Revert "blend: improve precision"

This reverts commit 8b3adf4.
oov · Nov 14, 2018 · d45a460 · d45a460
1 parent 57e427b
commit d45a460
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Showing 9 changed files with 67,583 additions and 46 deletions.
diff --git a/blend/decl_amd64.go b/blend/decl_amd64.go
@@ -0,0 +1,7 @@
+package blend
+
+func drawNormalNRGBAToNRGBAFast(dest []byte, src []byte, alpha uint32, d0, s0, y int, sx0 int, sx1 int, sxDelta int, syDelta int, dx0 int, dx1 int, dxDelta int, dyDelta int)
+
+func init() {
+	drawNormalNRGBAToNRGBA = drawNormalNRGBAToNRGBAFast
+}
diff --git a/blend/genblend.go b/blend/genblend.go
@@ -473,6 +473,59 @@ func (d {{.Name.Lower}}) drawRGBAToRGBAUniform(dst *image.RGBA, r image.Rectangl
 }
 
 var draw{{.Name}}NRGBAToNRGBA drawFunc = func(dest []byte, src []byte, alpha uint32, d0, s0, y int, sx0 int, sx1 int, sxDelta int, syDelta int, dx0 int, dx1 int, dxDelta int, dyDelta int) {
+	alpha *= 32897
+	for ; y > 0; y-- {
+		dpix := dest[d0:]
+		spix := src[s0:]
+		for i, j := sx0, dx0; i != sx1; i, j = i+sxDelta, j+dxDelta {
+			sa := uint32(spix[i+3])
+			sb := uint32(spix[i+2])
+			sg := uint32(spix[i+1])
+			sr := uint32(spix[i])
+			tmp := (sa * alpha >> 23) * 32897
+			if tmp == 0 {
+				continue
+			}
+			da := uint32(dpix[j+3])
+			db := uint32(dpix[j+2])
+			dg := uint32(dpix[j+1])
+			dr := uint32(dpix[j])
+			a1 := (tmp * da) >> 23
+			a2 := (tmp * (255 - da)) >> 23
+			a3 := ((8388735 - tmp) * da) >> 23
+			a := a1 + a2 + a3
+			if a == 0 {
+				continue
+			}
+			var r, g, b uint32
+			{{if .CodePerChannel}}
+				{{.CodePerChannel.To8.Channel "r"}}
+				{{.CodePerChannel.To8.Channel "g"}}
+				{{.CodePerChannel.To8.Channel "b"}}
+			{{else if .Code}}
+				{{.Code.To8}}
+			{{else if .CodePerChannel16}}
+				{{.CodePerChannel16.To8.Channel "r"}}
+				{{.CodePerChannel16.To8.Channel "g"}}
+				{{.CodePerChannel16.To8.Channel "b"}}
+			{{else if .Code16}}
+				{{.Code16.To8}}
+			{{end}}
+			{{if .OverMax}}
+				dpix[j+3] = uint8(a)
+				dpix[j+2] = uint8(clip8((b*a1 + sb*a2 + db*a3) / a))
+				dpix[j+1] = uint8(clip8((g*a1 + sg*a2 + dg*a3) / a))
+				dpix[j+0] = uint8(clip8((r*a1 + sr*a2 + dr*a3) / a))
+			{{else}}
+				dpix[j+3] = uint8(a)
+				dpix[j+2] = uint8((b*a1 + sb*a2 + db*a3) / a)
+				dpix[j+1] = uint8((g*a1 + sg*a2 + dg*a3) / a)
+				dpix[j+0] = uint8((r*a1 + sr*a2 + dr*a3) / a)
+			{{end}}
+		}
+		d0 += dyDelta
+		s0 += syDelta
+	}
 {{define "drawMain1"}}
 	alpha *= 0x0101
 	for ; y > 0; y-- {
@@ -571,10 +624,10 @@ var draw{{.Name}}NRGBAToNRGBA drawFunc = func(dest []byte, src []byte, alpha uin
 		s0 += syDelta
 	}
 {{end}}
-	{{template "drawMain1" .}}
-	{{template "drawMain2" .}}
-	{{template "drawMain2_SetNRGBA" .}}
-	{{template "drawMain3" .}}
+{{template "drawMain1" .}}
+{{template "drawMain2" .}}
+{{template "drawMain2_SetNRGBA" .}}
+{{template "drawMain3" .}}
 }
 
 var draw{{.Name}}RGBAToNRGBA drawFunc = func(dest []byte, src []byte, alpha uint32, d0, s0, y int, sx0 int, sx1 int, sxDelta int, syDelta int, dx0 int, dx1 int, dxDelta int, dyDelta int) {

diff --git a/blend/gendivtable.go b/blend/gendivtable.go
@@ -0,0 +1,47 @@
+// +build ignore
+
+package main
+
+import (
+	"bytes"
+	"go/format"
+	"html/template"
+	"log"
+	"os"
+)
+
+var source = `// Code generated by gendivtable.go. DO NOT EDIT.
+
+package blend
+
+var divTable = [256]uint32{
+	{{range $i, $v := .N}}{{printf "0x%08x, // %d\n" $v $i}}{{end}}}
+`
+
+func main() {
+	t := template.Must(template.New("").Parse(source))
+
+	n := make([]int64, 256)
+	for i := int64(1); i < 256; i++ {
+		n[i] = 0xffffffff / i
+	}
+
+	b := bytes.NewBufferString("")
+	if err := t.Execute(b, map[string]interface{}{
+		"N": n,
+	}); err != nil {
+		log.Fatal(err)
+	}
+	buf, err := format.Source(b.Bytes())
+	if err != nil {
+		log.Fatal(err)
+	}
+	f, err := os.Create("zdivtable.go")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer f.Close()
+	if _, err = f.Write(buf); err != nil {
+		log.Fatal(err)
+	}
+}
diff --git a/blend/genrgba2nrgba.go b/blend/genrgba2nrgba.go
@@ -0,0 +1,49 @@
+// +build ignore
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"go/format"
+	"html/template"
+	"log"
+	"os"
+)
+
+var source = `// Code generated by genrgba2nrgba.go. DO NOT EDIT.
+package blend
+var rgbaToNRGBATable = [65536]uint16{
+	{{range $i, $v := .N}}{{printf "%s\n" $v}}{{end}}}
+`
+
+func main() {
+	t := template.Must(template.New("").Parse(source))
+
+	n := make([]string, 65536)
+	for i := 0; i < 256; i++ {
+		n[i<<8] = fmt.Sprintf("0, // %d * 255 / 0", i)
+		for j := 1; j < 256; j++ {
+			n[(i<<8)+j] = fmt.Sprintf("%d, // %d * 255 / %d", i*255/j, i, j)
+		}
+	}
+
+	b := bytes.NewBufferString("")
+	if err := t.Execute(b, map[string]interface{}{
+		"N": n,
+	}); err != nil {
+		log.Fatal(err)
+	}
+	buf, err := format.Source(b.Bytes())
+	if err != nil {
+		log.Fatal(err)
+	}
+	f, err := os.Create("zrgba2nrgbatable.go")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer f.Close()
+	if _, err = f.Write(buf); err != nil {
+		log.Fatal(err)
+	}
+}
diff --git a/blend/normal_amd64.s b/blend/normal_amd64.s
@@ -0,0 +1,139 @@
+#include "textflag.h"
+
+TEXT	·drawNormalNRGBAToNRGBAFast(SB),0,$0-144
+   MOVL alpha+48(FP), AX
+   IMULL $0x00008081, AX
+   MOVL AX, alpha+48(FP)
+
+   MOVQ src+24(FP), SI
+   ADDQ s0+64(FP), SI
+   MOVQ dest+0(FP), DI
+   ADDQ d0+56(FP), DI
+   MOVQ y+72(FP), BX
+
+   MOVQ dyDelta+136(FP), R12
+   MOVQ syDelta+104(FP), R13
+   MOVQ sxDelta+96(FP), R14
+
+   MOVQ $0x0000808180818081, AX
+   MOVQ AX, X14
+
+   PXOR X15, X15
+
+LOOPY:
+   MOVQ sx0+80(FP), R15
+
+   LOOPX:
+      MOVL (SI)(R15*1), AX
+      SHRL $24, AX
+      CMPB AX, $0
+      JZ NEXTX
+
+      ANDQ $0xff, AX
+      MULL alpha+48(FP)
+      SHRQ $23, AX
+      CMPB AX, $0
+      JZ NEXTX
+
+      MOVL AX, X0
+      MOVL (DI)(R15*1), X1
+      PSRLDQ $3, X1
+      MOVQ $0xff, AX
+      MOVQ AX, X2
+
+      PUNPCKLBW X0, X0
+      PUNPCKLWL X0, X0 // sa sa sa sa
+      PXOR X2, X0 // sa sa sa 255-sa
+
+      PUNPCKLBW X1, X1
+      PUNPCKLWL X1, X1 // da da da da
+      PSLLDQ $1, X2
+      PXOR X2, X1 // 00 da 255-da da
+
+      PUNPCKLBW X15, X0
+      PUNPCKLBW X15, X1
+      PMULLW X1, X0
+
+      MOVL (SI)(R15*1), X2 // sa sr sg sb
+      MOVL (DI)(R15*1), X3 // da dr dg db
+      MOVOA X2, X4 // 00  r  g  b
+
+      PMULHUW X14, X0
+
+      PUNPCKLBW  X2, X3 // sa da sr dr sg dg sb db
+      PUNPCKLBW X15, X4 // 00 00 00  r 00  g 00  b
+      PUNPCKLWL  X4, X3 // 00 00 sa da 00  r sr dr 00  g sg dg 00  b sb db
+      MOVOA X3, X2
+      PSRLDQ $8, X2
+
+      PSRLW $7, X0 // 0000 sa*da/255 sa*(255-da)/255 (255-sa)*da/255
+
+      MOVOA X0, X1
+      MOVOA X0, X5
+      PSRLDQ $2, X5
+      PADDW X5, X1
+      PSRLDQ $2, X5
+      PADDW X5, X1 // a
+
+      PUNPCKLBW X15, X2 // 00 00 00 00 00 sa 00 da 00 00 00  r 00 sr 00 dr
+      PUNPCKLBW X15, X3 // 00 00 00  g 00 sg 00 dg 00 00 00  b 00 sb 00 db
+      PUNPCKLQDQ X0, X0
+      PMULLW X0, X2
+      PMULLW X0, X3
+
+      MOVOA X2, X0
+      PSRLDQ $2, X0
+      PADDW X0, X2
+      PSRLDQ $2, X0
+      PADDW X0, X2 // 00 00 00 00 00 sa 00 da 00 00 00  r
+
+      MOVOA X3, X0
+      PSRLDQ $2, X0
+      PADDW X0, X3
+      PSRLDQ $2, X0
+      PADDW X0, X3 // 00 00 00  g 00 sg 00 dg 00 00 00  b
+
+      MOVQ $0xffff, AX
+      MOVQ AX, X5
+      INCL AX
+      MOVQ AX, X4
+      PAND X5, X1
+      MOVL X1, DX
+      CMPL DX, $2
+      JB DIVEND
+      LEAQ ·divTable(SB), AX
+      MOVL (AX)(DX*4), X0
+
+      PUNPCKLQDQ X0, X0
+      PUNPCKLQDQ X4, X4
+      PUNPCKLQDQ X5, X5
+
+      PAND X5, X2
+      PMULDQ X0, X2
+      PADDQ X4, X2
+      PSRLDQ $4, X2
+
+      PAND X5, X3
+      PMULDQ X0, X3
+      PADDQ X4, X3
+      PSRLDQ $4, X3
+
+      DIVEND:
+      MOVOA X3, X4
+      PSRLDQ $8, X3
+
+      PUNPCKLBW  X3, X4 // g b
+      PUNPCKLBW  X1, X2 // a r
+      PUNPCKLWL  X2, X4 // a r g b
+      MOVL X4, (DI)(R15*1)
+
+      NEXTX:
+      ADDQ R14, R15
+      CMPQ R15, sx1+88(FP)
+      JNE LOOPX
+
+   ADDQ R12, DI
+   ADDQ R13, SI
+   DECQ BX
+   JNZ LOOPY
+   RET
diff --git a/blend/util.go b/blend/util.go
@@ -1,3 +1,5 @@
+//go:generate go run gendivtable.go
+//go:generate go run genrgba2nrgba.go
 //go:generate go run genblend.go
 //go:generate go run genporterduff.go