fix(转换能力): 修复PDF字体及细线渲染

internal/base/font/cff.go

@@ -260,6 +260,21 @@ func SanitizeCFF(data []byte) ([]byte, error) {
 		if kind == 1 {
 			return normalizeCFFType1(data, topDict)
 		}
+		private, err := readType2Private(data, topDict[18], &type2Font{})
+		if err != nil {
+			return nil, err
+		}
+		count := len(private)
+		if err := normalizeCFFPrivate(private); err != nil {
+			return nil, err
+		}
+		if len(private) != count {
+			font, err := readType2Font(data)
+			if err != nil {
+				return nil, err
+			}
+			return rebuildNamedCFF(data, font, font.chars, nil)
+		}
 		return data, nil
 	}
 	fdArrOff, err := cffDictOffset(data, topDict, 1236)
@@ -342,17 +357,21 @@ func SanitizeCFF(data []byte) ([]byte, error) {
 	return encodeSanitizedCFF(data[:hdrSize], nameIndexData, topDict, stringIndexData, globalSubrIndexData, charStringsData, finalPrivData, localSubrData), nil
 }
 
-// normalizeCFFPrivate 移除旧版CFF中不生效的缺省字段，拒绝需要额外解释的取值
+// normalizeCFFPrivate 移除废弃的加粗阈值及未加密标记，拒绝加密字形程序
 // 入参: dict 私有字典
 // 返回: error 不支持的旧版行为
 func normalizeCFFPrivate(dict cffDict) error {
-	for op, value := range map[int]float64{1215: 0, 1216: -1} {
-		if values, ok := dict[op]; ok {
-			if len(values) != 1 || values[0] != value {
-				return fmt.Errorf("unsupported legacy CFF private operator %d", op)
-			}
-			delete(dict, op)
+	if values, ok := dict[1215]; ok {
+		if len(values) != 1 || !finite(values[0]) {
+			return fmt.Errorf("invalid legacy CFF bold threshold")
 		}
+		delete(dict, 1215)
+	}
+	if values, ok := dict[1216]; ok {
+		if len(values) != 1 || values[0] != -1 {
+			return fmt.Errorf("unsupported legacy CFF private operator 1216")
+		}
+		delete(dict, 1216)
 	}
 	return nil
 }

internal/base/font/cff_subset.go

@@ -231,6 +231,9 @@ func rebuildNamedCFF(data []byte, font *type2Font, chars [][]byte, ids []uint16)
 	if err != nil {
 		return nil, err
 	}
+	if err := normalizeCFFPrivate(private); err != nil {
+		return nil, err
+	}
 	privateData, err := encodeCFFSubsetPrivate(private)
 	if err != nil {
 		return nil, err

internal/base/font/glyf.go

@@ -235,7 +235,7 @@ func (f *Outliner) phantomPoints(id uint16, data []byte) [4]ttPoint {
 	return [4]ttPoint{{x: left * 64, ox: left * 64}, {x: (left + int32(f.Font.GlyphAdvance(id))) * 64, ox: (left + int32(f.Font.GlyphAdvance(id))) * 64}, {y: top * 64, oy: top * 64}, {y: (top - int32(f.Font.GlyphVerticalAdvance(id))) * 64, oy: (top - int32(f.Font.GlyphVerticalAdvance(id))) * 64}}
 }
 
-// ttRecoverableHint 判断栈参数、指令引用或控制流错误是否允许保留执行前轮廓
+// ttRecoverableHint 判断栈参数、区点轮廓及函数引用或控制流错误是否允许保留执行前轮廓
 // 入参: err 指令错误
 // 返回: bool 是否可恢复
 func ttRecoverableHint(err error) bool {

internal/base/font/hint.go

@@ -25,7 +25,7 @@ import (
 // errTTStackUnderflow 表示字形程序缺少必需的栈参数
 var errTTStackUnderflow = errors.New("TrueType instruction stack underflow")
 
-// errTTInvalidReference 表示字形指令引用不存在的点或函数
+// errTTInvalidReference 表示字形指令引用不存在的区、点、轮廓或函数
 var errTTInvalidReference = errors.New("invalid TrueType instruction reference")
 
 // errTTInvalidControlFlow 表示条件分支未闭合或跳转超出字节码范围
@@ -380,7 +380,8 @@ func (v *ttInterpreter) execute(code []byte, depth int) error {
 			case op >= 0x13 && op <= 0x16:
 				z := v.pop()
 				if z < 0 || z > 1 {
-					return fmt.Errorf("invalid TrueType zone")
+					v.err = fmt.Errorf("%w: zone %d", errTTInvalidReference, z)
+					break
 				}
 				if op == 0x16 {
 					g.zone = [3]int32{z, z, z}
@@ -854,7 +855,7 @@ func (v *ttInterpreter) shift(op byte) {
 	if op <= 0x35 {
 		contour := v.pop()
 		if contour < 0 || int64(contour) >= int64(len(v.ends)) {
-			v.err = fmt.Errorf("invalid TrueType contour reference")
+			v.err = fmt.Errorf("%w: contour %d", errTTInvalidReference, contour)
 			return
 		}
 		if contour > 0 {
@@ -864,7 +865,7 @@ func (v *ttInterpreter) shift(op byte) {
 	} else {
 		target = v.pop()
 		if target < 0 || target > 1 {
-			v.err = fmt.Errorf("invalid TrueType zone")
+			v.err = fmt.Errorf("%w: zone %d", errTTInvalidReference, target)
 			return
 		}
 		to = len(v.zones[target])