feat(字体处理): 优化字体索引编码性能

internal/base/font/cff.go

@@ -826,10 +826,8 @@ func encodeNumberCFF(buf *bytes.Buffer, val float64) {
 // 返回: []byte 编码后的索引数据
 func encodeCFFIndex(items []([]byte)) []byte {
 	count := len(items)
-	buf := new(bytes.Buffer)
-	binary.Write(buf, binary.BigEndian, uint16(count))
 	if count == 0 {
-		return buf.Bytes()
+		return []byte{0, 0}
 	}
 	totalSize := 0
 	for _, item := range items {
@@ -845,25 +843,21 @@ func encodeCFFIndex(items []([]byte)) []byte {
 	if totalSize+1 > 16777215 {
 		offSize = 4
 	}
-	buf.WriteByte(byte(offSize))
+	base := 3 + (count+1)*offSize
+	data := make([]byte, base+totalSize)
+	binary.BigEndian.PutUint16(data, uint16(count))
+	data[2] = byte(offSize)
 	offset := 1
-	putOffset(buf, offset, offSize)
-	for _, item := range items {
-		offset += len(item)
-		putOffset(buf, offset, offSize)
+	for i := 0; i <= count; i++ {
+		for j := 0; j < offSize; j++ {
+			data[3+i*offSize+offSize-1-j] = byte(offset >> (8 * j))
 		}
-	for _, item := range items {
-		buf.Write(item)
+		if i < count {
+			copy(data[base+offset-1:], items[i])
+			offset += len(items[i])
 		}
-	return buf.Bytes()
 	}
-
-// putOffset 写入指定大小的偏移量
-// 入参: buf 缓冲区, val 偏移值, size 字节大小
-func putOffset(buf *bytes.Buffer, val int, size int) {
-	tmp := make([]byte, 4)
-	binary.BigEndian.PutUint32(tmp, uint32(val))
-	buf.Write(tmp[4-size:])
+	return data
 }
 
 // getCFFIndexCount 读取CFF索引的计数和大小

internal/base/font/util.go

@@ -91,19 +91,21 @@ func FileTables(data []byte, index int) (map[string][]byte, error) {
 // 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)
+	var a, b, c, d uint32
+	for len(data) >= 16 {
+		a += binary.BigEndian.Uint32(data[:4])
+		b += binary.BigEndian.Uint32(data[4:8])
+		c += binary.BigEndian.Uint32(data[8:12])
+		d += binary.BigEndian.Uint32(data[12:16])
+		data = data[16:]
 	}
-			sum += val
+	sum := a + b + c + d
+	for len(data) >= 4 {
+		sum += binary.BigEndian.Uint32(data[:4])
+		data = data[4:]
 	}
+	for i, value := range data {
+		sum += uint32(value) << (24 - 8*i)
 	}
 	return sum
 }

internal/base/image/image.go

@@ -722,6 +722,7 @@ func WithTransparentEdge(ctx context.Context, img image.Image) (image.Image, int
 	hasZero, hasVisible := false, false
 	var pixels []byte
 	var stride, step int
+	wideAlpha := false
 	switch src := source.(type) {
 	case *image.NRGBA:
 		pixels, stride, step = src.Pix, src.Stride, 4
@@ -729,9 +730,17 @@ func WithTransparentEdge(ctx context.Context, img image.Image) (image.Image, int
 		pixels, stride, step = src.Pix, src.Stride, 4
 	case *image.Alpha:
 		pixels, stride, step = src.Pix, src.Stride, 1
+	case *image.NRGBA64:
+		pixels, stride, step, wideAlpha = src.Pix, src.Stride, 8, true
+	case *image.RGBA64:
+		pixels, stride, step, wideAlpha = src.Pix, src.Stride, 8, true
+	case *image.Alpha16:
+		pixels, stride, step, wideAlpha = src.Pix, src.Stride, 2, true
+	case *colorImage:
+		pixels, stride, step, wideAlpha = src.Pix, src.Stride, 8, true
 	}
 	if pixels != nil {
-		hasZero = pixels[step-1] == 0
+		hasZero = pixels[step-1] == 0 && (!wideAlpha || pixels[step-2] == 0)
 		hasVisible = !hasZero
 	scan:
 		for y := 0; y < h; y++ {
@@ -745,7 +754,7 @@ func WithTransparentEdge(ctx context.Context, img image.Image) (image.Image, int
 						return nil, 0, err
 					}
 				}
-				if (pixels[offset] == 0) != hasZero {
+				if (pixels[offset] == 0 && (!wideAlpha || pixels[offset-1] == 0)) != hasZero {
 					hasZero, hasVisible = true, true
 					break scan
 				}

internal/base/image/scale.go

@@ -189,11 +189,8 @@ func rasterImageHorizontal(row []rasterImagePixel, src image.RGBA64Image, sample
 	clear(row)
 	first, last := samples[0], samples[len(samples)-1]
 	reversed := first.first > last.first || first.first == last.first && len(first.weights) > len(last.weights)
-	start, end := samples[0].first, samples[0].first+len(samples[0].weights)
-	for _, sample := range samples[1:] {
-		start = min(start, sample.first)
-		end = max(end, sample.first+len(sample.weights))
-	}
+	start := min(first.first, last.first)
+	end := max(first.first+len(first.weights), last.first+len(last.weights))
 	active, next := 0, 0
 	for x := start; x < end; x++ {
 		for next < len(samples) {
@@ -217,6 +214,7 @@ func rasterImageHorizontal(row []rasterImagePixel, src image.RGBA64Image, sample
 			active++
 		}
 		p := src.RGBA64At(x, y)
+		r, g, b, a := float64(p.R), float64(p.G), float64(p.B), float64(p.A)
 		for column := active; column < next; column++ {
 			index := column
 			if reversed {
@@ -226,10 +224,10 @@ func rasterImageHorizontal(row []rasterImagePixel, src image.RGBA64Image, sample
 			weight := sample.weights[x-sample.first]
 			if weight != 0 {
 				value := &row[index]
-				value.r += float64(p.R) * weight
-				value.g += float64(p.G) * weight
-				value.b += float64(p.B) * weight
-				value.a += float64(p.A) * weight
+				value.r += r * weight
+				value.g += g * weight
+				value.b += b * weight
+				value.a += a * weight
 			}
 		}
 	}

internal/base/image/storage.go

@@ -42,10 +42,14 @@ func StorageCost(img image.Image, limit int) int {
 		}
 		cost += cap(encoded.profile)
 		if encoded.profile != nil || encoded.pngColor != nil || encoded.config.ColorModel == color.CMYKModel {
-			if w > (limit-cost)/12/h {
+			pixelSize := 12
+			if encoded.config.ColorModel == color.RGBA64Model || encoded.config.ColorModel == color.NRGBA64Model {
+				pixelSize = 16
+			}
+			if w > (limit-cost)/pixelSize/h {
 				return limit + 1
 			}
-			pixels = w * h * 12
+			pixels = w * h * pixelSize
 		}
 		if result := encoded.result.Load(); result != nil && result.image != nil {
 			pixels = max(pixels, StorageCost(result.image, limit-cost))