// Checks if image is grayscale
func (c *Convertor) isGrayScale(img image.Image) bool {
model := img.ColorModel()
if model == color.GrayModel || model == color.Gray16Model {
return true
}
return false
}
// Encode writes the Image m to w in PNG format.
func (enc *Encoder) Encode(w io.Writer, m image.Image) 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.Bounds().Dx()), int64(m.Bounds().Dy())
if mw <= 0 || mh <= 0 || mw >= 1<<32 || mh >= 1<<32 {
return FormatError("invalid image size: " + strconv.FormatInt(mw, 10) + "x" + strconv.FormatInt(mh, 10))
}
var e encoder
e.enc = enc
e.w = w
e.m = m
e.st = simpleTransparency(m)
var pal color.Palette
// cbP8 encoding needs PalettedImage's ColorIndexAt method.
if _, ok := m.(image.PalettedImage); ok {
pal, _ = m.ColorModel().(color.Palette)
}
if pal != nil {
e.cb = cbP8
} else {
switch m.ColorModel() {
case color.GrayModel:
e.cb = cbG8
case color.Gray16Model:
e.cb = cbG16
case color.RGBAModel, color.NRGBAModel, color.AlphaModel:
if opaque(m) || e.st != nil {
e.cb = cbTC8
} else {
e.cb = cbTCA8
}
default:
if opaque(m) || e.st != nil {
e.cb = cbTC16
} else {
e.cb = cbTCA16
}
}
}
_, e.err = io.WriteString(w, pngHeader)
e.writeIHDR()
if pal != nil {
e.writePLTEAndTRNS(pal)
} else if e.st != nil {
e.writetRNS()
}
e.writeIDATs()
e.writeIEND()
return e.err
}
func ImageTransformByProfile(src_image image.Image, src_prof, dst_prof *Profile) (image.Image, error) {
var dst_image image.Image
rect := src_image.Bounds()
width := rect.Dx()
height := rect.Dy()
colorModel := src_image.ColorModel()
// 今のところ RGBA, YCbCr のみ対応
if (colorModel != color.YCbCrModel) && (colorModel != color.RGBAModel) {
return nil, fmt.Errorf("ImageTransformByProfile: Unsupported ColorModel(%d)", colorModel)
}
var src_rgba *image.RGBA
var src_ycbcr *image.YCbCr
if colorModel == color.YCbCrModel {
// YCbCr の場合は RGB に変換する
src_ycbcr = src_image.(*image.YCbCr)
src_rgba = image.NewRGBA(rect)
DrawYCbCr(src_rgba, rect, src_ycbcr, image.Pt(0, 0))
} else {
src_rgba = src_image.(*image.RGBA) // type assertions
}
transform := CreateTransform(src_prof, DATA_RGBA_8, dst_prof, DATA_RGBA_8)
defer transform.DeleteTransform()
if transform == nil {
return nil, fmt.Errorf("ImageTransformByProfile: CreateTransform Failedl(%d)", colorModel)
}
dst_rgba := image.NewRGBA(rect)
src_pix := src_rgba.Pix
dst_pix := dst_rgba.Pix
len_pix := len(src_pix)
transform.DoTransform(src_pix, dst_pix, len_pix)
// YCbCr の場合は RGB から戻す
if colorModel == color.YCbCrModel {
dst_ycbcr := image.NewYCbCr(rect, src_ycbcr.SubsampleRatio)
var x int
var y int
for y = 0; y < height; y++ {
for x = 0; x < width; x++ {
r, g, b, _ := dst_rgba.At(x, y).RGBA()
yy, cb, cr := color.RGBToYCbCr(uint8(r), uint8(g), uint8(b))
yi := dst_ycbcr.YOffset(x, y)
ci := dst_ycbcr.COffset(x, y)
dst_ycbcr.Y[yi] = yy
dst_ycbcr.Cb[ci] = cb
dst_ycbcr.Cr[ci] = cr
}
}
dst_image = image.Image(dst_ycbcr)
} else {
dst_image = image.Image(dst_rgba)
}
return dst_image, nil
}
func NewTexture(image image.Image, data interface{}) (texture *Texture, err error) {
iF, typ, f, t, e := ColorModelToGLTypes(image.ColorModel())
if e != nil {
return nil, nil
}
return NewTexture2(data, image.Bounds().Dx(), image.Bounds().Dy(), t, iF, typ, f), nil
}
func convertColor(im image.Image, col image.RGBA64Color) image.Color {
var outCol image.Color
switch im.ColorModel() {
case image.RGBAColorModel:
outCol = image.RGBAColorModel.Convert(col).(image.RGBAColor)
case image.NRGBAColorModel:
outCol = image.NRGBAColorModel.Convert(col).(image.NRGBAColor)
case image.GrayColorModel:
outCol = image.GrayColorModel.Convert(col).(image.GrayColor)
case image.Gray16ColorModel:
outCol = image.Gray16ColorModel.Convert(col).(image.Gray16Color)
default:
outCol = col
}
return outCol
}
func imgType(im image.Image, w, h int) imageng {
var scaled imageng
switch im.ColorModel() {
case image.RGBAColorModel:
scaled = image.NewRGBA(w, h)
case image.NRGBAColorModel:
scaled = image.NewNRGBA(w, h)
case image.GrayColorModel:
scaled = image.NewGray(w, h)
case image.Gray16ColorModel:
scaled = image.NewGray16(w, h)
default:
scaled = image.NewRGBA64(w, h)
}
return scaled
}
// Encode writes the Image m to w in PNG format. Any Image may be encoded, but
// images that are not image.NRGBA might be encoded lossily.
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.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))
}
var e encoder
e.w = w
e.m = m
pal, _ := m.(*image.Paletted)
if pal != nil {
e.cb = cbP8
} else {
switch m.ColorModel() {
case image.GrayColorModel:
e.cb = cbG8
case image.Gray16ColorModel:
e.cb = cbG16
case image.RGBAColorModel, image.NRGBAColorModel, image.AlphaColorModel:
if opaque(m) {
e.cb = cbTC8
} else {
e.cb = cbTCA8
}
default:
if opaque(m) {
e.cb = cbTC16
} else {
e.cb = cbTCA16
}
}
}
_, e.err = io.WriteString(w, pngHeader)
e.writeIHDR()
if pal != nil {
e.writePLTE(pal.Palette)
e.maybeWritetRNS(pal.Palette)
}
e.writeIDATs()
e.writeIEND()
return e.err
}
// 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")
}
// 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 LoadTextureFromImage(image image.Image) (tex *Texture, err error) {
/*
val := reflect.ValueOf(image)
pixs := val.FieldByName("Pix")
if pixs.IsValid() {
return
} else {
}
return nil, false, nil
*/
internalFormat, typ, format, target, e := ColorModelToGLTypes(image.ColorModel())
if e != nil {
return nil, nil
}
//
w := image.Bounds().Dx()
h := image.Bounds().Dy()
model := image.ColorModel()
var data []byte
switch model.(type) {
case color.Palette:
memHandle := Allocate(4 * h * w)
data = memHandle.Bytes()
defer memHandle.Release()
for x := 0; x < w; x++ {
for y := 0; y < h; y++ {
offset := (x + (y * w)) * 4
r, g, b, a := image.At(x, y).RGBA()
data[offset] = byte(r / 257)
data[offset+1] = byte(g / 257)
data[offset+2] = byte(b / 257)
data[offset+3] = byte(a / 257)
}
}
}
switch model {
case color.YCbCrModel:
memHandle := Allocate(3 * h * w)
data = memHandle.Bytes()
defer memHandle.Release()
for x := 0; x < w; x++ {
for y := 0; y < h; y++ {
offset := (x + y*w) * 3
r, g, b, _ := image.At(x, y).RGBA()
data[offset] = byte(r / 257)
data[offset+1] = byte(g / 257)
data[offset+2] = byte(b / 257)
}
}
case color.RGBAModel, color.NRGBAModel:
memHandle := Allocate(4 * h * w)
data = memHandle.Bytes()
defer memHandle.Release()
for x := 0; x < w; x++ {
for y := 0; y < h; y++ {
offset := (x + (y * w)) * 4
r, g, b, a := image.At(x, y).RGBA()
data[offset] = byte(r / 257)
data[offset+1] = byte(g / 257)
data[offset+2] = byte(b / 257)
data[offset+3] = byte(a / 257)
}
}
case color.RGBA64Model, color.NRGBA64Model:
memHandle := Allocate(4 * h * w)
data = memHandle.Bytes()
defer memHandle.Release()
for x := 0; x < w; x++ {
for y := 0; y < h; y++ {
offset := (x + y*w) * 4
r, g, b, a := image.At(x, y).RGBA()
data[offset] = byte(r / 257)
data[offset+1] = byte(g / 257)
data[offset+2] = byte(b / 257)
data[offset+3] = byte(a / 257)
}
}
default:
m, e := CustomColorModels[model]
if e {
return NewTexture2(m.Model.Data(), image.Bounds().Dx(), image.Bounds().Dy(), target, internalFormat, typ, format), nil
} else {
return nil, errors.New("unsupported format")
}
}
return NewTexture2(data, image.Bounds().Dx(), image.Bounds().Dy(), target, internalFormat, typ, format), 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 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")
}
func grid(img1 image.Image, fitHeight int, fitWidth int) [][]bool {
bounds := img1.Bounds()
width, height := bounds.Dx(), bounds.Dy()
grid := make([][]bool, fitWidth, fitWidth)
for col := 0; col < fitWidth; col++ {
r := make([]bool, fitHeight, fitHeight)
for row := 0; row < fitHeight; row++ {
isOn := pixelIsIntense(img1.At(interp(col, fitWidth, width), interp(row, fitHeight, height)), img1.ColorModel()).ActiveState()
r[fitHeight-1-row] = isOn
}
grid[col] = r
}
return grid
}
// 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")
}
