skia2/tests/SkRasterPipelineTest.cpp
mtklein fe2042e60f SkRasterPipeline: new APIs for fusion
Most visibly this adds a macro SK_RASTER_STAGE that cuts down on the boilerplate of defining a raster pipeline stage function.

Most interestingly, SK_RASTER_STAGE doesn't define a SkRasterPipeline::Fn, but rather a new type EasyFn.  This function is always static and inlined, and the details of interacting with the SkRasterPipeline::Stage are taken care of for you: ctx is just passed as a void*, and st->next() is always called.  All EasyFns have to do is take care of the meat of the work: update r,g,b, etc. and read and write from their context.

The really neat new feature here is that you can either add EasyFns to a pipeline with the new append() functions, _or_ call them directly yourself.  This lets you use the same set of pieces to build either a pipelined version of the function or a custom, fused version.  The bench shows this off.

On my desktop, the pipeline version of the bench takes about 25% more time to run than the fused one.

The old approach to creating stages still works fine.  I haven't updated SkXfermode.cpp or SkArithmeticMode.cpp because they seemed just as clear using Fn directly as they would have using EasyFn.

If this looks okay to you I will rework the comments in SkRasterPipeline to explain SK_RASTER_STAGE and EasyFn a bit as I've done here in the CL description.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2195853002

Review-Url: https://codereview.chromium.org/2195853002
2016-07-29 14:27:41 -07:00

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2.2 KiB
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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 "Test.h"
#include "SkRasterPipeline.h"
// load needs two variants, one to load 4 values...
SK_RASTER_STAGE(load) {
auto ptr = (const float*)ctx + x;
r = Sk4f{ptr[0]};
g = Sk4f{ptr[1]};
b = Sk4f{ptr[2]};
a = Sk4f{ptr[3]};
}
// ...and one to load a single value.
SK_RASTER_STAGE(load_tail) {
auto ptr = (const float*)ctx + x;
r = Sk4f{*ptr};
}
// square doesn't really care how many of its inputs are active, nor does it need a context.
SK_RASTER_STAGE(square) {
r *= r;
g *= g;
b *= b;
a *= a;
}
// Like load, store has a _tail variant.
SK_RASTER_STAGE(store) {
auto ptr = (float*)ctx + x;
ptr[0] = r[0];
ptr[1] = g[0];
ptr[2] = b[0];
ptr[3] = a[0];
}
SK_RASTER_STAGE(store_tail) {
auto ptr = (float*)ctx + x;
*ptr = r[0];
}
DEF_TEST(SkRasterPipeline, r) {
// We'll build up and run a simple pipeline that exercises the salient
// mechanics of SkRasterPipeline:
// - context pointers
// - stages sensitive to the number of pixels
// - stages insensitive to the number of pixels
//
// This pipeline loads up some values, squares them, then writes them back to memory.
const float src_vals[] = { 1,2,3,4,5 };
float dst_vals[] = { 0,0,0,0,0 };
SkRasterPipeline p;
p.append<load, load_tail>(src_vals);
p.append<square>();
p.append<store, store_tail>(dst_vals);
p.run(5);
REPORTER_ASSERT(r, dst_vals[0] == 1);
REPORTER_ASSERT(r, dst_vals[1] == 4);
REPORTER_ASSERT(r, dst_vals[2] == 9);
REPORTER_ASSERT(r, dst_vals[3] == 16);
REPORTER_ASSERT(r, dst_vals[4] == 25);
}
DEF_TEST(SkRasterPipeline_empty, r) {
// No asserts... just a test that this is safe to run.
SkRasterPipeline p;
p.run(20);
}
DEF_TEST(SkRasterPipeline_nonsense, r) {
// No asserts... just a test that this is safe to run and terminates.
// square() always calls st->next(); this makes sure we've always got something there to call.
SkRasterPipeline p;
p.append<square>();
p.run(20);
}