func AverageNRGBA64(rect image.Rectangle, img *image.NRGBA64) color.NRGBA64 {
// Only use the area of the rectangle that overlaps with the image bounds.
rect = rect.Intersect(img.Bounds())
// Determine whether or not there's any area over which to determine an
// average.
d := uint64(rect.Dx() * rect.Dy())
if d == 0 {
return color.NRGBA64{}
}
var r, g, b, a uint64
AllPointsRP(
func(pt image.Point) {
c := img.NRGBA64At(pt.X, pt.Y)
r += uint64(c.R)
g += uint64(c.G)
b += uint64(c.B)
a += uint64(c.A)
},
)(rect)
return color.NRGBA64{
R: uint16(r / d),
G: uint16(g / d),
B: uint16(b / d),
A: uint16(a / d),
}
}
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 resizeGeneric(in image.Image, out *image.NRGBA64, 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()
// reverse alpha-premultiplication.
if a != 0 {
r *= 0xffff
r /= a
g *= 0xffff
g /= a
b *= 0xffff
b /= a
}
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)
}
}
}
// Interpolate uint64/pixel images.
func interpolate1x64(src *image.NRGBA64, dstW, dstH int) image.Image {
srcRect := src.Bounds()
srcW := srcRect.Dx()
srcH := srcRect.Dy()
ww, hh := uint64(dstW), uint64(dstH)
dx, dy := uint64(srcW), uint64(srcH)
n, sum := dx*dy, make([]uint64, dstW*dstH)
for y := 0; y < srcH; y++ {
pixOffset := src.PixOffset(0, y)
for x := 0; x < srcW; x++ {
// Get the source pixel.
val64 := binary.BigEndian.Uint64([]byte(src.Pix[pixOffset+0 : pixOffset+8]))
pixOffset += 8
// Spread the source pixel over 1 or more destination rows.
py := uint64(y) * hh
for remy := hh; remy > 0; {
qy := dy - (py % dy)
if qy > remy {
qy = remy
}
// Spread the source pixel over 1 or more destination columns.
px := uint64(x) * ww
index := (py/dy)*ww + (px / dx)
for remx := ww; remx > 0; {
qx := dx - (px % dx)
if qx > remx {
qx = remx
}
qxy := qx * qy
sum[index] += val64 * qxy
index++
px += qx
remx -= qx
}
py += qy
remy -= qy
}
}
}
dst := image.NewNRGBA64(image.Rect(0, 0, dstW, dstH))
index := 0
for y := 0; y < dstH; y++ {
pixOffset := dst.PixOffset(0, y)
for x := 0; x < dstW; x++ {
binary.BigEndian.PutUint64(dst.Pix[pixOffset+0:pixOffset+8], sum[index]/n)
pixOffset += 8
index++
}
}
return dst
}
func putLineNRGBA64(flipXY bool, column []f32RGBA, x int, dst *image.NRGBA64) {
dy := dst.Bounds().Min.Y
dx := dst.Bounds().Min.X
for y, dst_c := range column {
dst_nrgba := color.NRGBA64{
R: clampF32ToUint16(f32_to_uint16 * dst_c.R),
G: clampF32ToUint16(f32_to_uint16 * dst_c.G),
B: clampF32ToUint16(f32_to_uint16 * dst_c.B),
A: clampF32ToUint16(f32_to_uint16 * dst_c.A),
}
if flipXY {
dst.SetNRGBA64(y+dx, x+dy, dst_nrgba)
} else {
dst.SetNRGBA64(x+dx, y+dy, dst_nrgba)
}
}
}
func fetchLineNRGBA64(flipXY bool, column []f32RGBA, x int, src *image.NRGBA64) {
dy := src.Bounds().Min.Y
dx := src.Bounds().Min.X
pix := src.Pix
var idx int
for y := 0; y != len(column); y++ {
if flipXY {
idx = src.PixOffset(y+dx, x+dy)
} else {
idx = src.PixOffset(x+dx, y+dy)
}
column[y].R = uint16_to_f32 * float32(uint16(pix[idx+0])<<8|uint16(pix[idx+1]))
column[y].G = uint16_to_f32 * float32(uint16(pix[idx+2])<<8|uint16(pix[idx+3]))
column[y].B = uint16_to_f32 * float32(uint16(pix[idx+4])<<8|uint16(pix[idx+5]))
column[y].A = uint16_to_f32 * float32(uint16(pix[idx+6])<<8|uint16(pix[idx+7]))
}
}
func nearestNRGBA64(in *image.NRGBA64, out *image.NRGBA64, 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 resize64(src *image.NRGBA64, dstW, dstH int) image.Image {
srcRect := src.Bounds()
srcW := srcRect.Dx()
srcH := srcRect.Dy()
dstW64, dstH64 := uint64(dstW), uint64(dstH)
srcW64, srcH64 := uint64(srcW), uint64(srcH)
dst := image.NewNRGBA64(image.Rect(0, 0, dstW, dstH))
var x, y uint64
dstI := 0
for y = 0; y < dstH64; y++ {
srcY := int(y * srcH64 / dstH64)
for x = 0; x < dstW64; x++ {
srcX := int(x * srcW64 / dstW64)
srcI := 8 * (srcY*srcW + srcX)
copy(dst.Pix[dstI:dstI+8], src.Pix[srcI:srcI+8])
dstI += 8
}
}
return dst
}
// Interpolate 4 interleaved uint16 per pixel images.
func interpolate4x16(src *image.NRGBA64, dstW, dstH int) image.Image {
srcRect := src.Bounds()
srcW := srcRect.Dx()
srcH := srcRect.Dy()
ww, hh := uint64(dstW), uint64(dstH)
dx, dy := uint64(srcW), uint64(srcH)
n, sum := dx*dy, make([]uint64, 4*dstW*dstH)
for y := 0; y < srcH; y++ {
pixOffset := src.PixOffset(0, y)
for x := 0; x < srcW; x++ {
// Get the source pixel.
r64 := uint64(binary.BigEndian.Uint16([]byte(src.Pix[pixOffset+0 : pixOffset+2])))
g64 := uint64(binary.BigEndian.Uint16([]byte(src.Pix[pixOffset+2 : pixOffset+4])))
b64 := uint64(binary.BigEndian.Uint16([]byte(src.Pix[pixOffset+4 : pixOffset+6])))
a64 := uint64(binary.BigEndian.Uint16([]byte(src.Pix[pixOffset+6 : pixOffset+8])))
pixOffset += 8
// Spread the source pixel over 1 or more destination rows.
py := uint64(y) * hh
for remy := hh; remy > 0; {
qy := dy - (py % dy)
if qy > remy {
qy = remy
}
// Spread the source pixel over 1 or more destination columns.
px := uint64(x) * ww
index := 4 * ((py/dy)*ww + (px / dx))
for remx := ww; remx > 0; {
qx := dx - (px % dx)
if qx > remx {
qx = remx
}
qxy := qx * qy
sum[index+0] += r64 * qxy
sum[index+1] += g64 * qxy
sum[index+2] += b64 * qxy
sum[index+3] += a64 * qxy
index += 4
px += qx
remx -= qx
}
py += qy
remy -= qy
}
}
}
dst := image.NewNRGBA64(image.Rect(0, 0, dstW, dstH))
for y := 0; y < dstH; y++ {
pixOffset := dst.PixOffset(0, y)
index := 4 * y * dstW
for x := 0; x < dstW; x++ {
binary.BigEndian.PutUint16(dst.Pix[pixOffset+0:pixOffset+2], uint16(sum[index+0]/n))
binary.BigEndian.PutUint16(dst.Pix[pixOffset+2:pixOffset+4], uint16(sum[index+1]/n))
binary.BigEndian.PutUint16(dst.Pix[pixOffset+4:pixOffset+6], uint16(sum[index+2]/n))
binary.BigEndian.PutUint16(dst.Pix[pixOffset+6:pixOffset+8], uint16(sum[index+3]/n))
pixOffset += 8
index += 4
}
}
return dst
}