submodule/skia/src/gpu/ganesh/GrProcessorAnalysis.cpp

   1 /*
   2  * Copyright 2014 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 "src/gpu/ganesh/GrCaps.h"
   9 #include "src/gpu/ganesh/GrFragmentProcessor.h"
  10 #include "src/gpu/ganesh/GrGeometryProcessor.h"
  11 #include "src/gpu/ganesh/GrProcessorAnalysis.h"
  12
  13 GrColorFragmentProcessorAnalysis::GrColorFragmentProcessorAnalysis(
  14         const GrProcessorAnalysisColor& input,
  15         std::unique_ptr<GrFragmentProcessor> const fps[],
  16         int count) {
  17     fCompatibleWithCoverageAsAlpha = true;
  18     fIsOpaque = input.isOpaque();
  19     fUsesLocalCoords = false;
  20     fWillReadDstColor = false;
  21     fProcessorsToEliminate = 0;
  22     fOutputColorKnown = input.isConstant(&fLastKnownOutputColor);
  23     for (int i = 0; i < count; ++i) {
  24         const GrFragmentProcessor* fp = fps[i].get();
  25         if (fOutputColorKnown && fp->hasConstantOutputForConstantInput(fLastKnownOutputColor,
  26                                                                        &fLastKnownOutputColor)) {
  27             ++fProcessorsToEliminate;
  28             fIsOpaque = fLastKnownOutputColor.isOpaque();
  29             // We reset these flags since the earlier fragment processors are being eliminated.
  30             fCompatibleWithCoverageAsAlpha = true;
  31             fUsesLocalCoords = false;
  32             fWillReadDstColor = false;
  33             continue;
  34         }
  35
  36         fOutputColorKnown = false;
  37         if (fIsOpaque && !fp->preservesOpaqueInput()) {
  38             fIsOpaque = false;
  39         }
  40         if (fCompatibleWithCoverageAsAlpha && !fp->compatibleWithCoverageAsAlpha()) {
  41             fCompatibleWithCoverageAsAlpha = false;
  42         }
  43         if (fp->usesSampleCoords()) {
  44             fUsesLocalCoords = true;
  45         }
  46         if (fp->willReadDstColor()) {
  47             fWillReadDstColor = true;
  48         }
  49     }
  50 }
  51
  52 bool GrColorFragmentProcessorAnalysis::requiresDstTexture(const GrCaps& caps) const {
  53     return this->willReadDstColor() && !caps.shaderCaps()->dstReadInShaderSupport();
  54 }