// 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.
// An *image.CMYK is also alwaysOpaque.
dsTypes = []struct{ dType, sType string }{
{"*image.RGBA", "*image.Gray"},
{"*image.RGBA", "*image.NRGBA"},
{"*image.RGBA", "*image.RGBA"},
{"*image.RGBA", "*image.YCbCr"},
{"*image.RGBA", "image.Image"},
{"Image", "image.Image"},
}
dTypes, sTypes []string
sTypesForDType = map[string][]string{}
subsampleRatios = []string{
"444",
"422",
"420",
"440",
}
ops = []string{"Over", "Src"}
// alwaysOpaque are those image.Image implementations that are always
// opaque. For these types, Over is equivalent to the faster Src, in the
// absence of a source mask.
alwaysOpaque = map[string]bool{
"*image.Gray": true,
"*image.YCbCr": true,
}
)
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
op string
}
func gen(w *bytes.Buffer, receiver string, codes ...string) {
expn(w, codeRoot, &data{receiver: receiver})
for _, code := range codes {
for _, t := range dsTypes {
for _, op := range ops {
if op == "Over" && alwaysOpaque[t.sType] {
continue
}
expn(w, code, &data{
dType: t.dType,
sType: t.sType,
receiver: receiver,
op: op,
})
}
}
}
}
func genKernel(w *bytes.Buffer) {
expn(w, codeKernelRoot, &data{})
for _, sType := range sTypes {
expn(w, codeKernelScaleLeafX, &data{
sType: sType,
})
}
for _, dType := range dTypes {
for _, op := range ops {
expn(w, codeKernelScaleLeafY, &data{
dType: dType,
op: op,
})
}
}
for _, t := range dsTypes {
for _, op := range ops {
if op == "Over" && alwaysOpaque[t.sType] {
continue
}
expn(w, codeKernelTransformLeaf, &data{
dType: t.dType,
sType: t.sType,
op: op,
})
}
}
}
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 "op":
return prefix + d.op + 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":
s := ""
if d.sType == "image.Image" {
s = "srcMask, smp := opts.SrcMask, opts.SrcMaskP\n"
}
return s +
"dstMask, dmp := opts.DstMask, opts.DstMaskP\n" +
"dstColorRGBA64 := &color.RGBA64{}\n" +
"dstColor := color.Color(dstColorRGBA64)"
}
case "preInner":
switch d.dType {
default:
return ";"
case "*image.RGBA":
return "d := " + pixOffset("dst", "dr.Min.X+adr.Min.X", "dr.Min.Y+int(dy)", "*4", "*dst.Stride")
}
case "preKernelOuter":
switch d.sType {
default:
return ";"
case "image.Image":
return "srcMask, smp := opts.SrcMask, opts.SrcMaskP"
}
case "preKernelInner":
switch d.dType {
default:
return ";"
case "*image.RGBA":
return "d := " + pixOffset("dst", "dr.Min.X+int(dx)", "dr.Min.Y+adr.Min.Y", "*4", "*dst.Stride")
}
case "blend":
args, _ := splitArgs(suffix)
if len(args) != 4 {
return ""
}
switch d.sType {
default:
return argf(args, ""+
"$3r = $0*$1r + $2*$3r\n"+
"$3g = $0*$1g + $2*$3g\n"+
"$3b = $0*$1b + $2*$3b\n"+
"$3a = $0*$1a + $2*$3a",
)
case "*image.Gray":
return argf(args, ""+
"$3r = $0*$1r + $2*$3r",
)
case "*image.YCbCr":
return argf(args, ""+
"$3r = $0*$1r + $2*$3r\n"+
"$3g = $0*$1g + $2*$3g\n"+
"$3b = $0*$1b + $2*$3b",
)
}
case "clampToAlpha":
if alwaysOpaque[d.sType] {
return ";"
}
// Go uses alpha-premultiplied color. The naive computation can lead to
// invalid colors, e.g. red > alpha, when some weights are negative.
return `
if pr > pa {
pr = pa
}
if pg > pa {
pg = pa
}
if pb > pa {
pb = pa
}
`
case "convFtou":
args, _ := splitArgs(suffix)
if len(args) != 2 {
return ""
}
switch d.sType {
default:
return argf(args, ""+
"$0r := uint32($1r)\n"+
"$0g := uint32($1g)\n"+
"$0b := uint32($1b)\n"+
"$0a := uint32($1a)",
)
case "*image.Gray":
return argf(args, ""+
"$0r := uint32($1r)",
)
case "*image.YCbCr":
return argf(args, ""+
"$0r := uint32($1r)\n"+
"$0g := uint32($1g)\n"+
"$0b := uint32($1b)",
)
}
case "outputu":
args, _ := splitArgs(suffix)
if len(args) != 3 {
return ""
}
switch d.op {
case "Over":
switch d.dType {
default:
log.Fatalf("bad dType %q", d.dType)
case "Image":
return argf(args, ""+
"qr, qg, qb, qa := dst.At($0, $1).RGBA()\n"+
"if dstMask != nil {\n"+
" _, _, _, ma := dstMask.At(dmp.X + $0, dmp.Y + $1).RGBA()\n"+
" $2r = $2r * ma / 0xffff\n"+
" $2g = $2g * ma / 0xffff\n"+
" $2b = $2b * ma / 0xffff\n"+
" $2a = $2a * ma / 0xffff\n"+
"}\n"+
"$2a1 := 0xffff - $2a\n"+
"dstColorRGBA64.R = uint16(qr*$2a1/0xffff + $2r)\n"+
"dstColorRGBA64.G = uint16(qg*$2a1/0xffff + $2g)\n"+
"dstColorRGBA64.B = uint16(qb*$2a1/0xffff + $2b)\n"+
"dstColorRGBA64.A = uint16(qa*$2a1/0xffff + $2a)\n"+
"dst.Set($0, $1, dstColor)",
)
case "*image.RGBA":
return argf(args, ""+
"$2a1 := (0xffff - $2a) * 0x101\n"+
"dst.Pix[d+0] = uint8((uint32(dst.Pix[d+0])*$2a1/0xffff + $2r) >> 8)\n"+
"dst.Pix[d+1] = uint8((uint32(dst.Pix[d+1])*$2a1/0xffff + $2g) >> 8)\n"+
"dst.Pix[d+2] = uint8((uint32(dst.Pix[d+2])*$2a1/0xffff + $2b) >> 8)\n"+
"dst.Pix[d+3] = uint8((uint32(dst.Pix[d+3])*$2a1/0xffff + $2a) >> 8)",
)
}
case "Src":
switch d.dType {
default:
log.Fatalf("bad dType %q", d.dType)
case "Image":
return argf(args, ""+
"if dstMask != nil {\n"+
" qr, qg, qb, qa := dst.At($0, $1).RGBA()\n"+
" _, _, _, ma := dstMask.At(dmp.X + $0, dmp.Y + $1).RGBA()\n"+
" pr = pr * ma / 0xffff\n"+
" pg = pg * ma / 0xffff\n"+
" pb = pb * ma / 0xffff\n"+
" pa = pa * ma / 0xffff\n"+
" $2a1 := 0xffff - ma\n"+ // Note that this is ma, not $2a.
" dstColorRGBA64.R = uint16(qr*$2a1/0xffff + $2r)\n"+
" dstColorRGBA64.G = uint16(qg*$2a1/0xffff + $2g)\n"+
" dstColorRGBA64.B = uint16(qb*$2a1/0xffff + $2b)\n"+
" dstColorRGBA64.A = uint16(qa*$2a1/0xffff + $2a)\n"+
" dst.Set($0, $1, dstColor)\n"+
"} else {\n"+
" dstColorRGBA64.R = uint16($2r)\n"+
" dstColorRGBA64.G = uint16($2g)\n"+
" dstColorRGBA64.B = uint16($2b)\n"+
" dstColorRGBA64.A = uint16($2a)\n"+
" dst.Set($0, $1, dstColor)\n"+
"}",
)
case "*image.RGBA":
switch d.sType {
default:
return argf(args, ""+
"dst.Pix[d+0] = uint8($2r >> 8)\n"+
"dst.Pix[d+1] = uint8($2g >> 8)\n"+
"dst.Pix[d+2] = uint8($2b >> 8)\n"+
"dst.Pix[d+3] = uint8($2a >> 8)",
)
case "*image.Gray":
return argf(args, ""+
"out := uint8($2r >> 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",
)
case "*image.YCbCr":
return argf(args, ""+
"dst.Pix[d+0] = uint8($2r >> 8)\n"+
"dst.Pix[d+1] = uint8($2g >> 8)\n"+
"dst.Pix[d+2] = uint8($2b >> 8)\n"+
"dst.Pix[d+3] = 0xff",
)
}
}
}
case "outputf":
args, _ := splitArgs(suffix)
if len(args) != 5 {
return ""
}
ret := ""
switch d.op {
case "Over":
switch d.dType {
default:
log.Fatalf("bad dType %q", d.dType)
case "Image":
ret = argf(args, ""+
"qr, qg, qb, qa := dst.At($0, $1).RGBA()\n"+
"$3r0 := uint32($2($3r * $4))\n"+
"$3g0 := uint32($2($3g * $4))\n"+
"$3b0 := uint32($2($3b * $4))\n"+
"$3a0 := uint32($2($3a * $4))\n"+
"if dstMask != nil {\n"+
" _, _, _, ma := dstMask.At(dmp.X + $0, dmp.Y + $1).RGBA()\n"+
" $3r0 = $3r0 * ma / 0xffff\n"+
" $3g0 = $3g0 * ma / 0xffff\n"+
" $3b0 = $3b0 * ma / 0xffff\n"+
" $3a0 = $3a0 * ma / 0xffff\n"+
"}\n"+
"$3a1 := 0xffff - $3a0\n"+
"dstColorRGBA64.R = uint16(qr*$3a1/0xffff + $3r0)\n"+
"dstColorRGBA64.G = uint16(qg*$3a1/0xffff + $3g0)\n"+
"dstColorRGBA64.B = uint16(qb*$3a1/0xffff + $3b0)\n"+
"dstColorRGBA64.A = uint16(qa*$3a1/0xffff + $3a0)\n"+
"dst.Set($0, $1, dstColor)",
)
case "*image.RGBA":
ret = argf(args, ""+
"$3r0 := uint32($2($3r * $4))\n"+
"$3g0 := uint32($2($3g * $4))\n"+
"$3b0 := uint32($2($3b * $4))\n"+
"$3a0 := uint32($2($3a * $4))\n"+
"$3a1 := (0xffff - uint32($3a0)) * 0x101\n"+
"dst.Pix[d+0] = uint8((uint32(dst.Pix[d+0])*$3a1/0xffff + $3r0) >> 8)\n"+
"dst.Pix[d+1] = uint8((uint32(dst.Pix[d+1])*$3a1/0xffff + $3g0) >> 8)\n"+
"dst.Pix[d+2] = uint8((uint32(dst.Pix[d+2])*$3a1/0xffff + $3b0) >> 8)\n"+
"dst.Pix[d+3] = uint8((uint32(dst.Pix[d+3])*$3a1/0xffff + $3a0) >> 8)",
)
}
case "Src":
switch d.dType {
default:
log.Fatalf("bad dType %q", d.dType)
case "Image":
ret = argf(args, ""+
"if dstMask != nil {\n"+
" qr, qg, qb, qa := dst.At($0, $1).RGBA()\n"+
" _, _, _, ma := dstMask.At(dmp.X + $0, dmp.Y + $1).RGBA()\n"+
" pr := uint32($2($3r * $4)) * ma / 0xffff\n"+
" pg := uint32($2($3g * $4)) * ma / 0xffff\n"+
" pb := uint32($2($3b * $4)) * ma / 0xffff\n"+
" pa := uint32($2($3a * $4)) * ma / 0xffff\n"+
" pa1 := 0xffff - ma\n"+ // Note that this is ma, not pa.
" dstColorRGBA64.R = uint16(qr*pa1/0xffff + pr)\n"+
" dstColorRGBA64.G = uint16(qg*pa1/0xffff + pg)\n"+
" dstColorRGBA64.B = uint16(qb*pa1/0xffff + pb)\n"+
" dstColorRGBA64.A = uint16(qa*pa1/0xffff + pa)\n"+
" dst.Set($0, $1, dstColor)\n"+
"} else {\n"+
" dstColorRGBA64.R = $2($3r * $4)\n"+
" dstColorRGBA64.G = $2($3g * $4)\n"+
" dstColorRGBA64.B = $2($3b * $4)\n"+
" dstColorRGBA64.A = $2($3a * $4)\n"+
" dst.Set($0, $1, dstColor)\n"+
"}",
)
case "*image.RGBA":
switch d.sType {
default:
ret = argf(args, ""+
"dst.Pix[d+0] = uint8($2($3r * $4) >> 8)\n"+
"dst.Pix[d+1] = uint8($2($3g * $4) >> 8)\n"+
"dst.Pix[d+2] = uint8($2($3b * $4) >> 8)\n"+
"dst.Pix[d+3] = uint8($2($3a * $4) >> 8)",
)
case "*image.Gray":
ret = argf(args, ""+
"out := uint8($2($3r * $4) >> 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",
)
case "*image.YCbCr":
ret = argf(args, ""+
"dst.Pix[d+0] = uint8($2($3r * $4) >> 8)\n"+
"dst.Pix[d+1] = uint8($2($3g * $4) >> 8)\n"+
"dst.Pix[d+2] = uint8($2($3b * $4) >> 8)\n"+
"dst.Pix[d+3] = 0xff",
)
}
}
}
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"
}
// TODO: there's no need to multiply by 0x101 in the switch below if
// the next thing we're going to do is shift right by 8.
buf := new(bytes.Buffer)
switch d.sType {
default:
log.Fatalf("bad sType %q", d.sType)
case "image.Image":
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],
)
if d.dType == "" || d.dType == "Image" {
fmt.Fprintf(buf, ""+
"if srcMask != nil {\n"+
" _, _, _, ma := srcMask.At(smp.X+%s, smp.Y+%s).RGBA()\n"+
" %sr%s = %sr%s * ma / 0xffff\n"+
" %sg%s = %sg%s * ma / 0xffff\n"+
" %sb%s = %sb%s * ma / 0xffff\n"+
" %sa%s = %sa%s * ma / 0xffff\n"+
"}\n",
args[0], args[1],
lhs, tmp, lhs, tmp,
lhs, tmp, lhs, tmp,
lhs, tmp, lhs, tmp,
lhs, tmp, lhs, tmp,
)
}
case "*image.Gray":
fmt.Fprintf(buf, ""+
"%si := %s\n"+
"%sr%s := uint32(src.Pix[%si]) * 0x101\n",
lhs, pixOffset("src", args[0], args[1], "", "*src.Stride"),
lhs, tmp, lhs,
)
case "*image.NRGBA":
fmt.Fprintf(buf, ""+
"%si := %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, pixOffset("src", args[0], args[1], "*4", "*src.Stride"),
lhs, tmp, lhs,
lhs, tmp, lhs, lhs, tmp,
lhs, tmp, lhs, lhs, tmp,
lhs, tmp, lhs, lhs, tmp,
)
case "*image.RGBA":
fmt.Fprintf(buf, ""+
"%si := %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, pixOffset("src", args[0], args[1], "*4", "*src.Stride"),
lhs, tmp, lhs,
lhs, tmp, lhs,
lhs, tmp, lhs,
lhs, tmp, lhs,
)
case "*image.YCbCr":
fmt.Fprintf(buf, ""+
"%si := %s\n"+
"%sj := %s\n"+
"%s\n",
lhs, pixOffset("src", args[0], args[1], "", "*src.YStride"),
lhs, cOffset(args[0], args[1], d.sratio),
ycbcrToRGB(lhs, tmp),
)
}
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,
)
case "*image.YCbCr":
fmt.Fprintf(buf, ""+
"%sr %s float64(%sru)%s\n"+
"%sg %s float64(%sgu)%s\n"+
"%sb %s float64(%sbu)%s\n",
lhs, eqOp, lhs, extra,
lhs, eqOp, lhs, extra,
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":
switch d.sType {
case "*image.Gray":
if strings.HasPrefix(strings.TrimSpace(prefix), "pa * ") {
return "1,"
}
return "pr,"
case "*image.YCbCr":
if strings.HasPrefix(strings.TrimSpace(prefix), "pa * ") {
return "1,"
}
}
return prefix
case "tweakPr":
if d.sType == "*image.Gray" {
return "pr *= s.invTotalWeightFFFF"
}
return ";"
case "tweakVarP":
switch d.sType {
case "*image.Gray":
return strings.Replace(prefix, "var pr, pg, pb, pa", "var pr", 1)
case "*image.YCbCr":
return strings.Replace(prefix, "var pr, pg, pb, pa", "var pr, pg, pb", 1)
}
return prefix
}
return ""
}
func expnSwitch(op, dType string, expandBoth bool, template string) string {
if op == "" && dType != "anyDType" {
lines := []string{"switch op {"}
for _, op = range ops {
lines = append(lines,
fmt.Sprintf("case %s:", op),
expnSwitch(op, dType, expandBoth, template),
)
}
lines = append(lines, "}")
return strings.Join(lines, "\n")
}
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 dType != "" {
// v is the sType. Skip those always-opaque sTypes, where Over is
// equivalent to Src.
if op == "Over" && alwaysOpaque[v] {
continue
}
}
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(op, dType, template))
} else {
lines = append(lines, expnLine(template, &data{dType: dType, sType: v, op: op}))
}
} else if !expandBoth {
lines = append(lines, expnLine(template, &data{dType: v, op: op}))
} else {
lines = append(lines, expnSwitch(op, v, false, template))
}
}
lines = append(lines, "}")
return strings.Join(lines, "\n")
}
func expnSwitchYCbCr(op, dType, template string) string {
lines := []string{
"switch src.SubsampleRatio {",
"default:",
expnLine(template, &data{dType: dType, sType: "image.Image", op: op}),
}
for _, sratio := range subsampleRatios {
lines = append(lines,
fmt.Sprintf("case image.YCbCrSubsampleRatio%s:", sratio),
expnLine(template, &data{dType: dType, sType: "*image.YCbCr", sratio: sratio, op: op}),
)
}
lines = append(lines, "}")
return strings.Join(lines, "\n")
}
func argf(args []string, s string) string {
if len(args) > 9 {
panic("too many args")
}
for i, a := range args {
old := fmt.Sprintf("$%d", i)
s = strings.Replace(s, old, a, -1)
}
return s
}
func pixOffset(m, x, y, xstride, ystride string) string {
return fmt.Sprintf("(%s-%s.Rect.Min.Y)%s + (%s-%s.Rect.Min.X)%s", y, m, ystride, x, m, xstride)
}
func cOffset(x, y, sratio string) string {
switch sratio {
case "444":
return fmt.Sprintf("( %s - src.Rect.Min.Y )*src.CStride + ( %s - src.Rect.Min.X )", y, x)
case "422":
return fmt.Sprintf("( %s - src.Rect.Min.Y )*src.CStride + ((%s)/2 - src.Rect.Min.X/2)", y, x)
case "420":
return fmt.Sprintf("((%s)/2 - src.Rect.Min.Y/2)*src.CStride + ((%s)/2 - src.Rect.Min.X/2)", y, x)
case "440":
return fmt.Sprintf("((%s)/2 - src.Rect.Min.Y/2)*src.CStride + ( %s - src.Rect.Min.X )", y, x)
}
return fmt.Sprintf("unsupported sratio %q", sratio)
}
func ycbcrToRGB(lhs, tmp string) string {
s := `
// This is an inline version of image/color/ycbcr.go's YCbCr.RGBA method.
$yy1 := int(src.Y[$i]) * 0x10101
$cb1 := int(src.Cb[$j]) - 128
$cr1 := int(src.Cr[$j]) - 128
$r@ := ($yy1 + 91881*$cr1) >> 8
$g@ := ($yy1 - 22554*$cb1 - 46802*$cr1) >> 8
$b@ := ($yy1 + 116130*$cb1) >> 8
if $r@ < 0 {
$r@ = 0
} else if $r@ > 0xffff {
$r@ = 0xffff
}
if $g@ < 0 {
$g@ = 0
} else if $g@ > 0xffff {
$g@ = 0xffff
}
if $b@ < 0 {
$b@ = 0
} else if $b@ > 0xffff {
$b@ = 0xffff
}
`
s = strings.Replace(s, "$", lhs, -1)
s = strings.Replace(s, "@", tmp, -1)
return s
}
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, op Op, opts *Options) {
// Try to simplify a Scale to a Copy when DstMask is not specified.
// If DstMask is not nil, Copy will call Scale back with same dr and sr, and cause stack overflow.
if dr.Size() == sr.Size() && (opts == nil || opts.DstMask == nil) {
Copy(dst, dr.Min, src, sr, op, opts)
return
}
var o Options
if opts != nil {
o = *opts
}
// adr is the affected destination pixels.
adr := dst.Bounds().Intersect(dr)
adr, o.DstMask = clipAffectedDestRect(adr, o.DstMask, o.DstMaskP)
if adr.Empty() || sr.Empty() {
return
}
// Make adr relative to dr.Min.
adr = adr.Sub(dr.Min)
if op == Over && o.SrcMask == nil && opaque(src) {
op = Src
}
// 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.
//
// Similarly, the fast paths assume that the masks are nil.
if o.DstMask != nil || o.SrcMask != nil || !sr.In(src.Bounds()) {
switch op {
case Over:
z.scale_Image_Image_Over(dst, dr, adr, src, sr, &o)
case Src:
z.scale_Image_Image_Src(dst, dr, adr, src, sr, &o)
}
} else if _, ok := src.(*image.Uniform); ok {
Draw(dst, dr, src, src.Bounds().Min, op)
} else {
$switch z.scale_$dTypeRN_$sTypeRN$sratio_$op(dst, dr, adr, src, sr, &o)
}
}
func (z $receiver) Transform(dst Image, s2d f64.Aff3, src image.Image, sr image.Rectangle, op Op, opts *Options) {
// Try to simplify a Transform to a Copy.
if s2d[0] == 1 && s2d[1] == 0 && s2d[3] == 0 && s2d[4] == 1 {
dx := int(s2d[2])
dy := int(s2d[5])
if float64(dx) == s2d[2] && float64(dy) == s2d[5] {
Copy(dst, image.Point{X: sr.Min.X + dx, Y: sr.Min.X + dy}, src, sr, op, opts)
return
}
}
var o Options
if opts != nil {
o = *opts
}
dr := transformRect(&s2d, &sr)
// adr is the affected destination pixels.
adr := dst.Bounds().Intersect(dr)
adr, o.DstMask = clipAffectedDestRect(adr, o.DstMask, o.DstMaskP)
if adr.Empty() || sr.Empty() {
return
}
if op == Over && o.SrcMask == nil && opaque(src) {
op = Src
}
d2s := invert(&s2d)
// bias is a translation of the mapping from dst coordinates to src
// coordinates such that the latter temporarily have non-negative X
// and Y coordinates. This allows us to write int(f) instead of
// int(math.Floor(f)), since "round to zero" and "round down" are
// equivalent when f >= 0, but the former is much cheaper. The X--
// and Y-- are because the TransformLeaf methods have a "sx -= 0.5"
// adjustment.
bias := transformRect(&d2s, &adr).Min
bias.X--
bias.Y--
d2s[2] -= float64(bias.X)
d2s[5] -= float64(bias.Y)
// Make adr relative to dr.Min.
adr = adr.Sub(dr.Min)
// 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.
//
// Similarly, the fast paths assume that the masks are nil.
if o.DstMask != nil || o.SrcMask != nil || !sr.In(src.Bounds()) {
switch op {
case Over:
z.transform_Image_Image_Over(dst, dr, adr, &d2s, src, sr, bias, &o)
case Src:
z.transform_Image_Image_Src(dst, dr, adr, &d2s, src, sr, bias, &o)
}
} else if u, ok := src.(*image.Uniform); ok {
transform_Uniform(dst, dr, adr, &d2s, u, sr, bias, op)
} else {
$switch z.transform_$dTypeRN_$sTypeRN$sratio_$op(dst, dr, adr, &d2s, src, sr, bias, &o)
}
}
`
codeNNScaleLeaf = `
func (nnInterpolator) scale_$dTypeRN_$sTypeRN$sratio_$op(dst $dType, dr, adr image.Rectangle, src $sType, sr image.Rectangle, opts *Options) {
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_$op(dst $dType, dr, adr image.Rectangle, d2s *f64.Aff3, src $sType, sr image.Rectangle, bias image.Point, opts *Options) {
$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
sx0 := int(d2s[0]*dxf + d2s[1]*dyf + d2s[2]) + bias.X
sy0 := int(d2s[3]*dxf + d2s[4]*dyf + d2s[5]) + bias.Y
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_$op(dst $dType, dr, adr image.Rectangle, src $sType, sr image.Rectangle, opts *Options) {
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]
$convFtou[p, s11]
$outputu[dr.Min.X + int(dx), dr.Min.Y + int(dy), p]
}
}
}
`
codeABLTransformLeaf = `
func (ablInterpolator) transform_$dTypeRN_$sTypeRN$sratio_$op(dst $dType, dr, adr image.Rectangle, d2s *f64.Aff3, src $sType, sr image.Rectangle, bias image.Point, opts *Options) {
$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
sx := d2s[0]*dxf + d2s[1]*dyf + d2s[2]
sy := d2s[3]*dxf + d2s[4]*dyf + d2s[5]
if !(image.Point{int(sx) + bias.X, int(sy) + bias.Y}).In(sr) {
continue
}
sx -= 0.5
sx0 := int(sx)
xFrac0 := sx - float64(sx0)
xFrac1 := 1 - xFrac0
sx0 += bias.X
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
sy0 := int(sy)
yFrac0 := sy - float64(sy0)
yFrac1 := 1 - yFrac0
sy0 += bias.Y
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]
$convFtou[p, s11]
$outputu[dr.Min.X + int(dx), dr.Min.Y + int(dy), p]
}
}
}
`
codeKernelRoot = `
func (z *kernelScaler) Scale(dst Image, dr image.Rectangle, src image.Image, sr image.Rectangle, op Op, 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, op, opts)
return
}
var o Options
if opts != nil {
o = *opts
}
// adr is the affected destination pixels.
adr := dst.Bounds().Intersect(dr)
adr, o.DstMask = clipAffectedDestRect(adr, o.DstMask, o.DstMaskP)
if adr.Empty() || sr.Empty() {
return
}
// Make adr relative to dr.Min.
adr = adr.Sub(dr.Min)
if op == Over && o.SrcMask == nil && opaque(src) {
op = Src
}
if _, ok := src.(*image.Uniform); ok && o.DstMask == nil && o.SrcMask == nil && sr.In(src.Bounds()) {
Draw(dst, dr, src, src.Bounds().Min, op)
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.
var tmp [][4]float64
if z.pool.New != nil {
tmpp := z.pool.Get().(*[][4]float64)
defer z.pool.Put(tmpp)
tmp = *tmpp
} else {
tmp = z.makeTmpBuf()
}
// 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.
//
// Similarly, the fast paths assume that the masks are nil.
if o.SrcMask != nil || !sr.In(src.Bounds()) {
z.scaleX_Image(tmp, src, sr, &o)
} else {
$switchS z.scaleX_$sTypeRN$sratio(tmp, src, sr, &o)
}
if o.DstMask != nil {
switch op {
case Over:
z.scaleY_Image_Over(dst, dr, adr, tmp, &o)
case Src:
z.scaleY_Image_Src(dst, dr, adr, tmp, &o)
}
} else {
$switchD z.scaleY_$dTypeRN_$op(dst, dr, adr, tmp, &o)
}
}
func (q *Kernel) Transform(dst Image, s2d f64.Aff3, src image.Image, sr image.Rectangle, op Op, opts *Options) {
var o Options
if opts != nil {
o = *opts
}
dr := transformRect(&s2d, &sr)
// adr is the affected destination pixels.
adr := dst.Bounds().Intersect(dr)
adr, o.DstMask = clipAffectedDestRect(adr, o.DstMask, o.DstMaskP)
if adr.Empty() || sr.Empty() {
return
}
if op == Over && o.SrcMask == nil && opaque(src) {
op = Src
}
d2s := invert(&s2d)
// bias is a translation of the mapping from dst coordinates to src
// coordinates such that the latter temporarily have non-negative X
// and Y coordinates. This allows us to write int(f) instead of
// int(math.Floor(f)), since "round to zero" and "round down" are
// equivalent when f >= 0, but the former is much cheaper. The X--
// and Y-- are because the TransformLeaf methods have a "sx -= 0.5"
// adjustment.
bias := transformRect(&d2s, &adr).Min
bias.X--
bias.Y--
d2s[2] -= float64(bias.X)
d2s[5] -= float64(bias.Y)
// Make adr relative to dr.Min.
adr = adr.Sub(dr.Min)
if u, ok := src.(*image.Uniform); ok && o.DstMask != nil && o.SrcMask != nil && sr.In(src.Bounds()) {
transform_Uniform(dst, dr, adr, &d2s, u, sr, bias, op)
return
}
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.
//
// Similarly, the fast paths assume that the masks are nil.
if o.DstMask != nil || o.SrcMask != nil || !sr.In(src.Bounds()) {
switch op {
case Over:
q.transform_Image_Image_Over(dst, dr, adr, &d2s, src, sr, bias, xscale, yscale, &o)
case Src:
q.transform_Image_Image_Src(dst, dr, adr, &d2s, src, sr, bias, xscale, yscale, &o)
}
} else {
$switch q.transform_$dTypeRN_$sTypeRN$sratio_$op(dst, dr, adr, &d2s, src, sr, bias, xscale, yscale, &o)
}
}
`
codeKernelScaleLeafX = `
func (z *kernelScaler) scaleX_$sTypeRN$sratio(tmp [][4]float64, src $sType, sr image.Rectangle, opts *Options) {
t := 0
$preKernelOuter
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_$op(dst $dType, dr, adr image.Rectangle, tmp [][4]float64, opts *Options) {
$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
}
$clampToAlpha
$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_$op(dst $dType, dr, adr image.Rectangle, d2s *f64.Aff3, src $sType, sr image.Rectangle, bias image.Point, xscale, yscale float64, opts *Options) {
// 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
sx := d2s[0]*dxf + d2s[1]*dyf + d2s[2]
sy := d2s[3]*dxf + d2s[4]*dyf + d2s[5]
if !(image.Point{int(sx) + bias.X, int(sy) + bias.Y}).In(sr) {
continue
}
// TODO: adjust the bias so that we can use int(f) instead
// of math.Floor(f) and math.Ceil(f).
sx += float64(bias.X)
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 += float64(bias.Y)
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++ {
if yWeight := yWeights[ky - iy]; yWeight != 0 {
for kx := ix; kx < jx; kx++ {
if w := xWeights[kx - ix] * yWeight; w != 0 {
p += $srcf[kx, ky] * w
}
}
}
}
$clampToAlpha
$outputf[dr.Min.X + int(dx), dr.Min.Y + int(dy), fffftou, p, 1]
}
}
}
`
)
