mirror of
https://github.com/xiaoqidun/ofdgo.git
synced 2026-10-29 17:27:08 +08:00
60 lines
1.8 KiB
Go
60 lines
1.8 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 ofdgo
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import (
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"fmt"
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"sync"
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"github.com/tdewolff/canvas"
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)
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// canvasFontLoadMu 保护绘图后端加载无名称字体时使用的共享状态
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var canvasFontLoadMu sync.Mutex
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// loadCanvasFont 串行加载绘图字体，不改动原始字体数据
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// 入参: data 字体数据, index 集合索引, style 字体样式
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// 返回: *canvas.Font 绘图字体, error 加载错误
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func loadCanvasFont(data []byte, index int, style canvas.FontStyle) (*canvas.Font, error) {
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canvasFontLoadMu.Lock()
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defer canvasFontLoadMu.Unlock()
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return canvas.LoadFont(data, index, style)
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}
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// decodeFontContainer 展开字体封装，保留原始OpenType表及CFF2轮廓
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// 入参: data 字体文件
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// 返回: []byte OpenType数据, error 格式错误
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func decodeFontContainer(data []byte) ([]byte, error) {
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if len(data) < 12 {
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return nil, fmt.Errorf("invalid font header")
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}
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switch string(data[:4]) {
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case "\x00\x01\x00\x00", "OTTO", "true", "ttcf":
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return data, nil
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case "wOFF":
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return decodeWOFF(data)
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case "wOF2":
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decoded, handled, err := decodeWOFF2(data)
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if handled {
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return decoded, err
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}
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}
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loaded, err := loadCanvasFont(data, 0, canvas.FontRegular)
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if err != nil {
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return nil, err
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}
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return serializeOTF(loaded.Tables)
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}
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