From db4f8510171c8e3c142552b69ea12e203f3461c3 Mon Sep 17 00:00:00 2001 From: xiaoqidun Date: Fri, 2 Jan 2026 13:46:06 +0800 Subject: [PATCH] =?UTF-8?q?feat(=E5=AD=97=E4=BD=93=E6=B8=B2=E6=9F=93):=20?= =?UTF-8?q?=E5=8A=A0=E5=BC=BA=E5=86=85=E5=B5=8C=E5=AD=97=E4=BD=93=E6=B8=B2?= =?UTF-8?q?=E6=9F=93=E6=88=90=E5=8A=9F=E7=8E=87?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ofdgo_font.go | 223 ++++++++++++++++++++++++++++++++++++++++++++++ ofdgo_renderer.go | 15 ++-- 2 files changed, 232 insertions(+), 6 deletions(-) create mode 100644 ofdgo_font.go diff --git a/ofdgo_font.go b/ofdgo_font.go new file mode 100644 index 0000000..5fb8264 --- /dev/null +++ b/ofdgo_font.go @@ -0,0 +1,223 @@ +// 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" + "encoding/binary" + "fmt" +) + +// FixFontData 修复字体数据 +// 本函数主要解决嵌入字体缺失 OS/2 表导致部分渲染库（如 tdewolff/font）Panic 的问题 +// 通过解析 hhea 表获取 Ascender/Descender 等度量信息，构造并注入一个标准的 OS/2 表 +// 入参: data 原始字体文件数据 +// 返回: bool 是否进行了修补, []byte 修复后的字体数据, error 错误信息 +func FixFontData(data []byte) (bool, []byte, error) { + if len(data) < 12 { + return false, data, nil + } + numTables := binary.BigEndian.Uint16(data[4:6]) + hasOS2 := false + type TableRecord struct { + Tag string + CheckSum uint32 + Offset uint32 + Length uint32 + } + tables := make([]TableRecord, 0, numTables) + var hhea TableRecord + hasHhea := false + pos := 12 + for i := 0; i < int(numTables); i++ { + if len(data) < pos+16 { + return false, data, nil + } + tag := string(data[pos : pos+4]) + checkSum := binary.BigEndian.Uint32(data[pos+4 : pos+8]) + offset := binary.BigEndian.Uint32(data[pos+8 : pos+12]) + length := binary.BigEndian.Uint32(data[pos+12 : pos+16]) + tables = append(tables, TableRecord{tag, checkSum, offset, length}) + if tag == "OS/2" { + hasOS2 = true + } + if tag == "hhea" { + hhea = TableRecord{tag, checkSum, offset, length} + hasHhea = true + } + pos += 16 + } + if hasOS2 { + return false, data, nil + } + if !hasHhea { + return false, data, nil + } + if uint32(len(data)) < hhea.Offset+hhea.Length { + return false, data, nil + } + hheaData := data[hhea.Offset : hhea.Offset+hhea.Length] + if len(hheaData) < 10 { + return false, data, nil + } + ascender := int16(binary.BigEndian.Uint16(hheaData[4:6])) + descender := int16(binary.BigEndian.Uint16(hheaData[6:8])) + os2 := new(bytes.Buffer) + binary.Write(os2, binary.BigEndian, uint16(3)) + binary.Write(os2, binary.BigEndian, int16(500)) + binary.Write(os2, binary.BigEndian, uint16(400)) + binary.Write(os2, binary.BigEndian, uint16(5)) + binary.Write(os2, binary.BigEndian, uint16(0)) + for i := 0; i < 11; i++ { + binary.Write(os2, binary.BigEndian, int16(0)) + } + os2.Write(make([]byte, 10)) + binary.Write(os2, binary.BigEndian, uint32(0)) + binary.Write(os2, binary.BigEndian, uint32(0)) + binary.Write(os2, binary.BigEndian, uint32(0)) + binary.Write(os2, binary.BigEndian, uint32(0)) + os2.WriteString("PfEd") + binary.Write(os2, binary.BigEndian, uint16(0x0040)) + binary.Write(os2, binary.BigEndian, uint16(0x0020)) + binary.Write(os2, binary.BigEndian, uint16(0xFFFD)) + binary.Write(os2, binary.BigEndian, ascender) + binary.Write(os2, binary.BigEndian, descender) + binary.Write(os2, binary.BigEndian, int16(0)) + binary.Write(os2, binary.BigEndian, uint16(ascender)) + if descender < 0 { + binary.Write(os2, binary.BigEndian, uint16(-descender)) + } else { + binary.Write(os2, binary.BigEndian, uint16(descender)) + } + binary.Write(os2, binary.BigEndian, uint32(1)) + binary.Write(os2, binary.BigEndian, uint32(0)) + binary.Write(os2, binary.BigEndian, int16(0)) + binary.Write(os2, binary.BigEndian, int16(0)) + binary.Write(os2, binary.BigEndian, uint16(0)) + binary.Write(os2, binary.BigEndian, uint16(0x0020)) + binary.Write(os2, binary.BigEndian, uint16(0)) + os2Data := os2.Bytes() + os2CheckSum := calcTableChecksum(os2Data) + newNumTables := numTables + 1 + entrySelector := 0 + for 1<<(entrySelector+1) <= int(newNumTables) { + entrySelector++ + } + searchRange := 1 << (entrySelector + 4) + rangeShift := int(newNumTables)*16 - searchRange + buf := new(bytes.Buffer) + buf.Write(data[0:4]) + binary.Write(buf, binary.BigEndian, uint16(newNumTables)) + binary.Write(buf, binary.BigEndian, uint16(searchRange)) + binary.Write(buf, binary.BigEndian, uint16(entrySelector)) + binary.Write(buf, binary.BigEndian, uint16(rangeShift)) + newTables := append(tables, TableRecord{ + Tag: "OS/2", + CheckSum: os2CheckSum, + Offset: 0, + Length: uint32(len(os2Data)), + }) + for i := 0; i < len(newTables); i++ { + for j := i + 1; j < len(newTables); j++ { + if newTables[i].Tag > newTables[j].Tag { + newTables[i], newTables[j] = newTables[j], newTables[i] + } + } + } + headerSize := 12 + 16*uint32(len(newTables)) + currentOffset := headerSize + for i := range newTables { + t := &newTables[i] + t.Offset = currentOffset + currentOffset += align4(t.Length) + } + for _, t := range newTables { + buf.WriteString(t.Tag) + binary.Write(buf, binary.BigEndian, t.CheckSum) + binary.Write(buf, binary.BigEndian, t.Offset) + binary.Write(buf, binary.BigEndian, t.Length) + } + for _, t := range newTables { + var tableData []byte + if t.Tag == "OS/2" { + tableData = os2Data + } else { + found := false + for _, old := range tables { + if old.Tag == t.Tag { + if uint32(len(data)) < old.Offset+old.Length { + return false, data, nil + } + tableData = data[old.Offset : old.Offset+old.Length] + found = true + break + } + } + if !found { + return false, data, fmt.Errorf("lost table %s", t.Tag) + } + } + buf.Write(tableData) + padding := align4(t.Length) - t.Length + for k := uint32(0); k < padding; k++ { + buf.WriteByte(0) + } + } + fullData := buf.Bytes() + var newHeadOffset uint32 + var newHeadLength uint32 + for _, t := range newTables { + if t.Tag == "head" { + newHeadOffset = t.Offset + newHeadLength = t.Length + } + } + if newHeadLength >= 12 { + checkSumAdjPos := newHeadOffset + 8 + binary.BigEndian.PutUint32(fullData[checkSumAdjPos:checkSumAdjPos+4], 0) + cs := calcTableChecksum(fullData) + adjustment := 0xB1B0AFBA - cs + binary.BigEndian.PutUint32(fullData[checkSumAdjPos:checkSumAdjPos+4], adjustment) + } + return true, fullData, nil +} + +// align4 计算 4 字节对齐后的长度 +// 入参: n 原始长度 +// 返回: uint32 对齐后的长度 +func align4(n uint32) uint32 { + return (n + 3) & ^uint32(3) +} + +// calcTableChecksum 计算字体表校验和 +// 入参: data 表数据 +// 返回: uint32 校验和 +func calcTableChecksum(data []byte) uint32 { + var sum uint32 + length := len(data) + for i := 0; i < length; i += 4 { + if i+4 <= length { + sum += binary.BigEndian.Uint32(data[i : i+4]) + } else { + var val uint32 + rem := data[i:] + for j, b := range rem { + val |= uint32(b) << (24 - 8*j) + } + sum += val + } + } + return sum +} diff --git a/ofdgo_renderer.go b/ofdgo_renderer.go index c4286cf..0e36c56 100644 --- a/ofdgo_renderer.go +++ b/ofdgo_renderer.go @@ -542,7 +542,10 @@ func (r *Renderer) loadFont(fontID string) *canvas.FontFamily { ff := canvas.NewFontFamily(of.FontName) if of.FontFile != "" { if fontData, err := r.Reader.ResData(of.FontFile); err == nil { - fontStyle := canvas.FontRegular + if _, fixedData, err := FixFontData(fontData); err == nil { + fontData = fixedData + } + var fontStyle canvas.FontStyle if of.Bold { fontStyle |= canvas.FontBold } @@ -590,15 +593,15 @@ func (r *Renderer) loadFont(fontID string) *canvas.FontFamily { names := []string{of.FamilyName, of.FontName} aliases := map[string]string{ "simhei": "SimHei", - "黑体": "SimHei", + "黑体": "SimHei", "microsoft yahei": "Microsoft YaHei", - "微软雅黑": "Microsoft YaHei", + "微软雅黑": "Microsoft YaHei", "simsun": "SimSun", - "宋体": "SimSun", + "宋体": "SimSun", "kaiti": "KaiTi", - "楷体": "KaiTi", + "楷体": "KaiTi", "fangsong": "FangSong", - "仿宋": "FangSong", + "仿宋": "FangSong", "arial": "Arial", "segoe ui": "Segoe UI", "times new roman": "Times New Roman",