSequence(sequence, mark.Sequence)
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}
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if count == 0 {
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return nil, false
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}
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merged := *first
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merged.Replacement = replacement
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merged.Sequence = sequence
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merged.Glyphs = make([]pdfgo.Glyph, 0, count)
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merged.Positions = make([]pdfgo.Point, 0, count)
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for _, mark := range marks {
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dx, dy := mark.Matrix[4]-first.Matrix[4], mark.Matrix[5]-first.Matrix[5]
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offset := pdfgo.Point{X: inverse[0]*dx + inverse[2]*dy, Y: inverse[1]*dx + inverse[3]*dy}
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for _, point := range mark.Positions {
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point.X += offset.X
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point.Y += offset.Y
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if math.IsNaN(point.X) || math.IsNaN(point.Y) || math.IsInf(point.X, 0) || math.IsInf(point.Y, 0) {
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return nil, false
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}
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merged.Positions = append(merged.Positions, point)
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}
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merged.Glyphs = append(merged.Glyphs, mark.Glyphs...)
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}
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return &merged, true
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}
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// CommonSequence 查找两个内容区段的最近共同外层，不将合并内容归入单个子区段
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// 入参: first 首个区段, second 后续区段
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// 返回: *pdfgo.ContentSequence 共同区段，没有共同区段时为空
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func CommonSequence(first, second *pdfgo.ContentSequence) *pdfgo.ContentSequence {
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if first == second {
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return first
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}
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if first == nil || second == nil {
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return nil
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}
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depth := func(sequence *pdfgo.ContentSequence) int {
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count := 0
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for ; sequence != nil; sequence = sequence.Parent {
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count++
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}
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return count
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}
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a, b := depth(first), depth(second)
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for ; a > b; a-- {
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first = first.Parent
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}
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for ; b > a; b-- {
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second = second.Parent
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}
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for first != second {
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first, second = first.Parent, second.Parent
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}
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return first
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}
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