feat(字体处理): 完善字体兼容及图像性能

ofdgo_font_cff.go

@@ -30,12 +30,6 @@ import (
 // cffDict 使用float64存储所有数值，以统一处理整数和实数
 type cffDict map[int][]float64
 
-// type2Operand Type2操作数
-type type2Operand struct {
-	value    int
-	outStart int
-}
-
 // wrapCFFToOTF 将CFF裸数据包装为OpenType字体格式
 // 入参: cffData CFF字体数据
 // 返回: []byte OTF字体数据, map[rune]uint16 字符映射, error 错误信息
@@ -46,9 +40,10 @@ func wrapCFFToOTF(cffData []byte) ([]byte, map[rune]uint16, error) {
 	}
 	mapping := getCmapFromCFF(cffData, int(numGlyphs))
 	sanitized, err := sanitizeCFF(cffData)
-	if err == nil {
-		cffData = sanitized
+	if err != nil {
+		return nil, nil, err
 	}
+	cffData = sanitized
 	cffData, err = normalizeCFFCharstrings(cffData)
 	if err != nil {
 		return nil, nil, err
@@ -114,8 +109,10 @@ func normalizeCFFCharstrings(data []byte) ([]byte, error) {
 	if charStart < topStart+topSize || charSize == 0 || charStart+charSize > len(data) {
 		return nil, fmt.Errorf("invalid CFF charstrings")
 	}
-	chars := readCFFIndexItems(data, charStart)
-	changed := false
+	chars, changed, err := normalizeType2Programs(data)
+	if err != nil {
+		return nil, err
+	}
 	var explicitCharset []byte
 	if charset := dict[15]; len(charset) == 1 && (charset[0] == 1 || charset[0] == 2) {
 		sids, _, _, _, ok := getCFFCharsetInfo(data, len(chars))
@@ -128,22 +125,6 @@ func normalizeCFFCharstrings(data []byte) ([]byte, error) {
 		}
 		changed = true
 	}
-	for index, charstring := range chars {
-		normalized, inserted, err := explicitType2CounterStems(charstring)
-		if err != nil {
-			return nil, err
-		}
-		changed = changed || inserted
-		if bytes.Contains(normalized, []byte{12, 0}) {
-			var removed bool
-			normalized, removed, err = stripType2Dotsection(normalized)
-			if err != nil {
-				return nil, err
-			}
-			changed = changed || removed
-		}
-		chars[index] = normalized
-	}
 	if !changed {
 		return data, nil
 	}
@@ -197,110 +178,6 @@ func normalizeCFFCharstrings(data []byte) ([]byte, error) {
 	return result, nil
 }
 
-// explicitType2CounterStems 将计数掩码前省略的vstemhm补为显式指令，不改变笔画提示及掩码
-// 入参: data Type2字形程序
-// 返回: []byte 等价程序, bool 是否发生变更, error 字节码错误
-func explicitType2CounterStems(data []byte) ([]byte, bool, error) {
-	operands, hints := 0, 0
-	for index := 0; index < len(data); {
-		start, op := index, data[index]
-		index++
-		switch {
-		case op == 28:
-			index += 2
-			operands++
-		case op == 255:
-			index += 4
-			operands++
-		case op >= 247:
-			index++
-			operands++
-		case op >= 32:
-			operands++
-		case op == 1 || op == 3 || op == 18 || op == 23:
-			hints += operands / 2
-			operands = 0
-		case op == 19 || op == 20:
-			hints += operands / 2
-			index += (hints + 7) / 8
-			if index > len(data) {
-				return nil, false, fmt.Errorf("incomplete Type2 hint mask")
-			}
-			if op == 20 && operands >= 2 {
-				result := make([]byte, 0, len(data)+1)
-				result = append(result, data[:start]...)
-				result = append(result, 23)
-				return append(result, data[start:]...), true, nil
-			}
-			operands = 0
-		case op == 12 && index < len(data) && data[index] == 0:
-			index++
-		default:
-			return data, false, nil
-		}
-		if index > len(data) {
-			return nil, false, fmt.Errorf("incomplete Type2 operand")
-		}
-	}
-	return data, false, nil
-}
-
-// stripType2Dotsection 保留字形指令与掩码并移除无效果的旧指令
-// 入参: data Type2字形程序
-// 返回: []byte 标准化后的程序, bool 是否发生变更, error 错误信息
-func stripType2Dotsection(data []byte) ([]byte, bool, error) {
-	var result []byte
-	stack, hints := 0, 0
-	for index := 0; index < len(data); {
-		start := index
-		operator := int(data[index])
-		index++
-		switch {
-		case operator == 28:
-			index += 2
-			stack++
-		case operator == 255:
-			index += 4
-			stack++
-		case operator >= 247 && operator <= 254:
-			index++
-			stack++
-		case operator >= 32:
-			stack++
-		case operator == 12:
-			if index >= len(data) {
-				return nil, false, fmt.Errorf("incomplete Type2 operator")
-			}
-			operator = 1200 + int(data[index])
-			index++
-			if operator == 1200 {
-				if result == nil {
-					result = append(make([]byte, 0, len(data)-2), data[:start]...)
-				}
-				continue
-			}
-		default:
-			if operator == 1 || operator == 3 || operator == 18 || operator == 23 || operator == 19 || operator == 20 {
-				hints += stack / 2
-			}
-			if operator == 19 || operator == 20 {
-				index += (hints + 7) / 8
-			}
-			stack = 0
-		}
-		if index > len(data) {
-			return nil, false, fmt.Errorf("incomplete Type2 charstring")
-		}
-		if result != nil {
-			result = append(result, data[start:index]...)
-		}
-	}
-	if result == nil {
-		return data, false, nil
-	}
-	return result, true, nil
-}
-
 // sanitizeCFF 尝试清洗CFF数据，转换CID字体并合并FontMatrix
 // 入参: data 原始CFF数据
 // 返回: []byte 清洗后的CFF数据, error 错误信息
@@ -451,23 +328,55 @@ func sanitizeMultiFDCFF(data []byte, hdrSize int, nameIndexData []byte, topDict
 		return nil, fmt.Errorf("missing charstrings")
 	}
 	charStringsOff := int(charStringsOffs[0])
-	charStrings := readCFFIndexItems(data, charStringsOff)
+	charStrings, _, err := readType2Index(data, charStringsOff)
+	if err != nil {
+		return nil, err
+	}
 	if len(charStrings) == 0 {
 		return nil, fmt.Errorf("missing charstrings")
 	}
-	fdSelect := make([]int, len(charStrings))
-	if fdSelectVals, ok := topDict[1237]; ok && len(fdSelectVals) > 0 {
-		fdSelect = parseCFFFDSelect(data, int(fdSelectVals[0]), len(charStrings))
+	fdSelectVals := topDict[1237]
+	if len(fdSelectVals) != 1 || !finite(fdSelectVals[0]) || fdSelectVals[0] < 0 || fdSelectVals[0] >= float64(len(data)) || fdSelectVals[0] != math.Trunc(fdSelectVals[0]) {
+		return nil, fmt.Errorf("invalid CFF FDSelect offset")
 	}
-	globalSubrs := readCFFIndexItems(globalSubrIndexData, 0)
-	localSubrs, privateDicts := readCFFLocalSubrs(data, fdArrOff, fdCount)
-	inlined := make([][]byte, len(charStrings))
-	for gid, cs := range charStrings {
-		fd := 0
-		if gid < len(fdSelect) && fdSelect[gid] >= 0 && fdSelect[gid] < len(localSubrs) {
-			fd = fdSelect[gid]
+	fdSelect, err := readType2FDSelect(data, int(fdSelectVals[0]), len(charStrings), fdCount)
+	if err != nil {
+		return nil, err
+	}
+	globalSubrs, _, err := readType2Index(globalSubrIndexData, 0)
+	if err != nil {
+		return nil, err
+	}
+	fdItems, _, err := readType2Index(data, fdArrOff)
+	if err != nil {
+		return nil, err
+	}
+	if len(fdItems) != fdCount {
+		return nil, fmt.Errorf("invalid CFF FDArray count")
+	}
+	fonts := make([]type2Font, fdCount)
+	privateDicts := make([]cffDict, fdCount)
+	for fd, item := range fdItems {
+		fonts[fd] = type2Font{data: data, chars: charStrings, globals: globalSubrs, seed: 1}
+		privateDicts[fd], err = readType2Private(data, parseCFFDict(item)[18], &fonts[fd])
+		if err != nil {
+			return nil, fmt.Errorf("CFF font dictionary %d: %w", fd, err)
 		}
-		inlined[gid] = removeType2Hints(inlineType2CharString(cs, localSubrs[fd], globalSubrs, 0))
+	}
+	inlined := make([][]byte, len(charStrings))
+	var stack [48]float64
+	for gid, cs := range charStrings {
+		font := &fonts[fdSelect[gid]]
+		var output bytes.Buffer
+		steps := 0
+		state := type2State{font: font, args: stack[:0], widthTarget: &fonts[0], width: font.def, seed: font.seed + uint64(gid), steps: &steps, output: &output, stripHints: true}
+		if len(cs) == 0 {
+			cs = []byte{14}
+		}
+		if _, err := state.run(cs, 0); err != nil {
+			return nil, fmt.Errorf("CFF glyph %d: %w", gid, err)
+		}
+		inlined[gid] = output.Bytes()
 	}
 	delete(topDict, 1230)
 	delete(topDict, 1236)
@@ -487,7 +396,7 @@ func sanitizeMultiFDCFF(data []byte, hdrSize int, nameIndexData []byte, topDict
 	}
 	finalPrivData := encodeCFFDict(privateDict)
 	charStringsData := encodeCFFIndex(inlined)
-	return encodeSanitizedCFF(data[:hdrSize], nameIndexData, topDict, stringIndexData, globalSubrIndexData, charStringsData, finalPrivData, nil), nil
+	return encodeSanitizedCFF(data[:hdrSize], nameIndexData, topDict, stringIndexData, encodeCFFIndex(nil), charStringsData, finalPrivData, nil), nil
 }
 
 // encodeSanitizedCFF 按字典编码长度收敛偏移并组装规范化字体
@@ -939,201 +848,6 @@ func parseCFFFDSelect(data []byte, offset int, numGlyphs int) []int {
 	return result
 }
 
-// readCFFLocalSubrs 读取CID CFF的本地子程序
-// 入参: data CFF数据, fdArrOff FDArray偏移, fdCount FD数量
-// 返回: [][][]byte 本地子程序列表, []cffDict Private字典列表
-func readCFFLocalSubrs(data []byte, fdArrOff int, fdCount int) ([][][]byte, []cffDict) {
-	fdItems := readCFFIndexItems(data, fdArrOff)
-	localSubrs := make([][][]byte, fdCount)
-	privateDicts := make([]cffDict, fdCount)
-	for i := 0; i < fdCount && i < len(fdItems); i++ {
-		fdDict := parseCFFDict(fdItems[i])
-		privVals, ok := fdDict[18]
-		if !ok || len(privVals) != 2 {
-			privateDicts[i] = make(cffDict)
-			continue
-		}
-		privSize := int(privVals[0])
-		privOff := int(privVals[1])
-		if privSize <= 0 || privOff < 0 || privOff+privSize > len(data) {
-			privateDicts[i] = make(cffDict)
-			continue
-		}
-		privData := data[privOff : privOff+privSize]
-		privDict := parseCFFDict(privData)
-		privateDicts[i] = privDict
-		if subrVals, ok := privDict[19]; ok && len(subrVals) > 0 {
-			subrOff := privOff + int(subrVals[0])
-			if subrOff >= 0 && subrOff < len(data) {
-				localSubrs[i] = readCFFIndexItems(data, subrOff)
-			}
-		}
-	}
-	return localSubrs, privateDicts
-}
-
-// inlineType2CharString 内联Type2 CharString子程序调用
-// 入参: data CharString数据, localSubrs 本地子程序, globalSubrs 全局子程序, depth 递归深度
-// 返回: []byte 内联后的CharString数据
-func inlineType2CharString(data []byte, localSubrs, globalSubrs [][]byte, depth int) []byte {
-	if depth > 8 {
-		return data
-	}
-	out := make([]byte, 0, len(data))
-	var stack []type2Operand
-	hintCount := 0
-	for i := 0; i < len(data); {
-		b := data[i]
-		if b == 28 && i+2 < len(data) {
-			start := len(out)
-			out = append(out, data[i:i+3]...)
-			stack = append(stack, type2Operand{value: int(parseShortInt(data, i)), outStart: start})
-			i += 3
-			continue
-		}
-		if b >= 32 && b <= 246 {
-			start := len(out)
-			out = append(out, b)
-			stack = append(stack, type2Operand{value: int(parseNumberType2(data, i)), outStart: start})
-			i++
-			continue
-		}
-		if b >= 247 && b <= 254 && i+1 < len(data) {
-			start := len(out)
-			out = append(out, data[i:i+2]...)
-			stack = append(stack, type2Operand{value: int(parseNumberType2(data, i)), outStart: start})
-			i += 2
-			continue
-		}
-		if b == 255 && i+4 < len(data) {
-			start := len(out)
-			out = append(out, data[i:i+5]...)
-			stack = append(stack, type2Operand{value: int(parseNumberType2(data, i)), outStart: start})
-			i += 5
-			continue
-		}
-		if b == 10 || b == 29 {
-			if len(stack) > 0 {
-				operand := stack[len(stack)-1]
-				out = out[:operand.outStart]
-				subrs := localSubrs
-				if b == 29 {
-					subrs = globalSubrs
-				}
-				idx := operand.value + cffSubrBias(len(subrs))
-				if idx >= 0 && idx < len(subrs) {
-					subr := inlineType2CharString(subrs[idx], localSubrs, globalSubrs, depth+1)
-					if len(subr) > 0 && subr[len(subr)-1] == 11 {
-						subr = subr[:len(subr)-1]
-					}
-					out = append(out, subr...)
-				}
-				stack = nil
-			}
-			i++
-			continue
-		}
-		if b == 11 && depth > 0 {
-			return out
-		}
-		out = append(out, b)
-		i++
-		op := int(b)
-		if b == 12 && i < len(data) {
-			out = append(out, data[i])
-			op = 1200 + int(data[i])
-			i++
-		}
-		switch op {
-		case 1, 3, 18, 23:
-			hintCount += len(stack) / 2
-		case 19, 20:
-			hintCount += len(stack) / 2
-			maskBytes := (hintCount + 7) / 8
-			if i+maskBytes > len(data) {
-				maskBytes = len(data) - i
-			}
-			out = append(out, data[i:i+maskBytes]...)
-			i += maskBytes
-		}
-		stack = nil
-	}
-	return out
-}
-
-// removeType2Hints 移除Type2 CharString的hint指令
-// 入参: data CharString数据
-// 返回: []byte 移除hint后的CharString数据
-func removeType2Hints(data []byte) []byte {
-	out := make([]byte, 0, len(data))
-	var stack []type2Operand
-	hintCount := 0
-	for i := 0; i < len(data); {
-		b := data[i]
-		if b == 28 && i+2 < len(data) {
-			start := len(out)
-			out = append(out, data[i:i+3]...)
-			stack = append(stack, type2Operand{value: int(parseShortInt(data, i)), outStart: start})
-			i += 3
-			continue
-		}
-		if b >= 32 && b <= 246 {
-			start := len(out)
-			out = append(out, b)
-			stack = append(stack, type2Operand{value: int(parseNumberType2(data, i)), outStart: start})
-			i++
-			continue
-		}
-		if b >= 247 && b <= 254 && i+1 < len(data) {
-			start := len(out)
-			out = append(out, data[i:i+2]...)
-			stack = append(stack, type2Operand{value: int(parseNumberType2(data, i)), outStart: start})
-			i += 2
-			continue
-		}
-		if b == 255 && i+4 < len(data) {
-			start := len(out)
-			out = append(out, data[i:i+5]...)
-			stack = append(stack, type2Operand{value: int(parseNumberType2(data, i)), outStart: start})
-			i += 5
-			continue
-		}
-		op := int(b)
-		opLen := 1
-		if b == 12 && i+1 < len(data) {
-			op = 1200 + int(data[i+1])
-			opLen = 2
-		}
-		switch op {
-		case 1, 3, 18, 23:
-			if len(stack) > 0 {
-				out = out[:stack[0].outStart]
-			}
-			hintCount += len(stack) / 2
-			stack = nil
-			i += opLen
-			continue
-		case 19, 20:
-			if len(stack) > 0 {
-				out = out[:stack[0].outStart]
-			}
-			hintCount += len(stack) / 2
-			i += opLen
-			maskBytes := (hintCount + 7) / 8
-			if i+maskBytes > len(data) {
-				maskBytes = len(data) - i
-			}
-			i += maskBytes
-			stack = nil
-			continue
-		}
-		out = append(out, data[i:i+opLen]...)
-		i += opLen
-		stack = nil
-	}
-	return out
-}
-
 // cffSubrBias 获取Type2子程序偏移
 // 入参: count 子程序数量
 // 返回: int 偏移量
@@ -1147,136 +861,42 @@ func cffSubrBias(count int) int {
 	return 32768
 }
 
-// parseCFFWidths 从CFF数据中解析Glyph宽度
+// parseCFFWidths 从Type2执行状态获取字宽，保留首个清栈指令的宽度语义
 // 入参: data CFF数据, numGlyphs 字形数量
-// 返回: []uint16 宽度列表, error 错误信息
+// 返回: []uint16 宽度列表, error 字体或执行错误
 func parseCFFWidths(data []byte, numGlyphs int) ([]uint16, error) {
-	if len(data) < 4 {
-		return nil, fmt.Errorf("data too short")
+	font, err := readType2Font(data)
+	if err != nil {
+		return nil, err
 	}
-	hdrSize := int(data[2])
-	offset := hdrSize
-	_, sz := getCFFIndexCount(data, offset)
-	offset += sz
-	topDictData, sz := getCFFIndexData(data, offset)
-	offset += sz
-	if topDictData == nil {
-		return nil, fmt.Errorf("failed to read top dict")
+	if len(font.chars) != numGlyphs {
+		return nil, fmt.Errorf("CFF glyph count differs from metrics")
 	}
-	topDict := parseCFFDict(topDictData)
-	_, sz = getCFFIndexCount(data, offset)
-	offset += sz
-	_, sz = getCFFIndexCount(data, offset)
-	offset += sz
-	var nominalWidthX float64 = 0
-	var defaultWidthX float64 = 0
-	if vals, ok := topDict[18]; ok && len(vals) == 2 {
-		privSize := int(vals[0])
-		privOff := int(vals[1])
-		if privSize > 0 && privOff+privSize <= len(data) {
-			privData := data[privOff : privOff+privSize]
-			privDict := parseCFFDict(privData)
-			if v, ok := privDict[20]; ok && len(v) > 0 {
-				defaultWidthX = v[0]
-			}
-			if v, ok := privDict[21]; ok && len(v) > 0 {
-				nominalWidthX = v[0]
+	widths := make([]uint16, numGlyphs)
+	var stack [48]float64
+	for gid, program := range font.chars {
+		if len(program) == 0 {
+			program = []byte{14}
+		}
+		steps := 0
+		state := type2State{font: font, args: stack[:0], width: font.def, widthOnly: true, seed: font.seed + uint64(gid), steps: &steps}
+		if _, err := state.run(program, 0); err != nil && !state.widthSet {
+			state.width = font.def
+		}
+		if gid == 0 && state.width < 0 {
+			steps = 0
+			empty := type2State{font: font, args: stack[:0], width: font.def, seed: font.seed, steps: &steps}
+			_, err := empty.run(program, 0)
+			if err == nil && !empty.pathStarted && !empty.changed {
+				state.width = 0
 			}
 		}
+		if !finite(state.width) || state.width < 0 || state.width > math.MaxUint16 {
+			return nil, fmt.Errorf("CFF glyph %d width cannot be represented", gid)
+		}
+		widths[gid] = uint16(math.Round(state.width))
 	}
-	if vals, ok := topDict[17]; ok && len(vals) > 0 {
-		charStrOff := int(vals[0])
-		count, _ := getCFFIndexCount(data, charStrOff)
-		limit := count
-		if numGlyphs < limit {
-			limit = numGlyphs
-		}
-		widths := make([]uint16, numGlyphs)
-		for i := range widths {
-			widths[i] = uint16(defaultWidthX)
-		}
-		for i := 0; i < limit; i++ {
-			offSize := int(data[charStrOff+2])
-			p1 := charStrOff + 3 + i*offSize
-			p2 := p1 + offSize
-			off1 := readCFFOffset(data, p1, offSize)
-			off2 := readCFFOffset(data, p2, offSize)
-			dataStartBase := charStrOff + 3 + (count+1)*offSize
-			start := dataStartBase + (off1 - 1)
-			length := off2 - off1
-			if start < 0 || start+length > len(data) {
-				widths[i] = uint16(defaultWidthX)
-				continue
-			}
-			csData := data[start : start+length]
-			w := scanCharStringWidth(csData, nominalWidthX, defaultWidthX)
-			widths[i] = uint16(w)
-		}
-		return widths, nil
-	}
-	return nil, fmt.Errorf("no charstrings")
-}
-
-// scanCharStringWidth 扫描CharString获取宽度
-// 入参: data CharString数据, nominal 名义宽度, def 默认宽度
-// 返回: float64 宽度值
-func scanCharStringWidth(data []byte, nominal, def float64) float64 {
-	stackDepth := 0
-	i := 0
-	firstVal := 0.0
-	for i < len(data) {
-		b := data[i]
-		if b <= 31 {
-			if b == 28 {
-				i += 3
-				stackDepth++
-				if stackDepth == 1 {
-					firstVal = parseShortInt(data, i-3)
-				}
-			} else if b == 29 {
-				i += 5
-				stackDepth++
-			} else if b == 12 {
-				i += 2
-				if stackDepth%2 != 0 {
-					return nominal + firstVal
-				}
-				return def
-			} else if b == 19 || b == 20 {
-				if stackDepth%2 != 0 {
-					return nominal + firstVal
-				}
-				return def
-			} else {
-				if stackDepth%2 != 0 {
-					return nominal + firstVal
-				}
-				return def
-			}
-		} else {
-			stackDepth++
-			if stackDepth == 1 {
-				firstVal = parseNumberType2(data, i)
-			}
-			if b >= 32 && b <= 246 {
-				i++
-			} else if b >= 247 && b <= 250 {
-				i += 2
-			} else if b >= 251 && b <= 254 {
-				i += 2
-			} else if b == 255 {
-				i += 5
-			}
-		}
-	}
-	return def
-}
-
-// parseShortInt 解析短整数 (Type 2 CharString)
-// 入参: data 数据, idx 索引
-// 返回: float64 浮点值
-func parseShortInt(data []byte, idx int) float64 {
-	return float64(int16(binary.BigEndian.Uint16(data[idx+1:])))
+	return widths, nil
 }
 
 // parseNumberType2 解析Number (Type 2)

ofdgo_font_ttf.go

@@ -40,10 +40,10 @@ func fixTrueType(data []byte, fixCmap, fixName bool) (bool, []byte, map[rune]uin
 		tag := string(data[pos : pos+4])
 		offset := binary.BigEndian.Uint32(data[pos+8 : pos+12])
 		length := binary.BigEndian.Uint32(data[pos+12 : pos+16])
-		if uint32(len(data)) >= offset+length {
-			existingTables[tag] = data[offset : offset+length]
+		if uint64(offset)+uint64(length) <= uint64(len(data)) {
+			existingTables[tag] = data[int(offset) : int(offset)+int(length)]
 			padding := (4 - (length & 3)) & 3
-			if offset%4 != 0 || uint32(len(data))-offset-length < padding {
+			if offset%4 != 0 || len(data)-int(offset)-int(length) < int(padding) {
 				malformedDirectory = true
 			}
 		} else {
@@ -53,6 +53,18 @@ func fixTrueType(data []byte, fixCmap, fixName bool) (bool, []byte, map[rune]uin
 	}
 	if existingTables["CFF "] != nil {
 		isCFFSfnt = true
+		sanitized, err := sanitizeCFF(existingTables["CFF "])
+		if err != nil {
+			return false, data, nil, false, err
+		}
+		normalized, err := normalizeCFFCharstrings(sanitized)
+		if err != nil {
+			return false, data, nil, false, err
+		}
+		if !bytes.Equal(normalized, existingTables["CFF "]) {
+			existingTables["CFF "] = normalized
+			malformedDirectory = true
+		}
 	}
 	cmap, err := normalizeCmap(existingTables["cmap"])
 	if err != nil {

ofdgo_font_type2.go

@@ -0,0 +1,502 @@
+// 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"
+	"math"
+	"slices"
+)
+
+// type2Font 保存Type2字形程序、子程序及私有字宽
+type type2Font struct {
+	data         []byte
+	chars        [][]byte
+	locals       [][]byte
+	globals      [][]byte
+	names        map[string]int
+	nominal, def float64
+	seed         uint64
+}
+
+// type2State 按Type2规范保存跨子程序共享的执行状态
+type type2State struct {
+	font             *type2Font
+	widthTarget      *type2Font
+	args             []float64
+	transient        [32]float64
+	stored           uint32
+	width            float64
+	widthSet         bool
+	widthOnly        bool
+	hints            int
+	x, y             float64
+	outX, outY       float64
+	originX, originY float64
+	component        bool
+	stripHints       bool
+	pathStarted      bool
+	changed          bool
+	output           *bytes.Buffer
+	seed             uint64
+	steps            *int
+}
+
+// readType2Index 读取并校验CFF索引的全部偏移，不复制程序字节
+// 入参: data 字体数据, offset 索引偏移
+// 返回: [][]byte 索引项, int 索引结束位置, error 错误信息
+func readType2Index(data []byte, offset int) ([][]byte, int, error) {
+	if offset < 0 || offset > len(data)-2 {
+		return nil, 0, fmt.Errorf("truncated CFF index")
+	}
+	count := int(binary.BigEndian.Uint16(data[offset:]))
+	if count == 0 {
+		return nil, offset + 2, nil
+	}
+	if offset > len(data)-3 {
+		return nil, 0, fmt.Errorf("truncated CFF index header")
+	}
+	width := int(data[offset+2])
+	if width < 1 || width > 4 || count+1 > (len(data)-offset-3)/width {
+		return nil, 0, fmt.Errorf("invalid CFF index offsets")
+	}
+	base := offset + 3 + (count+1)*width
+	items := make([][]byte, count)
+	previous := uint64(0)
+	for index := 0; index <= count; index++ {
+		value := uint64(0)
+		for _, b := range data[offset+3+index*width : offset+3+(index+1)*width] {
+			value = value<<8 | uint64(b)
+		}
+		if value < 1 || value-1 > uint64(len(data)-base) || value < previous || index == 0 && value != 1 {
+			return nil, 0, fmt.Errorf("invalid CFF index range")
+		}
+		if index != 0 {
+			items[index-1] = data[base+int(previous)-1 : base+int(value)-1]
+		}
+		previous = value
+	}
+	return items, base + int(previous) - 1, nil
+}
+
+// readType2Font 读取单FD字体的Type2执行资源，CID字体先经字体规范化
+// 入参: data CFF字体数据
+// 返回: *type2Font 执行资源, error 错误信息
+func readType2Font(data []byte) (*type2Font, error) {
+	if !isBareCFFData(data) {
+		return nil, fmt.Errorf("invalid CFF header")
+	}
+	names, end, err := readType2Index(data, int(data[2]))
+	if err != nil {
+		return nil, fmt.Errorf("invalid CFF name index: %w", err)
+	}
+	if len(names) != 1 {
+		return nil, fmt.Errorf("invalid CFF font count")
+	}
+	tops, end, err := readType2Index(data, end)
+	if err != nil {
+		return nil, fmt.Errorf("invalid CFF top index: %w", err)
+	}
+	if len(tops) != 1 {
+		return nil, fmt.Errorf("invalid CFF top dictionary count")
+	}
+	_, end, err = readType2Index(data, end)
+	if err != nil {
+		return nil, err
+	}
+	globals, _, err := readType2Index(data, end)
+	if err != nil {
+		return nil, err
+	}
+	dict := parseCFFDict(tops[0])
+	if value, ok := dict[1206]; ok && (len(value) != 1 || value[0] != 2) {
+		return nil, fmt.Errorf("unsupported CFF charstring type")
+	}
+	if _, cid := dict[1230]; cid {
+		return nil, fmt.Errorf("CID CFF requires FD normalization")
+	}
+	offset := dict[17]
+	if len(offset) != 1 || !finite(offset[0]) || offset[0] < 0 || offset[0] > float64(len(data)) || offset[0] != math.Trunc(offset[0]) {
+		return nil, fmt.Errorf("invalid CFF charstrings offset")
+	}
+	chars, _, err := readType2Index(data, int(offset[0]))
+	if err != nil {
+		return nil, fmt.Errorf("invalid CFF charstrings: %w", err)
+	}
+	if len(chars) == 0 {
+		return nil, fmt.Errorf("empty CFF charstrings")
+	}
+	font := &type2Font{data: data, chars: chars, globals: globals, seed: 1}
+	if _, err := readType2Private(data, dict[18], font); err != nil {
+		return nil, err
+	}
+	return font, nil
+}
+
+// readType2Private 读取FD私有字宽、随机种子和局部子程序
+// 入参: data 字体数据, values Private范围, font 执行资源
+// 返回: cffDict 私有字典, error 范围或字段错误
+func readType2Private(data []byte, values []float64, font *type2Font) (cffDict, error) {
+	private := cffDict{}
+	var err error
+	if values != nil {
+		if len(values) != 2 || !finite(values[0]) || !finite(values[1]) || values[0] < 0 || values[1] < 0 || values[0] > float64(len(data)) || values[1] > float64(len(data))-values[0] || values[0] != math.Trunc(values[0]) || values[1] != math.Trunc(values[1]) {
+			return nil, fmt.Errorf("invalid CFF private range")
+		}
+		start := int(values[1])
+		private = parseCFFDict(data[start : start+int(values[0])])
+		for op, target := range map[int]*float64{20: &font.def, 21: &font.nominal} {
+			if value, ok := private[op]; ok {
+				if len(value) != 1 || !finite(value[0]) {
+					return nil, fmt.Errorf("invalid CFF private width")
+				}
+				*target = value[0]
+			}
+		}
+		if value, ok := private[1219]; ok {
+			if len(value) != 1 || !finite(value[0]) || value[0] < math.MinInt32 || value[0] > math.MaxInt32 || value[0] != math.Trunc(value[0]) {
+				return nil, fmt.Errorf("invalid CFF random seed")
+			}
+			font.seed = uint64(int64(value[0])) | 1
+		}
+		if value, ok := private[19]; ok {
+			if len(value) != 1 || !finite(value[0]) || value[0] < 0 || value[0] > float64(len(data)-start) || value[0] != math.Trunc(value[0]) {
+				return nil, fmt.Errorf("invalid CFF local subroutine offset")
+			}
+			font.locals, _, err = readType2Index(data, start+int(value[0]))
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+	return private, nil
+}
+
+// normalizeType2Programs 展开组合字形和求值指令，普通字形保留原程序及提示
+// 无法规范化的字形保留原程序，由实际使用时的轮廓解析校验
+// 入参: data CFF字体数据
+// 返回: [][]byte 字形程序, bool 是否变更, error 错误信息
+func normalizeType2Programs(data []byte) ([][]byte, bool, error) {
+	font, err := readType2Font(data)
+	if err != nil {
+		return nil, false, err
+	}
+	result := slices.Clone(font.chars)
+	changed := false
+	var stack [48]float64
+	for gid, program := range font.chars {
+		if len(program) == 0 {
+			continue
+		}
+		steps := 0
+		state := type2State{font: font, args: stack[:0], width: font.def, seed: font.seed + uint64(gid), steps: &steps}
+		_, err := state.run(program, 0)
+		if err != nil {
+			continue
+		}
+		if !state.changed {
+			continue
+		}
+		var output bytes.Buffer
+		steps = 0
+		state = type2State{font: font, args: stack[:0], width: font.def, seed: font.seed + uint64(gid), steps: &steps, output: &output}
+		if _, err := state.run(program, 0); err != nil {
+			return nil, false, fmt.Errorf("CFF glyph %d: %w", gid, err)
+		}
+		result[gid] = output.Bytes()
+		changed = true
+	}
+	return result, changed, nil
+}
+
+// push 按Type2规范附录B校验并追加操作数
+// 入参: value 操作数
+// 返回: error 栈或数值错误
+func (s *type2State) push(value float64) error {
+	if !finite(value) || len(s.args) >= 48 {
+		return fmt.Errorf("invalid Type2 operand stack")
+	}
+	s.args = append(s.args, value)
+	return nil
+}
+
+// emit 写入已经求值的操作数及指令，分析阶段不分配输出
+// 入参: op 操作符, values 操作数
+// 返回: error 数值编码或程序长度错误
+func (s *type2State) emit(op int, values []float64) error {
+	if s.output == nil {
+		return nil
+	}
+	for _, value := range values {
+		if err := encodeType2Number(s.output, value); err != nil {
+			return err
+		}
+	}
+	if op >= 1200 {
+		s.output.WriteByte(12)
+		s.output.WriteByte(byte(op - 1200))
+	} else {
+		s.output.WriteByte(byte(op))
+	}
+	if s.output.Len() > 65535 {
+		return fmt.Errorf("expanded Type2 charstring exceeds 65535 bytes")
+	}
+	return nil
+}
+
+// takeWidth 在首次清栈指令前提取可选字宽，组件不写入自身字宽
+// 入参: explicit 是否含字宽
+// 返回: error 字宽编码错误
+func (s *type2State) takeWidth(explicit bool) error {
+	if s.widthSet {
+		return nil
+	}
+	s.widthSet = true
+	if explicit {
+		s.width = s.font.nominal + s.args[0]
+		if !finite(s.width) {
+			return fmt.Errorf("invalid Type2 width")
+		}
+		if s.output != nil && !s.component && s.widthTarget == nil {
+			if err := encodeType2Number(s.output, s.args[0]); err != nil {
+				return err
+			}
+		}
+		copy(s.args, s.args[1:])
+		s.args = s.args[:len(s.args)-1]
+	}
+	if s.output != nil && !s.component && s.widthTarget != nil && s.width != s.widthTarget.def {
+		return encodeType2Number(s.output, s.width-s.widthTarget.nominal)
+	}
+	return nil
+}
+
+// run 执行Type2程序，操作数和暂存数组在子程序间共享
+// 入参: data 字形或子程序, depth 调用深度
+// 返回: bool 是否结束字形, error 指令错误
+func (s *type2State) run(data []byte, depth int) (bool, error) {
+	if depth > 10 || len(data) > 65535 {
+		return false, fmt.Errorf("Type2 implementation limit exceeded")
+	}
+	for index := 0; index < len(data); {
+		(*s.steps)++
+		if *s.steps > 1<<20 {
+			return false, fmt.Errorf("Type2 execution limit exceeded")
+		}
+		op := int(data[index])
+		start := index
+		index++
+		if op == 28 || op >= 32 {
+			length := 1
+			if op == 28 {
+				length = 3
+			} else if op == 255 {
+				length = 5
+			} else if op >= 247 {
+				length = 2
+			}
+			if length > len(data)-start {
+				return false, fmt.Errorf("truncated Type2 number")
+			}
+			index = start + length
+			if err := s.push(parseNumberType2(data, start)); err != nil {
+				return false, err
+			}
+			continue
+		}
+		if op == 12 {
+			if index == len(data) {
+				return false, fmt.Errorf("truncated Type2 operator")
+			}
+			op = 1200 + int(data[index])
+			index++
+		}
+		switch op {
+		case 10, 29:
+			if len(s.args) == 0 {
+				return false, fmt.Errorf("missing Type2 subroutine number")
+			}
+			value := s.args[len(s.args)-1]
+			s.args = s.args[:len(s.args)-1]
+			subrs := s.font.locals
+			if op == 29 {
+				subrs = s.font.globals
+			}
+			value += float64(cffSubrBias(len(subrs)))
+			if value < 0 || value >= float64(len(subrs)) || value != math.Trunc(value) {
+				return false, fmt.Errorf("invalid Type2 subroutine number")
+			}
+			ended, err := s.run(subrs[int(value)], depth+1)
+			if ended || err != nil {
+				return ended, err
+			}
+		case 11:
+			if depth == 0 {
+				return false, fmt.Errorf("Type2 return outside subroutine")
+			}
+			return false, nil
+		case 1, 3, 18, 23, 19, 20:
+			if err := s.takeWidth(len(s.args)%2 == 1); err != nil {
+				return false, err
+			}
+			if s.widthOnly {
+				return true, nil
+			}
+			if len(s.args)%2 != 0 || s.hints+len(s.args)/2 > 96 {
+				return false, fmt.Errorf("invalid Type2 stem hints")
+			}
+			s.hints += len(s.args) / 2
+			if op == 19 || op == 20 {
+				if s.hints == 0 {
+					return false, fmt.Errorf("Type2 mask has no stem hints")
+				}
+				length := (s.hints + 7) / 8
+				if length > len(data)-index {
+					return false, fmt.Errorf("truncated Type2 hint mask")
+				}
+				if !s.component && !s.stripHints && len(s.args) > 0 {
+					if err := s.emit(23, s.args); err != nil {
+						return false, err
+					}
+					if op == 20 {
+						s.changed = true
+					}
+				}
+				if !s.component && !s.stripHints {
+					if err := s.emit(op, nil); err != nil {
+						return false, err
+					}
+					if s.output != nil {
+						s.output.Write(data[index : index+length])
+					}
+				}
+				index += length
+			} else if !s.component && !s.stripHints {
+				if err := s.emit(op, s.args); err != nil {
+					return false, err
+				}
+			}
+			s.args = s.args[:0]
+		case 4, 21, 22:
+			count := 1
+			if op == 21 {
+				count = 2
+			}
+			if err := s.takeWidth(len(s.args) == count+1); err != nil {
+				return false, err
+			}
+			if len(s.args) != count {
+				return false, fmt.Errorf("invalid Type2 moveto operands")
+			}
+			if s.widthOnly {
+				return true, nil
+			}
+			if op != 4 {
+				s.x += s.args[0]
+			}
+			if op != 22 {
+				s.y += s.args[count-1]
+			}
+			if !finite(s.x) || !finite(s.y) {
+				return false, fmt.Errorf("invalid Type2 current point")
+			}
+			if s.component {
+				if err := s.emit(21, []float64{s.x + s.originX - s.outX, s.y + s.originY - s.outY}); err != nil {
+					return false, err
+				}
+			} else if err := s.emit(op, s.args); err != nil {
+				return false, err
+			}
+			s.outX, s.outY = s.x+s.originX, s.y+s.originY
+			s.pathStarted = true
+			s.args = s.args[:0]
+		case 14:
+			if err := s.takeWidth(len(s.args) == 1 || len(s.args) == 5); err != nil {
+				return false, err
+			}
+			if s.widthOnly {
+				return true, nil
+			}
+			if len(s.args) == 4 {
+				if s.component {
+					return false, fmt.Errorf("nested Type2 composite glyph")
+				}
+				if err := s.appendComponent(s.args[2], 0, 0); err != nil {
+					return false, err
+				}
+				if err := s.appendComponent(s.args[3], s.args[0], s.args[1]); err != nil {
+					return false, err
+				}
+				s.changed = true
+			} else if len(s.args) != 0 {
+				return false, fmt.Errorf("invalid Type2 endchar operands")
+			}
+			if !s.component {
+				if err := s.emit(14, nil); err != nil {
+					return false, err
+				}
+			}
+			return true, nil
+		case 1200:
+			s.changed = true
+		case 5, 6, 7, 8, 24, 25, 26, 27, 30, 31, 1234, 1235, 1236, 1237:
+			if !s.pathStarted {
+				return false, fmt.Errorf("Type2 path has no moveto")
+			}
+			if err := s.draw(op); err != nil {
+				return false, err
+			}
+		default:
+			if err := s.calculate(op); err != nil {
+				return false, err
+			}
+			s.changed = true
+		}
+	}
+	return false, fmt.Errorf("Type2 program has no terminator")
+}
+
+// appendComponent 按StandardEncoding查找组合组件，保持源字宽与独立暂存状态
+// 入参: code 标准字符码, x 横向偏移, y 纵向偏移
+// 返回: error 组件或指令错误
+func (s *type2State) appendComponent(code, x, y float64) error {
+	if code < 0 || code > 255 || code != math.Trunc(code) || type1StandardNames[int(code)] == "" {
+		return fmt.Errorf("invalid Type2 component code")
+	}
+	if s.font.names == nil {
+		sids, _, _, index, ok := getCFFCharsetInfo(s.font.data, len(s.font.chars))
+		if !ok {
+			return fmt.Errorf("invalid Type2 composite charset")
+		}
+		s.font.names = make(map[string]int, len(sids))
+		for gid, sid := range sids {
+			s.font.names[getCFFSIDString(s.font.data, index, sid)] = gid
+		}
+	}
+	name := type1StandardNames[int(code)]
+	gid, ok := s.font.names[name]
+	if !ok {
+		return fmt.Errorf("missing Type2 component %s", name)
+	}
+	child := type2State{font: s.font, width: s.font.def, component: true, output: s.output, originX: x, originY: y, outX: s.outX, outY: s.outY, seed: s.font.seed + uint64(gid), steps: s.steps}
+	_, err := child.run(s.font.chars[gid], 0)
+	if err != nil {
+		return fmt.Errorf("invalid Type2 component %s: %w", name, err)
+	}
+	s.outX, s.outY = child.outX, child.outY
+	return nil
+}

ofdgo_font_type2_fd.go

@@ -0,0 +1,69 @@
+// 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 (
+	"encoding/binary"
+	"fmt"
+)
+
+// readType2FDSelect 校验CID字体的逐字形FD归属和范围终点
+// 入参: data 字体数据, offset FDSelect偏移, count 字形数, fonts FD数量
+// 返回: []int FD索引, error 格式或范围错误
+func readType2FDSelect(data []byte, offset, count, fonts int) ([]int, error) {
+	if offset < 0 || offset >= len(data) || count <= 0 || fonts <= 0 {
+		return nil, fmt.Errorf("invalid CFF FDSelect range")
+	}
+	result := make([]int, count)
+	switch data[offset] {
+	case 0:
+		if count > len(data)-offset-1 {
+			return nil, fmt.Errorf("truncated CFF FDSelect")
+		}
+		for gid, fd := range data[offset+1 : offset+1+count] {
+			if int(fd) >= fonts {
+				return nil, fmt.Errorf("invalid CFF font dictionary index")
+			}
+			result[gid] = int(fd)
+		}
+	case 3:
+		if offset > len(data)-3 {
+			return nil, fmt.Errorf("truncated CFF FDSelect header")
+		}
+		ranges := int(binary.BigEndian.Uint16(data[offset+1:]))
+		start := offset + 3
+		if ranges == 0 || ranges > (len(data)-start-2)/3 {
+			return nil, fmt.Errorf("invalid CFF FDSelect ranges")
+		}
+		if binary.BigEndian.Uint16(data[start:]) != 0 || int(binary.BigEndian.Uint16(data[start+3*ranges:])) != count {
+			return nil, fmt.Errorf("invalid CFF FDSelect endpoints")
+		}
+		for index := 0; index < ranges; index++ {
+			pos := start + 3*index
+			first := int(binary.BigEndian.Uint16(data[pos:]))
+			last := int(binary.BigEndian.Uint16(data[pos+3:]))
+			fd := int(data[pos+2])
+			if last <= first || last > count || fd >= fonts {
+				return nil, fmt.Errorf("invalid CFF FDSelect interval")
+			}
+			for gid := first; gid < last; gid++ {
+				result[gid] = fd
+			}
+		}
+	default:
+		return nil, fmt.Errorf("unsupported CFF FDSelect format %d", data[offset])
+	}
+	return result, nil
+}

ofdgo_font_type2_stack.go

@@ -0,0 +1,268 @@
+// 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 (
+	"fmt"
+	"math"
+	"slices"
+)
+
+// calculate 求值Type2算术、条件、栈及暂存指令，不写入输出程序
+// 入参: op 操作符
+// 返回: error 操作数或运算错误
+func (s *type2State) calculate(op int) error {
+	count := 0
+	switch op {
+	case 1223:
+		s.seed = uint64(uint32(s.seed*1664525 + 1013904223))
+		return s.push(float64(s.seed+1) / 4294967296)
+	case 1205, 1209, 1214, 1218, 1221, 1226, 1227, 1229:
+		count = 1
+	case 1203, 1204, 1210, 1211, 1212, 1215, 1220, 1224, 1228, 1230:
+		count = 2
+	case 1222:
+		count = 4
+	default:
+		return fmt.Errorf("unsupported Type2 operator %d", op)
+	}
+	if len(s.args) < count {
+		return fmt.Errorf("missing Type2 operands for operator %d", op)
+	}
+	values := s.args[len(s.args)-count:]
+	value := values[0]
+	switch op {
+	case 1203:
+		value = 0
+		if values[0] != 0 && values[1] != 0 {
+			value = 1
+		}
+	case 1204:
+		value = 0
+		if values[0] != 0 || values[1] != 0 {
+			value = 1
+		}
+	case 1205:
+		value = 0
+		if values[0] == 0 {
+			value = 1
+		}
+	case 1209:
+		value = math.Abs(value)
+	case 1210:
+		value += values[1]
+	case 1211:
+		value -= values[1]
+	case 1212:
+		value /= values[1]
+	case 1214:
+		value = -value
+	case 1215:
+		value = 0
+		if values[0] == values[1] {
+			value = 1
+		}
+	case 1218:
+		s.args = s.args[:len(s.args)-1]
+		return nil
+	case 1220, 1221:
+		index := values[count-1]
+		if index < 0 || index >= float64(len(s.transient)) || index != math.Trunc(index) {
+			return fmt.Errorf("invalid Type2 transient index")
+		}
+		if op == 1220 {
+			s.transient[int(index)] = value
+			s.stored |= 1 << uint(index)
+			s.args = s.args[:len(s.args)-2]
+			return nil
+		}
+		if s.stored&(1<<uint(index)) == 0 {
+			return fmt.Errorf("uninitialized Type2 transient value")
+		}
+		value = s.transient[int(index)]
+	case 1222:
+		if values[2] > values[3] {
+			value = values[1]
+		}
+	case 1224:
+		value *= values[1]
+	case 1226:
+		value = math.Sqrt(value)
+	case 1227:
+		return s.push(value)
+	case 1228:
+		values[0], values[1] = values[1], values[0]
+		return nil
+	case 1229:
+		if value != math.Trunc(value) || value >= float64(len(s.args)-1) {
+			return fmt.Errorf("invalid Type2 stack index")
+		}
+		index := max(0, value)
+		if len(s.args) < 2 {
+			return fmt.Errorf("empty Type2 indexed stack")
+		}
+		value = s.args[len(s.args)-2-int(index)]
+	case 1230:
+		n, j := values[0], values[1]
+		if n < 0 || n > float64(len(s.args)-2) || n != math.Trunc(n) || j != math.Trunc(j) {
+			return fmt.Errorf("invalid Type2 stack roll")
+		}
+		s.args = s.args[:len(s.args)-2]
+		if n == 0 {
+			return nil
+		}
+		shift := int(math.Mod(j, n))
+		if shift < 0 {
+			shift += int(n)
+		}
+		tail := s.args[len(s.args)-int(n):]
+		slices.Reverse(tail)
+		slices.Reverse(tail[:shift])
+		slices.Reverse(tail[shift:])
+		return nil
+	}
+	s.args = s.args[:len(s.args)-count]
+	return s.push(value)
+}
+
+// draw 校验Type2路径指令并推进当前点，保留曲线及Flex编码
+// 入参: op 操作符
+// 返回: error 路径操作数或输出错误
+func (s *type2State) draw(op int) error {
+	a := s.args
+	valid := true
+	dx, dy := 0.0, 0.0
+	switch op {
+	case 5:
+		valid = len(a) >= 2 && len(a)%2 == 0
+		if valid {
+			for i := 0; i < len(a); i += 2 {
+				dx, dy = dx+a[i], dy+a[i+1]
+			}
+		}
+	case 6, 7:
+		valid = len(a) > 0
+		for i, value := range a {
+			if (i%2 == 0) == (op == 6) {
+				dx += value
+			} else {
+				dy += value
+			}
+		}
+	case 8, 24, 25:
+		start, end := 0, len(a)
+		if op == 24 {
+			end -= 2
+			valid = len(a) >= 8 && end%6 == 0
+		} else if op == 25 {
+			start = len(a) - 6
+			valid = len(a) >= 8 && start%2 == 0
+		} else {
+			valid = len(a) >= 6 && len(a)%6 == 0
+		}
+		if valid {
+			for i := start; i < end; i += 2 {
+				dx, dy = dx+a[i], dy+a[i+1]
+			}
+			for i := 0; i < start; i += 2 {
+				dx, dy = dx+a[i], dy+a[i+1]
+			}
+			if end < len(a) {
+				dx, dy = dx+a[end], dy+a[end+1]
+			}
+		}
+	case 26, 27:
+		valid = len(a) >= 4 && (len(a)%4 == 0 || len(a)%4 == 1)
+		if valid {
+			i := 0
+			if len(a)%4 == 1 {
+				if op == 26 {
+					dx = a[0]
+				} else {
+					dy = a[0]
+				}
+				i++
+			}
+			for ; i < len(a); i += 4 {
+				if op == 26 {
+					dx, dy = dx+a[i+1], dy+a[i]+a[i+2]+a[i+3]
+				} else {
+					dx, dy = dx+a[i]+a[i+1]+a[i+3], dy+a[i+2]
+				}
+			}
+		}
+	case 30, 31:
+		valid = len(a) >= 4 && (len(a)%4 == 0 || len(a)%4 == 1)
+		if valid {
+			horizontal := op == 31
+			for i := 0; i+4 <= len(a); i += 4 {
+				if horizontal {
+					dx, dy = dx+a[i]+a[i+1], dy+a[i+2]+a[i+3]
+				} else {
+					dx, dy = dx+a[i+1]+a[i+3], dy+a[i]+a[i+2]
+				}
+				if i+5 == len(a) {
+					if horizontal {
+						dx += a[i+4]
+					} else {
+						dy += a[i+4]
+					}
+				}
+				horizontal = !horizontal
+			}
+		}
+	case 1234:
+		valid = len(a) == 7
+		if valid {
+			dx = a[0] + a[1] + a[3] + a[4] + a[5] + a[6]
+		}
+	case 1235:
+		valid = len(a) == 13
+		if valid {
+			for i := 0; i < 12; i += 2 {
+				dx, dy = dx+a[i], dy+a[i+1]
+			}
+		}
+	case 1236:
+		valid = len(a) == 9
+		if valid {
+			dx = a[0] + a[2] + a[4] + a[5] + a[6] + a[8]
+		}
+	case 1237:
+		valid = len(a) == 11
+		if valid {
+			for i := 0; i < 10; i += 2 {
+				dx, dy = dx+a[i], dy+a[i+1]
+			}
+			if math.Abs(dx) > math.Abs(dy) {
+				dx, dy = dx+a[10], 0
+			} else {
+				dx, dy = 0, dy+a[10]
+			}
+		}
+	default:
+		valid = false
+	}
+	if !valid || !finite(s.x+dx) || !finite(s.y+dy) {
+		return fmt.Errorf("invalid Type2 path operands for operator %d", op)
+	}
+	if err := s.emit(op, a); err != nil {
+		return err
+	}
+	s.x, s.y = s.x+dx, s.y+dy
+	s.outX, s.outY = s.x+s.originX, s.y+s.originY
+	s.args = s.args[:0]
+	return nil
+}

ofdgo_image.go

@@ -91,21 +91,21 @@ func (s *transparentEdgeImage64) Bounds() image.Rectangle { return s.rect }
 // 返回: color.Model 颜色模型
 func (s *transparentEdgeImage64) ColorModel() color.Model { return color.NRGBA64Model }
 
-// At 读取十六位原始颜色，透明邻域使用最小非零透明度保留边缘颜色
+// NRGBA64At 读取十六位原始颜色，透明邻域使用最小非零透明度保留边缘颜色
 // 入参: x 横向坐标, y 纵向坐标
-// 返回: color.Color 非预乘颜色
-func (s *transparentEdgeImage64) At(x, y int) color.Color {
+// 返回: color.NRGBA64 非预乘颜色
+func (s *transparentEdgeImage64) NRGBA64At(x, y int) color.NRGBA64 {
 	if !image.Pt(x, y).In(s.rect) {
 		return color.NRGBA64{}
 	}
 	b := s.source.Bounds()
 	sx, sy := b.Min.X+min(max(x-1, 0), b.Dx()-1), b.Min.Y+min(max(y-1, 0), b.Dy()-1)
-	c := color.NRGBA64Model.Convert(s.source.At(sx, sy)).(color.NRGBA64)
+	c := imageNRGBA64At(s.source, sx, sy)
 	if c.A == 0 {
 		var best color.NRGBA64
 		for ny := max(sy-1, b.Min.Y); ny < min(sy+2, b.Max.Y); ny++ {
 			for nx := max(sx-1, b.Min.X); nx < min(sx+2, b.Max.X); nx++ {
-				v := color.NRGBA64Model.Convert(s.source.At(nx, ny)).(color.NRGBA64)
+				v := imageNRGBA64At(s.source, nx, ny)
 				if v.A > best.A {
 					best = v
 				}
@@ -122,11 +122,16 @@ func (s *transparentEdgeImage64) At(x, y int) color.Color {
 	return c
 }
 
+// At 返回非预乘十六位像素颜色
+// 入参: x 横向坐标, y 纵向坐标
+// 返回: color.Color 像素颜色
+func (s *transparentEdgeImage64) At(x, y int) color.Color { return s.NRGBA64At(x, y) }
+
 // RGBA64At 返回保留原采样精度的预乘颜色
 // 入参: x 横向坐标, y 纵向坐标
 // 返回: color.RGBA64 预乘颜色
 func (s *transparentEdgeImage64) RGBA64At(x, y int) color.RGBA64 {
-	r, g, b, a := s.At(x, y).RGBA()
+	r, g, b, a := s.NRGBA64At(x, y).RGBA()
 	return color.RGBA64{R: uint16(r), G: uint16(g), B: uint16(b), A: uint16(a)}
 }
 
@@ -426,6 +431,38 @@ func imageNRGBAAt(img image.Image, x, y int) color.NRGBA {
 	return color.NRGBAModel.Convert(img.At(x, y)).(color.NRGBA)
 }
 
+// imageNRGBA64At 读取十六位非预乘像素，原生图像避免颜色装箱
+// 入参: img 图片对象, x X坐标, y Y坐标
+// 返回: color.NRGBA64 NRGBA64像素
+func imageNRGBA64At(img image.Image, x, y int) color.NRGBA64 {
+	switch src := img.(type) {
+	case *image.NRGBA64:
+		return src.NRGBA64At(x, y)
+	case *image.Gray16:
+		c := src.Gray16At(x, y)
+		return color.NRGBA64{R: c.Y, G: c.Y, B: c.Y, A: 0xffff}
+	case *image.Alpha16:
+		c := src.Alpha16At(x, y)
+		if c.A == 0 {
+			return color.NRGBA64{}
+		}
+		return color.NRGBA64{R: 0xffff, G: 0xffff, B: 0xffff, A: c.A}
+	case *image.RGBA, *image.RGBA64:
+		c := src.(image.RGBA64Image).RGBA64At(x, y)
+		if c.A == 0 {
+			return color.NRGBA64{}
+		}
+		r, g, b, a := uint32(c.R), uint32(c.G), uint32(c.B), uint32(c.A)
+		if a != 0xffff {
+			r = r * 0xffff / a
+			g = g * 0xffff / a
+			b = b * 0xffff / a
+		}
+		return color.NRGBA64{R: uint16(r), G: uint16(g), B: uint16(b), A: c.A}
+	}
+	return color.NRGBA64Model.Convert(img.At(x, y)).(color.NRGBA64)
+}
+
 // transparentEdgeColor 获取透明像素相邻的可见颜色
 // 入参: img 图片对象, x X坐标, y Y坐标
 // 返回: color.NRGBA 颜色, bool 是否存在