kc3-lang/angle/src/compiler/translator/TranslatorGLSL.cpp

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• Author : Qingqing Deng
  Date : 2015-04-08 14:25:06
  Hash : ad0d0799
  Message : Expand ShShaderOutput for different GLSL versions BUG=angleproject:968 Change-Id: I2d4c0a8e9a91a940922da4501c22124da0c0399c Reviewed-on: https://chromium-review.googlesource.com/264840 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Olli Etuaho <oetuaho@nvidia.com> Tested-by: Jamie Madill <jmadill@chromium.org>

• src/compiler/translator/TranslatorGLSL.cpp

• //
  // Copyright (c) 2002-2013 The ANGLE Project Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  //
  
  #include "compiler/translator/TranslatorGLSL.h"
  
  #include "angle_gl.h"
  #include "compiler/translator/BuiltInFunctionEmulatorGLSL.h"
  #include "compiler/translator/EmulatePrecision.h"
  #include "compiler/translator/OutputGLSL.h"
  #include "compiler/translator/VersionGLSL.h"
  
  namespace
  {
  
  // To search for what output variables are used in a fragment shader.
  // We handle gl_FragColor and gl_FragData at the moment.
  class TFragmentOutSearcher : public TIntermTraverser
  {
    public:
      TFragmentOutSearcher()
          : mUsesGlFragColor(false),
            mUsesGlFragData(false)
      {
      }
  
      bool usesGlFragColor() const
      {
          return mUsesGlFragColor;
      }
  
      bool usesGlFragData() const
      {
          return mUsesGlFragData;
      }
  
    protected:
      virtual void visitSymbol(TIntermSymbol *node) override
      {
          if (node->getSymbol() == "gl_FragColor")
          {
              mUsesGlFragColor = true;
          }
          else if (node->getSymbol() == "gl_FragData")
          {
              mUsesGlFragData = true;
          }
      }
  
    private:
      bool mUsesGlFragColor;
      bool mUsesGlFragData;
  };
  
  }  // namespace anonymous
  
  TranslatorGLSL::TranslatorGLSL(sh::GLenum type,
                                 ShShaderSpec spec,
                                 ShShaderOutput output)
      : TCompiler(type, spec, output) {
  }
  
  void TranslatorGLSL::initBuiltInFunctionEmulator(BuiltInFunctionEmulator *emu, int compileOptions)
  {
      if (compileOptions & SH_EMULATE_BUILT_IN_FUNCTIONS)
          InitBuiltInFunctionEmulatorForGLSL(emu, getShaderType());
  }
  
  void TranslatorGLSL::translate(TIntermNode *root, int) {
      TInfoSinkBase& sink = getInfoSink().obj;
  
      // Write GLSL version.
      writeVersion(root);
  
      writePragma();
  
      // Write extension behaviour as needed
      writeExtensionBehavior();
  
      bool precisionEmulation = getResources().WEBGL_debug_shader_precision && getPragma().debugShaderPrecision;
  
      if (precisionEmulation)
      {
          EmulatePrecision emulatePrecision;
          root->traverse(&emulatePrecision);
          emulatePrecision.updateTree();
          emulatePrecision.writeEmulationHelpers(sink, getOutputType());
      }
  
      // Write emulated built-in functions if needed.
      if (!getBuiltInFunctionEmulator().IsOutputEmpty())
      {
          sink << "// BEGIN: Generated code for built-in function emulation\n\n";
          sink << "#define webgl_emu_precision\n\n";
          getBuiltInFunctionEmulator().OutputEmulatedFunctions(sink);
          sink << "// END: Generated code for built-in function emulation\n\n";
      }
  
      // Write array bounds clamping emulation if needed.
      getArrayBoundsClamper().OutputClampingFunctionDefinition(sink);
  
      // Declare gl_FragColor and glFragData as webgl_FragColor and webgl_FragData
      // if it's core profile shaders and they are used.
      if (getShaderType() == GL_FRAGMENT_SHADER && IsGLSL130OrNewer(getOutputType()))
      {
          TFragmentOutSearcher searcher;
          root->traverse(&searcher);
          ASSERT(!(searcher.usesGlFragData() && searcher.usesGlFragColor()));
          if (searcher.usesGlFragColor())
          {
              sink << "out vec4 webgl_FragColor;\n";
          }
          if (searcher.usesGlFragData())
          {
              sink << "out vec4 webgl_FragData[gl_MaxDrawBuffers];\n";
          }
      }
  
      // Write translated shader.
      TOutputGLSL outputGLSL(sink,
                             getArrayIndexClampingStrategy(),
                             getHashFunction(),
                             getNameMap(),
                             getSymbolTable(),
                             getShaderVersion(),
                             getOutputType());
      root->traverse(&outputGLSL);
  }
  
  void TranslatorGLSL::writeVersion(TIntermNode *root)
  {
      TVersionGLSL versionGLSL(getShaderType(), getPragma(), getOutputType());
      root->traverse(&versionGLSL);
      int version = versionGLSL.getVersion();
      // We need to write version directive only if it is greater than 110.
      // If there is no version directive in the shader, 110 is implied.
      if (version > 110)
      {
          TInfoSinkBase& sink = getInfoSink().obj;
          sink << "#version " << version << "\n";
      }
  }
  
  void TranslatorGLSL::writeExtensionBehavior() {
      TInfoSinkBase& sink = getInfoSink().obj;
      const TExtensionBehavior& extBehavior = getExtensionBehavior();
      for (TExtensionBehavior::const_iterator iter = extBehavior.begin();
           iter != extBehavior.end(); ++iter) {
          if (iter->second == EBhUndefined)
              continue;
  
          // For GLSL output, we don't need to emit most extensions explicitly,
          // but some we need to translate.
          if (iter->first == "GL_EXT_shader_texture_lod") {
              sink << "#extension GL_ARB_shader_texture_lod : "
                   << getBehaviorString(iter->second) << "\n";
          }
      }
  }