func Pixel(x, y int, img *image.RGBA64, wg *sync.WaitGroup) {
var r, g, b, a uint64
for i := 0; i < *spp; i++ {
for j := 0; j < *spp; j++ {
X := (float64(x)+float64(i)/float64(*spp))/float64(*ppp) - float64(*ppi)/2
Y := float64(*ppi)/2 - (float64(y)+float64(j)/float64(*spp))/float64(*ppp)
c := Ray(X+*basex, Y+*basey, *basez,
X/float64(*ppi)*epsilon,
Y/float64(*ppi)*epsilon,
epsilon,
farZ)
r += uint64(c.R)
g += uint64(c.G)
b += uint64(c.B)
a += uint64(c.A)
}
}
img.SetRGBA64(x, y, color.RGBA64{
uint16(r / uint64(*spp) / uint64(*spp)),
uint16(g / uint64(*spp) / uint64(*spp)),
uint16(b / uint64(*spp) / uint64(*spp)),
uint16(a / uint64(*spp) / uint64(*spp)),
})
wg.Done()
}
func resizeNRGBA64(in *image.NRGBA64, out *image.RGBA64, scale float64, coeffs []int32, offset []int, filterLength int) {
newBounds := out.Bounds()
maxX := in.Bounds().Dx() - 1
for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
row := in.Pix[x*in.Stride:]
for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
var rgba [4]int64
var sum int64
start := offset[y]
ci := y * filterLength
for i := 0; i < filterLength; i++ {
coeff := coeffs[ci+i]
if coeff != 0 {
xi := start + i
switch {
case uint(xi) < uint(maxX):
xi *= 8
case xi >= maxX:
xi = 8 * maxX
default:
xi = 0
}
// Forward alpha-premultiplication
a := int64(uint16(row[xi+6])<<8 | uint16(row[xi+7]))
r := int64(uint16(row[xi+0])<<8|uint16(row[xi+1])) * a
r /= 0xffff
g := int64(uint16(row[xi+2])<<8|uint16(row[xi+3])) * a
g /= 0xffff
b := int64(uint16(row[xi+4])<<8|uint16(row[xi+5])) * a
b /= 0xffff
rgba[0] += int64(coeff) * r
rgba[1] += int64(coeff) * g
rgba[2] += int64(coeff) * b
rgba[3] += int64(coeff) * a
sum += int64(coeff)
}
}
xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
value := clampUint16(rgba[0] / sum)
out.Pix[xo+0] = uint8(value >> 8)
out.Pix[xo+1] = uint8(value)
value = clampUint16(rgba[1] / sum)
out.Pix[xo+2] = uint8(value >> 8)
out.Pix[xo+3] = uint8(value)
value = clampUint16(rgba[2] / sum)
out.Pix[xo+4] = uint8(value >> 8)
out.Pix[xo+5] = uint8(value)
value = clampUint16(rgba[3] / sum)
out.Pix[xo+6] = uint8(value >> 8)
out.Pix[xo+7] = uint8(value)
}
}
}
func newAtFuncRGBA64(p *image.RGBA64) AtFunc {
return func(x, y int) (r, g, b, a uint32) {
i := p.PixOffset(x, y)
r = uint32(p.Pix[i+0])<<8 | uint32(p.Pix[i+1])
g = uint32(p.Pix[i+2])<<8 | uint32(p.Pix[i+3])
b = uint32(p.Pix[i+4])<<8 | uint32(p.Pix[i+5])
a = uint32(p.Pix[i+6])<<8 | uint32(p.Pix[i+7])
return
}
}
func convertRGBA64(dest *Image, src *image.RGBA64) {
var x, y, i, si int
for x = dest.Rect.Min.X; x < dest.Rect.Max.X; x++ {
for y = dest.Rect.Min.Y; y < dest.Rect.Max.Y; y++ {
si = src.PixOffset(x, y)
i = dest.PixOffset(x, y)
dest.Pix[i+0] = src.Pix[si+4]
dest.Pix[i+1] = src.Pix[si+2]
dest.Pix[i+2] = src.Pix[si+0]
dest.Pix[i+3] = src.Pix[si+6]
}
}
}
func (s *Server) decodeRawEncoding(r io.Reader, rect *image.RGBA64) error {
for y := rect.Rect.Min.Y; y < rect.Rect.Max.Y; y++ {
for x := rect.Rect.Min.X; x < rect.Rect.Max.X; x++ {
pixel, err := s.readPixel(r)
if err != nil {
log.Println("error reading pixel %d, %d", x, y)
return err
}
rect.Set(x, y, pixel)
}
}
return nil
}
func newSetFuncRGBA64(p *image.RGBA64) SetFunc {
return func(x, y int, r, g, b, a uint32) {
i := p.PixOffset(x, y)
r16, g16, b16, a16 := uint16(r), uint16(g), uint16(b), uint16(a)
p.Pix[i+0] = uint8(r16 >> 8)
p.Pix[i+1] = uint8(r16)
p.Pix[i+2] = uint8(g16 >> 8)
p.Pix[i+3] = uint8(g16)
p.Pix[i+4] = uint8(b16 >> 8)
p.Pix[i+5] = uint8(b16)
p.Pix[i+6] = uint8(a16 >> 8)
p.Pix[i+7] = uint8(a16)
}
}
func resizeGeneric(in image.Image, out *image.RGBA64, scale float64, coeffs []int32, offset []int, filterLength int) {
newBounds := out.Bounds()
maxX := in.Bounds().Dx() - 1
for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
var rgba [4]int64
var sum int64
start := offset[y]
ci := y * filterLength
for i := 0; i < filterLength; i++ {
coeff := coeffs[ci+i]
if coeff != 0 {
xi := start + i
switch {
case xi < 0:
xi = 0
case xi >= maxX:
xi = maxX
}
r, g, b, a := in.At(xi+in.Bounds().Min.X, x+in.Bounds().Min.Y).RGBA()
rgba[0] += int64(coeff) * int64(r)
rgba[1] += int64(coeff) * int64(g)
rgba[2] += int64(coeff) * int64(b)
rgba[3] += int64(coeff) * int64(a)
sum += int64(coeff)
}
}
offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
value := clampUint16(rgba[0] / sum)
out.Pix[offset+0] = uint8(value >> 8)
out.Pix[offset+1] = uint8(value)
value = clampUint16(rgba[1] / sum)
out.Pix[offset+2] = uint8(value >> 8)
out.Pix[offset+3] = uint8(value)
value = clampUint16(rgba[2] / sum)
out.Pix[offset+4] = uint8(value >> 8)
out.Pix[offset+5] = uint8(value)
value = clampUint16(rgba[3] / sum)
out.Pix[offset+6] = uint8(value >> 8)
out.Pix[offset+7] = uint8(value)
}
}
}
func resizeRGBA64(in *image.RGBA64, out *image.RGBA64, scale float64, coeffs []int32, offset []int, filterLength int) {
newBounds := out.Bounds()
maxX := in.Bounds().Dx() - 1
for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
row := in.Pix[x*in.Stride:]
for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
var rgba [4]int64
var sum int64
start := offset[y]
ci := (y - newBounds.Min.Y) * filterLength
for i := 0; i < filterLength; i++ {
coeff := coeffs[ci+i]
if coeff != 0 {
xi := start + i
switch {
case xi < 0:
xi = 0
case xi >= maxX:
xi = 8 * maxX
default:
xi *= 8
}
rgba[0] += int64(coeff) * int64(uint16(row[xi+0])<<8|uint16(row[xi+1]))
rgba[1] += int64(coeff) * int64(uint16(row[xi+2])<<8|uint16(row[xi+3]))
rgba[2] += int64(coeff) * int64(uint16(row[xi+4])<<8|uint16(row[xi+5]))
rgba[3] += int64(coeff) * int64(uint16(row[xi+6])<<8|uint16(row[xi+7]))
sum += int64(coeff)
}
}
xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
value := clampUint16(rgba[0] / sum)
out.Pix[xo+0] = uint8(value >> 8)
out.Pix[xo+1] = uint8(value)
value = clampUint16(rgba[1] / sum)
out.Pix[xo+2] = uint8(value >> 8)
out.Pix[xo+3] = uint8(value)
value = clampUint16(rgba[2] / sum)
out.Pix[xo+4] = uint8(value >> 8)
out.Pix[xo+5] = uint8(value)
value = clampUint16(rgba[3] / sum)
out.Pix[xo+6] = uint8(value >> 8)
out.Pix[xo+7] = uint8(value)
}
}
}
func nearestRGBA64(in *image.RGBA64, out *image.RGBA64, scale float64, coeffs []bool, offset []int, filterLength int) {
newBounds := out.Bounds()
maxX := in.Bounds().Dx() - 1
for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
row := in.Pix[x*in.Stride:]
for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
var rgba [4]float32
var sum float32
start := offset[y]
ci := y * filterLength
for i := 0; i < filterLength; i++ {
if coeffs[ci+i] {
xi := start + i
switch {
case uint(xi) < uint(maxX):
xi *= 8
case xi >= maxX:
xi = 8 * maxX
default:
xi = 0
}
rgba[0] += float32(uint16(row[xi+0])<<8 | uint16(row[xi+1]))
rgba[1] += float32(uint16(row[xi+2])<<8 | uint16(row[xi+3]))
rgba[2] += float32(uint16(row[xi+4])<<8 | uint16(row[xi+5]))
rgba[3] += float32(uint16(row[xi+6])<<8 | uint16(row[xi+7]))
sum++
}
}
xo := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
value := floatToUint16(rgba[0] / sum)
out.Pix[xo+0] = uint8(value >> 8)
out.Pix[xo+1] = uint8(value)
value = floatToUint16(rgba[1] / sum)
out.Pix[xo+2] = uint8(value >> 8)
out.Pix[xo+3] = uint8(value)
value = floatToUint16(rgba[2] / sum)
out.Pix[xo+4] = uint8(value >> 8)
out.Pix[xo+5] = uint8(value)
value = floatToUint16(rgba[3] / sum)
out.Pix[xo+6] = uint8(value >> 8)
out.Pix[xo+7] = uint8(value)
}
}
}
func nearestGeneric(in image.Image, out *image.RGBA64, scale float64, coeffs []bool, offset []int, filterLength int) {
newBounds := out.Bounds()
maxX := in.Bounds().Dx() - 1
for x := newBounds.Min.X; x < newBounds.Max.X; x++ {
for y := newBounds.Min.Y; y < newBounds.Max.Y; y++ {
var rgba [4]float32
var sum float32
start := offset[y]
ci := (y - newBounds.Min.Y) * filterLength
for i := 0; i < filterLength; i++ {
if coeffs[ci+i] {
xi := start + i
switch {
case xi < 0:
xi = 0
case xi >= maxX:
xi = maxX
}
r, g, b, a := in.At(xi+in.Bounds().Min.X, x+in.Bounds().Min.Y).RGBA()
rgba[0] += float32(r)
rgba[1] += float32(g)
rgba[2] += float32(b)
rgba[3] += float32(a)
sum++
}
}
offset := (y-newBounds.Min.Y)*out.Stride + (x-newBounds.Min.X)*8
value := floatToUint16(rgba[0] / sum)
out.Pix[offset+0] = uint8(value >> 8)
out.Pix[offset+1] = uint8(value)
value = floatToUint16(rgba[1] / sum)
out.Pix[offset+2] = uint8(value >> 8)
out.Pix[offset+3] = uint8(value)
value = floatToUint16(rgba[2] / sum)
out.Pix[offset+4] = uint8(value >> 8)
out.Pix[offset+5] = uint8(value)
value = floatToUint16(rgba[3] / sum)
out.Pix[offset+6] = uint8(value >> 8)
out.Pix[offset+7] = uint8(value)
}
}
}
// Resize a rectangle image slice
func resizeSlice(input image.Image, output *image.RGBA64, interp InterpolationFunction, scale, adjust, offset float32, slice image.Rectangle, c chan int) {
filter := interp(input, float32(clampFactor(scale)))
var u float32
var color color.RGBA64
for y := slice.Min.Y; y < slice.Max.Y; y++ {
u = scale*(float32(y)+adjust) + offset
filter.SetKernelWeights(u)
for x := slice.Min.X; x < slice.Max.X; x++ {
color = filter.Interpolate(u, x)
i := output.PixOffset(x, y)
output.Pix[i+0] = uint8(color.R >> 8)
output.Pix[i+1] = uint8(color.R)
output.Pix[i+2] = uint8(color.G >> 8)
output.Pix[i+3] = uint8(color.G)
output.Pix[i+4] = uint8(color.B >> 8)
output.Pix[i+5] = uint8(color.B)
output.Pix[i+6] = uint8(color.A >> 8)
output.Pix[i+7] = uint8(color.A)
}
}
c <- 1
}
// decode decodes the IDAT data into an image.
func (d *decoder) decode() (image.Image, error) {
r, err := zlib.NewReader(d)
if err != nil {
return nil, err
}
defer r.Close()
bitsPerPixel := 0
pixOffset := 0
var (
gray *image.Gray
rgba *image.RGBA
paletted *image.Paletted
nrgba *image.NRGBA
gray16 *image.Gray16
rgba64 *image.RGBA64
nrgba64 *image.NRGBA64
img image.Image
)
switch d.cb {
case cbG1, cbG2, cbG4, cbG8:
bitsPerPixel = d.depth
gray = image.NewGray(image.Rect(0, 0, d.width, d.height))
img = gray
case cbGA8:
bitsPerPixel = 16
nrgba = image.NewNRGBA(image.Rect(0, 0, d.width, d.height))
img = nrgba
case cbTC8:
bitsPerPixel = 24
rgba = image.NewRGBA(image.Rect(0, 0, d.width, d.height))
img = rgba
case cbP1, cbP2, cbP4, cbP8:
bitsPerPixel = d.depth
paletted = image.NewPaletted(image.Rect(0, 0, d.width, d.height), d.palette)
img = paletted
case cbTCA8:
bitsPerPixel = 32
nrgba = image.NewNRGBA(image.Rect(0, 0, d.width, d.height))
img = nrgba
case cbG16:
bitsPerPixel = 16
gray16 = image.NewGray16(image.Rect(0, 0, d.width, d.height))
img = gray16
case cbGA16:
bitsPerPixel = 32
nrgba64 = image.NewNRGBA64(image.Rect(0, 0, d.width, d.height))
img = nrgba64
case cbTC16:
bitsPerPixel = 48
rgba64 = image.NewRGBA64(image.Rect(0, 0, d.width, d.height))
img = rgba64
case cbTCA16:
bitsPerPixel = 64
nrgba64 = image.NewNRGBA64(image.Rect(0, 0, d.width, d.height))
img = nrgba64
}
bytesPerPixel := (bitsPerPixel + 7) / 8
// cr and pr are the bytes for the current and previous row.
// The +1 is for the per-row filter type, which is at cr[0].
cr := make([]uint8, 1+(bitsPerPixel*d.width+7)/8)
pr := make([]uint8, 1+(bitsPerPixel*d.width+7)/8)
for y := 0; y < d.height; y++ {
// Read the decompressed bytes.
_, err := io.ReadFull(r, cr)
if err != nil {
return nil, err
}
// Apply the filter.
cdat := cr[1:]
pdat := pr[1:]
switch cr[0] {
case ftNone:
// No-op.
case ftSub:
for i := bytesPerPixel; i < len(cdat); i++ {
cdat[i] += cdat[i-bytesPerPixel]
}
case ftUp:
for i, p := range pdat {
cdat[i] += p
}
case ftAverage:
for i := 0; i < bytesPerPixel; i++ {
cdat[i] += pdat[i] / 2
}
for i := bytesPerPixel; i < len(cdat); i++ {
cdat[i] += uint8((int(cdat[i-bytesPerPixel]) + int(pdat[i])) / 2)
}
case ftPaeth:
filterPaeth(cdat, pdat, bytesPerPixel)
default:
return nil, FormatError("bad filter type")
}
// Convert from bytes to colors.
switch d.cb {
case cbG1:
for x := 0; x < d.width; x += 8 {
b := cdat[x/8]
for x2 := 0; x2 < 8 && x+x2 < d.width; x2++ {
gray.SetGray(x+x2, y, color.Gray{(b >> 7) * 0xff})
b <<= 1
}
}
case cbG2:
for x := 0; x < d.width; x += 4 {
b := cdat[x/4]
for x2 := 0; x2 < 4 && x+x2 < d.width; x2++ {
gray.SetGray(x+x2, y, color.Gray{(b >> 6) * 0x55})
b <<= 2
}
}
case cbG4:
for x := 0; x < d.width; x += 2 {
b := cdat[x/2]
for x2 := 0; x2 < 2 && x+x2 < d.width; x2++ {
gray.SetGray(x+x2, y, color.Gray{(b >> 4) * 0x11})
b <<= 4
}
}
case cbG8:
copy(gray.Pix[pixOffset:], cdat)
pixOffset += gray.Stride
case cbGA8:
for x := 0; x < d.width; x++ {
ycol := cdat[2*x+0]
nrgba.SetNRGBA(x, y, color.NRGBA{ycol, ycol, ycol, cdat[2*x+1]})
}
case cbTC8:
pix, i, j := rgba.Pix, pixOffset, 0
for x := 0; x < d.width; x++ {
pix[i+0] = cdat[j+0]
pix[i+1] = cdat[j+1]
pix[i+2] = cdat[j+2]
pix[i+3] = 0xff
i += 4
j += 3
}
pixOffset += rgba.Stride
case cbP1:
for x := 0; x < d.width; x += 8 {
b := cdat[x/8]
for x2 := 0; x2 < 8 && x+x2 < d.width; x2++ {
idx := b >> 7
if len(paletted.Palette) <= int(idx) {
paletted.Palette = paletted.Palette[:int(idx)+1]
}
paletted.SetColorIndex(x+x2, y, idx)
b <<= 1
}
}
case cbP2:
for x := 0; x < d.width; x += 4 {
b := cdat[x/4]
for x2 := 0; x2 < 4 && x+x2 < d.width; x2++ {
idx := b >> 6
if len(paletted.Palette) <= int(idx) {
paletted.Palette = paletted.Palette[:int(idx)+1]
}
paletted.SetColorIndex(x+x2, y, idx)
b <<= 2
}
}
case cbP4:
for x := 0; x < d.width; x += 2 {
b := cdat[x/2]
for x2 := 0; x2 < 2 && x+x2 < d.width; x2++ {
idx := b >> 4
if len(paletted.Palette) <= int(idx) {
paletted.Palette = paletted.Palette[:int(idx)+1]
}
paletted.SetColorIndex(x+x2, y, idx)
b <<= 4
}
}
case cbP8:
if len(paletted.Palette) != 255 {
for x := 0; x < d.width; x++ {
if len(paletted.Palette) <= int(cdat[x]) {
paletted.Palette = paletted.Palette[:int(cdat[x])+1]
}
}
}
copy(paletted.Pix[pixOffset:], cdat)
pixOffset += paletted.Stride
case cbTCA8:
copy(nrgba.Pix[pixOffset:], cdat)
pixOffset += nrgba.Stride
case cbG16:
for x := 0; x < d.width; x++ {
ycol := uint16(cdat[2*x+0])<<8 | uint16(cdat[2*x+1])
gray16.SetGray16(x, y, color.Gray16{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.SetNRGBA64(x, y, color.NRGBA64{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.SetRGBA64(x, y, color.RGBA64{rcol, gcol, bcol, 0xffff})
}
case cbTCA16:
for x := 0; x < d.width; x++ {
rcol := uint16(cdat[8*x+0])<<8 | uint16(cdat[8*x+1])
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.SetNRGBA64(x, y, color.NRGBA64{rcol, gcol, bcol, acol})
}
}
// The current row for y is the previous row for y+1.
pr, cr = cr, pr
}
// Check for EOF, to verify the zlib checksum.
n, err := r.Read(pr[:1])
if err != io.EOF {
return nil, FormatError(err.Error())
}
if n != 0 || d.idatLength != 0 {
return nil, FormatError("too much pixel data")
}
return img, nil
}
// readImagePass reads a single image pass, sized according to the pass number.
func (d *decoder) readImagePass(r io.Reader, pass int, allocateOnly bool) (image.Image, error) {
var bitsPerPixel int = 0
pixOffset := 0
var (
gray *image.Gray
rgba *image.RGBA
paletted *image.Paletted
nrgba *image.NRGBA
gray16 *image.Gray16
rgba64 *image.RGBA64
nrgba64 *image.NRGBA64
img image.Image
)
width, height := d.width, d.height
if d.interlace == itAdam7 && !allocateOnly {
p := interlacing[pass]
// Add the multiplication factor and subtract one, effectively rounding up.
width = (width - p.xOffset + p.xFactor - 1) / p.xFactor
height = (height - p.yOffset + p.yFactor - 1) / p.yFactor
// A PNG image can't have zero width or height, but for an interlaced
// image, an individual pass might have zero width or height. If so, we
// shouldn't even read a per-row filter type byte, so return early.
if width == 0 || height == 0 {
return nil, nil
}
}
switch d.cb {
case cbG1, cbG2, cbG4, cbG8:
bitsPerPixel = d.depth
gray = image.NewGray(image.Rect(0, 0, width, height))
img = gray
case cbGA8:
bitsPerPixel = 16
nrgba = image.NewNRGBA(image.Rect(0, 0, width, height))
img = nrgba
case cbTC8:
bitsPerPixel = 24
rgba = image.NewRGBA(image.Rect(0, 0, width, height))
img = rgba
case cbP1, cbP2, cbP4, cbP8:
bitsPerPixel = d.depth
paletted = image.NewPaletted(image.Rect(0, 0, width, height), d.palette)
img = paletted
case cbTCA8:
bitsPerPixel = 32
nrgba = image.NewNRGBA(image.Rect(0, 0, width, height))
img = nrgba
case cbG16:
bitsPerPixel = 16
gray16 = image.NewGray16(image.Rect(0, 0, width, height))
img = gray16
case cbGA16:
bitsPerPixel = 32
nrgba64 = image.NewNRGBA64(image.Rect(0, 0, width, height))
img = nrgba64
case cbTC16:
bitsPerPixel = 48
rgba64 = image.NewRGBA64(image.Rect(0, 0, width, height))
img = rgba64
case cbTCA16:
bitsPerPixel = 64
nrgba64 = image.NewNRGBA64(image.Rect(0, 0, width, height))
img = nrgba64
}
if allocateOnly {
return img, nil
}
bytesPerPixel := (bitsPerPixel + 7) / 8
// The +1 is for the per-row filter type, which is at cr[0].
rowSize := 1 + (bitsPerPixel*width+7)/8
// cr and pr are the bytes for the current and previous row.
cr := make([]uint8, rowSize)
pr := make([]uint8, rowSize)
for y := 0; y < height; y++ {
// Read the decompressed bytes.
_, err := io.ReadFull(r, cr)
if err != nil {
if err == io.EOF || err == io.ErrUnexpectedEOF {
return nil, FormatError("not enough pixel data")
}
return nil, err
}
// Apply the filter.
cdat := cr[1:]
pdat := pr[1:]
switch cr[0] {
case ftNone:
// No-op.
case ftSub:
for i := bytesPerPixel; i < len(cdat); i++ {
cdat[i] += cdat[i-bytesPerPixel]
}
case ftUp:
for i, p := range pdat {
cdat[i] += p
}
case ftAverage:
// The first column has no column to the left of it, so it is a
// special case. We know that the first column exists because we
// check above that width != 0, and so len(cdat) != 0.
for i := 0; i < bytesPerPixel; i++ {
cdat[i] += pdat[i] / 2
}
for i := bytesPerPixel; i < len(cdat); i++ {
cdat[i] += uint8((int(cdat[i-bytesPerPixel]) + int(pdat[i])) / 2)
}
case ftPaeth:
filterPaeth(cdat, pdat, bytesPerPixel)
default:
return nil, FormatError("bad filter type")
}
// Convert from bytes to colors.
switch d.cb {
case cbG1:
for x := 0; x < width; x += 8 {
b := cdat[x/8]
for x2 := 0; x2 < 8 && x+x2 < width; x2++ {
gray.SetGray(x+x2, y, color.Gray{(b >> 7) * 0xff})
b <<= 1
}
}
case cbG2:
for x := 0; x < width; x += 4 {
b := cdat[x/4]
for x2 := 0; x2 < 4 && x+x2 < width; x2++ {
gray.SetGray(x+x2, y, color.Gray{(b >> 6) * 0x55})
b <<= 2
}
}
case cbG4:
for x := 0; x < width; x += 2 {
b := cdat[x/2]
for x2 := 0; x2 < 2 && x+x2 < width; x2++ {
gray.SetGray(x+x2, y, color.Gray{(b >> 4) * 0x11})
b <<= 4
}
}
case cbG8:
copy(gray.Pix[pixOffset:], cdat)
pixOffset += gray.Stride
case cbGA8:
for x := 0; x < width; x++ {
ycol := cdat[2*x+0]
nrgba.SetNRGBA(x, y, color.NRGBA{ycol, ycol, ycol, cdat[2*x+1]})
}
case cbTC8:
pix, i, j := rgba.Pix, pixOffset, 0
for x := 0; x < width; x++ {
pix[i+0] = cdat[j+0]
pix[i+1] = cdat[j+1]
pix[i+2] = cdat[j+2]
pix[i+3] = 0xff
i += 4
j += 3
}
pixOffset += rgba.Stride
case cbP1:
for x := 0; x < width; x += 8 {
b := cdat[x/8]
for x2 := 0; x2 < 8 && x+x2 < width; x2++ {
idx := b >> 7
if len(paletted.Palette) <= int(idx) {
paletted.Palette = paletted.Palette[:int(idx)+1]
}
paletted.SetColorIndex(x+x2, y, idx)
b <<= 1
}
}
case cbP2:
for x := 0; x < width; x += 4 {
b := cdat[x/4]
for x2 := 0; x2 < 4 && x+x2 < width; x2++ {
idx := b >> 6
if len(paletted.Palette) <= int(idx) {
paletted.Palette = paletted.Palette[:int(idx)+1]
}
paletted.SetColorIndex(x+x2, y, idx)
b <<= 2
}
}
case cbP4:
for x := 0; x < width; x += 2 {
b := cdat[x/2]
for x2 := 0; x2 < 2 && x+x2 < width; x2++ {
idx := b >> 4
if len(paletted.Palette) <= int(idx) {
paletted.Palette = paletted.Palette[:int(idx)+1]
}
paletted.SetColorIndex(x+x2, y, idx)
b <<= 4
}
}
case cbP8:
if len(paletted.Palette) != 255 {
for x := 0; x < width; x++ {
if len(paletted.Palette) <= int(cdat[x]) {
paletted.Palette = paletted.Palette[:int(cdat[x])+1]
}
}
}
copy(paletted.Pix[pixOffset:], cdat)
pixOffset += paletted.Stride
case cbTCA8:
copy(nrgba.Pix[pixOffset:], cdat)
pixOffset += nrgba.Stride
case cbG16:
for x := 0; x < width; x++ {
ycol := uint16(cdat[2*x+0])<<8 | uint16(cdat[2*x+1])
gray16.SetGray16(x, y, color.Gray16{ycol})
}
case cbGA16:
for x := 0; x < 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.SetNRGBA64(x, y, color.NRGBA64{ycol, ycol, ycol, acol})
}
case cbTC16:
for x := 0; x < 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.SetRGBA64(x, y, color.RGBA64{rcol, gcol, bcol, 0xffff})
}
case cbTCA16:
for x := 0; x < width; x++ {
rcol := uint16(cdat[8*x+0])<<8 | uint16(cdat[8*x+1])
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.SetNRGBA64(x, y, color.NRGBA64{rcol, gcol, bcol, acol})
}
}
// The current row for y is the previous row for y+1.
pr, cr = cr, pr
}
return img, nil
}
func (d *decoder) idatReader(idat io.Reader) (image.Image, os.Error) {
r, err := zlib.NewReader(idat)
if err != nil {
return nil, err
}
defer r.Close()
bpp := 0 // Bytes per pixel.
maxPalette := uint8(0)
var (
gray *image.Gray
rgba *image.RGBA
paletted *image.Paletted
nrgba *image.NRGBA
gray16 *image.Gray16
rgba64 *image.RGBA64
nrgba64 *image.NRGBA64
img image.Image
)
switch d.cb {
case cbG8:
bpp = 1
gray = image.NewGray(d.width, d.height)
img = gray
case cbTC8:
bpp = 3
rgba = image.NewRGBA(d.width, d.height)
img = rgba
case cbP8:
bpp = 1
paletted = image.NewPaletted(d.width, d.height, d.palette)
img = paletted
maxPalette = uint8(len(d.palette) - 1)
case cbTCA8:
bpp = 4
nrgba = image.NewNRGBA(d.width, d.height)
img = nrgba
case cbG16:
bpp = 2
gray16 = image.NewGray16(d.width, d.height)
img = gray16
case cbTC16:
bpp = 6
rgba64 = image.NewRGBA64(d.width, d.height)
img = rgba64
case cbTCA16:
bpp = 8
nrgba64 = image.NewNRGBA64(d.width, d.height)
img = nrgba64
}
// cr and pr are the bytes for the current and previous row.
// The +1 is for the per-row filter type, which is at cr[0].
cr := make([]uint8, 1+bpp*d.width)
pr := make([]uint8, 1+bpp*d.width)
for y := 0; y < d.height; y++ {
// Read the decompressed bytes.
_, err := io.ReadFull(r, cr)
if err != nil {
return nil, err
}
// Apply the filter.
cdat := cr[1:]
pdat := pr[1:]
switch cr[0] {
case ftNone:
// No-op.
case ftSub:
for i := bpp; i < len(cdat); i++ {
cdat[i] += cdat[i-bpp]
}
case ftUp:
for i := 0; i < len(cdat); i++ {
cdat[i] += pdat[i]
}
case ftAverage:
for i := 0; i < bpp; i++ {
cdat[i] += pdat[i] / 2
}
for i := bpp; i < len(cdat); i++ {
cdat[i] += uint8((int(cdat[i-bpp]) + int(pdat[i])) / 2)
}
case ftPaeth:
for i := 0; i < bpp; i++ {
cdat[i] += paeth(0, pdat[i], 0)
}
for i := bpp; i < len(cdat); i++ {
cdat[i] += paeth(cdat[i-bpp], pdat[i], pdat[i-bpp])
}
default:
return nil, FormatError("bad filter type")
}
// Convert from bytes to colors.
switch d.cb {
case cbG8:
for x := 0; x < d.width; x++ {
gray.Set(x, y, image.GrayColor{cdat[x]})
}
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})
}
case cbP8:
for x := 0; x < d.width; x++ {
if cdat[x] > maxPalette {
return nil, FormatError("palette index out of range")
}
paletted.SetColorIndex(x, y, cdat[x])
}
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]})
}
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})
}
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})
}
case cbTCA16:
for x := 0; x < d.width; x++ {
rcol := uint16(cdat[8*x+0])<<8 | uint16(cdat[8*x+1])
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})
}
}
// The current row for y is the previous row for y+1.
pr, cr = cr, pr
}
return img, nil
}
// Set a pixel in img by blending c on top of whatever color is
// already there
func blend(pt image.Point, c color.Color, img *image.RGBA64) {
cc := over(c, img.At(pt.X, pt.Y))
img.Set(pt.X, pt.Y, cc)
}
func (d *decoder) idatReader(idat io.Reader) (image.Image, os.Error) {
r, err := zlib.NewReader(idat)
if err != nil {
return nil, err
}
defer r.Close()
bitsPerPixel := 0
maxPalette := uint8(0)
var (
gray *image.Gray
rgba *image.RGBA
paletted *image.Paletted
nrgba *image.NRGBA
gray16 *image.Gray16
rgba64 *image.RGBA64
nrgba64 *image.NRGBA64
img image.Image
)
switch d.cb {
case cbG1, cbG2, cbG4, cbG8:
bitsPerPixel = d.depth
gray = image.NewGray(d.width, d.height)
img = gray
case cbGA8:
bitsPerPixel = 16
nrgba = image.NewNRGBA(d.width, d.height)
img = nrgba
case cbTC8:
bitsPerPixel = 24
rgba = image.NewRGBA(d.width, d.height)
img = rgba
case cbP1, cbP2, cbP4, cbP8:
bitsPerPixel = d.depth
paletted = image.NewPaletted(d.width, d.height, d.palette)
img = paletted
maxPalette = uint8(len(d.palette) - 1)
case cbTCA8:
bitsPerPixel = 32
nrgba = image.NewNRGBA(d.width, d.height)
img = nrgba
case cbG16:
bitsPerPixel = 16
gray16 = image.NewGray16(d.width, d.height)
img = gray16
case cbGA16:
bitsPerPixel = 32
nrgba64 = image.NewNRGBA64(d.width, d.height)
img = nrgba64
case cbTC16:
bitsPerPixel = 48
rgba64 = image.NewRGBA64(d.width, d.height)
img = rgba64
case cbTCA16:
bitsPerPixel = 64
nrgba64 = image.NewNRGBA64(d.width, d.height)
img = nrgba64
}
bytesPerPixel := (bitsPerPixel + 7) / 8
// cr and pr are the bytes for the current and previous row.
// The +1 is for the per-row filter type, which is at cr[0].
cr := make([]uint8, 1+(bitsPerPixel*d.width+7)/8)
pr := make([]uint8, 1+(bitsPerPixel*d.width+7)/8)
for y := 0; y < d.height; y++ {
// Read the decompressed bytes.
_, err := io.ReadFull(r, cr)
if err != nil {
return nil, err
}
// Apply the filter.
cdat := cr[1:]
pdat := pr[1:]
switch cr[0] {
case ftNone:
// No-op.
case ftSub:
for i := bytesPerPixel; i < len(cdat); i++ {
cdat[i] += cdat[i-bytesPerPixel]
}
case ftUp:
for i := 0; i < len(cdat); i++ {
cdat[i] += pdat[i]
}
case ftAverage:
for i := 0; i < bytesPerPixel; i++ {
cdat[i] += pdat[i] / 2
}
for i := bytesPerPixel; i < len(cdat); i++ {
cdat[i] += uint8((int(cdat[i-bytesPerPixel]) + int(pdat[i])) / 2)
}
case ftPaeth:
for i := 0; i < bytesPerPixel; i++ {
cdat[i] += paeth(0, pdat[i], 0)
}
for i := bytesPerPixel; i < len(cdat); i++ {
cdat[i] += paeth(cdat[i-bytesPerPixel], pdat[i], pdat[i-bytesPerPixel])
}
default:
return nil, FormatError("bad filter type")
}
// Convert from bytes to colors.
switch d.cb {
case cbG1:
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})
b <<= 1
}
}
case cbG2:
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})
b <<= 2
}
}
case cbG4:
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})
b <<= 4
}
}
case cbG8:
for x := 0; x < d.width; x++ {
gray.Set(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]})
}
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})
}
case cbP1:
for x := 0; x < d.width; x += 8 {
b := cdat[x/8]
for x2 := 0; x2 < 8 && x+x2 < d.width; x2++ {
idx := b >> 7
if idx > maxPalette {
return nil, FormatError("palette index out of range")
}
paletted.SetColorIndex(x+x2, y, idx)
b <<= 1
}
}
case cbP2:
for x := 0; x < d.width; x += 4 {
b := cdat[x/4]
for x2 := 0; x2 < 4 && x+x2 < d.width; x2++ {
idx := b >> 6
if idx > maxPalette {
return nil, FormatError("palette index out of range")
}
paletted.SetColorIndex(x+x2, y, idx)
b <<= 2
}
}
case cbP4:
for x := 0; x < d.width; x += 2 {
b := cdat[x/2]
for x2 := 0; x2 < 2 && x+x2 < d.width; x2++ {
idx := b >> 4
if idx > maxPalette {
return nil, FormatError("palette index out of range")
}
paletted.SetColorIndex(x+x2, y, idx)
b <<= 4
}
}
case cbP8:
for x := 0; x < d.width; x++ {
if cdat[x] > maxPalette {
return nil, FormatError("palette index out of range")
}
paletted.SetColorIndex(x, y, cdat[x])
}
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]})
}
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})
}
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})
}
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})
}
case cbTCA16:
for x := 0; x < d.width; x++ {
rcol := uint16(cdat[8*x+0])<<8 | uint16(cdat[8*x+1])
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})
}
}
// The current row for y is the previous row for y+1.
pr, cr = cr, pr
}
return img, nil
}
