/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef Sk4px_DEFINED
#define Sk4px_DEFINED
#include "SkNx.h"
#include "SkColor.h"
#include "SkColorData.h"
// This file may be included multiple times by .cpp files with different flags, leading
// to different definitions. Usually that doesn't matter because it's all inlined, but
// in Debug modes the compilers may not inline everything. So wrap everything in an
// anonymous namespace to give each includer their own silo of this code (or the linker
// will probably pick one randomly for us, which is rarely correct).
namespace {
// 1, 2 or 4 SkPMColors, generally vectorized.
class Sk4px : public Sk16b {
public:
static Sk4px DupAlpha(SkAlpha a) { return Sk16b(a); } // a -> aaaa aaaa aaaa aaaa
static Sk4px DupPMColor(SkPMColor c); // argb -> argb argb argb argb
Sk4px(const Sk16b& v) : INHERITED(v) {}
Sk4px alphas() const; // ARGB argb XYZW xyzw -> AAAA aaaa XXXX xxxx
// Mask away color or alpha lanes.
Sk4px zeroColors() const; // ARGB argb XYZW xyzw -> A000 a000 X000 x000
Sk4px zeroAlphas() const; // ARGB argb XYZW xyzw -> 0RGB 0rgb 0YZW 0yzw
Sk4px inv() const { return Sk16b(255) - *this; }
// When loading or storing fewer than 4 SkPMColors, we use the low lanes.
static Sk4px Load4(const SkPMColor[4]); // PMColor[4] -> ARGB argb XYZW xyzw
static Sk4px Load2(const SkPMColor[2]); // PMColor[2] -> ARGB argb ???? ????
static Sk4px Load1(const SkPMColor[1]); // PMColor[1] -> ARGB ???? ???? ????
// Ditto for Alphas... Load2Alphas fills the low two lanes of Sk4px.
static Sk4px Load4Alphas(const SkAlpha[4]); // AaXx -> AAAA aaaa XXXX xxxx
static Sk4px Load2Alphas(const SkAlpha[2]); // Aa -> AAAA aaaa ???? ????
void store4(SkPMColor[4]) const;
void store2(SkPMColor[2]) const;
void store1(SkPMColor[1]) const;
// 1, 2, or 4 SkPMColors with 16-bit components.
// This is most useful as the result of a multiply, e.g. from mulWiden().
class Wide : public Sk16h {
public:
Wide(const Sk16h& v) : Sk16h(v) {}
// Pack the top byte of each component back down into 4 SkPMColors.
Sk4px addNarrowHi(const Sk16h&) const;
// Rounds, i.e. (x+127) / 255.
Sk4px div255() const;
// These just keep the types as Wide so the user doesn't have to keep casting.
Wide operator * (const Wide& o) const { return INHERITED::operator*(o); }
Wide operator + (const Wide& o) const { return INHERITED::operator+(o); }
Wide operator - (const Wide& o) const { return INHERITED::operator-(o); }
Wide operator >> (int bits) const { return INHERITED::operator>>(bits); }
Wide operator << (int bits) const { return INHERITED::operator<<(bits); }
static Wide Min(const Wide& a, const Wide& b) { return INHERITED::Min(a,b); }
Wide thenElse(const Wide& t, const Wide& e) const { return INHERITED::thenElse(t,e); }
private:
typedef Sk16h INHERITED;
};
Wide widenLo() const; // ARGB -> 0A 0R 0G 0B
Wide widenHi() const; // ARGB -> A0 R0 G0 B0
Wide widenLoHi() const; // ARGB -> AA RR GG BB
Wide mulWiden(const Sk16b&) const; // 8-bit x 8-bit -> 16-bit components.
// The only 8-bit multiply we use is 8-bit x 8-bit -> 16-bit. Might as well make it pithy.
Wide operator * (const Sk4px& o) const { return this->mulWiden(o); }
// These just keep the types as Sk4px so the user doesn't have to keep casting.
Sk4px operator + (const Sk4px& o) const { return INHERITED::operator+(o); }
Sk4px operator - (const Sk4px& o) const { return INHERITED::operator-(o); }
Sk4px operator < (const Sk4px& o) const { return INHERITED::operator<(o); }
Sk4px thenElse(const Sk4px& t, const Sk4px& e) const { return INHERITED::thenElse(t,e); }
// Generally faster than (*this * o).div255().
// May be incorrect by +-1, but is always exactly correct when *this or o is 0 or 255.
Sk4px approxMulDiv255(const Sk16b& o) const {
// (x*y + x) / 256 meets these criteria. (As of course does (x*y + y) / 256 by symmetry.)
// FYI: (x*y + 255) / 256 also meets these criteria. In my brief testing, it was slower.
return this->widenLo().addNarrowHi(*this * o);
}
// A generic driver that maps fn over a src array into a dst array.
// fn should take an Sk4px (4 src pixels) and return an Sk4px (4 dst pixels).
template <typename Fn>
static void MapSrc(int n, SkPMColor* dst, const SkPMColor* src, const Fn& fn) {
SkASSERT(dst);
SkASSERT(src);
// This looks a bit odd, but it helps loop-invariant hoisting across different calls to fn.
// Basically, we need to make sure we keep things inside a single loop.
while (n > 0) {
if (n >= 8) {
Sk4px dst0 = fn(Load4(src+0)),
dst4 = fn(Load4(src+4));
dst0.store4(dst+0);
dst4.store4(dst+4);
dst += 8; src += 8; n -= 8;
continue; // Keep our stride at 8 pixels as long as possible.
}
SkASSERT(n <= 7);
if (n >= 4) {
fn(Load4(src)).store4(dst);
dst += 4; src += 4; n -= 4;
}
if (n >= 2) {
fn(Load2(src)).store2(dst);
dst += 2; src += 2; n -= 2;
}
if (n >= 1) {
fn(Load1(src)).store1(dst);
}
break;
}
}
// As above, but with dst4' = fn(dst4, src4).
template <typename Fn>
static void MapDstSrc(int n, SkPMColor* dst, const SkPMColor* src, const Fn& fn) {
SkASSERT(dst);
SkASSERT(src);
while (n > 0) {
if (n >= 8) {
Sk4px dst0 = fn(Load4(dst+0), Load4(src+0)),
dst4 = fn(Load4(dst+4), Load4(src+4));
dst0.store4(dst+0);
dst4.store4(dst+4);
dst += 8; src += 8; n -= 8;
continue; // Keep our stride at 8 pixels as long as possible.
}
SkASSERT(n <= 7);
if (n >= 4) {
fn(Load4(dst), Load4(src)).store4(dst);
dst += 4; src += 4; n -= 4;
}
if (n >= 2) {
fn(Load2(dst), Load2(src)).store2(dst);
dst += 2; src += 2; n -= 2;
}
if (n >= 1) {
fn(Load1(dst), Load1(src)).store1(dst);
}
break;
}
}
// As above, but with dst4' = fn(dst4, alpha4).
template <typename Fn>
static void MapDstAlpha(int n, SkPMColor* dst, const SkAlpha* a, const Fn& fn) {
SkASSERT(dst);
SkASSERT(a);
while (n > 0) {
if (n >= 8) {
Sk4px dst0 = fn(Load4(dst+0), Load4Alphas(a+0)),
dst4 = fn(Load4(dst+4), Load4Alphas(a+4));
dst0.store4(dst+0);
dst4.store4(dst+4);
dst += 8; a += 8; n -= 8;
continue; // Keep our stride at 8 pixels as long as possible.
}
SkASSERT(n <= 7);
if (n >= 4) {
fn(Load4(dst), Load4Alphas(a)).store4(dst);
dst += 4; a += 4; n -= 4;
}
if (n >= 2) {
fn(Load2(dst), Load2Alphas(a)).store2(dst);
dst += 2; a += 2; n -= 2;
}
if (n >= 1) {
fn(Load1(dst), DupAlpha(*a)).store1(dst);
}
break;
}
}
// As above, but with dst4' = fn(dst4, src4, alpha4).
template <typename Fn>
static void MapDstSrcAlpha(int n, SkPMColor* dst, const SkPMColor* src, const SkAlpha* a,
const Fn& fn) {
SkASSERT(dst);
SkASSERT(src);
SkASSERT(a);
while (n > 0) {
if (n >= 8) {
Sk4px dst0 = fn(Load4(dst+0), Load4(src+0), Load4Alphas(a+0)),
dst4 = fn(Load4(dst+4), Load4(src+4), Load4Alphas(a+4));
dst0.store4(dst+0);
dst4.store4(dst+4);
dst += 8; src += 8; a += 8; n -= 8;
continue; // Keep our stride at 8 pixels as long as possible.
}
SkASSERT(n <= 7);
if (n >= 4) {
fn(Load4(dst), Load4(src), Load4Alphas(a)).store4(dst);
dst += 4; src += 4; a += 4; n -= 4;
}
if (n >= 2) {
fn(Load2(dst), Load2(src), Load2Alphas(a)).store2(dst);
dst += 2; src += 2; a += 2; n -= 2;
}
if (n >= 1) {
fn(Load1(dst), Load1(src), DupAlpha(*a)).store1(dst);
}
break;
}
}
private:
typedef Sk16b INHERITED;
};
} // namespace
#ifdef SKNX_NO_SIMD
#include "../opts/Sk4px_none.h"
#else
#if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2
#include "../opts/Sk4px_SSE2.h"
#elif defined(SK_ARM_HAS_NEON)
#include "../opts/Sk4px_NEON.h"
#else
#include "../opts/Sk4px_none.h"
#endif
#endif
#endif//Sk4px_DEFINED