// Interpolate 4 interleaved uint8 per pixel images.
func interpolate4x8(src *image.NRGBA, 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(src.Pix[pixOffset+0])
g64 := uint64(src.Pix[pixOffset+1])
b64 := uint64(src.Pix[pixOffset+2])
a64 := uint64(src.Pix[pixOffset+3])
pixOffset += 4
// 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.NewNRGBA(image.Rect(0, 0, dstW, dstH))
for y := 0; y < dstH; y++ {
pixOffset := dst.PixOffset(0, y)
for x := 0; x < dstW; x++ {
dst.Pix[pixOffset+0] = uint8(sum[pixOffset+0] / n)
dst.Pix[pixOffset+1] = uint8(sum[pixOffset+1] / n)
dst.Pix[pixOffset+2] = uint8(sum[pixOffset+2] / n)
dst.Pix[pixOffset+3] = uint8(sum[pixOffset+3] / n)
pixOffset += 4
}
}
return dst
}
func newSetFuncNRGBA(p *image.NRGBA) SetFunc {
return func(x, y int, r, g, b, a uint32) {
r, g, b, a = RGBAToNRGBA(r, g, b, a)
i := p.PixOffset(x, y)
p.Pix[i+0] = uint8(r >> 8)
p.Pix[i+1] = uint8(g >> 8)
p.Pix[i+2] = uint8(b >> 8)
p.Pix[i+3] = uint8(a >> 8)
}
}
// Interpolate uint32/pixel images.
func interpolate1x32(src *image.NRGBA, 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 := uint64(binary.BigEndian.Uint32([]byte(src.Pix[pixOffset+0 : pixOffset+4])))
pixOffset += 4
// 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.NewNRGBA(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.PutUint32(dst.Pix[pixOffset+0:pixOffset+4], uint32(sum[index]/n))
pixOffset += 4
index++
}
}
return dst
}
func convertNRGBA(dest *Image, src *image.NRGBA) {
var x, y, i, si int
var a uint16
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)
a = uint16(src.Pix[si+3])
dest.Pix[i+0] = uint8((uint16(src.Pix[si+2]) * a) / 0xff)
dest.Pix[i+1] = uint8((uint16(src.Pix[si+1]) * a) / 0xff)
dest.Pix[i+2] = uint8((uint16(src.Pix[si+0]) * a) / 0xff)
dest.Pix[i+3] = src.Pix[si+3]
}
}
}
// Takes an average of the biome colors of the surrounding area
func calculateBiome(bs *blocksSnapshot, x, z int, img *image.NRGBA) (byte, byte, byte) {
count := 0
var r, g, b int
for xx := -2; xx <= 2; xx++ {
for zz := -2; zz <= 2; zz++ {
biome := bs.biome(x+xx, z+zz)
ix := biome.ColorIndex & 0xFF
iy := biome.ColorIndex >> 8
offset := img.PixOffset(ix, iy)
r += int(img.Pix[offset])
g += int(img.Pix[offset+1])
b += int(img.Pix[offset+2])
count++
}
}
return byte(r / count), byte(g / count), byte(b / count)
}
// Draws the "src" onto the "dst" image at the given x/y bounds, maintaining
// the original size. Pixels with have an alpha of 0x00 are not draw, and
// all others are drawn with an alpha of 0xFF
func fastDraw(dst *image.NRGBA, src *image.NRGBA, x, y int) {
bounds := src.Bounds()
maxY := bounds.Max.Y
maxX := bounds.Max.X * 4
pointer := dst.PixOffset(x, y)
for row := 0; row < maxY; row += 1 {
for i := 0; i < maxX; i += 4 {
srcPx := row*src.Stride + i
dstPx := row*dst.Stride + i + pointer
if src.Pix[srcPx+3] != 0 {
dst.Pix[dstPx+0] = src.Pix[srcPx+0]
dst.Pix[dstPx+1] = src.Pix[srcPx+1]
dst.Pix[dstPx+2] = src.Pix[srcPx+2]
dst.Pix[dstPx+3] = 0xFF
}
}
}
}
func newAtFuncNRGBA(p *image.NRGBA) AtFunc {
return func(x, y int) (r, g, b, a uint32) {
i := p.PixOffset(x, y)
a = uint32(p.Pix[i+3])
a |= a << 8
if a == 0 {
return
}
r = uint32(p.Pix[i+0])
r |= r << 8
g = uint32(p.Pix[i+1])
g |= g << 8
b = uint32(p.Pix[i+2])
b |= b << 8
if a == 0xffff {
return
}
r = r * a / 0xffff
g = g * a / 0xffff
b = b * a / 0xffff
return
}
}
// fast nearest-neighbor resize, no filtering
func resizeNearest(src *image.NRGBA, width, height int) *image.NRGBA {
dstW, dstH := width, height
srcBounds := src.Bounds()
srcW := srcBounds.Dx()
srcH := srcBounds.Dy()
srcMinX := srcBounds.Min.X
srcMinY := srcBounds.Min.Y
srcMaxX := srcBounds.Max.X
srcMaxY := srcBounds.Max.Y
dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
dx := float64(srcW) / float64(dstW)
dy := float64(srcH) / float64(dstH)
// divide image to parts for parallel processing
numGoroutines := runtime.NumCPU()
goMaxProcs := runtime.GOMAXPROCS(0)
if numGoroutines > goMaxProcs {
numGoroutines = goMaxProcs
}
if numGoroutines > dstH {
numGoroutines = dstH
}
partSize := dstH / numGoroutines
doneChan := make(chan bool, numGoroutines)
for part := 0; part < numGoroutines; part++ {
partStart := part * partSize
partEnd := (part + 1) * partSize
if part == numGoroutines-1 {
partEnd = dstH
}
go func(partStart, partEnd int) {
for dstY := partStart; dstY < partEnd; dstY++ {
fy := float64(srcMinY) + (float64(dstY)+0.5)*dy - 0.5
for dstX := 0; dstX < dstW; dstX++ {
fx := float64(srcMinX) + (float64(dstX)+0.5)*dx - 0.5
srcX := int(math.Min(math.Max(math.Floor(fx+0.5), float64(srcMinX)), float64(srcMaxX)))
srcY := int(math.Min(math.Max(math.Floor(fy+0.5), float64(srcMinY)), float64(srcMaxY)))
srcOffset := src.PixOffset(srcX, srcY)
dstOffset := dst.PixOffset(dstX, dstY)
dst.Pix[dstOffset+0] = src.Pix[srcOffset+0]
dst.Pix[dstOffset+1] = src.Pix[srcOffset+1]
dst.Pix[dstOffset+2] = src.Pix[srcOffset+2]
dst.Pix[dstOffset+3] = src.Pix[srcOffset+3]
}
}
doneChan <- true
}(partStart, partEnd)
}
// wait for goroutines to finish
for part := 0; part < numGoroutines; part++ {
<-doneChan
}
return dst
}
func resizeVertical(src *image.NRGBA, height int, filter resamplingFilter) *image.NRGBA {
srcBounds := src.Bounds()
srcW := srcBounds.Dx()
srcH := srcBounds.Dy()
srcMinX := srcBounds.Min.X
srcMinY := srcBounds.Min.Y
srcMaxY := srcBounds.Max.Y
dstW := srcW
dstH := height
dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
dY := float64(srcH) / float64(dstH)
scaleY := math.Max(dY, 1.0)
rY := math.Ceil(scaleY * filter.Support)
// divide image to parts for parallel processing
numGoroutines := runtime.NumCPU()
goMaxProcs := runtime.GOMAXPROCS(0)
if numGoroutines > goMaxProcs {
numGoroutines = goMaxProcs
}
if numGoroutines > dstH {
numGoroutines = dstH
}
partSize := dstH / numGoroutines
doneChan := make(chan bool, numGoroutines)
for part := 0; part < numGoroutines; part++ {
partStart := part * partSize
partEnd := (part + 1) * partSize
if part == numGoroutines-1 {
partEnd = dstH
}
go func(partStart, partEnd int) {
for dstY := partStart; dstY < partEnd; dstY++ {
fY := float64(srcMinY) + (float64(dstY)+0.5)*dY - 0.5
startY := int(math.Ceil(fY - rY))
if startY < srcMinY {
startY = srcMinY
}
endY := int(math.Floor(fY + rY))
if endY > srcMaxY-1 {
endY = srcMaxY - 1
}
// cache weights
weightSum := 0.0
weights := make([]float64, int(rY+2)*2)
for y := startY; y <= endY; y++ {
w := filter.Kernel((float64(y) - fY) / scaleY)
weightSum += w
weights[y-startY] = w
}
for dstX := 0; dstX < dstW; dstX++ {
srcX := srcMinX + dstX
r, g, b, a := 0.0, 0.0, 0.0, 0.0
for y := startY; y <= endY; y++ {
weight := weights[y-startY]
i := src.PixOffset(srcX, y)
r += float64(src.Pix[i+0]) * weight
g += float64(src.Pix[i+1]) * weight
b += float64(src.Pix[i+2]) * weight
a += float64(src.Pix[i+3]) * weight
}
r = math.Min(math.Max(r/weightSum, 0.0), 255.0)
g = math.Min(math.Max(g/weightSum, 0.0), 255.0)
b = math.Min(math.Max(b/weightSum, 0.0), 255.0)
a = math.Min(math.Max(a/weightSum, 0.0), 255.0)
j := dst.PixOffset(dstX, dstY)
dst.Pix[j+0] = uint8(r + 0.5)
dst.Pix[j+1] = uint8(g + 0.5)
dst.Pix[j+2] = uint8(b + 0.5)
dst.Pix[j+3] = uint8(a + 0.5)
}
}
doneChan <- true
}(partStart, partEnd)
}
// wait for goroutines to finish
for part := 0; part < numGoroutines; part++ {
<-doneChan
}
return dst
}
func resizeHorizontal(src *image.NRGBA, width int, filter resamplingFilter) *image.NRGBA {
srcBounds := src.Bounds()
srcW := srcBounds.Dx()
srcH := srcBounds.Dy()
srcMinX := srcBounds.Min.X
srcMinY := srcBounds.Min.Y
srcMaxX := srcBounds.Max.X
dstW := width
dstH := srcH
dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
dX := float64(srcW) / float64(dstW)
scaleX := math.Max(dX, 1.0)
rX := math.Ceil(scaleX * filter.Support)
// divide image to parts for parallel processing
numGoroutines := runtime.NumCPU()
goMaxProcs := runtime.GOMAXPROCS(0)
if numGoroutines > goMaxProcs {
numGoroutines = goMaxProcs
}
if numGoroutines > dstW {
numGoroutines = dstW
}
partSize := dstW / numGoroutines
doneChan := make(chan bool, numGoroutines)
for part := 0; part < numGoroutines; part++ {
partStart := part * partSize
partEnd := (part + 1) * partSize
if part == numGoroutines-1 {
partEnd = dstW
}
go func(partStart, partEnd int) {
for dstX := partStart; dstX < partEnd; dstX++ {
fX := float64(srcMinX) + (float64(dstX)+0.5)*dX - 0.5
startX := int(math.Ceil(fX - rX))
if startX < srcMinX {
startX = srcMinX
}
endX := int(math.Floor(fX + rX))
if endX > srcMaxX-1 {
endX = srcMaxX - 1
}
// cache weights
weightSum := 0.0
weights := make([]float64, int(rX+2)*2)
for x := startX; x <= endX; x++ {
w := filter.Kernel((float64(x) - fX) / scaleX)
weightSum += w
weights[x-startX] = w
}
for dstY := 0; dstY < dstH; dstY++ {
srcY := srcMinY + dstY
r, g, b, a := 0.0, 0.0, 0.0, 0.0
for x := startX; x <= endX; x++ {
weight := weights[x-startX]
i := src.PixOffset(x, srcY)
r += float64(src.Pix[i+0]) * weight
g += float64(src.Pix[i+1]) * weight
b += float64(src.Pix[i+2]) * weight
a += float64(src.Pix[i+3]) * weight
}
r = math.Min(math.Max(r/weightSum, 0.0), 255.0)
g = math.Min(math.Max(g/weightSum, 0.0), 255.0)
b = math.Min(math.Max(b/weightSum, 0.0), 255.0)
a = math.Min(math.Max(a/weightSum, 0.0), 255.0)
j := dst.PixOffset(dstX, dstY)
dst.Pix[j+0] = uint8(r + 0.5)
dst.Pix[j+1] = uint8(g + 0.5)
dst.Pix[j+2] = uint8(b + 0.5)
dst.Pix[j+3] = uint8(a + 0.5)
}
}
doneChan <- true
}(partStart, partEnd)
}
// wait for goroutines to finish
for part := 0; part < numGoroutines; part++ {
<-doneChan
}
return dst
}
func resizeVertical(src *image.NRGBA, height int, filter ResampleFilter) *image.NRGBA {
srcBounds := src.Bounds()
srcW := srcBounds.Dx()
srcH := srcBounds.Dy()
srcMinX := srcBounds.Min.X
srcMinY := srcBounds.Min.Y
srcMaxY := srcBounds.Max.Y
dstW := srcW
dstH := height
dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
dY := float64(srcH) / float64(dstH)
scaleY := math.Max(dY, 1.0)
rY := math.Ceil(scaleY * filter.Support)
weights := make([]float64, int(rY+2)*2)
for dstY := 0; dstY < dstH; dstY++ {
fY := float64(srcMinY) + (float64(dstY)+0.5)*dY - 0.5
startY := int(math.Ceil(fY - rY))
if startY < srcMinY {
startY = srcMinY
}
endY := int(math.Floor(fY + rY))
if endY > srcMaxY-1 {
endY = srcMaxY - 1
}
// cache weights
weightSum := 0.0
for y := startY; y <= endY; y++ {
w := filter.Kernel((float64(y) - fY) / scaleY)
weightSum += w
weights[y-startY] = w
}
for dstX := 0; dstX < dstW; dstX++ {
srcX := srcMinX + dstX
r, g, b, a := 0.0, 0.0, 0.0, 0.0
for y := startY; y <= endY; y++ {
weight := weights[y-startY]
i := src.PixOffset(srcX, y)
r += float64(src.Pix[i+0]) * weight
g += float64(src.Pix[i+1]) * weight
b += float64(src.Pix[i+2]) * weight
a += float64(src.Pix[i+3]) * weight
}
r = math.Min(math.Max(r/weightSum, 0.0), 255.0)
g = math.Min(math.Max(g/weightSum, 0.0), 255.0)
b = math.Min(math.Max(b/weightSum, 0.0), 255.0)
a = math.Min(math.Max(a/weightSum, 0.0), 255.0)
j := dst.PixOffset(dstX, dstY)
dst.Pix[j+0] = uint8(r + 0.5)
dst.Pix[j+1] = uint8(g + 0.5)
dst.Pix[j+2] = uint8(b + 0.5)
dst.Pix[j+3] = uint8(a + 0.5)
}
}
return dst
}
func resizeHorizontal(src *image.NRGBA, width int, filter ResampleFilter) *image.NRGBA {
srcBounds := src.Bounds()
srcW := srcBounds.Dx()
srcH := srcBounds.Dy()
srcMinX := srcBounds.Min.X
srcMinY := srcBounds.Min.Y
srcMaxX := srcBounds.Max.X
dstW := width
dstH := srcH
dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
dX := float64(srcW) / float64(dstW)
scaleX := math.Max(dX, 1.0)
rX := math.Ceil(scaleX * filter.Support)
weights := make([]float64, int(rX+2)*2)
for dstX := 0; dstX < dstW; dstX++ {
fX := float64(srcMinX) + (float64(dstX)+0.5)*dX - 0.5
startX := int(math.Ceil(fX - rX))
if startX < srcMinX {
startX = srcMinX
}
endX := int(math.Floor(fX + rX))
if endX > srcMaxX-1 {
endX = srcMaxX - 1
}
// cache weights
weightSum := 0.0
for x := startX; x <= endX; x++ {
w := filter.Kernel((float64(x) - fX) / scaleX)
weightSum += w
weights[x-startX] = w
}
for dstY := 0; dstY < dstH; dstY++ {
srcY := srcMinY + dstY
r, g, b, a := 0.0, 0.0, 0.0, 0.0
for x := startX; x <= endX; x++ {
weight := weights[x-startX]
i := src.PixOffset(x, srcY)
r += float64(src.Pix[i+0]) * weight
g += float64(src.Pix[i+1]) * weight
b += float64(src.Pix[i+2]) * weight
a += float64(src.Pix[i+3]) * weight
}
r = math.Min(math.Max(r/weightSum, 0.0), 255.0)
g = math.Min(math.Max(g/weightSum, 0.0), 255.0)
b = math.Min(math.Max(b/weightSum, 0.0), 255.0)
a = math.Min(math.Max(a/weightSum, 0.0), 255.0)
j := dst.PixOffset(dstX, dstY)
dst.Pix[j+0] = uint8(r + 0.5)
dst.Pix[j+1] = uint8(g + 0.5)
dst.Pix[j+2] = uint8(b + 0.5)
dst.Pix[j+3] = uint8(a + 0.5)
}
}
return dst
}