DEF_TEST(SkColorSpace_New_TransferFnStages, r) {
// We'll create a little SkRasterPipelineBlitter-like scenario,
// blending the same src color over the same dst color, but with
// three different transfer functions, for simplicity the same for src and dst.
SkColor src = 0x7f7f0000;
SkColor dsts[3];
for (SkColor& dst : dsts) {
dst = 0xff007f00;
}
auto gamut = SkMatrix44::I();
auto blending = SkColorSpace_New::Blending::Linear;
SkColorSpace_New linear{SkColorSpace_New::TransferFn::MakeLinear(), gamut, blending},
srgb{SkColorSpace_New::TransferFn::MakeSRGB(), gamut, blending},
gamma{SkColorSpace_New::TransferFn::MakeGamma(3), gamut, blending};
SkColor* dst = dsts;
for (const SkColorSpace_New* cs : {&linear, &srgb, &gamma}) {
SkJumper_MemoryCtx src_ctx = { &src, 0 },
dst_ctx = { dst++, 0 };
SkRasterPipeline_<256> p;
p.append(SkRasterPipeline::load_8888, &src_ctx);
cs->transferFn().linearizeSrc(&p);
p.append(SkRasterPipeline::premul);
p.append(SkRasterPipeline::load_8888_dst, &dst_ctx);
cs->transferFn().linearizeDst(&p);
p.append(SkRasterPipeline::premul_dst);
p.append(SkRasterPipeline::srcover);
p.append(SkRasterPipeline::unpremul);
cs->transferFn().encodeSrc(&p);
p.append(SkRasterPipeline::store_8888, &dst_ctx);
p.run(0,0,1,1);
}
// Double check the uninteresting channels: alpha's opaque, no blue.
REPORTER_ASSERT(r, SkColorGetA(dsts[0]) == 0xff && SkColorGetB(dsts[0]) == 0x00);
REPORTER_ASSERT(r, SkColorGetA(dsts[1]) == 0xff && SkColorGetB(dsts[1]) == 0x00);
REPORTER_ASSERT(r, SkColorGetA(dsts[2]) == 0xff && SkColorGetB(dsts[2]) == 0x00);
// Because we're doing linear blending, a more-exponential transfer function will
// brighten the encoded values more when linearizing. So we expect to see that
// linear is darker than sRGB, and sRGB in turn is darker than gamma 3.
REPORTER_ASSERT(r, SkColorGetR(dsts[0]) < SkColorGetR(dsts[1]));
REPORTER_ASSERT(r, SkColorGetR(dsts[1]) < SkColorGetR(dsts[2]));
REPORTER_ASSERT(r, SkColorGetG(dsts[0]) < SkColorGetG(dsts[1]));
REPORTER_ASSERT(r, SkColorGetG(dsts[1]) < SkColorGetG(dsts[2]));
}
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];
void* dst = &color;
SkRasterPipeline_<256> p;
p.append(SkRasterPipeline::uniform_color, &color);
p.append(SkRasterPipeline::to_srgb);
p.append(SkRasterPipeline::store_f32, &dst);
p.run(0,0,4);
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);
}
}
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_roundtrip, r) {
uint32_t reds[256];
for (int i = 0; i < 256; i++) {
reds[i] = i;
}
auto ptr = (void*)reds;
SkRasterPipeline_<256> p;
p.append(SkRasterPipeline::load_8888, &ptr);
p.append_from_srgb(kUnpremul_SkAlphaType);
p.append(SkRasterPipeline::to_srgb);
p.append(SkRasterPipeline::store_8888, &ptr);
p.run(0,0,256);
for (int i = 0; i < 256; i++) {
if (reds[i] != (uint32_t)i) {
ERRORF(r, "%d doesn't round trip, %d", i, reds[i]);
}
}
}
SkBlitter* SkRasterPipelineBlitter::Create(const SkPixmap& dst,
const SkPaint& paint,
SkArenaAlloc* alloc,
const SkRasterPipeline& shaderPipeline,
SkShaderBase::Context* burstCtx,
bool is_opaque,
bool is_constant) {
auto blitter = alloc->make<SkRasterPipelineBlitter>(dst,
paint.getBlendMode(),
alloc,
burstCtx);
// Our job in this factory is to fill out the blitter's color pipeline.
// This is the common front of the full blit pipelines, each constructed lazily on first use.
// The full blit pipelines handle reading and writing the dst, blending, coverage, dithering.
auto colorPipeline = &blitter->fColorPipeline;
// Let's get the shader in first.
if (burstCtx) {
colorPipeline->append(SkRasterPipeline::load_f32, &blitter->fShaderOutput);
} else {
colorPipeline->extend(shaderPipeline);
}
// If there's a color filter it comes next.
if (auto colorFilter = paint.getColorFilter()) {
colorFilter->appendStages(colorPipeline, dst.colorSpace(), alloc, is_opaque);
is_opaque = is_opaque && (colorFilter->getFlags() & SkColorFilter::kAlphaUnchanged_Flag);
}
// Not all formats make sense to dither (think, F16). We set their dither rate to zero.
// We need to decide if we're going to dither now to keep is_constant accurate.
if (paint.isDither()) {
switch (dst.info().colorType()) {
default: blitter->fDitherRate = 0.0f; break;
case kARGB_4444_SkColorType: blitter->fDitherRate = 1/15.0f; break;
case kRGB_565_SkColorType: blitter->fDitherRate = 1/63.0f; break;
case kGray_8_SkColorType:
case kRGBA_8888_SkColorType:
case kBGRA_8888_SkColorType: blitter->fDitherRate = 1/255.0f; break;
}
// TODO: for constant colors, we could try to measure the effect of dithering, and if
// it has no value (i.e. all variations result in the same 32bit color, then we
// could disable it (for speed, by not adding the stage).
}
is_constant = is_constant && (blitter->fDitherRate == 0.0f);
// We're logically done here. The code between here and return blitter is all optimization.
// A pipeline that's still constant here can collapse back into a constant color.
if (is_constant) {
SkPM4f storage;
SkPM4f* constantColor = &storage;
colorPipeline->append(SkRasterPipeline::store_f32, &constantColor);
colorPipeline->run(0,0,1);
colorPipeline->reset();
colorPipeline->append_uniform_color(alloc, *constantColor);
is_opaque = constantColor->a() == 1.0f;
}
// We can strength-reduce SrcOver into Src when opaque.
if (is_opaque && blitter->fBlend == SkBlendMode::kSrcOver) {
blitter->fBlend = SkBlendMode::kSrc;
}
// When we're drawing a constant color in Src mode, we can sometimes just memset.
// (The previous two optimizations help find more opportunities for this one.)
if (is_constant && blitter->fBlend == SkBlendMode::kSrc) {
// Run our color pipeline all the way through to produce what we'd memset when we can.
// Not all blits can memset, so we need to keep colorPipeline too.
SkRasterPipeline_<256> p;
p.extend(*colorPipeline);
blitter->fDstPtr = &blitter->fMemsetColor;
blitter->append_store(&p);
p.run(0,0,1);
blitter->fCanMemsetInBlitH = true;
}
return blitter;
}