Imported Upstream version 57upstream/57

6 files changed, 186 insertions, 23 deletions

diff --git a/src/pkg/image/image.go b/src/pkg/image/image.go
index 5f398a304..222d21ade 100644
--- a/src/pkg/image/image.go
+++ b/src/pkg/image/image.go
@@ -51,6 +51,13 @@ func (p *RGBA) Set(x, y int, c Color) {
 	p.Pix[y*p.Stride+x] = toRGBAColor(c).(RGBAColor)
 }
 
+func (p *RGBA) SetRGBA(x, y int, c RGBAColor) {
+	if !p.Rect.Contains(Point{x, y}) {
+		return
+	}
+	p.Pix[y*p.Stride+x] = c
+}
+
 // Opaque scans the entire image and returns whether or not it is fully opaque.
 func (p *RGBA) Opaque() bool {
 	if p.Rect.Empty() {
@@ -103,6 +110,13 @@ func (p *RGBA64) Set(x, y int, c Color) {
 	p.Pix[y*p.Stride+x] = toRGBA64Color(c).(RGBA64Color)
 }
 
+func (p *RGBA64) SetRGBA64(x, y int, c RGBA64Color) {
+	if !p.Rect.Contains(Point{x, y}) {
+		return
+	}
+	p.Pix[y*p.Stride+x] = c
+}
+
 // Opaque scans the entire image and returns whether or not it is fully opaque.
 func (p *RGBA64) Opaque() bool {
 	if p.Rect.Empty() {
@@ -155,6 +169,13 @@ func (p *NRGBA) Set(x, y int, c Color) {
 	p.Pix[y*p.Stride+x] = toNRGBAColor(c).(NRGBAColor)
 }
 
+func (p *NRGBA) SetNRGBA(x, y int, c NRGBAColor) {
+	if !p.Rect.Contains(Point{x, y}) {
+		return
+	}
+	p.Pix[y*p.Stride+x] = c
+}
+
 // Opaque scans the entire image and returns whether or not it is fully opaque.
 func (p *NRGBA) Opaque() bool {
 	if p.Rect.Empty() {
@@ -207,6 +228,13 @@ func (p *NRGBA64) Set(x, y int, c Color) {
 	p.Pix[y*p.Stride+x] = toNRGBA64Color(c).(NRGBA64Color)
 }
 
+func (p *NRGBA64) SetNRGBA64(x, y int, c NRGBA64Color) {
+	if !p.Rect.Contains(Point{x, y}) {
+		return
+	}
+	p.Pix[y*p.Stride+x] = c
+}
+
 // Opaque scans the entire image and returns whether or not it is fully opaque.
 func (p *NRGBA64) Opaque() bool {
 	if p.Rect.Empty() {
@@ -252,13 +280,20 @@ func (p *Alpha) At(x, y int) Color {
 	return p.Pix[y*p.Stride+x]
 }
 
-func (p *Alpha) Set(x, y int, c Color) {
+func (p *Alpha) Set(x, y int, c AlphaColor) {
 	if !p.Rect.Contains(Point{x, y}) {
 		return
 	}
 	p.Pix[y*p.Stride+x] = toAlphaColor(c).(AlphaColor)
 }
 
+func (p *Alpha) SetAlpha(x, y int, c AlphaColor) {
+	if !p.Rect.Contains(Point{x, y}) {
+		return
+	}
+	p.Pix[y*p.Stride+x] = c
+}
+
 // Opaque scans the entire image and returns whether or not it is fully opaque.
 func (p *Alpha) Opaque() bool {
 	if p.Rect.Empty() {
@@ -311,6 +346,13 @@ func (p *Alpha16) Set(x, y int, c Color) {
 	p.Pix[y*p.Stride+x] = toAlpha16Color(c).(Alpha16Color)
 }
 
+func (p *Alpha16) SetAlpha16(x, y int, c Alpha16Color) {
+	if !p.Rect.Contains(Point{x, y}) {
+		return
+	}
+	p.Pix[y*p.Stride+x] = c
+}
+
 // Opaque scans the entire image and returns whether or not it is fully opaque.
 func (p *Alpha16) Opaque() bool {
 	if p.Rect.Empty() {
@@ -363,6 +405,13 @@ func (p *Gray) Set(x, y int, c Color) {
 	p.Pix[y*p.Stride+x] = toGrayColor(c).(GrayColor)
 }
 
+func (p *Gray) SetGray(x, y int, c GrayColor) {
+	if !p.Rect.Contains(Point{x, y}) {
+		return
+	}
+	p.Pix[y*p.Stride+x] = c
+}
+
 // Opaque scans the entire image and returns whether or not it is fully opaque.
 func (p *Gray) Opaque() bool {
 	return true
@@ -401,6 +450,13 @@ func (p *Gray16) Set(x, y int, c Color) {
 	p.Pix[y*p.Stride+x] = toGray16Color(c).(Gray16Color)
 }
 
+func (p *Gray16) SetGray16(x, y int, c Gray16Color) {
+	if !p.Rect.Contains(Point{x, y}) {
+		return
+	}
+	p.Pix[y*p.Stride+x] = c
+}
+
 // Opaque scans the entire image and returns whether or not it is fully opaque.
 func (p *Gray16) Opaque() bool {
 	return true
diff --git a/src/pkg/image/jpeg/writer.go b/src/pkg/image/jpeg/writer.go
index 505cce04f..52b3dc4e2 100644
--- a/src/pkg/image/jpeg/writer.go
+++ b/src/pkg/image/jpeg/writer.go
@@ -391,6 +391,31 @@ func toYCbCr(m image.Image, p image.Point, yBlock, cbBlock, crBlock *block) {
 	}
 }
 
+// rgbaToYCbCr is a specialized version of toYCbCr for image.RGBA images.
+func rgbaToYCbCr(m *image.RGBA, p image.Point, yBlock, cbBlock, crBlock *block) {
+	b := m.Bounds()
+	xmax := b.Max.X - 1
+	ymax := b.Max.Y - 1
+	for j := 0; j < 8; j++ {
+		sj := p.Y + j
+		if sj > ymax {
+			sj = ymax
+		}
+		yoff := sj * m.Stride
+		for i := 0; i < 8; i++ {
+			sx := p.X + i
+			if sx > xmax {
+				sx = xmax
+			}
+			col := &m.Pix[yoff+sx]
+			yy, cb, cr := ycbcr.RGBToYCbCr(col.R, col.G, col.B)
+			yBlock[8*j+i] = int(yy)
+			cbBlock[8*j+i] = int(cb)
+			crBlock[8*j+i] = int(cr)
+		}
+	}
+}
+
 // scale scales the 16x16 region represented by the 4 src blocks to the 8x8
 // dst block.
 func scale(dst *block, src *[4]block) {
@@ -431,13 +456,18 @@ func (e *encoder) writeSOS(m image.Image) {
 		prevDCY, prevDCCb, prevDCCr int
 	)
 	bounds := m.Bounds()
+	rgba, _ := m.(*image.RGBA)
 	for y := bounds.Min.Y; y < bounds.Max.Y; y += 16 {
 		for x := bounds.Min.X; x < bounds.Max.X; x += 16 {
 			for i := 0; i < 4; i++ {
 				xOff := (i & 1) * 8
 				yOff := (i & 2) * 4
 				p := image.Point{x + xOff, y + yOff}
-				toYCbCr(m, p, &yBlock, &cbBlock[i], &crBlock[i])
+				if rgba != nil {
+					rgbaToYCbCr(rgba, p, &yBlock, &cbBlock[i], &crBlock[i])
+				} else {
+					toYCbCr(m, p, &yBlock, &cbBlock[i], &crBlock[i])
+				}
 				prevDCY = e.writeBlock(&yBlock, 0, prevDCY)
 			}
 			scale(&cBlock, &cbBlock)
diff --git a/src/pkg/image/jpeg/writer_test.go b/src/pkg/image/jpeg/writer_test.go
index 00922dd5c..7aec70f01 100644
--- a/src/pkg/image/jpeg/writer_test.go
+++ b/src/pkg/image/jpeg/writer_test.go
@@ -8,6 +8,8 @@ import (
 	"bytes"
 	"image"
 	"image/png"
+	"io/ioutil"
+	"rand"
 	"os"
 	"testing"
 )
@@ -85,3 +87,29 @@ func TestWriter(t *testing.T) {
 		}
 	}
 }
+
+func BenchmarkEncodeRGBOpaque(b *testing.B) {
+	b.StopTimer()
+	img := image.NewRGBA(640, 480)
+	// Set all pixels to 0xFF alpha to force opaque mode.
+	bo := img.Bounds()
+	rnd := rand.New(rand.NewSource(123))
+	for y := bo.Min.Y; y < bo.Max.Y; y++ {
+		for x := bo.Min.X; x < bo.Max.X; x++ {
+			img.Set(x, y, image.RGBAColor{
+				uint8(rnd.Intn(256)),
+				uint8(rnd.Intn(256)),
+				uint8(rnd.Intn(256)),
+				255})
+		}
+	}
+	if !img.Opaque() {
+		panic("expected image to be opaque")
+	}
+	b.SetBytes(640 * 480 * 4)
+	b.StartTimer()
+	options := &Options{Quality: 90}
+	for i := 0; i < b.N; i++ {
+		Encode(ioutil.Discard, img, options)
+	}
+}
diff --git a/src/pkg/image/png/reader.go b/src/pkg/image/png/reader.go
index b30a951c1..8c76afa72 100644
--- a/src/pkg/image/png/reader.go
+++ b/src/pkg/image/png/reader.go
@@ -378,7 +378,7 @@ func (d *decoder) idatReader(idat io.Reader) (image.Image, os.Error) {
 			for x := 0; x < d.width; x += 8 {
 				b := cdat[x/8]
 				for x2 := 0; x2 < 8 && x+x2 < d.width; x2++ {
-					gray.Set(x+x2, y, image.GrayColor{(b >> 7) * 0xff})
+					gray.SetGray(x+x2, y, image.GrayColor{(b >> 7) * 0xff})
 					b <<= 1
 				}
 			}
@@ -386,7 +386,7 @@ func (d *decoder) idatReader(idat io.Reader) (image.Image, os.Error) {
 			for x := 0; x < d.width; x += 4 {
 				b := cdat[x/4]
 				for x2 := 0; x2 < 4 && x+x2 < d.width; x2++ {
-					gray.Set(x+x2, y, image.GrayColor{(b >> 6) * 0x55})
+					gray.SetGray(x+x2, y, image.GrayColor{(b >> 6) * 0x55})
 					b <<= 2
 				}
 			}
@@ -394,22 +394,22 @@ func (d *decoder) idatReader(idat io.Reader) (image.Image, os.Error) {
 			for x := 0; x < d.width; x += 2 {
 				b := cdat[x/2]
 				for x2 := 0; x2 < 2 && x+x2 < d.width; x2++ {
-					gray.Set(x+x2, y, image.GrayColor{(b >> 4) * 0x11})
+					gray.SetGray(x+x2, y, image.GrayColor{(b >> 4) * 0x11})
 					b <<= 4
 				}
 			}
 		case cbG8:
 			for x := 0; x < d.width; x++ {
-				gray.Set(x, y, image.GrayColor{cdat[x]})
+				gray.SetGray(x, y, image.GrayColor{cdat[x]})
 			}
 		case cbGA8:
 			for x := 0; x < d.width; x++ {
 				ycol := cdat[2*x+0]
-				nrgba.Set(x, y, image.NRGBAColor{ycol, ycol, ycol, cdat[2*x+1]})
+				nrgba.SetNRGBA(x, y, image.NRGBAColor{ycol, ycol, ycol, cdat[2*x+1]})
 			}
 		case cbTC8:
 			for x := 0; x < d.width; x++ {
-				rgba.Set(x, y, image.RGBAColor{cdat[3*x+0], cdat[3*x+1], cdat[3*x+2], 0xff})
+				rgba.SetRGBA(x, y, image.RGBAColor{cdat[3*x+0], cdat[3*x+1], cdat[3*x+2], 0xff})
 			}
 		case cbP1:
 			for x := 0; x < d.width; x += 8 {
@@ -456,25 +456,25 @@ func (d *decoder) idatReader(idat io.Reader) (image.Image, os.Error) {
 			}
 		case cbTCA8:
 			for x := 0; x < d.width; x++ {
-				nrgba.Set(x, y, image.NRGBAColor{cdat[4*x+0], cdat[4*x+1], cdat[4*x+2], cdat[4*x+3]})
+				nrgba.SetNRGBA(x, y, image.NRGBAColor{cdat[4*x+0], cdat[4*x+1], cdat[4*x+2], cdat[4*x+3]})
 			}
 		case cbG16:
 			for x := 0; x < d.width; x++ {
 				ycol := uint16(cdat[2*x+0])<<8 | uint16(cdat[2*x+1])
-				gray16.Set(x, y, image.Gray16Color{ycol})
+				gray16.SetGray16(x, y, image.Gray16Color{ycol})
 			}
 		case cbGA16:
 			for x := 0; x < d.width; x++ {
 				ycol := uint16(cdat[4*x+0])<<8 | uint16(cdat[4*x+1])
 				acol := uint16(cdat[4*x+2])<<8 | uint16(cdat[4*x+3])
-				nrgba64.Set(x, y, image.NRGBA64Color{ycol, ycol, ycol, acol})
+				nrgba64.SetNRGBA64(x, y, image.NRGBA64Color{ycol, ycol, ycol, acol})
 			}
 		case cbTC16:
 			for x := 0; x < d.width; x++ {
 				rcol := uint16(cdat[6*x+0])<<8 | uint16(cdat[6*x+1])
 				gcol := uint16(cdat[6*x+2])<<8 | uint16(cdat[6*x+3])
 				bcol := uint16(cdat[6*x+4])<<8 | uint16(cdat[6*x+5])
-				rgba64.Set(x, y, image.RGBA64Color{rcol, gcol, bcol, 0xffff})
+				rgba64.SetRGBA64(x, y, image.RGBA64Color{rcol, gcol, bcol, 0xffff})
 			}
 		case cbTCA16:
 			for x := 0; x < d.width; x++ {
@@ -482,7 +482,7 @@ func (d *decoder) idatReader(idat io.Reader) (image.Image, os.Error) {
 				gcol := uint16(cdat[8*x+2])<<8 | uint16(cdat[8*x+3])
 				bcol := uint16(cdat[8*x+4])<<8 | uint16(cdat[8*x+5])
 				acol := uint16(cdat[8*x+6])<<8 | uint16(cdat[8*x+7])
-				nrgba64.Set(x, y, image.NRGBA64Color{rcol, gcol, bcol, acol})
+				nrgba64.SetNRGBA64(x, y, image.NRGBA64Color{rcol, gcol, bcol, acol})
 			}
 		}
 
diff --git a/src/pkg/image/png/writer.go b/src/pkg/image/png/writer.go
index 081d06bf5..2d593f6a7 100644
--- a/src/pkg/image/png/writer.go
+++ b/src/pkg/image/png/writer.go
@@ -263,7 +263,12 @@ func writeImage(w io.Writer, m image.Image, cb int) os.Error {
 	defer zw.Close()
 
 	bpp := 0 // Bytes per pixel.
+
+	// Used by fast paths for common image types
 	var paletted *image.Paletted
+	var rgba *image.RGBA
+	rgba, _ = m.(*image.RGBA)
+
 	switch cb {
 	case cbG8:
 		bpp = 1
@@ -303,12 +308,24 @@ func writeImage(w io.Writer, m image.Image, cb int) os.Error {
 				cr[0][x+1] = c.Y
 			}
 		case cbTC8:
-			for x := b.Min.X; x < b.Max.X; x++ {
-				// We have previously verified that the alpha value is fully opaque.
-				r, g, b, _ := m.At(x, y).RGBA()
-				cr[0][3*x+1] = uint8(r >> 8)
-				cr[0][3*x+2] = uint8(g >> 8)
-				cr[0][3*x+3] = uint8(b >> 8)
+			// We have previously verified that the alpha value is fully opaque.
+			cr0 := cr[0]
+			if rgba != nil {
+				yoff := y * rgba.Stride
+				xoff := 3*b.Min.X + 1
+				for _, color := range rgba.Pix[yoff+b.Min.X : yoff+b.Max.X] {
+					cr0[xoff] = color.R
+					cr0[xoff+1] = color.G
+					cr0[xoff+2] = color.B
+					xoff += 3
+				}
+			} else {
+				for x := b.Min.X; x < b.Max.X; x++ {
+					r, g, b, _ := m.At(x, y).RGBA()
+					cr0[3*x+1] = uint8(r >> 8)
+					cr0[3*x+2] = uint8(g >> 8)
+					cr0[3*x+3] = uint8(b >> 8)
+				}
 			}
 		case cbP8:
 			rowOffset := y * paletted.Stride
diff --git a/src/pkg/image/png/writer_test.go b/src/pkg/image/png/writer_test.go
index 4d9929f31..6b054aaa8 100644
--- a/src/pkg/image/png/writer_test.go
+++ b/src/pkg/image/png/writer_test.go
@@ -5,10 +5,10 @@
 package png
 
 import (
-	"bytes"
 	"fmt"
 	"image"
 	"io"
+	"io/ioutil"
 	"os"
 	"testing"
 )
@@ -81,10 +81,42 @@ func BenchmarkEncodePaletted(b *testing.B) {
 			image.RGBAColor{0, 0, 0, 255},
 			image.RGBAColor{255, 255, 255, 255},
 		})
+	b.SetBytes(640 * 480 * 1)
 	b.StartTimer()
-	buffer := new(bytes.Buffer)
 	for i := 0; i < b.N; i++ {
-		buffer.Reset()
-		Encode(buffer, img)
+		Encode(ioutil.Discard, img)
+	}
+}
+
+func BenchmarkEncodeRGBOpaque(b *testing.B) {
+	b.StopTimer()
+	img := image.NewRGBA(640, 480)
+	// Set all pixels to 0xFF alpha to force opaque mode.
+	bo := img.Bounds()
+	for y := bo.Min.Y; y < bo.Max.Y; y++ {
+		for x := bo.Min.X; x < bo.Max.X; x++ {
+			img.Set(x, y, image.RGBAColor{0, 0, 0, 255})
+		}
+	}
+	if !img.Opaque() {
+		panic("expected image to be opaque")
+	}
+	b.SetBytes(640 * 480 * 4)
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		Encode(ioutil.Discard, img)
+	}
+}
+
+func BenchmarkEncodeRGBA(b *testing.B) {
+	b.StopTimer()
+	img := image.NewRGBA(640, 480)
+	if img.Opaque() {
+		panic("expected image to not be opaque")
+	}
+	b.SetBytes(640 * 480 * 4)
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		Encode(ioutil.Discard, img)
 	}
 }