skia2/tests/SRGBTest.cpp

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/*
* 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 "SkPM4f.h"
#include "SkRasterPipeline.h"
#include "SkSRGB.h"
#include "SkTypes.h"
#include "Test.h"
#include <math.h>
#include "../src/jumper/SkJumper.h"
static uint8_t linear_to_srgb(float l) {
return (uint8_t)sk_linear_to_srgb(Sk4f{l})[0];
}
DEF_TEST(sk_linear_to_srgb, r) {
// All bytes should round trip.
for (int i = 0; i < 256; i++) {
int actual = linear_to_srgb(sk_linear_from_srgb[i]);
if (i != actual) {
ERRORF(r, "%d -> %d\n", i, actual);
}
}
// Should be monotonic between 0 and 1.
uint8_t prev = 0;
for (float f = FLT_MIN; f <= 1.0f; ) { // We don't bother checking denorm values.
uint8_t srgb = linear_to_srgb(f);
REPORTER_ASSERT(r, srgb >= prev);
prev = srgb;
union { float flt; uint32_t bits; } pun = { f };
pun.bits++;
SkDEBUGCODE(pun.bits += 127);
f = pun.flt;
}
}
DEF_TEST(sk_pipeline_srgb_roundtrip, r) {
uint32_t reds[256];
for (int i = 0; i < 256; i++) {
reds[i] = i;
}
SkJumper_MemoryCtx ptr = { reds, 0 };
SkRasterPipeline_<256> p;
p.append(SkRasterPipeline::load_8888, &ptr);
p.append(SkRasterPipeline::from_srgb);
p.append(SkRasterPipeline::to_srgb);
p.append(SkRasterPipeline::store_8888, &ptr);
p.run(0,0,256,1);
for (int i = 0; i < 256; i++) {
if (reds[i] != (uint32_t)i) {
ERRORF(r, "%d doesn't round trip, %d", i, reds[i]);
}
}
}
DEF_TEST(sk_pipeline_srgb_edge_cases, r) {
// We need to run at least 4 pixels to make sure we hit all specializations.
SkPM4f colors[4] = { {{0,1,1,1}}, {{0,0,0,0}}, {{0,0,0,0}}, {{0,0,0,0}} };
auto& color = colors[0];
SkJumper_MemoryCtx dst = { &color, 0 };
SkSTArenaAlloc<256> alloc;
SkRasterPipeline p(&alloc);
p.append_constant_color(&alloc, color);
p.append(SkRasterPipeline::to_srgb);
p.append(SkRasterPipeline::store_f32, &dst);
p.run(0,0,4,1);
if (color.r() != 0.0f) {
ERRORF(r, "expected to_srgb() to map 0.0f to 0.0f, got %f", color.r());
}
if (color.g() != 1.0f) {
float f = color.g();
uint32_t x;
memcpy(&x, &f, 4);
ERRORF(r, "expected to_srgb() to map 1.0f to 1.0f, got %f (%08x)", color.g(), x);
}
}