SkRasterPipeline.cpp revision f6a1a2179ad6bf37dd81a658b30d12bfbdfa5c3f 
1/*
2 * Copyright 2016 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "SkOpts.h"
9#include "SkRasterPipeline.h"
10
11SkRasterPipeline::SkRasterPipeline() {}
12
13void SkRasterPipeline::append(StockStage stage, void* ctx) {
14    SkASSERT(stage != from_srgb);
15    fStages.push_back({stage, ctx});
16}
17
18void SkRasterPipeline::extend(const SkRasterPipeline& src) {
19    fStages.insert(fStages.end(),
20                   src.fStages.begin(), src.fStages.end());
21}
22
23void SkRasterPipeline::run(size_t x, size_t n) const {
24    if (!fStages.empty()) {
25        SkOpts::run_pipeline(x,n, fStages.data(), SkToInt(fStages.size()));
26    }
27}
28
29std::function<void(size_t, size_t)> SkRasterPipeline::compile() const {
30    return SkOpts::compile_pipeline(fStages.data(), SkToInt(fStages.size()));
31}
32
33void SkRasterPipeline::dump() const {
34    SkDebugf("SkRasterPipeline, %d stages\n", SkToInt(fStages.size()));
35    for (auto&& st : fStages) {
36        const char* name = "";
37        switch (st.stage) {
38        #define M(x) case x: name = #x; break;
39            SK_RASTER_PIPELINE_STAGES(M)
40        #undef M
41        }
42        SkDebugf("\t%s\n", name);
43    }
44    SkDebugf("\n");
45}
46
47// It's pretty easy to start with sound premultiplied linear floats, pack those
48// to sRGB encoded bytes, then read them back to linear floats and find them not
49// quite premultiplied, with a color channel just a smidge greater than the alpha
50// channel.  This can happen basically any time we have different transfer
51// functions for alpha and colors... sRGB being the only one we draw into.
52
53// This is an annoying problem with no known good solution.  So apply the clamp hammer.
54
55void SkRasterPipeline::append_from_srgb(SkAlphaType at) {
56    //this->append(from_srgb);
57    fStages.push_back({from_srgb, nullptr});
58
59    if (at == kPremul_SkAlphaType) {
60        this->append(SkRasterPipeline::clamp_a);
61    }
62}
63