From 500caaeda74dd9c660279036293f4b2997cf0b03 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Sat, 9 Sep 2017 09:42:37 +0200 Subject: Add vendor --- vendor/golang.org/x/image/draw/gen.go | 1403 +++++++++++++++++++++++++++++++++ 1 file changed, 1403 insertions(+) create mode 100644 vendor/golang.org/x/image/draw/gen.go (limited to 'vendor/golang.org/x/image/draw/gen.go') diff --git a/vendor/golang.org/x/image/draw/gen.go b/vendor/golang.org/x/image/draw/gen.go new file mode 100644 index 0000000..65a7123 --- /dev/null +++ b/vendor/golang.org/x/image/draw/gen.go @@ -0,0 +1,1403 @@ +// 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. + if dr.Size() == sr.Size() { + 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] + } + } + } + ` +) -- cgit v1.2.3