blob: 4048e19c84c88fbed7ecd92132bb87a651a79a8d [file] [log] [blame]
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build ignore
package main
import (
"bytes"
"flag"
"fmt"
"go/format"
"io/ioutil"
"log"
"os"
"strings"
)
var debug = flag.Bool("debug", false, "")
func main() {
flag.Parse()
w := new(bytes.Buffer)
w.WriteString("// generated by \"go run gen.go\". DO NOT EDIT.\n\n" +
"package draw\n\nimport (\n" +
"\"image\"\n" +
"\"image/color\"\n" +
"\"math\"\n" +
"\n" +
"\"golang.org/x/image/math/f64\"\n" +
")\n")
gen(w, "nnInterpolator", codeNNScaleLeaf, codeNNTransformLeaf)
gen(w, "ablInterpolator", codeABLScaleLeaf, codeABLTransformLeaf)
genKernel(w)
if *debug {
os.Stdout.Write(w.Bytes())
return
}
out, err := format.Source(w.Bytes())
if err != nil {
log.Fatal(err)
}
if err := ioutil.WriteFile("impl.go", out, 0660); err != nil {
log.Fatal(err)
}
}
var (
// dsTypes are the (dst image type, src image type) pairs to generate
// scale_DType_SType implementations for. The last element in the slice
// should be the fallback pair ("Image", "image.Image").
//
// TODO: add *image.CMYK src type after Go 1.5 is released.
dsTypes = []struct{ dType, sType string }{
{"*image.RGBA", "*image.Gray"},
{"*image.RGBA", "*image.NRGBA"},
{"*image.RGBA", "*image.RGBA"},
{"*image.RGBA", "*image.Uniform"},
{"*image.RGBA", "*image.YCbCr"},
{"*image.RGBA", "image.Image"},
{"Image", "image.Image"},
}
dTypes, sTypes []string
sTypesForDType = map[string][]string{}
subsampleRatios = []string{
"444",
"422",
"420",
"440",
}
)
func init() {
dTypesSeen := map[string]bool{}
sTypesSeen := map[string]bool{}
for _, t := range dsTypes {
if !sTypesSeen[t.sType] {
sTypesSeen[t.sType] = true
sTypes = append(sTypes, t.sType)
}
if !dTypesSeen[t.dType] {
dTypesSeen[t.dType] = true
dTypes = append(dTypes, t.dType)
}
sTypesForDType[t.dType] = append(sTypesForDType[t.dType], t.sType)
}
sTypesForDType["anyDType"] = sTypes
}
type data struct {
dType string
sType string
sratio string
receiver string
}
func gen(w *bytes.Buffer, receiver string, codes ...string) {
expn(w, codeRoot, &data{receiver: receiver})
for _, code := range codes {
for _, t := range dsTypes {
expn(w, code, &data{
dType: t.dType,
sType: t.sType,
receiver: receiver,
})
}
}
}
func genKernel(w *bytes.Buffer) {
expn(w, codeKernelRoot, &data{})
for _, sType := range sTypes {
expn(w, codeKernelScaleLeafX, &data{
sType: sType,
})
}
for _, dType := range dTypes {
expn(w, codeKernelScaleLeafY, &data{
dType: dType,
})
}
for _, t := range dsTypes {
expn(w, codeKernelTransformLeaf, &data{
dType: t.dType,
sType: t.sType,
})
}
}
func expn(w *bytes.Buffer, code string, d *data) {
if d.sType == "*image.YCbCr" && d.sratio == "" {
for _, sratio := range subsampleRatios {
e := *d
e.sratio = sratio
expn(w, code, &e)
}
return
}
for _, line := range strings.Split(code, "\n") {
line = expnLine(line, d)
if line == ";" {
continue
}
fmt.Fprintln(w, line)
}
}
func expnLine(line string, d *data) string {
for {
i := strings.IndexByte(line, '$')
if i < 0 {
break
}
prefix, s := line[:i], line[i+1:]
i = len(s)
for j, c := range s {
if !('A' <= c && c <= 'Z' || 'a' <= c && c <= 'z') {
i = j
break
}
}
dollar, suffix := s[:i], s[i:]
e := expnDollar(prefix, dollar, suffix, d)
if e == "" {
log.Fatalf("couldn't expand %q", line)
}
line = e
}
return line
}
// expnDollar expands a "$foo" fragment in a line of generated code. It returns
// the empty string if there was a problem. It returns ";" if the generated
// code is a no-op.
func expnDollar(prefix, dollar, suffix string, d *data) string {
switch dollar {
case "dType":
return prefix + d.dType + suffix
case "dTypeRN":
return prefix + relName(d.dType) + suffix
case "sratio":
return prefix + d.sratio + suffix
case "sType":
return prefix + d.sType + suffix
case "sTypeRN":
return prefix + relName(d.sType) + suffix
case "receiver":
return prefix + d.receiver + suffix
case "switch":
return expnSwitch("", true, suffix)
case "switchD":
return expnSwitch("", false, suffix)
case "switchS":
return expnSwitch("anyDType", false, suffix)
case "preOuter":
switch d.dType {
default:
return ";"
case "Image":
return "" +
"dstColorRGBA64 := &color.RGBA64{}\n" +
"dstColor := color.Color(dstColorRGBA64)"
}
case "preInner":
switch d.dType {
default:
return ";"
case "*image.RGBA":
return "d := dst.PixOffset(dr.Min.X+adr.Min.X, dr.Min.Y+int(dy))"
}
case "preKernelInner":
switch d.dType {
default:
return ";"
case "*image.RGBA":
return "d := dst.PixOffset(dr.Min.X+int(dx), dr.Min.Y+adr.Min.Y)"
}
case "blend":
args, _ := splitArgs(suffix)
if len(args) != 4 {
return ""
}
switch d.sType {
default:
return fmt.Sprintf(""+
"%sr = %s*%sr + %s*%sr\n"+
"%sg = %s*%sg + %s*%sg\n"+
"%sb = %s*%sb + %s*%sb\n"+
"%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],
)
case "*image.Gray":
return fmt.Sprintf(""+
"%sr = %s*%sr + %s*%sr",
args[3], args[0], args[1], args[2], args[3],
)
}
case "outputu":
args, _ := splitArgs(suffix)
if len(args) != 3 {
return ""
}
switch d.dType {
default:
log.Fatalf("bad dType %q", d.dType)
case "Image":
switch d.sType {
default:
return fmt.Sprintf(""+
"dstColorRGBA64.R = uint16(%sr)\n"+
"dstColorRGBA64.G = uint16(%sg)\n"+
"dstColorRGBA64.B = uint16(%sb)\n"+
"dstColorRGBA64.A = uint16(%sa)\n"+
"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":
switch d.sType {
default:
return fmt.Sprintf(""+
"dst.Pix[d+0] = uint8(uint32(%sr) >> 8)\n"+
"dst.Pix[d+1] = uint8(uint32(%sg) >> 8)\n"+
"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":
args, _ := splitArgs(suffix)
if len(args) != 5 {
return ""
}
ret := ""
switch d.dType {
default:
log.Fatalf("bad dType %q", d.dType)
case "Image":
switch d.sType {
default:
ret = fmt.Sprintf(""+
"dstColorRGBA64.R = %s(%sr * %s)\n"+
"dstColorRGBA64.G = %s(%sg * %s)\n"+
"dstColorRGBA64.B = %s(%sb * %s)\n"+
"dstColorRGBA64.A = %s(%sa * %s)\n"+
"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],
)
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":
switch d.sType {
default:
ret = fmt.Sprintf(""+
"dst.Pix[d+0] = uint8(%s(%sr * %s) >> 8)\n"+
"dst.Pix[d+1] = uint8(%s(%sg * %s) >> 8)\n"+
"dst.Pix[d+2] = uint8(%s(%sb * %s) >> 8)\n"+
"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],
)
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)
case "srcf", "srcu":
lhs, eqOp := splitEq(prefix)
if lhs == "" {
return ""
}
args, extra := splitArgs(suffix)
if len(args) != 2 {
return ""
}
tmp := ""
if dollar == "srcf" {
tmp = "u"
}
buf := new(bytes.Buffer)
switch d.sType {
default:
log.Fatalf("bad sType %q", d.sType)
case "image.Image", "*image.Uniform", "*image.YCbCr": // TODO: separate code for concrete types.
fmt.Fprintf(buf, "%sr%s, %sg%s, %sb%s, %sa%s := "+
"src.At(%s, %s).RGBA()\n",
lhs, tmp, lhs, tmp, lhs, tmp, lhs, tmp,
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.NRGBA":
// 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"+
"%sa%s := uint32(src.Pix[%si+3]) * 0x101\n"+
"%sr%s := uint32(src.Pix[%si+0]) * %sa%s / 0xff\n"+
"%sg%s := uint32(src.Pix[%si+1]) * %sa%s / 0xff\n"+
"%sb%s := uint32(src.Pix[%si+2]) * %sa%s / 0xff\n",
lhs, args[0], args[1],
lhs, tmp, lhs,
lhs, tmp, lhs, lhs, tmp,
lhs, tmp, lhs, lhs, tmp,
lhs, tmp, lhs, lhs, tmp,
)
case "*image.RGBA":
// 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+0]) * 0x101\n"+
"%sg%s := uint32(src.Pix[%si+1]) * 0x101\n"+
"%sb%s := uint32(src.Pix[%si+2]) * 0x101\n"+
"%sa%s := uint32(src.Pix[%si+3]) * 0x101\n",
lhs, args[0], args[1],
lhs, tmp, lhs,
lhs, tmp, lhs,
lhs, tmp, lhs,
lhs, tmp, lhs,
)
}
if dollar == "srcf" {
switch d.sType {
default:
fmt.Fprintf(buf, ""+
"%sr %s float64(%sru)%s\n"+
"%sg %s float64(%sgu)%s\n"+
"%sb %s float64(%sbu)%s\n"+
"%sa %s float64(%sau)%s\n",
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())
case "tweakD":
if d.dType == "*image.RGBA" {
return "d += dst.Stride"
}
return ";"
case "tweakDx":
if d.dType == "*image.RGBA" {
return strings.Replace(prefix, "dx++", "dx, d = dx+1, d+4", 1)
}
return prefix
case "tweakDy":
if d.dType == "*image.RGBA" {
return strings.Replace(prefix, "for dy, s", "for _, s", 1)
}
return prefix
case "tweakP":
if d.sType == "*image.Gray" {
if strings.HasPrefix(strings.TrimSpace(prefix), "pa * ") {
return "1,"
}
return "pr,"
}
return prefix
case "tweakPr":
if d.sType == "*image.Gray" {
return "pr *= s.invTotalWeightFFFF"
}
return ";"
case "tweakVarP":
if d.sType == "*image.Gray" {
return strings.Replace(prefix, "var pr, pg, pb, pa", "var pr", 1)
}
return prefix
}
return ""
}
func expnSwitch(dType string, expandBoth bool, template string) string {
switchVar := "dst"
if dType != "" {
switchVar = "src"
}
lines := []string{fmt.Sprintf("switch %s := %s.(type) {", switchVar, switchVar)}
fallback, values := "Image", dTypes
if dType != "" {
fallback, values = "image.Image", sTypesForDType[dType]
}
for _, v := range values {
if v == fallback {
lines = append(lines, "default:")
} else {
lines = append(lines, fmt.Sprintf("case %s:", v))
}
if dType != "" {
if v == "*image.YCbCr" {
lines = append(lines, expnSwitchYCbCr(dType, template))
} else {
lines = append(lines, expnLine(template, &data{dType: dType, sType: v}))
}
} else if !expandBoth {
lines = append(lines, expnLine(template, &data{dType: v}))
} else {
lines = append(lines, expnSwitch(v, false, template))
}
}
lines = append(lines, "}")
return strings.Join(lines, "\n")
}
func expnSwitchYCbCr(dType, template string) string {
lines := []string{
"switch src.SubsampleRatio {",
"default:",
expnLine(template, &data{dType: dType, sType: "image.Image"}),
}
for _, sratio := range subsampleRatios {
lines = append(lines,
fmt.Sprintf("case image.YCbCrSubsampleRatio%s:", sratio),
expnLine(template, &data{dType: dType, sType: "*image.YCbCr", sratio: sratio}),
)
}
lines = append(lines, "}")
return strings.Join(lines, "\n")
}
func split(s, sep string) (string, string) {
if i := strings.Index(s, sep); i >= 0 {
return strings.TrimSpace(s[:i]), strings.TrimSpace(s[i+len(sep):])
}
return "", ""
}
func splitEq(s string) (lhs, eqOp string) {
s = strings.TrimSpace(s)
if lhs, _ = split(s, ":="); lhs != "" {
return lhs, ":="
}
if lhs, _ = split(s, "+="); lhs != "" {
return lhs, "+="
}
return "", ""
}
func splitArgs(s string) (args []string, extra string) {
s = strings.TrimSpace(s)
if s == "" || s[0] != '[' {
return nil, ""
}
s = s[1:]
i := strings.IndexByte(s, ']')
if i < 0 {
return nil, ""
}
args, extra = strings.Split(s[:i], ","), s[i+1:]
for i := range args {
args[i] = strings.TrimSpace(args[i])
}
return args, extra
}
func relName(s string) string {
if i := strings.LastIndex(s, "."); i >= 0 {
return s[i+1:]
}
return s
}
const (
codeRoot = `
func (z $receiver) Scale(dst Image, dr image.Rectangle, src image.Image, sr image.Rectangle, opts *Options) {
// adr is the affected destination pixels, relative to dr.Min.
adr := dst.Bounds().Intersect(dr).Sub(dr.Min)
if adr.Empty() || sr.Empty() {
return
}
// sr is the source pixels. If it extends beyond the src bounds,
// we cannot use the type-specific fast paths, as they access
// the Pix fields directly without bounds checking.
if !sr.In(src.Bounds()) {
z.scale_Image_Image(dst, dr, adr, src, sr)
} else {
$switch z.scale_$dTypeRN_$sTypeRN$sratio(dst, dr, adr, src, sr)
}
}
func (z $receiver) Transform(dst Image, s2d *f64.Aff3, src image.Image, sr image.Rectangle, opts *Options) {
dr := transformRect(s2d, &sr)
// adr is the affected destination pixels, relative to dr.Min.
adr := dst.Bounds().Intersect(dr).Sub(dr.Min)
if adr.Empty() || sr.Empty() {
return
}
d2s := invert(s2d)
// sr is the source pixels. If it extends beyond the src bounds,
// we cannot use the type-specific fast paths, as they access
// the Pix fields directly without bounds checking.
if !sr.In(src.Bounds()) {
z.transform_Image_Image(dst, dr, adr, &d2s, src, sr)
} else {
$switch z.transform_$dTypeRN_$sTypeRN$sratio(dst, dr, adr, &d2s, src, sr)
}
}
`
codeNNScaleLeaf = `
func (nnInterpolator) scale_$dTypeRN_$sTypeRN$sratio(dst $dType, dr, adr image.Rectangle, src $sType, sr image.Rectangle) {
dw2 := uint64(dr.Dx()) * 2
dh2 := uint64(dr.Dy()) * 2
sw := uint64(sr.Dx())
sh := uint64(sr.Dy())
$preOuter
for dy := int32(adr.Min.Y); dy < int32(adr.Max.Y); dy++ {
sy := (2*uint64(dy) + 1) * sh / dh2
$preInner
for dx := int32(adr.Min.X); dx < int32(adr.Max.X); dx++ { $tweakDx
sx := (2*uint64(dx) + 1) * sw / dw2
p := $srcu[sr.Min.X + int(sx), sr.Min.Y + int(sy)]
$outputu[dr.Min.X + int(dx), dr.Min.Y + int(dy), p]
}
}
}
`
codeNNTransformLeaf = `
func (nnInterpolator) transform_$dTypeRN_$sTypeRN$sratio(dst $dType, dr, adr image.Rectangle, d2s *f64.Aff3, src $sType, sr image.Rectangle) {
$preOuter
for dy := int32(adr.Min.Y); dy < int32(adr.Max.Y); dy++ {
dyf := float64(dr.Min.Y + int(dy)) + 0.5
$preInner
for dx := int32(adr.Min.X); dx < int32(adr.Max.X); dx++ { $tweakDx
dxf := float64(dr.Min.X + int(dx)) + 0.5
// TODO: change the src origin so that we can say int(f) instead of int(math.Floor(f)).
sx0 := int(math.Floor(d2s[0]*dxf + d2s[1]*dyf + d2s[2]))
sy0 := int(math.Floor(d2s[3]*dxf + d2s[4]*dyf + d2s[5]))
if !(image.Point{sx0, sy0}).In(sr) {
continue
}
p := $srcu[sx0, sy0]
$outputu[dr.Min.X + int(dx), dr.Min.Y + int(dy), p]
}
}
}
`
codeABLScaleLeaf = `
func (ablInterpolator) scale_$dTypeRN_$sTypeRN$sratio(dst $dType, dr, adr image.Rectangle, src $sType, sr image.Rectangle) {
sw := int32(sr.Dx())
sh := int32(sr.Dy())
yscale := float64(sh) / float64(dr.Dy())
xscale := float64(sw) / float64(dr.Dx())
swMinus1, shMinus1 := sw - 1, sh - 1
$preOuter
for dy := int32(adr.Min.Y); dy < int32(adr.Max.Y); dy++ {
sy := (float64(dy)+0.5)*yscale - 0.5
// If sy < 0, we will clamp sy0 to 0 anyway, so it doesn't matter if
// we say int32(sy) instead of int32(math.Floor(sy)). Similarly for
// sx, below.
sy0 := int32(sy)
yFrac0 := sy - float64(sy0)
yFrac1 := 1 - yFrac0
sy1 := sy0 + 1
if sy < 0 {
sy0, sy1 = 0, 0
yFrac0, yFrac1 = 0, 1
} else if sy1 > shMinus1 {
sy0, sy1 = shMinus1, shMinus1
yFrac0, yFrac1 = 1, 0
}
$preInner
for dx := int32(adr.Min.X); dx < int32(adr.Max.X); dx++ { $tweakDx
sx := (float64(dx)+0.5)*xscale - 0.5
sx0 := int32(sx)
xFrac0 := sx - float64(sx0)
xFrac1 := 1 - xFrac0
sx1 := sx0 + 1
if sx < 0 {
sx0, sx1 = 0, 0
xFrac0, xFrac1 = 0, 1
} else if sx1 > swMinus1 {
sx0, sx1 = swMinus1, swMinus1
xFrac0, xFrac1 = 1, 0
}
s00 := $srcf[sr.Min.X + int(sx0), sr.Min.Y + int(sy0)]
s10 := $srcf[sr.Min.X + int(sx1), sr.Min.Y + int(sy0)]
$blend[xFrac1, s00, xFrac0, s10]
s01 := $srcf[sr.Min.X + int(sx0), sr.Min.Y + int(sy1)]
s11 := $srcf[sr.Min.X + int(sx1), sr.Min.Y + int(sy1)]
$blend[xFrac1, s01, xFrac0, s11]
$blend[yFrac1, s10, yFrac0, s11]
$outputu[dr.Min.X + int(dx), dr.Min.Y + int(dy), s11]
}
}
}
`
codeABLTransformLeaf = `
func (ablInterpolator) transform_$dTypeRN_$sTypeRN$sratio(dst $dType, dr, adr image.Rectangle, d2s *f64.Aff3, src $sType, sr image.Rectangle) {
$preOuter
for dy := int32(adr.Min.Y); dy < int32(adr.Max.Y); dy++ {
dyf := float64(dr.Min.Y + int(dy)) + 0.5
$preInner
for dx := int32(adr.Min.X); dx < int32(adr.Max.X); dx++ { $tweakDx
dxf := float64(dr.Min.X + int(dx)) + 0.5
// TODO: change the src origin so that we can say int(f) instead of int(math.Floor(f)).
sx := d2s[0]*dxf + d2s[1]*dyf + d2s[2]
sy := d2s[3]*dxf + d2s[4]*dyf + d2s[5]
if !(image.Point{int(math.Floor(sx)), int(math.Floor(sy))}).In(sr) {
continue
}
sx -= 0.5
sxf := math.Floor(sx)
xFrac0 := sx - sxf
xFrac1 := 1 - xFrac0
sx0 := int(sxf)
sx1 := sx0 + 1
if sx0 < sr.Min.X {
sx0, sx1 = sr.Min.X, sr.Min.X
xFrac0, xFrac1 = 0, 1
} else if sx1 >= sr.Max.X {
sx0, sx1 = sr.Max.X-1, sr.Max.X-1
xFrac0, xFrac1 = 1, 0
}
sy -= 0.5
syf := math.Floor(sy)
yFrac0 := sy - syf
yFrac1 := 1 - yFrac0
sy0 := int(syf)
sy1 := sy0 + 1
if sy0 < sr.Min.Y {
sy0, sy1 = sr.Min.Y, sr.Min.Y
yFrac0, yFrac1 = 0, 1
} else if sy1 >= sr.Max.Y {
sy0, sy1 = sr.Max.Y-1, sr.Max.Y-1
yFrac0, yFrac1 = 1, 0
}
s00 := $srcf[sx0, sy0]
s10 := $srcf[sx1, sy0]
$blend[xFrac1, s00, xFrac0, s10]
s01 := $srcf[sx0, sy1]
s11 := $srcf[sx1, sy1]
$blend[xFrac1, s01, xFrac0, s11]
$blend[yFrac1, s10, yFrac0, s11]
$outputu[dr.Min.X + int(dx), dr.Min.Y + int(dy), s11]
}
}
}
`
codeKernelRoot = `
func (z *kernelScaler) Scale(dst Image, dr image.Rectangle, src image.Image, sr image.Rectangle, opts *Options) {
if z.dw != int32(dr.Dx()) || z.dh != int32(dr.Dy()) || z.sw != int32(sr.Dx()) || z.sh != int32(sr.Dy()) {
z.kernel.Scale(dst, dr, src, sr, opts)
return
}
// adr is the affected destination pixels, relative to dr.Min.
adr := dst.Bounds().Intersect(dr).Sub(dr.Min)
if adr.Empty() || sr.Empty() {
return
}
// Create a temporary buffer:
// scaleX distributes the source image's columns over the temporary image.
// scaleY distributes the temporary image's rows over the destination image.
// TODO: is it worth having a sync.Pool for this temporary buffer?
tmp := make([][4]float64, z.dw*z.sh)
// sr is the source pixels. If it extends beyond the src bounds,
// we cannot use the type-specific fast paths, as they access
// the Pix fields directly without bounds checking.
if !sr.In(src.Bounds()) {
z.scaleX_Image(tmp, src, sr)
} else {
$switchS z.scaleX_$sTypeRN$sratio(tmp, src, sr)
}
$switchD z.scaleY_$dTypeRN(dst, dr, adr, tmp)
}
func (q *Kernel) Transform(dst Image, s2d *f64.Aff3, src image.Image, sr image.Rectangle, opts *Options) {
dr := transformRect(s2d, &sr)
// adr is the affected destination pixels, relative to dr.Min.
adr := dst.Bounds().Intersect(dr).Sub(dr.Min)
if adr.Empty() || sr.Empty() {
return
}
d2s := invert(s2d)
xscale := abs(d2s[0])
if s := abs(d2s[1]); xscale < s {
xscale = s
}
yscale := abs(d2s[3])
if s := abs(d2s[4]); yscale < s {
yscale = s
}
// sr is the source pixels. If it extends beyond the src bounds,
// we cannot use the type-specific fast paths, as they access
// the Pix fields directly without bounds checking.
if !sr.In(src.Bounds()) {
q.transform_Image_Image(dst, dr, adr, &d2s, src, sr, xscale, yscale)
} else {
$switch q.transform_$dTypeRN_$sTypeRN$sratio(dst, dr, adr, &d2s, src, sr, xscale, yscale)
}
}
`
codeKernelScaleLeafX = `
func (z *kernelScaler) scaleX_$sTypeRN$sratio(tmp [][4]float64, src $sType, sr image.Rectangle) {
t := 0
for y := int32(0); y < z.sh; y++ {
for _, s := range z.horizontal.sources {
var pr, pg, pb, pa float64 $tweakVarP
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
}
$tweakPr
tmp[t] = [4]float64{
pr * s.invTotalWeightFFFF, $tweakP
pg * s.invTotalWeightFFFF, $tweakP
pb * s.invTotalWeightFFFF, $tweakP
pa * s.invTotalWeightFFFF, $tweakP
}
t++
}
}
}
`
codeKernelScaleLeafY = `
func (z *kernelScaler) scaleY_$dTypeRN(dst $dType, dr, adr image.Rectangle, tmp [][4]float64) {
$preOuter
for dx := int32(adr.Min.X); dx < int32(adr.Max.X); dx++ {
$preKernelInner
for dy, s := range z.vertical.sources[adr.Min.Y:adr.Max.Y] { $tweakDy
var pr, pg, pb, pa float64
for _, c := range z.vertical.contribs[s.i:s.j] {
p := &tmp[c.coord*z.dw+dx]
pr += p[0] * c.weight
pg += p[1] * c.weight
pb += p[2] * c.weight
pa += p[3] * c.weight
}
$outputf[dr.Min.X + int(dx), dr.Min.Y + int(adr.Min.Y + dy), ftou, p, s.invTotalWeight]
$tweakD
}
}
}
`
codeKernelTransformLeaf = `
func (q *Kernel) transform_$dTypeRN_$sTypeRN$sratio(dst $dType, dr, adr image.Rectangle, d2s *f64.Aff3, src $sType, sr image.Rectangle, xscale, yscale float64) {
// When shrinking, broaden the effective kernel support so that we still
// visit every source pixel.
xHalfWidth, xKernelArgScale := q.Support, 1.0
if xscale > 1 {
xHalfWidth *= xscale
xKernelArgScale = 1 / xscale
}
yHalfWidth, yKernelArgScale := q.Support, 1.0
if yscale > 1 {
yHalfWidth *= yscale
yKernelArgScale = 1 / yscale
}
xWeights := make([]float64, 1 + 2*int(math.Ceil(xHalfWidth)))
yWeights := make([]float64, 1 + 2*int(math.Ceil(yHalfWidth)))
$preOuter
for dy := int32(adr.Min.Y); dy < int32(adr.Max.Y); dy++ {
dyf := float64(dr.Min.Y + int(dy)) + 0.5
$preInner
for dx := int32(adr.Min.X); dx < int32(adr.Max.X); dx++ { $tweakDx
dxf := float64(dr.Min.X + int(dx)) + 0.5
// TODO: change the src origin so that we can say int(f) instead of int(math.Floor(f)).
sx := d2s[0]*dxf + d2s[1]*dyf + d2s[2]
sy := d2s[3]*dxf + d2s[4]*dyf + d2s[5]
if !(image.Point{int(math.Floor(sx)), int(math.Floor(sy))}).In(sr) {
continue
}
sx -= 0.5
ix := int(math.Floor(sx - xHalfWidth))
if ix < sr.Min.X {
ix = sr.Min.X
}
jx := int(math.Ceil(sx + xHalfWidth))
if jx > sr.Max.X {
jx = sr.Max.X
}
totalXWeight := 0.0
for kx := ix; kx < jx; kx++ {
xWeight := 0.0
if t := abs((sx - float64(kx)) * xKernelArgScale); t < q.Support {
xWeight = q.At(t)
}
xWeights[kx - ix] = xWeight
totalXWeight += xWeight
}
for x := range xWeights[:jx-ix] {
xWeights[x] /= totalXWeight
}
sy -= 0.5
iy := int(math.Floor(sy - yHalfWidth))
if iy < sr.Min.Y {
iy = sr.Min.Y
}
jy := int(math.Ceil(sy + yHalfWidth))
if jy > sr.Max.Y {
jy = sr.Max.Y
}
totalYWeight := 0.0
for ky := iy; ky < jy; ky++ {
yWeight := 0.0
if t := abs((sy - float64(ky)) * yKernelArgScale); t < q.Support {
yWeight = q.At(t)
}
yWeights[ky - iy] = yWeight
totalYWeight += yWeight
}
for y := range yWeights[:jy-iy] {
yWeights[y] /= totalYWeight
}
var pr, pg, pb, pa float64 $tweakVarP
for ky := iy; ky < jy; ky++ {
yWeight := yWeights[ky - iy]
for kx := ix; kx < jx; kx++ {
p += $srcf[kx, ky] * xWeights[kx - ix] * yWeight
}
}
$outputf[dr.Min.X + int(dx), dr.Min.Y + int(dy), fffftou, p, 1]
}
}
}
`
)