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

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• Hash : 2a1e8f95
  Author :
  Date : 2017-07-14T11:49:36
  

  Refer to GLSL extensions through TExtension enum
  
  Extensions are now referred to by enum values instead of strings most
  of the time. This gets rid of unnecessary copying of strings. The code
  is easier to work with than before as typoing the extension enum names
  will be caught by the compiler.
  
  BUG=angleproject:2147
  TEST=angle_unittests
  
  Change-Id: Ifa61b9f86ef03211188fc23bc23a5ce4e4d8c390
  Reviewed-on: https://chromium-review.googlesource.com/571002
  Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
  Reviewed-by: Jamie Madill <jmadill@chromium.org>
  

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• src/compiler/translator/TranslatorESSL.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/TranslatorESSL.h"
  
  #include "compiler/translator/BuiltInFunctionEmulatorGLSL.h"
  #include "compiler/translator/EmulatePrecision.h"
  #include "compiler/translator/PrunePureLiteralStatements.h"
  #include "compiler/translator/RecordConstantPrecision.h"
  #include "compiler/translator/OutputESSL.h"
  #include "angle_gl.h"
  
  namespace sh
  {
  
  TranslatorESSL::TranslatorESSL(sh::GLenum type, ShShaderSpec spec)
      : TCompiler(type, spec, SH_ESSL_OUTPUT)
  {
  }
  
  void TranslatorESSL::initBuiltInFunctionEmulator(BuiltInFunctionEmulator *emu,
                                                   ShCompileOptions compileOptions)
  {
      if (compileOptions & SH_EMULATE_ATAN2_FLOAT_FUNCTION)
      {
          InitBuiltInAtanFunctionEmulatorForGLSLWorkarounds(emu);
      }
  }
  
  void TranslatorESSL::translate(TIntermBlock *root, ShCompileOptions compileOptions)
  {
      // The ESSL output doesn't define a default precision for float, so float literal statements
      // end up with no precision which is invalid ESSL.
      PrunePureLiteralStatements(root);
  
      TInfoSinkBase &sink = getInfoSink().obj;
  
      int shaderVer = getShaderVersion();
      if (shaderVer > 100)
      {
          sink << "#version " << shaderVer << " es\n";
      }
  
      // Write built-in extension behaviors.
      writeExtensionBehavior(compileOptions);
  
      // Write pragmas after extensions because some drivers consider pragmas
      // like non-preprocessor tokens.
      writePragma(compileOptions);
  
      bool precisionEmulation =
          getResources().WEBGL_debug_shader_precision && getPragma().debugShaderPrecision;
  
      if (precisionEmulation)
      {
          EmulatePrecision emulatePrecision(&getSymbolTable(), shaderVer);
          root->traverse(&emulatePrecision);
          emulatePrecision.updateTree();
          emulatePrecision.writeEmulationHelpers(sink, shaderVer, SH_ESSL_OUTPUT);
      }
  
      RecordConstantPrecision(root, &getSymbolTable());
  
      // Write emulated built-in functions if needed.
      if (!getBuiltInFunctionEmulator().isOutputEmpty())
      {
          sink << "// BEGIN: Generated code for built-in function emulation\n\n";
          if (getShaderType() == GL_FRAGMENT_SHADER)
          {
              sink << "#if defined(GL_FRAGMENT_PRECISION_HIGH)\n"
                   << "#define emu_precision highp\n"
                   << "#else\n"
                   << "#define emu_precision mediump\n"
                   << "#endif\n\n";
          }
          else
          {
              sink << "#define emu_precision highp\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);
  
      if (getShaderType() == GL_COMPUTE_SHADER && isComputeShaderLocalSizeDeclared())
      {
          const sh::WorkGroupSize &localSize = getComputeShaderLocalSize();
          sink << "layout (local_size_x=" << localSize[0] << ", local_size_y=" << localSize[1]
               << ", local_size_z=" << localSize[2] << ") in;\n";
      }
  
      if (getShaderType() == GL_GEOMETRY_SHADER_OES)
      {
          WriteGeometryShaderLayoutQualifiers(
              sink, getGeometryShaderInputPrimitiveType(), getGeometryShaderInvocations(),
              getGeometryShaderOutputPrimitiveType(), getGeometryShaderMaxVertices());
      }
  
      // Write translated shader.
      TOutputESSL outputESSL(sink, getArrayIndexClampingStrategy(), getHashFunction(), getNameMap(),
                             &getSymbolTable(), getShaderType(), shaderVer, precisionEmulation,
                             compileOptions);
  
      if (compileOptions & SH_TRANSLATE_VIEWID_OVR_TO_UNIFORM)
      {
          TName uniformName(TString("ViewID_OVR"));
          uniformName.setInternal(true);
          sink << "highp uniform int " << outputESSL.hashName(uniformName) << ";\n";
      }
  
      root->traverse(&outputESSL);
  }
  
  bool TranslatorESSL::shouldFlattenPragmaStdglInvariantAll()
  {
      // Not necessary when translating to ESSL.
      return false;
  }
  
  void TranslatorESSL::writeExtensionBehavior(ShCompileOptions compileOptions)
  {
      TInfoSinkBase &sink                   = getInfoSink().obj;
      const TExtensionBehavior &extBehavior = getExtensionBehavior();
      const bool isMultiviewExtEmulated =
          (compileOptions &
           (SH_TRANSLATE_VIEWID_OVR_TO_UNIFORM | SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW |
            SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER)) != 0u;
      for (TExtensionBehavior::const_iterator iter = extBehavior.begin(); iter != extBehavior.end();
           ++iter)
      {
          if (iter->second != EBhUndefined)
          {
              const bool isMultiview = (iter->first == TExtension::OVR_multiview);
              if (getResources().NV_shader_framebuffer_fetch &&
                  iter->first == TExtension::EXT_shader_framebuffer_fetch)
              {
                  sink << "#extension GL_NV_shader_framebuffer_fetch : "
                       << GetBehaviorString(iter->second) << "\n";
              }
              else if (getResources().NV_draw_buffers && iter->first == TExtension::EXT_draw_buffers)
              {
                  sink << "#extension GL_NV_draw_buffers : " << GetBehaviorString(iter->second)
                       << "\n";
              }
              else if (isMultiview && isMultiviewExtEmulated)
              {
                  if (getShaderType() == GL_VERTEX_SHADER &&
                      (compileOptions & SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER) != 0u)
                  {
                      // Emit the NV_viewport_array2 extension in a vertex shader if the
                      // SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER option is set and the
                      // OVR_multiview(2) extension is requested.
                      sink << "#extension GL_NV_viewport_array2 : require\n";
                  }
              }
              else if (iter->first == TExtension::OES_geometry_shader)
              {
                  sink << "#ifdef GL_OES_geometry_shader\n"
                       << "#extension GL_OES_geometry_shader : " << GetBehaviorString(iter->second)
                       << "\n"
                       << "#elif defined GL_EXT_geometry_shader\n"
                       << "#extension GL_EXT_geometry_shader : " << GetBehaviorString(iter->second)
                       << "\n";
                  if (iter->second == EBhRequire)
                  {
                      sink << "#else\n"
                           << "#error \"No geometry shader extensions available.\" // Only generate "
                              "this if the extension is \"required\"\n";
                  }
                  sink << "#endif\n";
              }
              else
              {
                  sink << "#extension " << GetExtensionNameString(iter->first) << " : "
                       << GetBehaviorString(iter->second) << "\n";
              }
          }
      }
  }
  
  }  // namespace sh
  

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