skia2/tests/Float16Test.cpp
msarett 6bdbf4412b Improve naive SkColorXform to half floats
This should give us a good baseline to explore using SkRasterPipeline.

A particular colorxform to half float drops from 425us to 282us on my desktop.

Color Xform to Half Float (HP z620)
Original                              425us
Trans16 (not 32)                      355us
Vector Trans16                        378us
Trans16 + Keep Halfs in Vector        335us
Vector Trans16 + Keep Halfs in Vector 282us
Final                                 282us

Color Xform to Half Float (Nexus 5X)
Original                              556us
Final                                 472us

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2159993003
CQ_INCLUDE_TRYBOTS=master.client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot

Review-Url: https://codereview.chromium.org/2159993003
2016-07-19 09:07:55 -07:00

106 lines
2.9 KiB
C++

/*
* 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 "Test.h"
#include "SkAutoPixmapStorage.h"
#include "SkColor.h"
#include "SkHalf.h"
#include "SkOpts.h"
#include "SkPixmap.h"
#include "SkPM4f.h"
#include "SkRandom.h"
static bool eq_within_half_float(float a, float b) {
const float kTolerance = 1.0f / (1 << (8 + 10));
SkHalf ha = SkFloatToHalf(a);
SkHalf hb = SkFloatToHalf(b);
float a2 = SkHalfToFloat(ha);
float b2 = SkHalfToFloat(hb);
return fabsf(a2 - b2) <= kTolerance;
}
static bool eq_within_half_float(const SkPM4f& a, const SkPM4f& b) {
for (int i = 0; i < 4; ++i) {
if (!eq_within_half_float(a.fVec[i], b.fVec[i])) {
return false;
}
}
return true;
}
DEF_TEST(color_half_float, reporter) {
const int w = 100;
const int h = 100;
SkImageInfo info = SkImageInfo::Make(w, h, kRGBA_F16_SkColorType, kPremul_SkAlphaType);
SkAutoPixmapStorage pm;
pm.alloc(info);
REPORTER_ASSERT(reporter, pm.getSafeSize() == SkToSizeT(w * h * sizeof(uint64_t)));
SkColor4f c4 { 1, 0.5f, 0.25f, 0.5f };
pm.erase(c4);
SkPM4f origpm4 = c4.premul();
for (int y = 0; y < pm.height(); ++y) {
for (int x = 0; x < pm.width(); ++x) {
SkPM4f pm4 = SkPM4f::FromF16(pm.addrF16(x, y));
REPORTER_ASSERT(reporter, eq_within_half_float(origpm4, pm4));
}
}
}
static uint32_t u(float f) {
uint32_t x;
memcpy(&x, &f, 4);
return x;
}
DEF_TEST(HalfToFloat_finite, r) {
for (uint32_t h = 0; h <= 0xffff; h++) {
float f = SkHalfToFloat(h);
if (isfinite(f)) {
float got = SkHalfToFloat_finite(h)[0];
if (got != f) {
SkDebugf("0x%04x -> 0x%08x (%g), want 0x%08x (%g)\n",
h,
u(got), got,
u(f), f);
}
REPORTER_ASSERT(r, SkHalfToFloat_finite(h)[0] == f);
uint64_t result;
SkFloatToHalf_finite(SkHalfToFloat_finite(h)).store(&result);
REPORTER_ASSERT(r, result == h);
}
}
}
DEF_TEST(FloatToHalf_finite, r) {
#if 0
for (uint64_t bits = 0; bits <= 0xffffffff; bits++) {
#else
SkRandom rand;
for (int i = 0; i < 1000000; i++) {
uint32_t bits = rand.nextU();
#endif
float f;
memcpy(&f, &bits, 4);
if (isfinite(f) && isfinite(SkHalfToFloat(SkFloatToHalf(f)))) {
uint16_t h1 = SkFloatToHalf_finite(Sk4f(f,0,0,0))[0],
h2 = SkFloatToHalf(f);
bool ok = (h1 == h2 || h1 == h2-1);
REPORTER_ASSERT(r, ok);
if (!ok) {
SkDebugf("%08x (%g) -> %04x, want %04x (%g)\n",
bits, f, h1, h2, SkHalfToFloat(h2));
break;
}
}
}
}