func modeTerrain(p *image.Paletted, l int) uint8 {
b := p.Bounds()
modeMap := make([]uint8, l)
var most, mode uint8
for i := b.Min.X; i < b.Max.X; i++ {
for j := b.Min.Y; j < b.Max.Y; j++ {
pos := p.ColorIndexAt(i, j)
modeMap[pos]++
if m := modeMap[pos]; m > most {
most = m
mode = pos
}
}
}
return mode
}
// An approximation of the sng command-line tool.
func sng(w io.WriteCloser, filename string, png image.Image) {
defer w.Close()
bounds := png.Bounds()
cm := png.ColorModel()
var bitdepth int
switch cm {
case color.RGBAModel, color.NRGBAModel, color.AlphaModel, color.GrayModel:
bitdepth = 8
default:
bitdepth = 16
}
cpm, _ := cm.(color.Palette)
var paletted *image.Paletted
if cpm != nil {
switch {
case len(cpm) <= 2:
bitdepth = 1
case len(cpm) <= 4:
bitdepth = 2
case len(cpm) <= 16:
bitdepth = 4
default:
bitdepth = 8
}
paletted = png.(*image.Paletted)
}
// Write the filename and IHDR.
io.WriteString(w, "#SNG: from "+filename+".png\nIHDR {\n")
fmt.Fprintf(w, " width: %d; height: %d; bitdepth: %d;\n", bounds.Dx(), bounds.Dy(), bitdepth)
switch {
case cm == color.RGBAModel, cm == color.RGBA64Model:
io.WriteString(w, " using color;\n")
case cm == color.NRGBAModel, cm == color.NRGBA64Model:
io.WriteString(w, " using color alpha;\n")
case cm == color.GrayModel, cm == color.Gray16Model:
io.WriteString(w, " using grayscale;\n")
case cpm != nil:
io.WriteString(w, " using color palette;\n")
default:
io.WriteString(w, "unknown PNG decoder color model\n")
}
io.WriteString(w, "}\n")
// We fake a gAMA output. The test files have a gAMA chunk but the go PNG parser ignores it
// (the PNG spec section 11.3 says "Ancillary chunks may be ignored by a decoder").
io.WriteString(w, "gAMA {1.0000}\n")
// Write the PLTE and tRNS (if applicable).
if cpm != nil {
lastAlpha := -1
io.WriteString(w, "PLTE {\n")
for i, c := range cpm {
r, g, b, a := c.RGBA()
if a != 0xffff {
lastAlpha = i
}
r >>= 8
g >>= 8
b >>= 8
fmt.Fprintf(w, " (%3d,%3d,%3d) # rgb = (0x%02x,0x%02x,0x%02x)\n", r, g, b, r, g, b)
}
io.WriteString(w, "}\n")
if lastAlpha != -1 {
io.WriteString(w, "tRNS {\n")
for i := 0; i <= lastAlpha; i++ {
_, _, _, a := cpm[i].RGBA()
a >>= 8
fmt.Fprintf(w, " %d", a)
}
io.WriteString(w, "}\n")
}
}
// Write the IMAGE.
io.WriteString(w, "IMAGE {\n pixels hex\n")
for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
switch {
case cm == color.GrayModel:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
gray := png.At(x, y).(color.Gray)
fmt.Fprintf(w, "%02x", gray.Y)
}
case cm == color.Gray16Model:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
gray16 := png.At(x, y).(color.Gray16)
fmt.Fprintf(w, "%04x ", gray16.Y)
}
case cm == color.RGBAModel:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
rgba := png.At(x, y).(color.RGBA)
fmt.Fprintf(w, "%02x%02x%02x ", rgba.R, rgba.G, rgba.B)
}
case cm == color.RGBA64Model:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
rgba64 := png.At(x, y).(color.RGBA64)
fmt.Fprintf(w, "%04x%04x%04x ", rgba64.R, rgba64.G, rgba64.B)
}
case cm == color.NRGBAModel:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
nrgba := png.At(x, y).(color.NRGBA)
fmt.Fprintf(w, "%02x%02x%02x%02x ", nrgba.R, nrgba.G, nrgba.B, nrgba.A)
}
case cm == color.NRGBA64Model:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
nrgba64 := png.At(x, y).(color.NRGBA64)
fmt.Fprintf(w, "%04x%04x%04x%04x ", nrgba64.R, nrgba64.G, nrgba64.B, nrgba64.A)
}
case cpm != nil:
var b, c int
for x := bounds.Min.X; x < bounds.Max.X; x++ {
b = b<<uint(bitdepth) | int(paletted.ColorIndexAt(x, y))
c++
if c == 8/bitdepth {
fmt.Fprintf(w, "%02x", b)
b = 0
c = 0
}
}
}
io.WriteString(w, "\n")
}
io.WriteString(w, "}\n")
}
func writeImage(w io.Writer, m image.Image, ct uint8) os.Error {
zw, err := zlib.NewDeflater(w)
if err != nil {
return err
}
defer zw.Close()
bpp := 0 // Bytes per pixel.
var paletted *image.Paletted
switch ct {
case ctTrueColor:
bpp = 3
case ctPaletted:
bpp = 1
paletted = m.(*image.Paletted)
case ctTrueColorAlpha:
bpp = 4
}
// cr[*] and pr are the bytes for the current and previous row.
// cr[0] is unfiltered (or equivalently, filtered with the ftNone filter).
// 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].
var cr [nFilter][]uint8
for i := 0; i < len(cr); i++ {
cr[i] = make([]uint8, 1+bpp*m.Width())
cr[i][0] = uint8(i)
}
pr := make([]uint8, 1+bpp*m.Width())
for y := 0; y < m.Height(); y++ {
// Convert from colors to bytes.
switch ct {
case ctTrueColor:
for x := 0; x < m.Width(); 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 >> 24)
cr[0][3*x+2] = uint8(g >> 24)
cr[0][3*x+3] = uint8(b >> 24)
}
case ctPaletted:
for x := 0; x < m.Width(); 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++ {
c := image.NRGBAColorModel.Convert(m.At(x, y)).(image.NRGBAColor)
cr[0][4*x+1] = c.R
cr[0][4*x+2] = c.G
cr[0][4*x+3] = c.B
cr[0][4*x+4] = c.A
}
}
// Apply the filter.
f := filter(cr[0:nFilter], pr, bpp)
// Write the compressed bytes.
_, err = zw.Write(cr[f])
if err != nil {
return err
}
// The current row for y is the previous row for y+1.
pr, cr[0] = cr[0], pr
}
return nil
}
func (g *generator) buildTerrain(mpath minecraft.Path, level *level, terrain, biomes, plants *image.Paletted, height, water *image.Gray, c chan paint) error {
b := terrain.Bounds()
proceed := make(chan uint8, 10)
errChan := make(chan error, 1)
go func() {
defer close(proceed)
cc := newCache(g.Terrain.Blocks)
for j := 0; j < b.Max.Y; j += 16 {
chunkZ := int32(j >> 4)
for i := 0; i < b.Max.X; i += 16 {
chunkX := int32(i >> 4)
h := int32(meanHeight(height.SubImage(image.Rect(i, j, i+16, j+16)).(*image.Gray)))
wh := int32(meanHeight(water.SubImage(image.Rect(i, j, i+16, j+16)).(*image.Gray)))
var t uint8
if wh >= h<<1 { // more water than land...
c <- paint{
color.RGBA{0, 0, 255, 255},
chunkX, chunkZ,
}
t = uint8(len(g.Terrain.Blocks) - 1)
h = wh
} else {
t = modeTerrain(terrain.SubImage(image.Rect(i, j, i+16, j+16)).(*image.Paletted), len(g.Terrain.Palette))
c <- paint{
g.Terrain.Palette[t],
chunkX, chunkZ,
}
}
if err := mpath.SetChunk(cc.getFromCache(chunkX, chunkZ, t, h)); err != nil {
errChan <- err
return
}
proceed <- t
}
}
}()
ts := make([]uint8, 0, 1024)
for i := 0; i < (b.Max.X>>4)+2; i++ {
ts = append(ts, <-proceed) // get far enough ahead so all chunks are surrounded before shaping, to get correct lighting
}
select {
case err := <-errChan:
return err
default:
}
for j := int32(0); j < int32(b.Max.Y); j += 16 {
chunkZ := j >> 4
for i := int32(0); i < int32(b.Max.X); i += 16 {
chunkX := i >> 4
var totalHeight int32
ot := ts[0]
ts = ts[1:]
oy, _ := level.GetHeight(i, j)
for x := i; x < i+16; x++ {
for z := j; z < j+16; z++ {
if biomes != nil {
level.SetBiome(x, z, g.Biomes.Values[biomes.ColorIndexAt(int(x), int(z))])
}
h := int32(height.GrayAt(int(x), int(z)).Y)
totalHeight += h
wl := int32(water.GrayAt(int(x), int(z)).Y)
y := oy
if h > y {
y = h
}
if wl > y {
y = wl
}
for ; y > h && y > wl; y-- {
level.SetBlock(x, y, z, minecraft.Block{})
}
if plants != nil {
p := g.Plants.Blocks[plants.ColorIndexAt(int(x), int(z))]
py := int32(1)
for ; py <= int32(p.Level); py++ {
level.SetBlock(x, y+py, z, p.Base)
}
level.SetBlock(x, y+py, z, p.Top)
}
for ; y > h; y-- {
level.SetBlock(x, y, z, minecraft.Block{ID: 9})
}
t := terrain.ColorIndexAt(int(x), int(z))
tb := g.Terrain.Blocks[t]
for ; y > h-int32(tb.Level); y-- {
level.SetBlock(x, y, z, tb.Top)
}
if t != ot {
h = 0
} else {
h = oy
}
for ; y >= h; y-- {
level.SetBlock(x, y, z, tb.Base)
}
}
}
c <- paint{
color.Alpha{uint8(totalHeight >> 8)},
chunkX, chunkZ,
}
select {
case p, ok := <-proceed:
if ok {
ts = append(ts, p)
}
case err := <-errChan:
return err
}
}
}
return nil
}
// An approximation of the sng command-line tool.
func sng(w io.WriteCloser, filename string, png image.Image) {
defer w.Close()
bounds := png.Bounds()
cm := png.ColorModel()
var bitdepth int
switch cm {
case color.RGBAModel, color.NRGBAModel, color.AlphaModel, color.GrayModel:
bitdepth = 8
default:
bitdepth = 16
}
cpm, _ := cm.(color.Palette)
var paletted *image.Paletted
if cpm != nil {
switch {
case len(cpm) <= 2:
bitdepth = 1
case len(cpm) <= 4:
bitdepth = 2
case len(cpm) <= 16:
bitdepth = 4
default:
bitdepth = 8
}
paletted = png.(*image.Paletted)
}
// Write the filename and IHDR.
io.WriteString(w, "#SNG: from "+filename+".png\nIHDR {\n")
fmt.Fprintf(w, " width: %d; height: %d; bitdepth: %d;\n", bounds.Dx(), bounds.Dy(), bitdepth)
if s, ok := fakeIHDRUsings[filename]; ok {
io.WriteString(w, s)
} else {
switch {
case cm == color.RGBAModel, cm == color.RGBA64Model:
io.WriteString(w, " using color;\n")
case cm == color.NRGBAModel, cm == color.NRGBA64Model:
io.WriteString(w, " using color alpha;\n")
case cm == color.GrayModel, cm == color.Gray16Model:
io.WriteString(w, " using grayscale;\n")
case cpm != nil:
io.WriteString(w, " using color palette;\n")
default:
io.WriteString(w, "unknown PNG decoder color model\n")
}
}
io.WriteString(w, "}\n")
// We fake a gAMA chunk. The test files have a gAMA chunk but the go PNG
// parser ignores it (the PNG spec section 11.3 says "Ancillary chunks may
// be ignored by a decoder").
if s, ok := fakegAMAs[filename]; ok {
io.WriteString(w, s)
} else {
io.WriteString(w, "gAMA {1.0000}\n")
}
// Write the PLTE and tRNS (if applicable).
useTransparent := false
if cpm != nil {
lastAlpha := -1
io.WriteString(w, "PLTE {\n")
for i, c := range cpm {
var r, g, b, a uint8
switch c := c.(type) {
case color.RGBA:
r, g, b, a = c.R, c.G, c.B, 0xff
case color.NRGBA:
r, g, b, a = c.R, c.G, c.B, c.A
default:
panic("unknown palette color type")
}
if a != 0xff {
lastAlpha = i
}
fmt.Fprintf(w, " (%3d,%3d,%3d) # rgb = (0x%02x,0x%02x,0x%02x)\n", r, g, b, r, g, b)
}
io.WriteString(w, "}\n")
if s, ok := fakebKGDs[filename]; ok {
io.WriteString(w, s)
}
if lastAlpha != -1 {
io.WriteString(w, "tRNS {\n")
for i := 0; i <= lastAlpha; i++ {
_, _, _, a := cpm[i].RGBA()
a >>= 8
fmt.Fprintf(w, " %d", a)
}
io.WriteString(w, "}\n")
}
} else if strings.HasPrefix(filename, "ft") {
if s, ok := fakebKGDs[filename]; ok {
io.WriteString(w, s)
}
// We fake a tRNS chunk. The test files' grayscale and truecolor
// transparent images all have their top left corner transparent.
switch c := png.At(0, 0).(type) {
case color.NRGBA:
if c.A == 0 {
useTransparent = true
io.WriteString(w, "tRNS {\n")
switch filename {
case "ftbbn0g01", "ftbbn0g02", "ftbbn0g04":
// The standard image package doesn't have a "gray with
// alpha" type. Instead, we use an image.NRGBA.
fmt.Fprintf(w, " gray: %d;\n", c.R)
default:
fmt.Fprintf(w, " red: %d; green: %d; blue: %d;\n", c.R, c.G, c.B)
}
io.WriteString(w, "}\n")
}
case color.NRGBA64:
if c.A == 0 {
useTransparent = true
io.WriteString(w, "tRNS {\n")
switch filename {
case "ftbwn0g16":
// The standard image package doesn't have a "gray16 with
// alpha" type. Instead, we use an image.NRGBA64.
fmt.Fprintf(w, " gray: %d;\n", c.R)
default:
fmt.Fprintf(w, " red: %d; green: %d; blue: %d;\n", c.R, c.G, c.B)
}
io.WriteString(w, "}\n")
}
}
}
// Write the IMAGE.
io.WriteString(w, "IMAGE {\n pixels hex\n")
for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
switch {
case cm == color.GrayModel:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
gray := png.At(x, y).(color.Gray)
fmt.Fprintf(w, "%02x", gray.Y)
}
case cm == color.Gray16Model:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
gray16 := png.At(x, y).(color.Gray16)
fmt.Fprintf(w, "%04x ", gray16.Y)
}
case cm == color.RGBAModel:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
rgba := png.At(x, y).(color.RGBA)
fmt.Fprintf(w, "%02x%02x%02x ", rgba.R, rgba.G, rgba.B)
}
case cm == color.RGBA64Model:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
rgba64 := png.At(x, y).(color.RGBA64)
fmt.Fprintf(w, "%04x%04x%04x ", rgba64.R, rgba64.G, rgba64.B)
}
case cm == color.NRGBAModel:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
nrgba := png.At(x, y).(color.NRGBA)
switch filename {
case "ftbbn0g01", "ftbbn0g02", "ftbbn0g04":
fmt.Fprintf(w, "%02x", nrgba.R)
default:
if useTransparent {
fmt.Fprintf(w, "%02x%02x%02x ", nrgba.R, nrgba.G, nrgba.B)
} else {
fmt.Fprintf(w, "%02x%02x%02x%02x ", nrgba.R, nrgba.G, nrgba.B, nrgba.A)
}
}
}
case cm == color.NRGBA64Model:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
nrgba64 := png.At(x, y).(color.NRGBA64)
switch filename {
case "ftbwn0g16":
fmt.Fprintf(w, "%04x ", nrgba64.R)
default:
if useTransparent {
fmt.Fprintf(w, "%04x%04x%04x ", nrgba64.R, nrgba64.G, nrgba64.B)
} else {
fmt.Fprintf(w, "%04x%04x%04x%04x ", nrgba64.R, nrgba64.G, nrgba64.B, nrgba64.A)
}
}
}
case cpm != nil:
var b, c int
for x := bounds.Min.X; x < bounds.Max.X; x++ {
b = b<<uint(bitdepth) | int(paletted.ColorIndexAt(x, y))
c++
if c == 8/bitdepth {
fmt.Fprintf(w, "%02x", b)
b = 0
c = 0
}
}
if c != 0 {
for c != 8/bitdepth {
b = b << uint(bitdepth)
c++
}
fmt.Fprintf(w, "%02x", b)
}
}
io.WriteString(w, "\n")
}
io.WriteString(w, "}\n")
}
func NewSimulation(img *image.Paletted) *Simulation {
size := img.Bounds().Size()
groups := make(map[*group]struct{}, 0)
matrix := newBucketMatrix(size.X, size.Y)
for y := 0; y < size.Y; y++ {
for x := 0; x < size.X; x++ {
c := img.ColorIndexAt(x, y)
if c > 0 && c <= maxCharge+1 {
topLeftBucket := matrix.get(x-1, y-1)
topBucket := matrix.get(x, y-1)
leftBucket := matrix.get(x-1, y)
var currentBucket *bucket
switch {
case nil == topBucket && nil == leftBucket:
currentBucket = newBucket()
groups[currentBucket.group] = struct{}{}
case nil == topBucket && nil != leftBucket:
currentBucket = leftBucket
case (nil != topBucket && nil == leftBucket) ||
topBucket == leftBucket ||
topBucket.group == leftBucket.group:
currentBucket = topBucket
default:
currentBucket = topBucket
delete(groups, topBucket.group)
topBucket.group.moveBucketsTo(leftBucket.group)
}
if nil != topLeftBucket && nil != topBucket && nil != leftBucket {
currentBucket.group.wire.isPowerSource = true
}
matrix.set(x, y, currentBucket)
currentBucket.addPixel(image.Point{x, y})
}
}
}
for y := 0; y < size.Y; y++ {
for x := 0; x < size.X; x++ {
if nil != matrix.get(x, y) {
continue
}
topBucket := matrix.get(x, y-1)
topRightBucket := matrix.get(x+1, y-1)
rightBucket := matrix.get(x+1, y)
bottomRightBucket := matrix.get(x+1, y+1)
bottomBucket := matrix.get(x, y+1)
bottomLeftBucket := matrix.get(x-1, y+1)
leftBucket := matrix.get(x-1, y)
topLeftBucket := matrix.get(x-1, y-1)
if nil == topLeftBucket && nil == topRightBucket && nil == bottomLeftBucket && nil == bottomRightBucket &&
nil != topBucket && nil != rightBucket && nil != bottomBucket && nil != leftBucket {
delete(groups, topBucket.group)
topBucket.group.moveBucketsTo(bottomBucket.group)
delete(groups, leftBucket.group)
leftBucket.group.moveBucketsTo(rightBucket.group)
}
}
}
transistors := make([]*transistor, 0)
for y := 0; y < size.Y; y++ {
for x := 0; x < size.X; x++ {
if nil != matrix.get(x, y) {
continue
}
topBucket := matrix.get(x, y-1)
topRightBucket := matrix.get(x+1, y-1)
rightBucket := matrix.get(x+1, y)
bottomRightBucket := matrix.get(x+1, y+1)
bottomBucket := matrix.get(x, y+1)
bottomLeftBucket := matrix.get(x-1, y+1)
leftBucket := matrix.get(x-1, y)
topLeftBucket := matrix.get(x-1, y-1)
switch {
case nil == bottomLeftBucket && nil == bottomRightBucket &&
nil == topBucket && nil != rightBucket && nil != bottomBucket && nil != leftBucket:
transistors = append(transistors,
newTransistor(image.Point{x, y}, bottomBucket.group.wire, rightBucket.group.wire, leftBucket.group.wire))
case nil == bottomLeftBucket && nil == topLeftBucket &&
nil != topBucket && nil == rightBucket && nil != bottomBucket && nil != leftBucket:
transistors = append(transistors,
newTransistor(image.Point{x, y}, leftBucket.group.wire, topBucket.group.wire, bottomBucket.group.wire))
case nil == topLeftBucket && nil == topRightBucket &&
nil != topBucket && nil != rightBucket && nil == bottomBucket && nil != leftBucket:
transistors = append(transistors,
newTransistor(image.Point{x, y}, topBucket.group.wire, rightBucket.group.wire, leftBucket.group.wire))
case nil == bottomRightBucket && nil == topRightBucket &&
nil != topBucket && nil != rightBucket && nil != bottomBucket && nil == leftBucket:
transistors = append(transistors,
newTransistor(image.Point{x, y}, rightBucket.group.wire, topBucket.group.wire, bottomBucket.group.wire))
}
}
}
wires := make([]*wire, len(groups))
wireStates := make([]wireState, len(groups))
i := 0
for k := range groups {
k.wire.index = i
wires[i] = k.wire
var charge uint8
if k.wire.isPowerSource {
charge = maxCharge
} else {
charge = 0
}
wireStates[i] = wireState{charge, k.wire}
i++
}
return &Simulation{&circuit{wires: wires, transistors: transistors}, wireStates}
}
// An approximation of the sng command-line tool.
func sng(w io.WriteCloser, filename string, png image.Image) {
defer w.Close()
bounds := png.Bounds()
cm := png.ColorModel()
var bitdepth int
switch cm {
case image.RGBAColorModel, image.NRGBAColorModel, image.AlphaColorModel, image.GrayColorModel:
bitdepth = 8
default:
bitdepth = 16
}
cpm, _ := cm.(image.PalettedColorModel)
var paletted *image.Paletted
if cpm != nil {
bitdepth = 8
paletted = png.(*image.Paletted)
}
// Write the filename and IHDR.
io.WriteString(w, "#SNG: from "+filename+".png\nIHDR {\n")
fmt.Fprintf(w, " width: %d; height: %d; bitdepth: %d;\n", bounds.Dx(), bounds.Dy(), bitdepth)
switch {
case cm == image.RGBAColorModel, cm == image.RGBA64ColorModel:
io.WriteString(w, " using color;\n")
case cm == image.NRGBAColorModel, cm == image.NRGBA64ColorModel:
io.WriteString(w, " using color alpha;\n")
case cm == image.GrayColorModel, cm == image.Gray16ColorModel:
io.WriteString(w, " using grayscale;\n")
case cpm != nil:
io.WriteString(w, " using color palette;\n")
default:
io.WriteString(w, "unknown PNG decoder color model\n")
}
io.WriteString(w, "}\n")
// We fake a gAMA output. The test files have a gAMA chunk but the go PNG parser ignores it
// (the PNG spec section 11.3 says "Ancillary chunks may be ignored by a decoder").
io.WriteString(w, "gAMA {1.0000}\n")
// Write the PLTE (if applicable).
if cpm != nil {
io.WriteString(w, "PLTE {\n")
for i := 0; i < len(cpm); i++ {
r, g, b, _ := cpm[i].RGBA()
r >>= 8
g >>= 8
b >>= 8
fmt.Fprintf(w, " (%3d,%3d,%3d) # rgb = (0x%02x,0x%02x,0x%02x)\n", r, g, b, r, g, b)
}
io.WriteString(w, "}\n")
}
// Write the IMAGE.
io.WriteString(w, "IMAGE {\n pixels hex\n")
for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
switch {
case cm == image.GrayColorModel:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
gray := png.At(x, y).(image.GrayColor)
fmt.Fprintf(w, "%02x", gray.Y)
}
case cm == image.Gray16ColorModel:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
gray16 := png.At(x, y).(image.Gray16Color)
fmt.Fprintf(w, "%04x ", gray16.Y)
}
case cm == image.RGBAColorModel:
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.RGBA64ColorModel:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
rgba64 := png.At(x, y).(image.RGBA64Color)
fmt.Fprintf(w, "%04x%04x%04x ", rgba64.R, rgba64.G, rgba64.B)
}
case cm == image.NRGBAColorModel:
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 cm == image.NRGBA64ColorModel:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
nrgba64 := png.At(x, y).(image.NRGBA64Color)
fmt.Fprintf(w, "%04x%04x%04x%04x ", nrgba64.R, nrgba64.G, nrgba64.B, nrgba64.A)
}
case cpm != nil:
for x := bounds.Min.X; x < bounds.Max.X; x++ {
fmt.Fprintf(w, "%02x", paletted.ColorIndexAt(x, y))
}
}
io.WriteString(w, "\n")
}
io.WriteString(w, "}\n")
}
// An approximation of the sng command-line tool.
func sng(w io.WriteCloser, filename string, png image.Image) {
defer w.Close()
// 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)
cm := png.ColorModel()
var paletted *image.Paletted
cpm, _ := cm.(image.PalettedColorModel)
switch {
case cm == image.RGBAColorModel:
io.WriteString(w, " using color;\n")
case cm == image.NRGBAColorModel:
io.WriteString(w, " using color alpha;\n")
case cpm != nil:
io.WriteString(w, " using color palette;\n")
paletted = png.(*image.Paletted)
default:
io.WriteString(w, "unknown PNG decoder color model\n")
}
io.WriteString(w, "}\n")
// We fake a gAMA output. The test files have a gAMA chunk but the go PNG parser ignores it
// (the PNG spec section 11.3 says "Ancillary chunks may be ignored by a decoder").
io.WriteString(w, "gAMA {1.0000}\n")
// Write the PLTE (if applicable).
if cpm != nil {
io.WriteString(w, "PLTE {\n")
for i := 0; i < len(cpm); i++ {
r, g, b, _ := cpm[i].RGBA()
r >>= 24
g >>= 24
b >>= 24
fmt.Fprintf(w, " (%3d,%3d,%3d) # rgb = (0x%02x,0x%02x,0x%02x)\n", r, g, b, r, g, b)
}
io.WriteString(w, "}\n")
}
// Write the IMAGE.
io.WriteString(w, "IMAGE {\n pixels hex\n")
for y := 0; y < png.Height(); y++ {
switch {
case cm == image.RGBAColorModel:
for x := 0; x < png.Width(); 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++ {
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++ {
fmt.Fprintf(w, "%02x", paletted.ColorIndexAt(x, y))
}
}
io.WriteString(w, "\n")
}
io.WriteString(w, "}\n")
}