mirror of
https://github.com/xiaoqidun/ofdgo.git
synced 2026-10-30 01:27:26 +08:00
98 lines
3.0 KiB
Go
98 lines
3.0 KiB
Go
// 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 (
|
|
"bytes"
|
|
"fmt"
|
|
"slices"
|
|
|
|
"github.com/tdewolff/font"
|
|
)
|
|
|
|
// subsetFonts 收集新增字体实际使用的字形，仅裁剪保存结果，不修改编辑资源或原文档字体。
|
|
// 返回: map[string][]byte 包内字体子集, error 错误信息
|
|
func (e *Editor) subsetFonts() (map[string][]byte, error) {
|
|
used := make(map[string]map[uint16]bool)
|
|
for _, resource := range e.resources {
|
|
if resource.font == nil {
|
|
continue
|
|
}
|
|
sfnt := e.fonts[resource.font.ID]
|
|
if sfnt.IsTrueType && !slices.ContainsFunc([]string{"fvar", "COLR", "CBDT", "sbix", "SVG "}, func(tag string) bool { return sfnt.Tables[tag] != nil }) {
|
|
used[resource.font.ID] = make(map[uint16]bool)
|
|
}
|
|
}
|
|
for _, page := range e.pages {
|
|
for _, layer := range page.Content.Layer {
|
|
for _, object := range layer.Objects {
|
|
if object.Type != "TextObject" {
|
|
continue
|
|
}
|
|
obj := object.TextObject
|
|
glyphs := used[obj.Font]
|
|
if glyphs == nil {
|
|
continue
|
|
}
|
|
for _, code := range obj.TextCode {
|
|
for _, char := range textCodeRunes(code.Value) {
|
|
glyphs[e.fonts[obj.Font].GlyphIndex(char)] = true
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
result := make(map[string][]byte)
|
|
for _, resource := range e.resources {
|
|
if resource.font == nil || len(used[resource.font.ID]) == 0 {
|
|
continue
|
|
}
|
|
glyphs := used[resource.font.ID]
|
|
glyphs[0] = true
|
|
ids := make([]uint16, 0, len(glyphs))
|
|
for id := range glyphs {
|
|
ids = append(ids, id)
|
|
}
|
|
slices.Sort(ids)
|
|
data, err := subsetEditorFont(resource.data, ids)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("subset font %s: %w", resource.font.FontName, err)
|
|
}
|
|
if len(data) < len(resource.data) {
|
|
result[resource.name] = data
|
|
}
|
|
}
|
|
return result, nil
|
|
}
|
|
|
|
// subsetEditorFont 裁剪TrueType字形及复合依赖，保留字符映射、名称、度量和提示指令。
|
|
// 入参: data 字体数据, glyphs 已排序的字形编号，包含0
|
|
// 返回: []byte 字体子集, error 错误信息
|
|
func subsetEditorFont(data []byte, glyphs []uint16) ([]byte, error) {
|
|
sfnt, err := font.ParseSFNT(bytes.Clone(data), 0)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
subset, err := sfnt.Subset(glyphs, font.SubsetOptions{Tables: []string{
|
|
"cmap", "head", "hhea", "hmtx", "maxp", "OS/2", "post", "glyf", "loca", "cvt ", "fpgm", "prep", "gasp",
|
|
}})
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
subset.Tables["name"] = sfnt.Tables["name"]
|
|
clear(subset.Tables["head"][8:12])
|
|
return serializeOTF(subset.Tables)
|
|
}
|