blob: 7bacf56af729dc1a96792d373aae4f216182f468 [file] [log] [blame]
#include "SkColorPriv.h"
#include "SkPMFloat.h"
#include <emmintrin.h>
// For set(), we widen our 8 bit components (fix8) to 8-bit components in 16 bits (fix8_16),
// then widen those to 8-bit-in-32-bits (fix8_32), convert those to floats (scaled),
// then finally scale those down from [0.0f, 255.0f] to [0.0f, 1.0f] into fColor.
// get() and clamped() do the opposite, working from [0.0f, 1.0f] floats to [0.0f, 255.0f],
// to 8-bit-in-32-bit, to 8-bit-in-16-bit, back down to 8-bit components.
// _mm_packus_epi16() gives us clamping for free while narrowing.
inline void SkPMFloat::set(SkPMColor c) {
SkPMColorAssert(c);
__m128i fix8 = _mm_set_epi32(0,0,0,c),
fix8_16 = _mm_unpacklo_epi8 (fix8, _mm_setzero_si128()),
fix8_32 = _mm_unpacklo_epi16(fix8_16, _mm_setzero_si128());
__m128 scaled = _mm_cvtepi32_ps(fix8_32);
_mm_store_ps(fColor, _mm_mul_ps(scaled, _mm_set1_ps(1.0f/255.0f)));
SkASSERT(this->isValid());
}
inline SkPMColor SkPMFloat::get() const {
SkASSERT(this->isValid());
return this->clamped(); // At the moment, we don't know anything faster.
}
inline SkPMColor SkPMFloat::clamped() const {
__m128 scaled = _mm_mul_ps(_mm_load_ps(fColor), _mm_set1_ps(255.0f));
__m128i fix8_32 = _mm_cvtps_epi32(scaled),
fix8_16 = _mm_packus_epi16(fix8_32, fix8_32),
fix8 = _mm_packus_epi16(fix8_16, fix8_16);
SkPMColor c = _mm_cvtsi128_si32(fix8);
SkPMColorAssert(c);
return c;
}