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mirror of https://github.com/golang/go synced 2024-11-12 07:00:21 -07:00

image: replace Width and Height by Bounds, and introduce the Point and

Rect types.

The actual image representation is unchanged. A future change will
replace the {[][]color} with {[]color, stride int, r Rectangle} and
possibly a clip region.

The draw.Color, draw.Point and draw.Rect types will be removed in a
future change. Trying to do it in this one polluted the diff with
trivia.

R=r, rsc
CC=golang-dev
https://golang.org/cl/1918047
This commit is contained in:
Nigel Tao 2010-08-10 12:08:52 +10:00
parent 46db2e3c25
commit 5eb35e4247
14 changed files with 234 additions and 105 deletions

View File

@ -669,7 +669,7 @@ func redraw(new bool) {
// if new && getwindow(display, Refmesg) < 0 {
// sysfatal("can't reattach to window");
// }
r := draw.Rect(0, 0, screen.Width(), screen.Height())
r := draw.Rect(screen.Bounds().MinX, screen.Bounds().Min.Y, screen, Bounds().Max.X, screen.Bounds().Max.Y)
pos.X = (pos.X - rboard.Min.X) / pcsz
pos.Y = (pos.Y - rboard.Min.Y) / pcsz
dx := r.Max.X - r.Min.X
@ -722,7 +722,7 @@ func quitter(c <-chan bool) {
func Play(pp []Piece, ctxt draw.Context) {
display = ctxt
screen = ctxt.Screen()
screenr = draw.Rect(0, 0, screen.Width(), screen.Height())
screenr = draw.Rect(screen.Bounds().MinX, screen.Bounds().Min.Y, screen, Bounds().Max.X, screen.Bounds().Max.Y)
pieces = pp
N = len(pieces[0].d)
initPieces()

View File

@ -88,9 +88,7 @@ func (c Color) SetAlpha(a uint8) Color {
return r<<24 | g<<16 | b<<8 | Color(a)
}
func (c Color) Width() int { return 1e9 }
func (c Color) Height() int { return 1e9 }
func (c Color) Bounds() image.Rectangle { return image.Rect(0, 0, 1e9, 1e9) }
func (c Color) At(x, y int) image.Color { return c }

View File

@ -43,13 +43,15 @@ func Draw(dst Image, r Rectangle, src image.Image, sp Point) {
// The implementation is simple and slow.
// TODO(nigeltao): Optimize this.
func DrawMask(dst Image, r Rectangle, src image.Image, sp Point, mask image.Image, mp Point, op Op) {
dx, dy := src.Width()-sp.X, src.Height()-sp.Y
sb := src.Bounds()
dx, dy := sb.Dx()-sp.X, sb.Dy()-sp.Y
if mask != nil {
if dx > mask.Width()-mp.X {
dx = mask.Width() - mp.X
mb := mask.Bounds()
if dx > mb.Dx()-mp.X {
dx = mb.Dx() - mp.X
}
if dy > mask.Height()-mp.Y {
dy = mask.Height() - mp.Y
if dy > mb.Dy()-mp.Y {
dy = mb.Dy() - mp.Y
}
}
if r.Dx() > dx {

View File

@ -97,10 +97,11 @@ var drawTests = []drawTest{
func makeGolden(dst image.Image, t drawTest) image.Image {
// Since golden is a newly allocated image, we don't have to check if the
// input source and mask images and the output golden image overlap.
golden := image.NewRGBA(dst.Width(), dst.Height())
for y := 0; y < golden.Height(); y++ {
b := dst.Bounds()
golden := image.NewRGBA(b.Dx(), b.Dy())
for y := b.Min.Y; y < b.Max.Y; y++ {
my, sy := y, y
for x := 0; x < golden.Width(); x++ {
for x := b.Min.X; x < b.Max.X; x++ {
mx, sx := x, x
const M = 1<<16 - 1
var dr, dg, db, da uint32
@ -129,9 +130,14 @@ loop:
for _, test := range drawTests {
dst := hgradRed(255)
// Draw the (src, mask, op) onto a copy of dst using a slow but obviously correct implementation.
b := dst.Bounds()
golden := makeGolden(dst, test)
if !b.Eq(golden.Bounds()) {
t.Errorf("draw %s: bounds %v versus %v", test.desc, dst.Bounds(), golden.Bounds())
continue
}
// Draw the same combination onto the actual dst using the optimized DrawMask implementation.
DrawMask(dst, Rect(0, 0, dst.Width(), dst.Height()), test.src, ZP, test.mask, ZP, test.op)
DrawMask(dst, Rect(b.Min.X, b.Min.Y, b.Max.X, b.Max.Y), test.src, ZP, test.mask, ZP, test.op)
// Check that the resultant pixel at (8, 8) matches what we expect
// (the expected value can be verified by hand).
if !eq(dst.At(8, 8), test.expected) {
@ -139,8 +145,8 @@ loop:
continue
}
// Check that the resultant dst image matches the golden output.
for y := 0; y < golden.Height(); y++ {
for x := 0; x < golden.Width(); x++ {
for y := b.Min.Y; y < b.Max.Y; y++ {
for x := b.Min.X; x < b.Max.X; x++ {
if !eq(dst.At(x, y), golden.At(x, y)) {
t.Errorf("draw %s: at (%d, %d), %v versus golden %v", test.desc, x, y, dst.At(x, y), golden.At(x, y))
continue loop

View File

@ -67,14 +67,17 @@ func (c *conn) flusher() {
return
}
b := c.img.Bounds()
if b.Empty() {
continue
}
// Each X request has a 16-bit length (in terms of 4-byte units). To avoid going over
// this limit, we send PutImage for each row of the image, rather than trying to paint
// the entire image in one X request. This approach could easily be optimized (or the
// X protocol may have an escape sequence to delimit very large requests).
// TODO(nigeltao): See what XCB's xcb_put_image does in this situation.
w, h := c.img.Width(), c.img.Height()
units := 6 + w
if units > 0xffff || h > 0xffff {
units := 6 + b.Dx()
if units > 0xffff || b.Dy() > 0xffff {
// This window is too large for X.
close(c.flush)
return
@ -86,10 +89,10 @@ func (c *conn) flusher() {
c.flushBuf0[3] = uint8(units >> 8)
setU32LE(c.flushBuf0[4:8], uint32(c.window))
setU32LE(c.flushBuf0[8:12], uint32(c.gc))
setU32LE(c.flushBuf0[12:16], 1<<16|uint32(w))
setU32LE(c.flushBuf0[12:16], 1<<16|uint32(b.Dx()))
c.flushBuf0[21] = 0x18 // depth = 24 bits.
for y := 0; y < h; y++ {
for y := b.Min.Y; y < b.Max.Y; y++ {
setU32LE(c.flushBuf0[16:20], uint32(y<<16))
_, err := c.w.Write(c.flushBuf0[0:24])
if err != nil {
@ -97,8 +100,8 @@ func (c *conn) flusher() {
return
}
p := c.img.Pixel[y]
for x := 0; x < w; {
nx := w - x
for x := b.Min.X; x < b.Max.X; {
nx := b.Max.X - x
if nx > len(c.flushBuf1)/4 {
nx = len(c.flushBuf1) / 4
}

View File

@ -24,15 +24,13 @@ var _ image.Image = (*Image)(nil)
func (m *Image) ColorModel() image.ColorModel { return ColorModel }
func (m *Image) Width() int {
func (m *Image) Bounds() image.Rectangle {
if len(m.Pixel) == 0 {
return 0
return image.ZR
}
return len(m.Pixel[0])
return image.Rectangle{image.ZP, image.Point{len(m.Pixel[0]), len(m.Pixel)}}
}
func (m *Image) Height() int { return len(m.Pixel) }
func (m *Image) At(x, y int) image.Color { return m.Pixel[y][x] }
func (m *Image) Set(x, y int, color image.Color) {

View File

@ -99,8 +99,8 @@ func (m *SpacewarPDP1) Init(ctxt draw.Context) {
m.ctxt = ctxt
m.kc = ctxt.KeyboardChan()
m.screen = ctxt.Screen()
m.dx = m.screen.Width()
m.dy = m.screen.Height()
m.dx = m.screen.Bounds().Dx()
m.dy = m.screen.Bounds().Dy()
m.colorModel = m.screen.ColorModel()
m.pix = make([][]uint8, m.dy)
for i := range m.pix {

View File

@ -8,6 +8,7 @@ TARG=image
GOFILES=\
color.go\
format.go\
geom.go\
image.go\
names.go\

125
src/pkg/image/geom.go Normal file
View File

@ -0,0 +1,125 @@
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package image
import (
"strconv"
)
// A Point is an X, Y coordinate pair. The axes increase right and down.
type Point struct {
X, Y int
}
// String returns a string representation of p like "(3,4)".
func (p Point) String() string {
return "(" + strconv.Itoa(p.X) + "," + strconv.Itoa(p.Y) + ")"
}
// Add returns the vector p+q.
func (p Point) Add(q Point) Point {
return Point{p.X + q.X, p.Y + q.Y}
}
// Sub returns the vector p-q.
func (p Point) Sub(q Point) Point {
return Point{p.X - q.X, p.Y - q.Y}
}
// ZP is the zero Point.
var ZP Point
// Pt is shorthand for Point{X, Y}.
func Pt(X, Y int) Point {
return Point{X, Y}
}
// A Rectangle contains the points with Min.X <= X < Max.X, Min.Y <= Y < Max.Y.
type Rectangle struct {
Min, Max Point
}
// String returns a string representation of r like "(3,4)-(6,5)".
func (r Rectangle) String() string {
return r.Min.String() + "-" + r.Max.String()
}
// Dx returns r's width.
func (r Rectangle) Dx() int {
return r.Max.X - r.Min.X
}
// Dy returns r's height.
func (r Rectangle) Dy() int {
return r.Max.Y - r.Min.Y
}
// Add returns the rectangle r translated by p.
func (r Rectangle) Add(p Point) Rectangle {
return Rectangle{
Point{r.Min.X + p.X, r.Min.Y + p.Y},
Point{r.Max.X + p.X, r.Max.Y + p.Y},
}
}
// Add returns the rectangle r translated by -p.
func (r Rectangle) Sub(p Point) Rectangle {
return Rectangle{
Point{r.Min.X - p.X, r.Min.Y - p.Y},
Point{r.Max.X - p.X, r.Max.Y - p.Y},
}
}
// Inset returns the rectangle r inset by n, which may be negative.
func (r Rectangle) Inset(n int) Rectangle {
return Rectangle{
Point{r.Min.X + n, r.Min.Y + n},
Point{r.Max.X - n, r.Max.Y - n},
}
}
// Empty returns whether the rectangle contains no points.
func (r Rectangle) Empty() bool {
return r.Min.X >= r.Max.X || r.Min.Y >= r.Max.Y
}
// Eq returns whether r and s are equal.
func (r Rectangle) Eq(s Rectangle) bool {
return r.Min.X == s.Min.X && r.Min.Y == s.Min.Y &&
r.Max.X == s.Max.X && r.Max.Y == s.Max.Y
}
// Overlaps returns whether r and s have a non-empty intersection.
func (r Rectangle) Overlaps(s Rectangle) bool {
return r.Min.X < s.Max.X && s.Min.X < r.Max.X &&
r.Min.Y < s.Max.Y && s.Min.Y < r.Max.Y
}
// Canon returns the canonical version of r. The returned rectangle has
// minimum and maximum coordinates swapped if necessary so that Min.X <= Max.X
// and Min.Y <= Max.Y.
func (r Rectangle) Canon() Rectangle {
if r.Max.X < r.Min.X {
r.Min.X, r.Max.X = r.Max.X, r.Min.X
}
if r.Max.Y < r.Min.Y {
r.Min.Y, r.Max.Y = r.Max.Y, r.Min.Y
}
return r
}
// ZR is the zero Rectangle.
var ZR Rectangle
// Rect is shorthand for Rectangle{Pt(x0, y0), Pt(x1, y1)}.
func Rect(x0, y0, x1, y1 int) Rectangle {
if x0 > x1 {
x0, x1 = x1, x0
}
if y0 > y1 {
y0, y1 = y1, y0
}
return Rectangle{Point{x0, y0}, Point{x1, y1}}
}

View File

@ -5,13 +5,16 @@
// The image package implements a basic 2-D image library.
package image
// An Image is a rectangular grid of Colors drawn from a ColorModel.
// An Image is a finite rectangular grid of Colors drawn from a ColorModel.
type Image interface {
// ColorModel returns the Image's ColorModel.
ColorModel() ColorModel
Width() int
Height() int
// At(0, 0) returns the upper-left pixel of the grid.
// At(Width()-1, Height()-1) returns the lower-right pixel.
// Bounds returns the domain for which At can return non-zero color.
// The bounds do not necessarily contain the point (0, 0).
Bounds() Rectangle
// At returns the color of the pixel at (x, y).
// At(Bounds().Min.X, Bounds().Min.Y) returns the upper-left pixel of the grid.
// At(Bounds().Max.X-1, Bounds().Max.Y-1) returns the lower-right one.
At(x, y int) Color
}
@ -23,18 +26,24 @@ type RGBA struct {
func (p *RGBA) ColorModel() ColorModel { return RGBAColorModel }
func (p *RGBA) Width() int {
func (p *RGBA) Bounds() Rectangle {
if len(p.Pixel) == 0 {
return 0
return ZR
}
return len(p.Pixel[0])
return Rectangle{ZP, Point{len(p.Pixel[0]), len(p.Pixel)}}
}
func (p *RGBA) Height() int { return len(p.Pixel) }
func (p *RGBA) At(x, y int) Color {
// TODO(nigeltao): Check if (x,y) is outside the bounds, and return zero.
// Similarly for the other concrete image types.
return p.Pixel[y][x]
}
func (p *RGBA) At(x, y int) Color { return p.Pixel[y][x] }
func (p *RGBA) Set(x, y int, c Color) { p.Pixel[y][x] = toRGBAColor(c).(RGBAColor) }
func (p *RGBA) Set(x, y int, c Color) {
// TODO(nigeltao): Check if (x,y) is outside the bounds, and return.
// Similarly for the other concrete image types.
p.Pixel[y][x] = toRGBAColor(c).(RGBAColor)
}
// Opaque scans the entire image and returns whether or not it is fully opaque.
func (p *RGBA) Opaque() bool {
@ -71,15 +80,13 @@ type RGBA64 struct {
func (p *RGBA64) ColorModel() ColorModel { return RGBA64ColorModel }
func (p *RGBA64) Width() int {
func (p *RGBA64) Bounds() Rectangle {
if len(p.Pixel) == 0 {
return 0
return ZR
}
return len(p.Pixel[0])
return Rectangle{ZP, Point{len(p.Pixel[0]), len(p.Pixel)}}
}
func (p *RGBA64) Height() int { return len(p.Pixel) }
func (p *RGBA64) At(x, y int) Color { return p.Pixel[y][x] }
func (p *RGBA64) Set(x, y int, c Color) { p.Pixel[y][x] = toRGBA64Color(c).(RGBA64Color) }
@ -119,15 +126,13 @@ type NRGBA struct {
func (p *NRGBA) ColorModel() ColorModel { return NRGBAColorModel }
func (p *NRGBA) Width() int {
func (p *NRGBA) Bounds() Rectangle {
if len(p.Pixel) == 0 {
return 0
return ZR
}
return len(p.Pixel[0])
return Rectangle{ZP, Point{len(p.Pixel[0]), len(p.Pixel)}}
}
func (p *NRGBA) Height() int { return len(p.Pixel) }
func (p *NRGBA) At(x, y int) Color { return p.Pixel[y][x] }
func (p *NRGBA) Set(x, y int, c Color) { p.Pixel[y][x] = toNRGBAColor(c).(NRGBAColor) }
@ -167,15 +172,13 @@ type NRGBA64 struct {
func (p *NRGBA64) ColorModel() ColorModel { return NRGBA64ColorModel }
func (p *NRGBA64) Width() int {
func (p *NRGBA64) Bounds() Rectangle {
if len(p.Pixel) == 0 {
return 0
return ZR
}
return len(p.Pixel[0])
return Rectangle{ZP, Point{len(p.Pixel[0]), len(p.Pixel)}}
}
func (p *NRGBA64) Height() int { return len(p.Pixel) }
func (p *NRGBA64) At(x, y int) Color { return p.Pixel[y][x] }
func (p *NRGBA64) Set(x, y int, c Color) { p.Pixel[y][x] = toNRGBA64Color(c).(NRGBA64Color) }
@ -215,15 +218,13 @@ type Alpha struct {
func (p *Alpha) ColorModel() ColorModel { return AlphaColorModel }
func (p *Alpha) Width() int {
func (p *Alpha) Bounds() Rectangle {
if len(p.Pixel) == 0 {
return 0
return ZR
}
return len(p.Pixel[0])
return Rectangle{ZP, Point{len(p.Pixel[0]), len(p.Pixel)}}
}
func (p *Alpha) Height() int { return len(p.Pixel) }
func (p *Alpha) At(x, y int) Color { return p.Pixel[y][x] }
func (p *Alpha) Set(x, y int, c Color) { p.Pixel[y][x] = toAlphaColor(c).(AlphaColor) }
@ -263,15 +264,13 @@ type Alpha16 struct {
func (p *Alpha16) ColorModel() ColorModel { return Alpha16ColorModel }
func (p *Alpha16) Width() int {
func (p *Alpha16) Bounds() Rectangle {
if len(p.Pixel) == 0 {
return 0
return ZR
}
return len(p.Pixel[0])
return Rectangle{ZP, Point{len(p.Pixel[0]), len(p.Pixel)}}
}
func (p *Alpha16) Height() int { return len(p.Pixel) }
func (p *Alpha16) At(x, y int) Color { return p.Pixel[y][x] }
func (p *Alpha16) Set(x, y int, c Color) { p.Pixel[y][x] = toAlpha16Color(c).(Alpha16Color) }
@ -311,15 +310,13 @@ type Gray struct {
func (p *Gray) ColorModel() ColorModel { return GrayColorModel }
func (p *Gray) Width() int {
func (p *Gray) Bounds() Rectangle {
if len(p.Pixel) == 0 {
return 0
return ZR
}
return len(p.Pixel[0])
return Rectangle{ZP, Point{len(p.Pixel[0]), len(p.Pixel)}}
}
func (p *Gray) Height() int { return len(p.Pixel) }
func (p *Gray) At(x, y int) Color { return p.Pixel[y][x] }
func (p *Gray) Set(x, y int, c Color) { p.Pixel[y][x] = toGrayColor(c).(GrayColor) }
@ -347,15 +344,13 @@ type Gray16 struct {
func (p *Gray16) ColorModel() ColorModel { return Gray16ColorModel }
func (p *Gray16) Width() int {
func (p *Gray16) Bounds() Rectangle {
if len(p.Pixel) == 0 {
return 0
return ZR
}
return len(p.Pixel[0])
return Rectangle{ZP, Point{len(p.Pixel[0]), len(p.Pixel)}}
}
func (p *Gray16) Height() int { return len(p.Pixel) }
func (p *Gray16) At(x, y int) Color { return p.Pixel[y][x] }
func (p *Gray16) Set(x, y int, c Color) { p.Pixel[y][x] = toGray16Color(c).(Gray16Color) }
@ -421,15 +416,13 @@ type Paletted struct {
func (p *Paletted) ColorModel() ColorModel { return p.Palette }
func (p *Paletted) Width() int {
func (p *Paletted) Bounds() Rectangle {
if len(p.Pixel) == 0 {
return 0
return ZR
}
return len(p.Pixel[0])
return Rectangle{ZP, Point{len(p.Pixel[0]), len(p.Pixel)}}
}
func (p *Paletted) Height() int { return len(p.Pixel) }
func (p *Paletted) At(x, y int) Color { return p.Palette[p.Pixel[y][x]] }
func (p *Paletted) ColorIndexAt(x, y int) uint8 {

View File

@ -25,9 +25,7 @@ func (c ColorImage) ColorModel() ColorModel {
return ColorModelFunc(func(Color) Color { return c.C })
}
func (c ColorImage) Width() int { return 1e9 }
func (c ColorImage) Height() int { return 1e9 }
func (c ColorImage) Bounds() Rectangle { return Rectangle{ZP, Point{1e9, 1e9}} }
func (c ColorImage) At(x, y int) Color { return c.C }

View File

@ -45,12 +45,13 @@ func readPng(filename string) (image.Image, os.Error) {
// An approximation of the sng command-line tool.
func sng(w io.WriteCloser, filename string, png image.Image) {
defer w.Close()
bounds := png.Bounds()
// For now, the go PNG parser only reads bitdepths of 8.
bitdepth := 8
// Write the filename and IHDR.
io.WriteString(w, "#SNG: from "+filename+".png\nIHDR {\n")
fmt.Fprintf(w, " width: %d; height: %d; bitdepth: %d;\n", png.Width(), png.Height(), bitdepth)
fmt.Fprintf(w, " width: %d; height: %d; bitdepth: %d;\n", bounds.Dx(), bounds.Dy(), bitdepth)
cm := png.ColorModel()
var paletted *image.Paletted
cpm, _ := cm.(image.PalettedColorModel)
@ -86,20 +87,20 @@ func sng(w io.WriteCloser, filename string, png image.Image) {
// Write the IMAGE.
io.WriteString(w, "IMAGE {\n pixels hex\n")
for y := 0; y < png.Height(); y++ {
for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
switch {
case cm == image.RGBAColorModel:
for x := 0; x < png.Width(); x++ {
for x := bounds.Min.X; x < bounds.Max.X; x++ {
rgba := png.At(x, y).(image.RGBAColor)
fmt.Fprintf(w, "%02x%02x%02x ", rgba.R, rgba.G, rgba.B)
}
case cm == image.NRGBAColorModel:
for x := 0; x < png.Width(); x++ {
for x := bounds.Min.X; x < bounds.Max.X; x++ {
nrgba := png.At(x, y).(image.NRGBAColor)
fmt.Fprintf(w, "%02x%02x%02x%02x ", nrgba.R, nrgba.G, nrgba.B, nrgba.A)
}
case cpm != nil:
for x := 0; x < png.Width(); x++ {
for x := bounds.Min.X; x < bounds.Max.X; x++ {
fmt.Fprintf(w, "%02x", paletted.ColorIndexAt(x, y))
}
}

View File

@ -41,8 +41,9 @@ func opaque(m image.Image) bool {
if o, ok := m.(opaquer); ok {
return o.Opaque()
}
for y := 0; y < m.Height(); y++ {
for x := 0; x < m.Width(); x++ {
b := m.Bounds()
for y := b.Min.Y; y < b.Max.Y; y++ {
for x := b.Min.X; x < b.Max.X; x++ {
_, _, _, a := m.At(x, y).RGBA()
if a != 0xffff {
return false
@ -91,8 +92,9 @@ func (e *encoder) writeChunk(b []byte, name string) {
}
func (e *encoder) writeIHDR() {
writeUint32(e.tmp[0:4], uint32(e.m.Width()))
writeUint32(e.tmp[4:8], uint32(e.m.Height()))
b := e.m.Bounds()
writeUint32(e.tmp[0:4], uint32(b.Dx()))
writeUint32(e.tmp[4:8], uint32(b.Dy()))
e.tmp[8] = 8 // bit depth
e.tmp[9] = e.colorType
e.tmp[10] = 0 // default compression method
@ -254,18 +256,19 @@ func writeImage(w io.Writer, m image.Image, ct uint8) os.Error {
// cr[ft], for non-zero filter types ft, are buffers for transforming cr[0] under the
// other PNG filter types. These buffers are allocated once and re-used for each row.
// The +1 is for the per-row filter type, which is at cr[*][0].
b := m.Bounds()
var cr [nFilter][]uint8
for i := 0; i < len(cr); i++ {
cr[i] = make([]uint8, 1+bpp*m.Width())
cr[i] = make([]uint8, 1+bpp*b.Dx())
cr[i][0] = uint8(i)
}
pr := make([]uint8, 1+bpp*m.Width())
pr := make([]uint8, 1+bpp*b.Dx())
for y := 0; y < m.Height(); y++ {
for y := b.Min.Y; y < b.Max.Y; y++ {
// Convert from colors to bytes.
switch ct {
case ctTrueColor:
for x := 0; x < m.Width(); x++ {
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)
@ -273,12 +276,12 @@ func writeImage(w io.Writer, m image.Image, ct uint8) os.Error {
cr[0][3*x+3] = uint8(b >> 8)
}
case ctPaletted:
for x := 0; x < m.Width(); x++ {
for x := b.Min.X; x < b.Max.X; x++ {
cr[0][x+1] = paletted.ColorIndexAt(x, y)
}
case ctTrueColorAlpha:
// Convert from image.Image (which is alpha-premultiplied) to PNG's non-alpha-premultiplied.
for x := 0; x < m.Width(); x++ {
for x := b.Min.X; x < b.Max.X; x++ {
c := image.NRGBAColorModel.Convert(m.At(x, y)).(image.NRGBAColor)
cr[0][4*x+1] = c.R
cr[0][4*x+2] = c.G
@ -327,7 +330,7 @@ func Encode(w io.Writer, m image.Image) os.Error {
// Obviously, negative widths and heights are invalid. Furthermore, the PNG
// spec section 11.2.2 says that zero is invalid. Excessively large images are
// also rejected.
mw, mh := int64(m.Width()), int64(m.Height())
mw, mh := int64(m.Bounds().Dx()), int64(m.Bounds().Dy())
if mw <= 0 || mh <= 0 || mw >= 1<<32 || mh >= 1<<32 {
return FormatError("invalid image size: " + strconv.Itoa64(mw) + "x" + strconv.Itoa64(mw))
}

View File

@ -13,11 +13,12 @@ import (
)
func diff(m0, m1 image.Image) os.Error {
if m0.Width() != m1.Width() || m0.Height() != m1.Height() {
return os.NewError(fmt.Sprintf("dimensions differ: %dx%d vs %dx%d", m0.Width(), m0.Height(), m1.Width(), m1.Height()))
b0, b1 := m0.Bounds(), m1.Bounds()
if !b0.Eq(b1) {
return os.NewError(fmt.Sprintf("dimensions differ: %v vs %v", b0, b1))
}
for y := 0; y < m0.Height(); y++ {
for x := 0; x < m0.Width(); x++ {
for y := b0.Min.Y; y < b0.Max.Y; y++ {
for x := b0.Min.X; x < b0.Max.X; x++ {
r0, g0, b0, a0 := m0.At(x, y).RGBA()
r1, g1, b1, a1 := m1.At(x, y).RGBA()
if r0 != r1 || g0 != g1 || b0 != b1 || a0 != a1 {