aw/golang-image
1
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

draw: add a fast path for Gray src images.

Browse Source 
benchmark                      old ns/op      new ns/op      delta
BenchmarkScaleSrcGray          9296680        552705         -94.05%
BenchmarkTformABSrcGray        6323894        817986         -87.07%
BenchmarkTformCRSrcGray        39229583       4193194        -89.31%

Change-Id: Ie7d43dfe323d49b245b47c3206b5aad2b50cb7fb
Reviewed-on: https://go-review.googlesource.com/7711
Reviewed-by: Rob Pike <r@golang.org>
This commit is contained in:
Nigel Tao 2015-03-18 14:29:15 +11:00
parent ff75b2d824
commit 2f47ec36fb
2 changed files with 221 additions and 153 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

232
draw/gen.go
View File

@ -197,7 +197,7 @@ func expnDollar(prefix, dollar, suffix string, d *data) string {
switch d.dType { switch d.dType {
default: default:
return ";" return ";"
case "*image.RGBA": case "*image.Gray", "*image.RGBA":
return "d := dst.PixOffset(dr.Min.X+adr.Min.X, dr.Min.Y+int(dy))" return "d := dst.PixOffset(dr.Min.X+adr.Min.X, dr.Min.Y+int(dy))"
} }
@ -205,7 +205,7 @@ func expnDollar(prefix, dollar, suffix string, d *data) string {
switch d.dType { switch d.dType {
default: default:
return ";" return ";"
case "*image.RGBA": case "*image.Gray", "*image.RGBA":
return "d := dst.PixOffset(dr.Min.X+int(dx), dr.Min.Y+adr.Min.Y)" return "d := dst.PixOffset(dr.Min.X+int(dx), dr.Min.Y+adr.Min.Y)"
} }
@ -214,16 +214,24 @@ func expnDollar(prefix, dollar, suffix string, d *data) string {
if len(args) != 4 { if len(args) != 4 {
return "" return ""
} }
return fmt.Sprintf(""+ switch d.sType {
"%sr = %s*%sr + %s*%sr\n"+ default:
"%sg = %s*%sg + %s*%sg\n"+ return fmt.Sprintf(""+
"%sb = %s*%sb + %s*%sb\n"+ "%sr = %s*%sr + %s*%sr\n"+
"%sa = %s*%sa + %s*%sa", "%sg = %s*%sg + %s*%sg\n"+
args[3], args[0], args[1], args[2], args[3], "%sb = %s*%sb + %s*%sb\n"+
args[3], args[0], args[1], args[2], args[3], "%sa = %s*%sa + %s*%sa",
args[3], args[0], args[1], args[2], args[3], args[3], args[0], args[1], args[2], args[3],
args[3], args[0], args[1], args[2], args[3], args[3], args[0], args[1], args[2], args[3],
) args[3], args[0], args[1], args[2], args[3],
args[3], args[0], args[1], args[2], args[3],
)
case "*image.Gray":
return fmt.Sprintf(""+
"%sr = %s*%sr + %s*%sr",
args[3], args[0], args[1], args[2], args[3],
)
}
case "outputu": case "outputu":
args, _ := splitArgs(suffix) args, _ := splitArgs(suffix)
@ -234,23 +242,49 @@ func expnDollar(prefix, dollar, suffix string, d *data) string {
default: default:
log.Fatalf("bad dType %q", d.dType) log.Fatalf("bad dType %q", d.dType)
case "Image": case "Image":
return fmt.Sprintf(""+ switch d.sType {
"dstColorRGBA64.R = uint16(%sr)\n"+ default:
"dstColorRGBA64.G = uint16(%sg)\n"+ return fmt.Sprintf(""+
"dstColorRGBA64.B = uint16(%sb)\n"+ "dstColorRGBA64.R = uint16(%sr)\n"+
"dstColorRGBA64.A = uint16(%sa)\n"+ "dstColorRGBA64.G = uint16(%sg)\n"+
"dst.Set(%s, %s, dstColor)", "dstColorRGBA64.B = uint16(%sb)\n"+
args[2], args[2], args[2], args[2], "dstColorRGBA64.A = uint16(%sa)\n"+
args[0], args[1], "dst.Set(%s, %s, dstColor)",
) args[2], args[2], args[2], args[2],
args[0], args[1],
)
case "*image.Gray":
return fmt.Sprintf(""+
"out := uint16(%sr)\n"+
"dstColorRGBA64.R = out\n"+
"dstColorRGBA64.G = out\n"+
"dstColorRGBA64.B = out\n"+
"dstColorRGBA64.A = 0xffff\n"+
"dst.Set(%s, %s, dstColor)",
args[2],
args[0], args[1],
)
}
case "*image.RGBA": case "*image.RGBA":
return fmt.Sprintf(""+ switch d.sType {
"dst.Pix[d+0] = uint8(uint32(%sr) >> 8)\n"+ default:
"dst.Pix[d+1] = uint8(uint32(%sg) >> 8)\n"+ return fmt.Sprintf(""+
"dst.Pix[d+2] = uint8(uint32(%sb) >> 8)\n"+ "dst.Pix[d+0] = uint8(uint32(%sr) >> 8)\n"+
"dst.Pix[d+3] = uint8(uint32(%sa) >> 8)", "dst.Pix[d+1] = uint8(uint32(%sg) >> 8)\n"+
args[2], args[2], args[2], args[2], "dst.Pix[d+2] = uint8(uint32(%sb) >> 8)\n"+
) "dst.Pix[d+3] = uint8(uint32(%sa) >> 8)",
args[2], args[2], args[2], args[2],
)
case "*image.Gray":
return fmt.Sprintf(""+
"out := uint8(uint32(%sr) >> 8)\n"+
"dst.Pix[d+0] = out\n"+
"dst.Pix[d+1] = out\n"+
"dst.Pix[d+2] = out\n"+
"dst.Pix[d+3] = 0xff",
args[2],
)
}
} }
case "outputf": case "outputf":
@ -263,29 +297,55 @@ func expnDollar(prefix, dollar, suffix string, d *data) string {
default: default:
log.Fatalf("bad dType %q", d.dType) log.Fatalf("bad dType %q", d.dType)
case "Image": case "Image":
ret = fmt.Sprintf(""+ switch d.sType {
"dstColorRGBA64.R = %s(%sr * %s)\n"+ default:
"dstColorRGBA64.G = %s(%sg * %s)\n"+ ret = fmt.Sprintf(""+
"dstColorRGBA64.B = %s(%sb * %s)\n"+ "dstColorRGBA64.R = %s(%sr * %s)\n"+
"dstColorRGBA64.A = %s(%sa * %s)\n"+ "dstColorRGBA64.G = %s(%sg * %s)\n"+
"dst.Set(%s, %s, dstColor)", "dstColorRGBA64.B = %s(%sb * %s)\n"+
args[2], args[3], args[4], "dstColorRGBA64.A = %s(%sa * %s)\n"+
args[2], args[3], args[4], "dst.Set(%s, %s, dstColor)",
args[2], args[3], args[4], args[2], args[3], args[4],
args[2], args[3], args[4], args[2], args[3], args[4],
args[0], args[1], args[2], args[3], args[4],
) args[2], args[3], args[4],
args[0], args[1],
)
case "*image.Gray":
ret = fmt.Sprintf(""+
"out := %s(%sr * %s)\n"+
"dstColorRGBA64.R = out\n"+
"dstColorRGBA64.G = out\n"+
"dstColorRGBA64.B = out\n"+
"dstColorRGBA64.A = 0xffff\n"+
"dst.Set(%s, %s, dstColor)",
args[2], args[3], args[4],
args[0], args[1],
)
}
case "*image.RGBA": case "*image.RGBA":
ret = fmt.Sprintf(""+ switch d.sType {
"dst.Pix[d+0] = uint8(%s(%sr * %s) >> 8)\n"+ default:
"dst.Pix[d+1] = uint8(%s(%sg * %s) >> 8)\n"+ ret = fmt.Sprintf(""+
"dst.Pix[d+2] = uint8(%s(%sb * %s) >> 8)\n"+ "dst.Pix[d+0] = uint8(%s(%sr * %s) >> 8)\n"+
"dst.Pix[d+3] = uint8(%s(%sa * %s) >> 8)", "dst.Pix[d+1] = uint8(%s(%sg * %s) >> 8)\n"+
args[2], args[3], args[4], "dst.Pix[d+2] = uint8(%s(%sb * %s) >> 8)\n"+
args[2], args[3], args[4], "dst.Pix[d+3] = uint8(%s(%sa * %s) >> 8)",
args[2], args[3], args[4], args[2], args[3], args[4],
args[2], args[3], args[4], args[2], args[3], args[4],
) args[2], args[3], args[4],
args[2], args[3], args[4],
)
case "*image.Gray":
ret = fmt.Sprintf(""+
"out := uint8(%s(%sr * %s) >> 8)\n"+
"dst.Pix[d+0] = out\n"+
"dst.Pix[d+1] = out\n"+
"dst.Pix[d+2] = out\n"+
"dst.Pix[d+3] = 0xff",
args[2], args[3], args[4],
)
}
} }
return strings.Replace(ret, " * 1)", ")", -1) return strings.Replace(ret, " * 1)", ")", -1)
@ -308,12 +368,20 @@ func expnDollar(prefix, dollar, suffix string, d *data) string {
switch d.sType { switch d.sType {
default: default:
log.Fatalf("bad sType %q", d.sType) log.Fatalf("bad sType %q", d.sType)
case "image.Image", "*image.Gray", "*image.NRGBA", "*image.Uniform", "*image.YCbCr": // TODO: separate code for concrete types. case "image.Image", "*image.NRGBA", "*image.Uniform", "*image.YCbCr": // TODO: separate code for concrete types.
fmt.Fprintf(buf, "%sr%s, %sg%s, %sb%s, %sa%s := "+ fmt.Fprintf(buf, "%sr%s, %sg%s, %sb%s, %sa%s := "+
"src.At(%s, %s).RGBA()\n", "src.At(%s, %s).RGBA()\n",
lhs, tmp, lhs, tmp, lhs, tmp, lhs, tmp, lhs, tmp, lhs, tmp, lhs, tmp, lhs, tmp,
args[0], args[1], args[0], args[1],
) )
case "*image.Gray":
// TODO: there's no need to multiply by 0x101 if the next thing
// we're going to do is shift right by 8.
fmt.Fprintf(buf, "%si := src.PixOffset(%s, %s)\n"+
"%sr%s := uint32(src.Pix[%si]) * 0x101\n",
lhs, args[0], args[1],
lhs, tmp, lhs,
)
case "*image.RGBA": case "*image.RGBA":
// TODO: there's no need to multiply by 0x101 if the next thing // TODO: there's no need to multiply by 0x101 if the next thing
// we're going to do is shift right by 8. // we're going to do is shift right by 8.
@ -331,16 +399,24 @@ func expnDollar(prefix, dollar, suffix string, d *data) string {
} }
if dollar == "srcf" { if dollar == "srcf" {
fmt.Fprintf(buf, ""+ switch d.sType {
"%sr %s float64(%sru)%s\n"+ default:
"%sg %s float64(%sgu)%s\n"+ fmt.Fprintf(buf, ""+
"%sb %s float64(%sbu)%s\n"+ "%sr %s float64(%sru)%s\n"+
"%sa %s float64(%sau)%s\n", "%sg %s float64(%sgu)%s\n"+
lhs, eqOp, lhs, extra, "%sb %s float64(%sbu)%s\n"+
lhs, eqOp, lhs, extra, "%sa %s float64(%sau)%s\n",
lhs, eqOp, lhs, extra, lhs, eqOp, lhs, extra,
lhs, eqOp, lhs, extra, lhs, eqOp, lhs, extra,
) lhs, eqOp, lhs, extra,
lhs, eqOp, lhs, extra,
)
case "*image.Gray":
fmt.Fprintf(buf, ""+
"%sr %s float64(%sru)%s\n",
lhs, eqOp, lhs, extra,
)
}
} }
return strings.TrimSpace(buf.String()) return strings.TrimSpace(buf.String())
@ -362,6 +438,27 @@ func expnDollar(prefix, dollar, suffix string, d *data) string {
return strings.Replace(suffix, "for dy, s", "for _, s", 1) return strings.Replace(suffix, "for dy, s", "for _, s", 1)
} }
return suffix return suffix
case "tweakP":
if d.sType == "*image.Gray" {
if strings.HasPrefix(strings.TrimSpace(suffix), "pa * ") {
return "1,"
}
return "pr,"
}
return suffix
case "tweakPr":
if d.sType == "*image.Gray" {
return "pr *= s.invTotalWeightFFFF"
}
return ";"
case "tweakVarP":
if d.sType == "*image.Gray" {
return strings.Replace(suffix, "var pr, pg, pb, pa", "var pr", 1)
}
return suffix
} }
return "" return ""
} }
@ -690,15 +787,16 @@ const (
t := 0 t := 0
for y := int32(0); y < z.sh; y++ { for y := int32(0); y < z.sh; y++ {
for _, s := range z.horizontal.sources { for _, s := range z.horizontal.sources {
var pr, pg, pb, pa float64 $tweakVarP var pr, pg, pb, pa float64
for _, c := range z.horizontal.contribs[s.i:s.j] { for _, c := range z.horizontal.contribs[s.i:s.j] {
p += $srcf[sr.Min.X + int(c.coord), sr.Min.Y + int(y)] * c.weight p += $srcf[sr.Min.X + int(c.coord), sr.Min.Y + int(y)] * c.weight
} }
$tweakPr
tmp[t] = [4]float64{ tmp[t] = [4]float64{
pr * s.invTotalWeightFFFF, $tweakP pr * s.invTotalWeightFFFF,
pg * s.invTotalWeightFFFF, $tweakP pg * s.invTotalWeightFFFF,
pb * s.invTotalWeightFFFF, $tweakP pb * s.invTotalWeightFFFF,
pa * s.invTotalWeightFFFF, $tweakP pa * s.invTotalWeightFFFF,
} }
t++ t++
} }
@ -804,7 +902,7 @@ const (
yWeights[y] /= totalYWeight yWeights[y] /= totalYWeight
} }
var pr, pg, pb, pa float64 $tweakVarP var pr, pg, pb, pa float64
for ky := iy; ky < jy; ky++ { for ky := iy; ky < jy; ky++ {
yWeight := yWeights[ky - iy] yWeight := yWeights[ky - iy]
for kx := ix; kx < jx; kx++ { for kx := ix; kx < jx; kx++ {

142
draw/impl.go
View File

@ -96,11 +96,13 @@ func (nnInterpolator) scale_RGBA_Gray(dst *image.RGBA, dr, adr image.Rectangle,
d := dst.PixOffset(dr.Min.X+adr.Min.X, dr.Min.Y+int(dy)) d := dst.PixOffset(dr.Min.X+adr.Min.X, dr.Min.Y+int(dy))
for dx := int32(adr.Min.X); dx < int32(adr.Max.X); dx, d = dx+1, d+4 { for dx := int32(adr.Min.X); dx < int32(adr.Max.X); dx, d = dx+1, d+4 {
sx := (2*uint64(dx) + 1) * sw / dw2 sx := (2*uint64(dx) + 1) * sw / dw2
pr, pg, pb, pa := src.At(sr.Min.X+int(sx), sr.Min.Y+int(sy)).RGBA() pi := src.PixOffset(sr.Min.X+int(sx), sr.Min.Y+int(sy))
dst.Pix[d+0] = uint8(uint32(pr) >> 8) pr := uint32(src.Pix[pi]) * 0x101
dst.Pix[d+1] = uint8(uint32(pg) >> 8) out := uint8(uint32(pr) >> 8)
dst.Pix[d+2] = uint8(uint32(pb) >> 8) dst.Pix[d+0] = out
dst.Pix[d+3] = uint8(uint32(pa) >> 8) dst.Pix[d+1] = out
dst.Pix[d+2] = out
dst.Pix[d+3] = 0xff
} }
} }
} }
@ -237,11 +239,13 @@ func (nnInterpolator) transform_RGBA_Gray(dst *image.RGBA, dr, adr image.Rectang
if !(image.Point{sx0, sy0}).In(sr) { if !(image.Point{sx0, sy0}).In(sr) {
continue continue
} }
pr, pg, pb, pa := src.At(sx0, sy0).RGBA() pi := src.PixOffset(sx0, sy0)
dst.Pix[d+0] = uint8(uint32(pr) >> 8) pr := uint32(src.Pix[pi]) * 0x101
dst.Pix[d+1] = uint8(uint32(pg) >> 8) out := uint8(uint32(pr) >> 8)
dst.Pix[d+2] = uint8(uint32(pb) >> 8) dst.Pix[d+0] = out
dst.Pix[d+3] = uint8(uint32(pa) >> 8) dst.Pix[d+1] = out
dst.Pix[d+2] = out
dst.Pix[d+3] = 0xff
} }
} }
} }
@ -493,42 +497,26 @@ func (ablInterpolator) scale_RGBA_Gray(dst *image.RGBA, dr, adr image.Rectangle,
xFrac0, xFrac1 = 1, 0 xFrac0, xFrac1 = 1, 0
} }
s00ru, s00gu, s00bu, s00au := src.At(sr.Min.X+int(sx0), sr.Min.Y+int(sy0)).RGBA() s00i := src.PixOffset(sr.Min.X+int(sx0), sr.Min.Y+int(sy0))
s00ru := uint32(src.Pix[s00i]) * 0x101
s00r := float64(s00ru) s00r := float64(s00ru)
s00g := float64(s00gu) s10i := src.PixOffset(sr.Min.X+int(sx1), sr.Min.Y+int(sy0))
s00b := float64(s00bu) s10ru := uint32(src.Pix[s10i]) * 0x101
s00a := float64(s00au)
s10ru, s10gu, s10bu, s10au := src.At(sr.Min.X+int(sx1), sr.Min.Y+int(sy0)).RGBA()
s10r := float64(s10ru) s10r := float64(s10ru)
s10g := float64(s10gu)
s10b := float64(s10bu)
s10a := float64(s10au)
s10r = xFrac1*s00r + xFrac0*s10r s10r = xFrac1*s00r + xFrac0*s10r
s10g = xFrac1*s00g + xFrac0*s10g s01i := src.PixOffset(sr.Min.X+int(sx0), sr.Min.Y+int(sy1))
s10b = xFrac1*s00b + xFrac0*s10b s01ru := uint32(src.Pix[s01i]) * 0x101
s10a = xFrac1*s00a + xFrac0*s10a
s01ru, s01gu, s01bu, s01au := src.At(sr.Min.X+int(sx0), sr.Min.Y+int(sy1)).RGBA()
s01r := float64(s01ru) s01r := float64(s01ru)
s01g := float64(s01gu) s11i := src.PixOffset(sr.Min.X+int(sx1), sr.Min.Y+int(sy1))
s01b := float64(s01bu) s11ru := uint32(src.Pix[s11i]) * 0x101
s01a := float64(s01au)
s11ru, s11gu, s11bu, s11au := src.At(sr.Min.X+int(sx1), sr.Min.Y+int(sy1)).RGBA()
s11r := float64(s11ru) s11r := float64(s11ru)
s11g := float64(s11gu)
s11b := float64(s11bu)
s11a := float64(s11au)
s11r = xFrac1*s01r + xFrac0*s11r s11r = xFrac1*s01r + xFrac0*s11r
s11g = xFrac1*s01g + xFrac0*s11g
s11b = xFrac1*s01b + xFrac0*s11b
s11a = xFrac1*s01a + xFrac0*s11a
s11r = yFrac1*s10r + yFrac0*s11r s11r = yFrac1*s10r + yFrac0*s11r
s11g = yFrac1*s10g + yFrac0*s11g out := uint8(uint32(s11r) >> 8)
s11b = yFrac1*s10b + yFrac0*s11b dst.Pix[d+0] = out
s11a = yFrac1*s10a + yFrac0*s11a dst.Pix[d+1] = out
dst.Pix[d+0] = uint8(uint32(s11r) >> 8) dst.Pix[d+2] = out
dst.Pix[d+1] = uint8(uint32(s11g) >> 8) dst.Pix[d+3] = 0xff
dst.Pix[d+2] = uint8(uint32(s11b) >> 8)
dst.Pix[d+3] = uint8(uint32(s11a) >> 8)
} }
} }
} }
@ -1066,42 +1054,26 @@ func (ablInterpolator) transform_RGBA_Gray(dst *image.RGBA, dr, adr image.Rectan
yFrac0, yFrac1 = 1, 0 yFrac0, yFrac1 = 1, 0
} }
s00ru, s00gu, s00bu, s00au := src.At(sx0, sy0).RGBA() s00i := src.PixOffset(sx0, sy0)
s00ru := uint32(src.Pix[s00i]) * 0x101
s00r := float64(s00ru) s00r := float64(s00ru)
s00g := float64(s00gu) s10i := src.PixOffset(sx1, sy0)
s00b := float64(s00bu) s10ru := uint32(src.Pix[s10i]) * 0x101
s00a := float64(s00au)
s10ru, s10gu, s10bu, s10au := src.At(sx1, sy0).RGBA()
s10r := float64(s10ru) s10r := float64(s10ru)
s10g := float64(s10gu)
s10b := float64(s10bu)
s10a := float64(s10au)
s10r = xFrac1*s00r + xFrac0*s10r s10r = xFrac1*s00r + xFrac0*s10r
s10g = xFrac1*s00g + xFrac0*s10g s01i := src.PixOffset(sx0, sy1)
s10b = xFrac1*s00b + xFrac0*s10b s01ru := uint32(src.Pix[s01i]) * 0x101
s10a = xFrac1*s00a + xFrac0*s10a
s01ru, s01gu, s01bu, s01au := src.At(sx0, sy1).RGBA()
s01r := float64(s01ru) s01r := float64(s01ru)
s01g := float64(s01gu) s11i := src.PixOffset(sx1, sy1)
s01b := float64(s01bu) s11ru := uint32(src.Pix[s11i]) * 0x101
s01a := float64(s01au)
s11ru, s11gu, s11bu, s11au := src.At(sx1, sy1).RGBA()
s11r := float64(s11ru) s11r := float64(s11ru)
s11g := float64(s11gu)
s11b := float64(s11bu)
s11a := float64(s11au)
s11r = xFrac1*s01r + xFrac0*s11r s11r = xFrac1*s01r + xFrac0*s11r
s11g = xFrac1*s01g + xFrac0*s11g
s11b = xFrac1*s01b + xFrac0*s11b
s11a = xFrac1*s01a + xFrac0*s11a
s11r = yFrac1*s10r + yFrac0*s11r s11r = yFrac1*s10r + yFrac0*s11r
s11g = yFrac1*s10g + yFrac0*s11g out := uint8(uint32(s11r) >> 8)
s11b = yFrac1*s10b + yFrac0*s11b dst.Pix[d+0] = out
s11a = yFrac1*s10a + yFrac0*s11a dst.Pix[d+1] = out
dst.Pix[d+0] = uint8(uint32(s11r) >> 8) dst.Pix[d+2] = out
dst.Pix[d+1] = uint8(uint32(s11g) >> 8) dst.Pix[d+3] = 0xff
dst.Pix[d+2] = uint8(uint32(s11b) >> 8)
dst.Pix[d+3] = uint8(uint32(s11a) >> 8)
} }
} }
} }
@ -1709,19 +1681,18 @@ func (z *kernelScaler) scaleX_Gray(tmp [][4]float64, src *image.Gray, sr image.R
t := 0 t := 0
for y := int32(0); y < z.sh; y++ { for y := int32(0); y < z.sh; y++ {
for _, s := range z.horizontal.sources { for _, s := range z.horizontal.sources {
var pr, pg, pb, pa float64 var pr float64
for _, c := range z.horizontal.contribs[s.i:s.j] { for _, c := range z.horizontal.contribs[s.i:s.j] {
pru, pgu, pbu, pau := src.At(sr.Min.X+int(c.coord), sr.Min.Y+int(y)).RGBA() pi := src.PixOffset(sr.Min.X+int(c.coord), sr.Min.Y+int(y))
pru := uint32(src.Pix[pi]) * 0x101
pr += float64(pru) * c.weight pr += float64(pru) * c.weight
pg += float64(pgu) * c.weight
pb += float64(pbu) * c.weight
pa += float64(pau) * c.weight
} }
pr *= s.invTotalWeightFFFF
tmp[t] = [4]float64{ tmp[t] = [4]float64{
pr * s.invTotalWeightFFFF, pr,
pg * s.invTotalWeightFFFF, pr,
pb * s.invTotalWeightFFFF, pr,
pa * s.invTotalWeightFFFF, 1,
} }
t++ t++
} }
@ -1965,21 +1936,20 @@ func (q *Kernel) transform_RGBA_Gray(dst *image.RGBA, dr, adr image.Rectangle, d
yWeights[y] /= totalYWeight yWeights[y] /= totalYWeight
} }
var pr, pg, pb, pa float64 var pr float64
for ky := iy; ky < jy; ky++ { for ky := iy; ky < jy; ky++ {
yWeight := yWeights[ky-iy] yWeight := yWeights[ky-iy]
for kx := ix; kx < jx; kx++ { for kx := ix; kx < jx; kx++ {
pru, pgu, pbu, pau := src.At(kx, ky).RGBA() pi := src.PixOffset(kx, ky)
pru := uint32(src.Pix[pi]) * 0x101
pr += float64(pru) * xWeights[kx-ix] * yWeight pr += float64(pru) * xWeights[kx-ix] * yWeight
pg += float64(pgu) * xWeights[kx-ix] * yWeight
pb += float64(pbu) * xWeights[kx-ix] * yWeight
pa += float64(pau) * xWeights[kx-ix] * yWeight
} }
} }
dst.Pix[d+0] = uint8(fffftou(pr) >> 8) out := uint8(fffftou(pr) >> 8)
dst.Pix[d+1] = uint8(fffftou(pg) >> 8) dst.Pix[d+0] = out
dst.Pix[d+2] = uint8(fffftou(pb) >> 8) dst.Pix[d+1] = out
dst.Pix[d+3] = uint8(fffftou(pa) >> 8) dst.Pix[d+2] = out
dst.Pix[d+3] = 0xff
} }
} }
} }