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fixed dependencies

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This commit is contained in:
nuknal
2024-10-24 15:46:01 +08:00
parent d16a5bd9c0
commit 1161e8d054
2005 changed files with 690883 additions and 0 deletions
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29
vendor/golang.org/x/image/vector/acc_amd64.go generated vendored Normal file
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// Copyright 2016 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.
//go:build !appengine && gc && !noasm
package vector
func haveSSE4_1() bool
var haveAccumulateSIMD = haveSSE4_1()
//go:noescape
func fixedAccumulateOpOverSIMD(dst []uint8, src []uint32)
//go:noescape
func fixedAccumulateOpSrcSIMD(dst []uint8, src []uint32)
//go:noescape
func fixedAccumulateMaskSIMD(buf []uint32)
//go:noescape
func floatingAccumulateOpOverSIMD(dst []uint8, src []float32)
//go:noescape
func floatingAccumulateOpSrcSIMD(dst []uint8, src []float32)
//go:noescape
func floatingAccumulateMaskSIMD(dst []uint32, src []float32)

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vendor/golang.org/x/image/vector/acc_amd64.s generated vendored Normal file
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vendor/golang.org/x/image/vector/acc_other.go generated vendored Normal file
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// Copyright 2016 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.
//go:build !amd64 || appengine || !gc || noasm
package vector
const haveAccumulateSIMD = false
func fixedAccumulateOpOverSIMD(dst []uint8, src []uint32) {}
func fixedAccumulateOpSrcSIMD(dst []uint8, src []uint32) {}
func fixedAccumulateMaskSIMD(buf []uint32) {}
func floatingAccumulateOpOverSIMD(dst []uint8, src []float32) {}
func floatingAccumulateOpSrcSIMD(dst []uint8, src []float32) {}
func floatingAccumulateMaskSIMD(dst []uint32, src []float32) {}

170
vendor/golang.org/x/image/vector/gen_acc_amd64.s.tmpl generated vendored Normal file
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// Copyright 2016 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 !appengine
// +build gc
// +build !noasm
#include "textflag.h"
// fl is short for floating point math. fx is short for fixed point math.
DATA flAlmost65536<>+0x00(SB)/8, $0x477fffff477fffff
DATA flAlmost65536<>+0x08(SB)/8, $0x477fffff477fffff
DATA flOne<>+0x00(SB)/8, $0x3f8000003f800000
DATA flOne<>+0x08(SB)/8, $0x3f8000003f800000
DATA flSignMask<>+0x00(SB)/8, $0x7fffffff7fffffff
DATA flSignMask<>+0x08(SB)/8, $0x7fffffff7fffffff
// scatterAndMulBy0x101 is a PSHUFB mask that brings the low four bytes of an
// XMM register to the low byte of that register's four uint32 values. It
// duplicates those bytes, effectively multiplying each uint32 by 0x101.
//
// It transforms a little-endian 16-byte XMM value from
// ijkl????????????
// to
// ii00jj00kk00ll00
DATA scatterAndMulBy0x101<>+0x00(SB)/8, $0x8080010180800000
DATA scatterAndMulBy0x101<>+0x08(SB)/8, $0x8080030380800202
// gather is a PSHUFB mask that brings the second-lowest byte of the XMM
// register's four uint32 values to the low four bytes of that register.
//
// It transforms a little-endian 16-byte XMM value from
// ?i???j???k???l??
// to
// ijkl000000000000
DATA gather<>+0x00(SB)/8, $0x808080800d090501
DATA gather<>+0x08(SB)/8, $0x8080808080808080
DATA fxAlmost65536<>+0x00(SB)/8, $0x0000ffff0000ffff
DATA fxAlmost65536<>+0x08(SB)/8, $0x0000ffff0000ffff
DATA inverseFFFF<>+0x00(SB)/8, $0x8000800180008001
DATA inverseFFFF<>+0x08(SB)/8, $0x8000800180008001
GLOBL flAlmost65536<>(SB), (NOPTR+RODATA), $16
GLOBL flOne<>(SB), (NOPTR+RODATA), $16
GLOBL flSignMask<>(SB), (NOPTR+RODATA), $16
GLOBL scatterAndMulBy0x101<>(SB), (NOPTR+RODATA), $16
GLOBL gather<>(SB), (NOPTR+RODATA), $16
GLOBL fxAlmost65536<>(SB), (NOPTR+RODATA), $16
GLOBL inverseFFFF<>(SB), (NOPTR+RODATA), $16
// func haveSSE4_1() bool
TEXT ·haveSSE4_1(SB), NOSPLIT, $0
MOVQ $1, AX
CPUID
SHRQ $19, CX
ANDQ $1, CX
MOVB CX, ret+0(FP)
RET
// ----------------------------------------------------------------------------
// func {{.LongName}}SIMD({{.Args}})
//
// XMM registers. Variable names are per
// https://github.com/google/font-rs/blob/master/src/accumulate.c
//
// xmm0 scratch
// xmm1 x
// xmm2 y, z
// xmm3 {{.XMM3}}
// xmm4 {{.XMM4}}
// xmm5 {{.XMM5}}
// xmm6 {{.XMM6}}
// xmm7 offset
// xmm8 {{.XMM8}}
// xmm9 {{.XMM9}}
// xmm10 {{.XMM10}}
TEXT ·{{.LongName}}SIMD(SB), NOSPLIT, ${{.FrameSize}}-{{.ArgsSize}}
{{.LoadArgs}}
// R10 = len(src) &^ 3
// R11 = len(src)
MOVQ R10, R11
ANDQ $-4, R10
{{.Setup}}
{{.LoadXMMRegs}}
// offset := XMM(0x00000000 repeated four times) // Cumulative sum.
XORPS X7, X7
// i := 0
MOVQ $0, R9
{{.ShortName}}Loop4:
// for i < (len(src) &^ 3)
CMPQ R9, R10
JAE {{.ShortName}}Loop1
// x = XMM(s0, s1, s2, s3)
//
// Where s0 is src[i+0], s1 is src[i+1], etc.
MOVOU (SI), X1
// scratch = XMM(0, s0, s1, s2)
// x += scratch // yields x == XMM(s0, s0+s1, s1+s2, s2+s3)
MOVOU X1, X0
PSLLO $4, X0
{{.Add}} X0, X1
// scratch = XMM(0, 0, 0, 0)
// scratch = XMM(scratch@0, scratch@0, x@0, x@1) // yields scratch == XMM(0, 0, s0, s0+s1)
// x += scratch // yields x == XMM(s0, s0+s1, s0+s1+s2, s0+s1+s2+s3)
XORPS X0, X0
SHUFPS $0x40, X1, X0
{{.Add}} X0, X1
// x += offset
{{.Add}} X7, X1
{{.ClampAndScale}}
{{.ConvertToInt32}}
{{.Store4}}
// offset = XMM(x@3, x@3, x@3, x@3)
MOVOU X1, X7
SHUFPS $0xff, X1, X7
// i += 4
// dst = dst[4:]
// src = src[4:]
ADDQ $4, R9
ADDQ ${{.DstElemSize4}}, DI
ADDQ $16, SI
JMP {{.ShortName}}Loop4
{{.ShortName}}Loop1:
// for i < len(src)
CMPQ R9, R11
JAE {{.ShortName}}End
// x = src[i] + offset
MOVL (SI), X1
{{.Add}} X7, X1
{{.ClampAndScale}}
{{.ConvertToInt32}}
{{.Store1}}
// offset = x
MOVOU X1, X7
// i += 1
// dst = dst[1:]
// src = src[1:]
ADDQ $1, R9
ADDQ ${{.DstElemSize1}}, DI
ADDQ $4, SI
JMP {{.ShortName}}Loop1
{{.ShortName}}End:
RET

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vendor/golang.org/x/image/vector/raster_fixed.go generated vendored Normal file
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// Copyright 2016 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.
package vector
// This file contains a fixed point math implementation of the vector
// graphics rasterizer.
const (
// ϕ is the number of binary digits after the fixed point.
//
// For example, if ϕ == 10 (and int1ϕ is based on the int32 type) then we
// are using 22.10 fixed point math.
//
// When changing this number, also change the assembly code (search for ϕ
// in the .s files).
ϕ = 9
fxOne int1ϕ = 1 << ϕ
fxOneAndAHalf int1ϕ = 1<<ϕ + 1<<(ϕ-1)
fxOneMinusIota int1ϕ = 1<<ϕ - 1 // Used for rounding up.
)
// int1ϕ is a signed fixed-point number with 1*ϕ binary digits after the fixed
// point.
type int1ϕ int32
// int2ϕ is a signed fixed-point number with 2*ϕ binary digits after the fixed
// point.
//
// The Rasterizer's bufU32 field, nominally of type []uint32 (since that slice
// is also used by other code), can be thought of as a []int2ϕ during the
// fixedLineTo method. Lines of code that are actually like:
//
// buf[i] += uint32(etc) // buf has type []uint32.
//
// can be thought of as
//
// buf[i] += int2ϕ(etc) // buf has type []int2ϕ.
type int2ϕ int32
func fixedMax(x, y int1ϕ) int1ϕ {
if x > y {
return x
}
return y
}
func fixedMin(x, y int1ϕ) int1ϕ {
if x < y {
return x
}
return y
}
func fixedFloor(x int1ϕ) int32 { return int32(x >> ϕ) }
func fixedCeil(x int1ϕ) int32 { return int32((x + fxOneMinusIota) >> ϕ) }
func (z *Rasterizer) fixedLineTo(bx, by float32) {
ax, ay := z.penX, z.penY
z.penX, z.penY = bx, by
dir := int1ϕ(1)
if ay > by {
dir, ax, ay, bx, by = -1, bx, by, ax, ay
}
// Horizontal line segments yield no change in coverage. Almost horizontal
// segments would yield some change, in ideal math, but the computation
// further below, involving 1 / (by - ay), is unstable in fixed point math,
// so we treat the segment as if it was perfectly horizontal.
if by-ay <= 0.000001 {
return
}
dxdy := (bx - ax) / (by - ay)
ayϕ := int1ϕ(ay * float32(fxOne))
byϕ := int1ϕ(by * float32(fxOne))
x := int1ϕ(ax * float32(fxOne))
y := fixedFloor(ayϕ)
yMax := fixedCeil(byϕ)
if yMax > int32(z.size.Y) {
yMax = int32(z.size.Y)
}
width := int32(z.size.X)
for ; y < yMax; y++ {
dy := fixedMin(int1ϕ(y+1)<<ϕ, byϕ) - fixedMax(int1ϕ(y)<<ϕ, ayϕ)
xNext := x + int1ϕ(float32(dy)*dxdy)
if y < 0 {
x = xNext
continue
}
buf := z.bufU32[y*width:]
d := dy * dir // d ranges up to ±1<<(1*ϕ).
x0, x1 := x, xNext
if x > xNext {
x0, x1 = x1, x0
}
x0i := fixedFloor(x0)
x0Floor := int1ϕ(x0i) << ϕ
x1i := fixedCeil(x1)
x1Ceil := int1ϕ(x1i) << ϕ
if x1i <= x0i+1 {
xmf := (x+xNext)>>1 - x0Floor
if i := clamp(x0i+0, width); i < uint(len(buf)) {
buf[i] += uint32(d * (fxOne - xmf))
}
if i := clamp(x0i+1, width); i < uint(len(buf)) {
buf[i] += uint32(d * xmf)
}
} else {
oneOverS := x1 - x0
twoOverS := 2 * oneOverS
x0f := x0 - x0Floor
oneMinusX0f := fxOne - x0f
oneMinusX0fSquared := oneMinusX0f * oneMinusX0f
x1f := x1 - x1Ceil + fxOne
x1fSquared := x1f * x1f
// These next two variables are unused, as rounding errors are
// minimized when we delay the division by oneOverS for as long as
// possible. These lines of code (and the "In ideal math" comments
// below) are commented out instead of deleted in order to aid the
// comparison with the floating point version of the rasterizer.
//
// a0 := ((oneMinusX0f * oneMinusX0f) >> 1) / oneOverS
// am := ((x1f * x1f) >> 1) / oneOverS
if i := clamp(x0i, width); i < uint(len(buf)) {
// In ideal math: buf[i] += uint32(d * a0)
D := oneMinusX0fSquared // D ranges up to ±1<<(2*ϕ).
D *= d // D ranges up to ±1<<(3*ϕ).
D /= twoOverS
buf[i] += uint32(D)
}
if x1i == x0i+2 {
if i := clamp(x0i+1, width); i < uint(len(buf)) {
// In ideal math: buf[i] += uint32(d * (fxOne - a0 - am))
//
// (x1i == x0i+2) and (twoOverS == 2 * (x1 - x0)) implies
// that twoOverS ranges up to +1<<(1*ϕ+2).
D := twoOverS<<ϕ - oneMinusX0fSquared - x1fSquared // D ranges up to ±1<<(2*ϕ+2).
D *= d // D ranges up to ±1<<(3*ϕ+2).
D /= twoOverS
buf[i] += uint32(D)
}
} else {
// This is commented out for the same reason as a0 and am.
//
// a1 := ((fxOneAndAHalf - x0f) << ϕ) / oneOverS
if i := clamp(x0i+1, width); i < uint(len(buf)) {
// In ideal math:
// buf[i] += uint32(d * (a1 - a0))
// or equivalently (but better in non-ideal, integer math,
// with respect to rounding errors),
// buf[i] += uint32(A * d / twoOverS)
// where
// A = (a1 - a0) * twoOverS
// = a1*twoOverS - a0*twoOverS
// Noting that twoOverS/oneOverS equals 2, substituting for
// a0 and then a1, given above, yields:
// A = a1*twoOverS - oneMinusX0fSquared
// = (fxOneAndAHalf-x0f)<<(ϕ+1) - oneMinusX0fSquared
// = fxOneAndAHalf<<(ϕ+1) - x0f<<(ϕ+1) - oneMinusX0fSquared
//
// This is a positive number minus two non-negative
// numbers. For an upper bound on A, the positive number is
// P = fxOneAndAHalf<<(ϕ+1)
// < (2*fxOne)<<(ϕ+1)
// = fxOne<<(ϕ+2)
// = 1<<(2*ϕ+2)
//
// For a lower bound on A, the two non-negative numbers are
// N = x0f<<(ϕ+1) + oneMinusX0fSquared
// ≤ x0f<<(ϕ+1) + fxOne*fxOne
// = x0f<<(ϕ+1) + 1<<(2*ϕ)
// < x0f<<(ϕ+1) + 1<<(2*ϕ+1)
// ≤ fxOne<<(ϕ+1) + 1<<(2*ϕ+1)
// = 1<<(2*ϕ+1) + 1<<(2*ϕ+1)
// = 1<<(2*ϕ+2)
//
// Thus, A ranges up to ±1<<(2*ϕ+2). It is possible to
// derive a tighter bound, but this bound is sufficient to
// reason about overflow.
D := (fxOneAndAHalf-x0f)<<(ϕ+1) - oneMinusX0fSquared // D ranges up to ±1<<(2*ϕ+2).
D *= d // D ranges up to ±1<<(3*ϕ+2).
D /= twoOverS
buf[i] += uint32(D)
}
dTimesS := uint32((d << (2 * ϕ)) / oneOverS)
for xi := x0i + 2; xi < x1i-1; xi++ {
if i := clamp(xi, width); i < uint(len(buf)) {
buf[i] += dTimesS
}
}
// This is commented out for the same reason as a0 and am.
//
// a2 := a1 + (int1ϕ(x1i-x0i-3)<<(2*ϕ))/oneOverS
if i := clamp(x1i-1, width); i < uint(len(buf)) {
// In ideal math:
// buf[i] += uint32(d * (fxOne - a2 - am))
// or equivalently (but better in non-ideal, integer math,
// with respect to rounding errors),
// buf[i] += uint32(A * d / twoOverS)
// where
// A = (fxOne - a2 - am) * twoOverS
// = twoOverS<<ϕ - a2*twoOverS - am*twoOverS
// Noting that twoOverS/oneOverS equals 2, substituting for
// am and then a2, given above, yields:
// A = twoOverS<<ϕ - a2*twoOverS - x1f*x1f
// = twoOverS<<ϕ - a1*twoOverS - (int1ϕ(x1i-x0i-3)<<(2*ϕ))*2 - x1f*x1f
// = twoOverS<<ϕ - a1*twoOverS - int1ϕ(x1i-x0i-3)<<(2*ϕ+1) - x1f*x1f
// Substituting for a1, given above, yields:
// A = twoOverS<<ϕ - ((fxOneAndAHalf-x0f)<<ϕ)*2 - int1ϕ(x1i-x0i-3)<<(2*ϕ+1) - x1f*x1f
// = twoOverS<<ϕ - (fxOneAndAHalf-x0f)<<(ϕ+1) - int1ϕ(x1i-x0i-3)<<(2*ϕ+1) - x1f*x1f
// = B<<ϕ - x1f*x1f
// where
// B = twoOverS - (fxOneAndAHalf-x0f)<<1 - int1ϕ(x1i-x0i-3)<<(ϕ+1)
// = (x1-x0)<<1 - (fxOneAndAHalf-x0f)<<1 - int1ϕ(x1i-x0i-3)<<(ϕ+1)
//
// Re-arranging the defintions given above:
// x0Floor := int1ϕ(x0i) << ϕ
// x0f := x0 - x0Floor
// x1Ceil := int1ϕ(x1i) << ϕ
// x1f := x1 - x1Ceil + fxOne
// combined with fxOne = 1<<ϕ yields:
// x0 = x0f + int1ϕ(x0i)<<ϕ
// x1 = x1f + int1ϕ(x1i-1)<<ϕ
// so that expanding (x1-x0) yields:
// B = (x1f-x0f + int1ϕ(x1i-x0i-1)<<ϕ)<<1 - (fxOneAndAHalf-x0f)<<1 - int1ϕ(x1i-x0i-3)<<(ϕ+1)
// = (x1f-x0f)<<1 + int1ϕ(x1i-x0i-1)<<(ϕ+1) - (fxOneAndAHalf-x0f)<<1 - int1ϕ(x1i-x0i-3)<<(ϕ+1)
// A large part of the second and fourth terms cancel:
// B = (x1f-x0f)<<1 - (fxOneAndAHalf-x0f)<<1 - int1ϕ(-2)<<(ϕ+1)
// = (x1f-x0f)<<1 - (fxOneAndAHalf-x0f)<<1 + 1<<(ϕ+2)
// = (x1f - fxOneAndAHalf)<<1 + 1<<(ϕ+2)
// The first term, (x1f - fxOneAndAHalf)<<1, is a negative
// number, bounded below by -fxOneAndAHalf<<1, which is
// greater than -fxOne<<2, or -1<<(ϕ+2). Thus, B ranges up
// to ±1<<(ϕ+2). One final simplification:
// B = x1f<<1 + (1<<(ϕ+2) - fxOneAndAHalf<<1)
const C = 1<<(ϕ+2) - fxOneAndAHalf<<1
D := x1f<<1 + C // D ranges up to ±1<<(1*ϕ+2).
D <<= ϕ // D ranges up to ±1<<(2*ϕ+2).
D -= x1fSquared // D ranges up to ±1<<(2*ϕ+3).
D *= d // D ranges up to ±1<<(3*ϕ+3).
D /= twoOverS
buf[i] += uint32(D)
}
}
if i := clamp(x1i, width); i < uint(len(buf)) {
// In ideal math: buf[i] += uint32(d * am)
D := x1fSquared // D ranges up to ±1<<(2*ϕ).
D *= d // D ranges up to ±1<<(3*ϕ).
D /= twoOverS
buf[i] += uint32(D)
}
}
x = xNext
}
}
func fixedAccumulateOpOver(dst []uint8, src []uint32) {
// Sanity check that len(dst) >= len(src).
if len(dst) < len(src) {
return
}
acc := int2ϕ(0)
for i, v := range src {
acc += int2ϕ(v)
a := acc
if a < 0 {
a = -a
}
a >>= 2*ϕ - 16
if a > 0xffff {
a = 0xffff
}
// This algorithm comes from the standard library's image/draw package.
dstA := uint32(dst[i]) * 0x101
maskA := uint32(a)
outA := dstA*(0xffff-maskA)/0xffff + maskA
dst[i] = uint8(outA >> 8)
}
}
func fixedAccumulateOpSrc(dst []uint8, src []uint32) {
// Sanity check that len(dst) >= len(src).
if len(dst) < len(src) {
return
}
acc := int2ϕ(0)
for i, v := range src {
acc += int2ϕ(v)
a := acc
if a < 0 {
a = -a
}
a >>= 2*ϕ - 8
if a > 0xff {
a = 0xff
}
dst[i] = uint8(a)
}
}
func fixedAccumulateMask(buf []uint32) {
acc := int2ϕ(0)
for i, v := range buf {
acc += int2ϕ(v)
a := acc
if a < 0 {
a = -a
}
a >>= 2*ϕ - 16
if a > 0xffff {
a = 0xffff
}
buf[i] = uint32(a)
}
}

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vendor/golang.org/x/image/vector/raster_floating.go generated vendored Normal file
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// Copyright 2016 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.
package vector
// This file contains a floating point math implementation of the vector
// graphics rasterizer.
import (
"math"
)
func floatingMax(x, y float32) float32 {
if x > y {
return x
}
return y
}
func floatingMin(x, y float32) float32 {
if x < y {
return x
}
return y
}
func floatingFloor(x float32) int32 { return int32(math.Floor(float64(x))) }
func floatingCeil(x float32) int32 { return int32(math.Ceil(float64(x))) }
func (z *Rasterizer) floatingLineTo(bx, by float32) {
ax, ay := z.penX, z.penY
z.penX, z.penY = bx, by
dir := float32(1)
if ay > by {
dir, ax, ay, bx, by = -1, bx, by, ax, ay
}
// Horizontal line segments yield no change in coverage. Almost horizontal
// segments would yield some change, in ideal math, but the computation
// further below, involving 1 / (by - ay), is unstable in floating point
// math, so we treat the segment as if it was perfectly horizontal.
if by-ay <= 0.000001 {
return
}
dxdy := (bx - ax) / (by - ay)
x := ax
y := floatingFloor(ay)
yMax := floatingCeil(by)
if yMax > int32(z.size.Y) {
yMax = int32(z.size.Y)
}
width := int32(z.size.X)
for ; y < yMax; y++ {
dy := floatingMin(float32(y+1), by) - floatingMax(float32(y), ay)
// The "float32" in expressions like "float32(foo*bar)" here and below
// look redundant, since foo and bar already have type float32, but are
// explicit in order to disable the compiler's Fused Multiply Add (FMA)
// instruction selection, which can improve performance but can result
// in different rounding errors in floating point computations.
//
// This package aims to have bit-exact identical results across all
// GOARCHes, and across pure Go code and assembly, so it disables FMA.
//
// See the discussion at
// https://groups.google.com/d/topic/golang-dev/Sti0bl2xUXQ/discussion
xNext := x + float32(dy*dxdy)
if y < 0 {
x = xNext
continue
}
buf := z.bufF32[y*width:]
d := float32(dy * dir)
x0, x1 := x, xNext
if x > xNext {
x0, x1 = x1, x0
}
x0i := floatingFloor(x0)
x0Floor := float32(x0i)
x1i := floatingCeil(x1)
x1Ceil := float32(x1i)
if x1i <= x0i+1 {
xmf := float32(0.5*(x+xNext)) - x0Floor
if i := clamp(x0i+0, width); i < uint(len(buf)) {
buf[i] += d - float32(d*xmf)
}
if i := clamp(x0i+1, width); i < uint(len(buf)) {
buf[i] += float32(d * xmf)
}
} else {
s := 1 / (x1 - x0)
x0f := x0 - x0Floor
oneMinusX0f := 1 - x0f
a0 := float32(0.5 * s * oneMinusX0f * oneMinusX0f)
x1f := x1 - x1Ceil + 1
am := float32(0.5 * s * x1f * x1f)
if i := clamp(x0i, width); i < uint(len(buf)) {
buf[i] += float32(d * a0)
}
if x1i == x0i+2 {
if i := clamp(x0i+1, width); i < uint(len(buf)) {
buf[i] += float32(d * (1 - a0 - am))
}
} else {
a1 := float32(s * (1.5 - x0f))
if i := clamp(x0i+1, width); i < uint(len(buf)) {
buf[i] += float32(d * (a1 - a0))
}
dTimesS := float32(d * s)
for xi := x0i + 2; xi < x1i-1; xi++ {
if i := clamp(xi, width); i < uint(len(buf)) {
buf[i] += dTimesS
}
}
a2 := a1 + float32(s*float32(x1i-x0i-3))
if i := clamp(x1i-1, width); i < uint(len(buf)) {
buf[i] += float32(d * (1 - a2 - am))
}
}
if i := clamp(x1i, width); i < uint(len(buf)) {
buf[i] += float32(d * am)
}
}
x = xNext
}
}
const (
// almost256 scales a floating point value in the range [0, 1] to a uint8
// value in the range [0x00, 0xff].
//
// 255 is too small. Floating point math accumulates rounding errors, so a
// fully covered src value that would in ideal math be float32(1) might be
// float32(1-ε), and uint8(255 * (1-ε)) would be 0xfe instead of 0xff. The
// uint8 conversion rounds to zero, not to nearest.
//
// 256 is too big. If we multiplied by 256, below, then a fully covered src
// value of float32(1) would translate to uint8(256 * 1), which can be 0x00
// instead of the maximal value 0xff.
//
// math.Float32bits(almost256) is 0x437fffff.
almost256 = 255.99998
// almost65536 scales a floating point value in the range [0, 1] to a
// uint16 value in the range [0x0000, 0xffff].
//
// math.Float32bits(almost65536) is 0x477fffff.
almost65536 = almost256 * 256
)
func floatingAccumulateOpOver(dst []uint8, src []float32) {
// Sanity check that len(dst) >= len(src).
if len(dst) < len(src) {
return
}
acc := float32(0)
for i, v := range src {
acc += v
a := acc
if a < 0 {
a = -a
}
if a > 1 {
a = 1
}
// This algorithm comes from the standard library's image/draw package.
dstA := uint32(dst[i]) * 0x101
maskA := uint32(almost65536 * a)
outA := dstA*(0xffff-maskA)/0xffff + maskA
dst[i] = uint8(outA >> 8)
}
}
func floatingAccumulateOpSrc(dst []uint8, src []float32) {
// Sanity check that len(dst) >= len(src).
if len(dst) < len(src) {
return
}
acc := float32(0)
for i, v := range src {
acc += v
a := acc
if a < 0 {
a = -a
}
if a > 1 {
a = 1
}
dst[i] = uint8(almost256 * a)
}
}
func floatingAccumulateMask(dst []uint32, src []float32) {
// Sanity check that len(dst) >= len(src).
if len(dst) < len(src) {
return
}
acc := float32(0)
for i, v := range src {
acc += v
a := acc
if a < 0 {
a = -a
}
if a > 1 {
a = 1
}
dst[i] = uint32(almost65536 * a)
}
}

472
vendor/golang.org/x/image/vector/vector.go generated vendored Normal file
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@@ -0,0 +1,472 @@
// Copyright 2016 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.
//go:generate go run gen.go
//go:generate asmfmt -w acc_amd64.s
// asmfmt is https://github.com/klauspost/asmfmt
// Package vector provides a rasterizer for 2-D vector graphics.
package vector // import "golang.org/x/image/vector"
// The rasterizer's design follows
// https://medium.com/@raphlinus/inside-the-fastest-font-renderer-in-the-world-75ae5270c445
//
// Proof of concept code is in
// https://github.com/google/font-go
//
// See also:
// http://nothings.org/gamedev/rasterize/
// http://projects.tuxee.net/cl-vectors/section-the-cl-aa-algorithm
// https://people.gnome.org/~mathieu/libart/internals.html#INTERNALS-SCANLINE
import (
"image"
"image/color"
"image/draw"
"math"
)
// floatingPointMathThreshold is the width or height above which the rasterizer
// chooses to used floating point math instead of fixed point math.
//
// Both implementations of line segmentation rasterization (see raster_fixed.go
// and raster_floating.go) implement the same algorithm (in ideal, infinite
// precision math) but they perform differently in practice. The fixed point
// math version is roughtly 1.25x faster (on GOARCH=amd64) on the benchmarks,
// but at sufficiently large scales, the computations will overflow and hence
// show rendering artifacts. The floating point math version has more
// consistent quality over larger scales, but it is significantly slower.
//
// This constant determines when to use the faster implementation and when to
// use the better quality implementation.
//
// The rationale for this particular value is that TestRasterizePolygon in
// vector_test.go checks the rendering quality of polygon edges at various
// angles, inscribed in a circle of diameter 512. It may be that a higher value
// would still produce acceptable quality, but 512 seems to work.
const floatingPointMathThreshold = 512
func lerp(t, px, py, qx, qy float32) (x, y float32) {
return px + t*(qx-px), py + t*(qy-py)
}
func clamp(i, width int32) uint {
if i < 0 {
return 0
}
if i < width {
return uint(i)
}
return uint(width)
}
// NewRasterizer returns a new Rasterizer whose rendered mask image is bounded
// by the given width and height.
func NewRasterizer(w, h int) *Rasterizer {
z := &Rasterizer{}
z.Reset(w, h)
return z
}
// Raster is a 2-D vector graphics rasterizer.
//
// The zero value is usable, in that it is a Rasterizer whose rendered mask
// image has zero width and zero height. Call Reset to change its bounds.
type Rasterizer struct {
// bufXxx are buffers of float32 or uint32 values, holding either the
// individual or cumulative area values.
//
// We don't actually need both values at any given time, and to conserve
// memory, the integration of the individual to the cumulative could modify
// the buffer in place. In other words, we could use a single buffer, say
// of type []uint32, and add some math.Float32bits and math.Float32frombits
// calls to satisfy the compiler's type checking. As of Go 1.7, though,
// there is a performance penalty between:
// bufF32[i] += x
// and
// bufU32[i] = math.Float32bits(x + math.Float32frombits(bufU32[i]))
//
// See golang.org/issue/17220 for some discussion.
bufF32 []float32
bufU32 []uint32
useFloatingPointMath bool
size image.Point
firstX float32
firstY float32
penX float32
penY float32
// DrawOp is the operator used for the Draw method.
//
// The zero value is draw.Over.
DrawOp draw.Op
// TODO: an exported field equivalent to the mask point in the
// draw.DrawMask function in the stdlib image/draw package?
}
// Reset resets a Rasterizer as if it was just returned by NewRasterizer.
//
// This includes setting z.DrawOp to draw.Over.
func (z *Rasterizer) Reset(w, h int) {
z.size = image.Point{w, h}
z.firstX = 0
z.firstY = 0
z.penX = 0
z.penY = 0
z.DrawOp = draw.Over
z.setUseFloatingPointMath(w > floatingPointMathThreshold || h > floatingPointMathThreshold)
}
func (z *Rasterizer) setUseFloatingPointMath(b bool) {
z.useFloatingPointMath = b
// Make z.bufF32 or z.bufU32 large enough to hold width * height samples.
if z.useFloatingPointMath {
if n := z.size.X * z.size.Y; n > cap(z.bufF32) {
z.bufF32 = make([]float32, n)
} else {
z.bufF32 = z.bufF32[:n]
for i := range z.bufF32 {
z.bufF32[i] = 0
}
}
} else {
if n := z.size.X * z.size.Y; n > cap(z.bufU32) {
z.bufU32 = make([]uint32, n)
} else {
z.bufU32 = z.bufU32[:n]
for i := range z.bufU32 {
z.bufU32[i] = 0
}
}
}
}
// Size returns the width and height passed to NewRasterizer or Reset.
func (z *Rasterizer) Size() image.Point {
return z.size
}
// Bounds returns the rectangle from (0, 0) to the width and height passed to
// NewRasterizer or Reset.
func (z *Rasterizer) Bounds() image.Rectangle {
return image.Rectangle{Max: z.size}
}
// Pen returns the location of the path-drawing pen: the last argument to the
// most recent XxxTo call.
func (z *Rasterizer) Pen() (x, y float32) {
return z.penX, z.penY
}
// ClosePath closes the current path.
func (z *Rasterizer) ClosePath() {
z.LineTo(z.firstX, z.firstY)
}
// MoveTo starts a new path and moves the pen to (ax, ay).
//
// The coordinates are allowed to be out of the Rasterizer's bounds.
func (z *Rasterizer) MoveTo(ax, ay float32) {
z.firstX = ax
z.firstY = ay
z.penX = ax
z.penY = ay
}
// LineTo adds a line segment, from the pen to (bx, by), and moves the pen to
// (bx, by).
//
// The coordinates are allowed to be out of the Rasterizer's bounds.
func (z *Rasterizer) LineTo(bx, by float32) {
if z.useFloatingPointMath {
z.floatingLineTo(bx, by)
} else {
z.fixedLineTo(bx, by)
}
}
// QuadTo adds a quadratic Bézier segment, from the pen via (bx, by) to (cx,
// cy), and moves the pen to (cx, cy).
//
// The coordinates are allowed to be out of the Rasterizer's bounds.
func (z *Rasterizer) QuadTo(bx, by, cx, cy float32) {
ax, ay := z.penX, z.penY
devsq := devSquared(ax, ay, bx, by, cx, cy)
if devsq >= 0.333 {
const tol = 3
n := 1 + int(math.Sqrt(math.Sqrt(tol*float64(devsq))))
t, nInv := float32(0), 1/float32(n)
for i := 0; i < n-1; i++ {
t += nInv
abx, aby := lerp(t, ax, ay, bx, by)
bcx, bcy := lerp(t, bx, by, cx, cy)
z.LineTo(lerp(t, abx, aby, bcx, bcy))
}
}
z.LineTo(cx, cy)
}
// CubeTo adds a cubic Bézier segment, from the pen via (bx, by) and (cx, cy)
// to (dx, dy), and moves the pen to (dx, dy).
//
// The coordinates are allowed to be out of the Rasterizer's bounds.
func (z *Rasterizer) CubeTo(bx, by, cx, cy, dx, dy float32) {
ax, ay := z.penX, z.penY
devsq := devSquared(ax, ay, bx, by, dx, dy)
if devsqAlt := devSquared(ax, ay, cx, cy, dx, dy); devsq < devsqAlt {
devsq = devsqAlt
}
if devsq >= 0.333 {
const tol = 3
n := 1 + int(math.Sqrt(math.Sqrt(tol*float64(devsq))))
t, nInv := float32(0), 1/float32(n)
for i := 0; i < n-1; i++ {
t += nInv
abx, aby := lerp(t, ax, ay, bx, by)
bcx, bcy := lerp(t, bx, by, cx, cy)
cdx, cdy := lerp(t, cx, cy, dx, dy)
abcx, abcy := lerp(t, abx, aby, bcx, bcy)
bcdx, bcdy := lerp(t, bcx, bcy, cdx, cdy)
z.LineTo(lerp(t, abcx, abcy, bcdx, bcdy))
}
}
z.LineTo(dx, dy)
}
// devSquared returns a measure of how curvy the sequence (ax, ay) to (bx, by)
// to (cx, cy) is. It determines how many line segments will approximate a
// Bézier curve segment.
//
// http://lists.nongnu.org/archive/html/freetype-devel/2016-08/msg00080.html
// gives the rationale for this evenly spaced heuristic instead of a recursive
// de Casteljau approach:
//
// The reason for the subdivision by n is that I expect the "flatness"
// computation to be semi-expensive (it's done once rather than on each
// potential subdivision) and also because you'll often get fewer subdivisions.
// Taking a circular arc as a simplifying assumption (ie a spherical cow),
// where I get n, a recursive approach would get 2^⌈lg n⌉, which, if I haven't
// made any horrible mistakes, is expected to be 33% more in the limit.
func devSquared(ax, ay, bx, by, cx, cy float32) float32 {
devx := ax - 2*bx + cx
devy := ay - 2*by + cy
return devx*devx + devy*devy
}
// Draw implements the Drawer interface from the standard library's image/draw
// package.
//
// The vector paths previously added via the XxxTo calls become the mask for
// drawing src onto dst.
func (z *Rasterizer) Draw(dst draw.Image, r image.Rectangle, src image.Image, sp image.Point) {
// TODO: adjust r and sp (and mp?) if src.Bounds() doesn't contain
// r.Add(sp.Sub(r.Min)).
if src, ok := src.(*image.Uniform); ok {
srcR, srcG, srcB, srcA := src.RGBA()
switch dst := dst.(type) {
case *image.Alpha:
// Fast path for glyph rendering.
if srcA == 0xffff {
if z.DrawOp == draw.Over {
z.rasterizeDstAlphaSrcOpaqueOpOver(dst, r)
} else {
z.rasterizeDstAlphaSrcOpaqueOpSrc(dst, r)
}
return
}
case *image.RGBA:
if z.DrawOp == draw.Over {
z.rasterizeDstRGBASrcUniformOpOver(dst, r, srcR, srcG, srcB, srcA)
} else {
z.rasterizeDstRGBASrcUniformOpSrc(dst, r, srcR, srcG, srcB, srcA)
}
return
}
}
if z.DrawOp == draw.Over {
z.rasterizeOpOver(dst, r, src, sp)
} else {
z.rasterizeOpSrc(dst, r, src, sp)
}
}
func (z *Rasterizer) accumulateMask() {
if z.useFloatingPointMath {
if n := z.size.X * z.size.Y; n > cap(z.bufU32) {
z.bufU32 = make([]uint32, n)
} else {
z.bufU32 = z.bufU32[:n]
}
if haveAccumulateSIMD {
floatingAccumulateMaskSIMD(z.bufU32, z.bufF32)
} else {
floatingAccumulateMask(z.bufU32, z.bufF32)
}
} else {
if haveAccumulateSIMD {
fixedAccumulateMaskSIMD(z.bufU32)
} else {
fixedAccumulateMask(z.bufU32)
}
}
}
func (z *Rasterizer) rasterizeDstAlphaSrcOpaqueOpOver(dst *image.Alpha, r image.Rectangle) {
// TODO: non-zero vs even-odd winding?
if r == dst.Bounds() && r == z.Bounds() {
// We bypass the z.accumulateMask step and convert straight from
// z.bufF32 or z.bufU32 to dst.Pix.
if z.useFloatingPointMath {
if haveAccumulateSIMD {
floatingAccumulateOpOverSIMD(dst.Pix, z.bufF32)
} else {
floatingAccumulateOpOver(dst.Pix, z.bufF32)
}
} else {
if haveAccumulateSIMD {
fixedAccumulateOpOverSIMD(dst.Pix, z.bufU32)
} else {
fixedAccumulateOpOver(dst.Pix, z.bufU32)
}
}
return
}
z.accumulateMask()
pix := dst.Pix[dst.PixOffset(r.Min.X, r.Min.Y):]
for y, y1 := 0, r.Max.Y-r.Min.Y; y < y1; y++ {
for x, x1 := 0, r.Max.X-r.Min.X; x < x1; x++ {
ma := z.bufU32[y*z.size.X+x]
i := y*dst.Stride + x
// This formula is like rasterizeOpOver's, simplified for the
// concrete dst type and opaque src assumption.
a := 0xffff - ma
pix[i] = uint8((uint32(pix[i])*0x101*a/0xffff + ma) >> 8)
}
}
}
func (z *Rasterizer) rasterizeDstAlphaSrcOpaqueOpSrc(dst *image.Alpha, r image.Rectangle) {
// TODO: non-zero vs even-odd winding?
if r == dst.Bounds() && r == z.Bounds() {
// We bypass the z.accumulateMask step and convert straight from
// z.bufF32 or z.bufU32 to dst.Pix.
if z.useFloatingPointMath {
if haveAccumulateSIMD {
floatingAccumulateOpSrcSIMD(dst.Pix, z.bufF32)
} else {
floatingAccumulateOpSrc(dst.Pix, z.bufF32)
}
} else {
if haveAccumulateSIMD {
fixedAccumulateOpSrcSIMD(dst.Pix, z.bufU32)
} else {
fixedAccumulateOpSrc(dst.Pix, z.bufU32)
}
}
return
}
z.accumulateMask()
pix := dst.Pix[dst.PixOffset(r.Min.X, r.Min.Y):]
for y, y1 := 0, r.Max.Y-r.Min.Y; y < y1; y++ {
for x, x1 := 0, r.Max.X-r.Min.X; x < x1; x++ {
ma := z.bufU32[y*z.size.X+x]
// This formula is like rasterizeOpSrc's, simplified for the
// concrete dst type and opaque src assumption.
pix[y*dst.Stride+x] = uint8(ma >> 8)
}
}
}
func (z *Rasterizer) rasterizeDstRGBASrcUniformOpOver(dst *image.RGBA, r image.Rectangle, sr, sg, sb, sa uint32) {
z.accumulateMask()
pix := dst.Pix[dst.PixOffset(r.Min.X, r.Min.Y):]
for y, y1 := 0, r.Max.Y-r.Min.Y; y < y1; y++ {
for x, x1 := 0, r.Max.X-r.Min.X; x < x1; x++ {
ma := z.bufU32[y*z.size.X+x]
// This formula is like rasterizeOpOver's, simplified for the
// concrete dst type and uniform src assumption.
a := 0xffff - (sa * ma / 0xffff)
i := y*dst.Stride + 4*x
pix[i+0] = uint8(((uint32(pix[i+0])*0x101*a + sr*ma) / 0xffff) >> 8)
pix[i+1] = uint8(((uint32(pix[i+1])*0x101*a + sg*ma) / 0xffff) >> 8)
pix[i+2] = uint8(((uint32(pix[i+2])*0x101*a + sb*ma) / 0xffff) >> 8)
pix[i+3] = uint8(((uint32(pix[i+3])*0x101*a + sa*ma) / 0xffff) >> 8)
}
}
}
func (z *Rasterizer) rasterizeDstRGBASrcUniformOpSrc(dst *image.RGBA, r image.Rectangle, sr, sg, sb, sa uint32) {
z.accumulateMask()
pix := dst.Pix[dst.PixOffset(r.Min.X, r.Min.Y):]
for y, y1 := 0, r.Max.Y-r.Min.Y; y < y1; y++ {
for x, x1 := 0, r.Max.X-r.Min.X; x < x1; x++ {
ma := z.bufU32[y*z.size.X+x]
// This formula is like rasterizeOpSrc's, simplified for the
// concrete dst type and uniform src assumption.
i := y*dst.Stride + 4*x
pix[i+0] = uint8((sr * ma / 0xffff) >> 8)
pix[i+1] = uint8((sg * ma / 0xffff) >> 8)
pix[i+2] = uint8((sb * ma / 0xffff) >> 8)
pix[i+3] = uint8((sa * ma / 0xffff) >> 8)
}
}
}
func (z *Rasterizer) rasterizeOpOver(dst draw.Image, r image.Rectangle, src image.Image, sp image.Point) {
z.accumulateMask()
out := color.RGBA64{}
outc := color.Color(&out)
for y, y1 := 0, r.Max.Y-r.Min.Y; y < y1; y++ {
for x, x1 := 0, r.Max.X-r.Min.X; x < x1; x++ {
sr, sg, sb, sa := src.At(sp.X+x, sp.Y+y).RGBA()
ma := z.bufU32[y*z.size.X+x]
// This algorithm comes from the standard library's image/draw
// package.
dr, dg, db, da := dst.At(r.Min.X+x, r.Min.Y+y).RGBA()
a := 0xffff - (sa * ma / 0xffff)
out.R = uint16((dr*a + sr*ma) / 0xffff)
out.G = uint16((dg*a + sg*ma) / 0xffff)
out.B = uint16((db*a + sb*ma) / 0xffff)
out.A = uint16((da*a + sa*ma) / 0xffff)
dst.Set(r.Min.X+x, r.Min.Y+y, outc)
}
}
}
func (z *Rasterizer) rasterizeOpSrc(dst draw.Image, r image.Rectangle, src image.Image, sp image.Point) {
z.accumulateMask()
out := color.RGBA64{}
outc := color.Color(&out)
for y, y1 := 0, r.Max.Y-r.Min.Y; y < y1; y++ {
for x, x1 := 0, r.Max.X-r.Min.X; x < x1; x++ {
sr, sg, sb, sa := src.At(sp.X+x, sp.Y+y).RGBA()
ma := z.bufU32[y*z.size.X+x]
// This algorithm comes from the standard library's image/draw
// package.
out.R = uint16(sr * ma / 0xffff)
out.G = uint16(sg * ma / 0xffff)
out.B = uint16(sb * ma / 0xffff)
out.A = uint16(sa * ma / 0xffff)
dst.Set(r.Min.X+x, r.Min.Y+y, outc)
}
}
}