/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkHalf.h"
#include "SkPM4fPriv.h"
#include "SkUtils.h"
#include "SkXfermode.h"
static void sk_memset64(uint64_t dst[], uint64_t value, int count) {
for (int i = 0; i < count; ++i) {
dst[i] = value;
}
}
enum DstType {
kU16_Dst,
kF16_Dst,
};
static Sk4f lerp_by_coverage(const Sk4f& src, const Sk4f& dst, uint8_t srcCoverage) {
return dst + (src - dst) * Sk4f(srcCoverage * (1/255.0f));
}
template <DstType D> Sk4f unit_to_bias(const Sk4f& x4) {
return (D == kU16_Dst) ? x4 * Sk4f(65535) : x4;
}
template <DstType D> Sk4f bias_to_unit(const Sk4f& x4) {
return (D == kU16_Dst) ? x4 * Sk4f(1.0f/65535) : x4;
}
// returns value already biased by 65535
static Sk4f load_from_u16(uint64_t value) {
return SkNx_cast<float>(Sk4h::Load(&value));
}
// takes floats already biased by 65535
static uint64_t store_to_u16(const Sk4f& x4) {
uint64_t value;
SkNx_cast<uint16_t>(x4 + Sk4f(0.5f)).store(&value);
return value;
}
// Returns dst in its "natural" bias (either unit-float or 16bit int)
//
template <DstType D> Sk4f load_from_dst(uint64_t dst) {
return (D == kU16_Dst) ? load_from_u16(dst) : SkHalfToFloat_01(dst);
}
// Assumes x4 is already in the "natural" bias (either unit-float or 16bit int)
template <DstType D> uint64_t store_to_dst(const Sk4f& x4) {
return (D == kU16_Dst) ? store_to_u16(x4) : SkFloatToHalf_01(x4);
}
static inline Sk4f pm_to_rgba_order(const Sk4f& x) {
if (SkPM4f::R == 0) {
return x; // we're already RGBA
} else {
// we're BGRA, so swap R and B
return SkNx_shuffle<2, 1, 0, 3>(x);
}
}
///////////////////////////////////////////////////////////////////////////////////////////////////
template <DstType D> void xfer_u64_1(const SkXfermode* xfer, uint64_t dst[],
const SkPM4f* src, int count, const SkAlpha aa[]) {
SkXfermodeProc4f proc = xfer->getProc4f();
SkPM4f d;
if (aa) {
for (int i = 0; i < count; ++i) {
Sk4f d4 = bias_to_unit<D>(load_from_dst<D>(dst[i]));
d4.store(d.fVec);
Sk4f r4 = unit_to_bias<D>(Sk4f::Load(proc(*src, d).fVec));
dst[i] = store_to_dst<D>(lerp_by_coverage(r4, d4, aa[i]));
}
} else {
for (int i = 0; i < count; ++i) {
bias_to_unit<D>(load_from_dst<D>(dst[i])).store(d.fVec);
Sk4f r4 = unit_to_bias<D>(Sk4f::Load(proc(*src, d).fVec));
dst[i] = store_to_dst<D>(r4);
}
}
}
template <DstType D> void xfer_u64_n(const SkXfermode* xfer, uint64_t dst[],
const SkPM4f src[], int count, const SkAlpha aa[]) {
SkXfermodeProc4f proc = xfer->getProc4f();
SkPM4f d;
if (aa) {
for (int i = 0; i < count; ++i) {
Sk4f d4 = bias_to_unit<D>(load_from_dst<D>(dst[i]));
d4.store(d.fVec);
Sk4f r4 = unit_to_bias<D>(Sk4f::Load(proc(src[i], d).fVec));
dst[i] = store_to_dst<D>(lerp_by_coverage(r4, d4, aa[i]));
}
} else {
for (int i = 0; i < count; ++i) {
bias_to_unit<D>(load_from_dst<D>(dst[i])).store(d.fVec);
Sk4f r4 = unit_to_bias<D>(Sk4f::Load(proc(src[i], d).fVec));
dst[i] = store_to_dst<D>(r4);
}
}
}
const SkXfermode::D64Proc gProcs_General[] = {
xfer_u64_n<kU16_Dst>, xfer_u64_n<kU16_Dst>,
xfer_u64_1<kU16_Dst>, xfer_u64_1<kU16_Dst>,
xfer_u64_n<kF16_Dst>, xfer_u64_n<kF16_Dst>,
xfer_u64_1<kF16_Dst>, xfer_u64_1<kF16_Dst>,
};
///////////////////////////////////////////////////////////////////////////////////////////////////
template <DstType D> void clear(const SkXfermode*, uint64_t dst[],
const SkPM4f*, int count, const SkAlpha aa[]) {
if (aa) {
for (int i = 0; i < count; ++i) {
if (aa[i]) {
const Sk4f d4 = load_from_dst<D>(dst[i]);
dst[i] = store_to_dst<D>(d4 * Sk4f((255 - aa[i]) * 1.0f/255));
}
}
} else {
sk_memset64(dst, 0, count);
}
}
const SkXfermode::D64Proc gProcs_Clear[] = {
clear<kU16_Dst>, clear<kU16_Dst>,
clear<kU16_Dst>, clear<kU16_Dst>,
clear<kF16_Dst>, clear<kF16_Dst>,
clear<kF16_Dst>, clear<kF16_Dst>,
};
///////////////////////////////////////////////////////////////////////////////////////////////////
template <DstType D> void src_1(const SkXfermode*, uint64_t dst[],
const SkPM4f* src, int count, const SkAlpha aa[]) {
const Sk4f s4 = pm_to_rgba_order(unit_to_bias<D>(Sk4f::Load(src->fVec)));
if (aa) {
for (int i = 0; i < count; ++i) {
const Sk4f d4 = load_from_dst<D>(dst[i]);
dst[i] = store_to_dst<D>(lerp_by_coverage(s4, d4, aa[i]));
}
} else {
sk_memset64(dst, store_to_dst<D>(s4), count);
}
}
template <DstType D> void src_n(const SkXfermode*, uint64_t dst[],
const SkPM4f src[], int count, const SkAlpha aa[]) {
if (aa) {
for (int i = 0; i < count; ++i) {
const Sk4f s4 = pm_to_rgba_order(unit_to_bias<D>(Sk4f::Load(src[i].fVec)));
const Sk4f d4 = load_from_dst<D>(dst[i]);
dst[i] = store_to_dst<D>(lerp_by_coverage(s4, d4, aa[i]));
}
} else {
for (int i = 0; i < count; ++i) {
const Sk4f s4 = pm_to_rgba_order(unit_to_bias<D>(Sk4f::Load(src[i].fVec)));
dst[i] = store_to_dst<D>(s4);
}
}
}
const SkXfermode::D64Proc gProcs_Src[] = {
src_n<kU16_Dst>, src_n<kU16_Dst>,
src_1<kU16_Dst>, src_1<kU16_Dst>,
src_n<kF16_Dst>, src_n<kF16_Dst>,
src_1<kF16_Dst>, src_1<kF16_Dst>,
};
///////////////////////////////////////////////////////////////////////////////////////////////////
static void dst(const SkXfermode*, uint64_t*, const SkPM4f*, int count, const SkAlpha[]) {}
const SkXfermode::D64Proc gProcs_Dst[] = {
dst, dst, dst, dst, dst, dst, dst, dst,
};
///////////////////////////////////////////////////////////////////////////////////////////////////
template <DstType D> void srcover_1(const SkXfermode*, uint64_t dst[],
const SkPM4f* src, int count, const SkAlpha aa[]) {
const Sk4f s4 = pm_to_rgba_order(Sk4f::Load(src->fVec));
const Sk4f dst_scale = Sk4f(1 - get_alpha(s4));
const Sk4f s4bias = unit_to_bias<D>(s4);
for (int i = 0; i < count; ++i) {
const Sk4f d4bias = load_from_dst<D>(dst[i]);
const Sk4f r4bias = s4bias + d4bias * dst_scale;
if (aa) {
dst[i] = store_to_dst<D>(lerp_by_coverage(r4bias, d4bias, aa[i]));
} else {
dst[i] = store_to_dst<D>(r4bias);
}
}
}
template <DstType D> void srcover_n(const SkXfermode*, uint64_t dst[],
const SkPM4f src[], int count, const SkAlpha aa[]) {
for (int i = 0; i < count; ++i) {
const Sk4f s4 = pm_to_rgba_order(Sk4f::Load(src[i].fVec));
const Sk4f dst_scale = Sk4f(1 - get_alpha(s4));
const Sk4f s4bias = unit_to_bias<D>(s4);
const Sk4f d4bias = load_from_dst<D>(dst[i]);
const Sk4f r4bias = s4bias + d4bias * dst_scale;
if (aa) {
dst[i] = store_to_dst<D>(lerp_by_coverage(r4bias, d4bias, aa[i]));
} else {
dst[i] = store_to_dst<D>(r4bias);
}
}
}
const SkXfermode::D64Proc gProcs_SrcOver[] = {
srcover_n<kU16_Dst>, src_n<kU16_Dst>,
srcover_1<kU16_Dst>, src_1<kU16_Dst>,
srcover_n<kF16_Dst>, src_n<kF16_Dst>,
srcover_1<kF16_Dst>, src_1<kF16_Dst>,
};
///////////////////////////////////////////////////////////////////////////////////////////////////
static SkXfermode::D64Proc find_proc(SkXfermode::Mode mode, uint32_t flags) {
SkASSERT(0 == (flags & ~7));
flags &= 7;
switch (mode) {
case SkXfermode::kClear_Mode: return gProcs_Clear[flags];
case SkXfermode::kSrc_Mode: return gProcs_Src[flags];
case SkXfermode::kDst_Mode: return gProcs_Dst[flags];
case SkXfermode::kSrcOver_Mode: return gProcs_SrcOver[flags];
default:
break;
}
return gProcs_General[flags];
}
SkXfermode::D64Proc SkXfermode::onGetD64Proc(uint32_t flags) const {
SkASSERT(0 == (flags & ~7));
flags &= 7;
Mode mode;
return this->asMode(&mode) ? find_proc(mode, flags) : gProcs_General[flags];
}
SkXfermode::D64Proc SkXfermode::GetD64Proc(SkXfermode* xfer, uint32_t flags) {
return xfer ? xfer->onGetD64Proc(flags) : find_proc(SkXfermode::kSrcOver_Mode, flags);
}