kc3-lang/angle/src/common/blocklayout.h

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• Author : Jamie Madill
  Date : 2014-08-27 11:44:15
  Hash : a6f267f9
  Message : Fix row-major layout tracking in interface blocks. Some block field types, such as nested structs, were bugged. This only affects our "CollectVariables" path, not our current HLSL UBO path. BUG=angle:466 Change-Id: I2b8daf58aa7ec1ad06a80d38f57e76087eacccdc Reviewed-on: https://chromium-review.googlesource.com/213503 Tested-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Nicolas Capens <capn@chromium.org>

• src/common/blocklayout.h

• //
  // Copyright (c) 2013-2014 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.
  //
  // blocklayout.h:
  //   Methods and classes related to uniform layout and packing in GLSL and HLSL.
  //
  
  #ifndef COMMON_BLOCKLAYOUT_H_
  #define COMMON_BLOCKLAYOUT_H_
  
  #include <cstddef>
  #include <vector>
  
  #include "angle_gl.h"
  #include <GLSLANG/ShaderLang.h>
  
  namespace sh
  {
  struct ShaderVariable;
  struct InterfaceBlockField;
  struct Uniform;
  struct Varying;
  struct InterfaceBlock;
  
  struct BlockMemberInfo
  {
      BlockMemberInfo(int offset, int arrayStride, int matrixStride, bool isRowMajorMatrix)
          : offset(offset),
            arrayStride(arrayStride),
            matrixStride(matrixStride),
            isRowMajorMatrix(isRowMajorMatrix)
      {}
  
      static BlockMemberInfo getDefaultBlockInfo()
      {
          return BlockMemberInfo(-1, -1, -1, false);
      }
  
      int offset;
      int arrayStride;
      int matrixStride;
      bool isRowMajorMatrix;
  };
  
  class BlockLayoutEncoder
  {
    public:
      BlockLayoutEncoder();
  
      BlockMemberInfo encodeType(GLenum type, unsigned int arraySize, bool isRowMajorMatrix);
  
      size_t getBlockSize() const { return mCurrentOffset * BytesPerComponent; }
      size_t getCurrentRegister() const { return mCurrentOffset / ComponentsPerRegister; }
      size_t getCurrentElement() const { return mCurrentOffset % ComponentsPerRegister; }
  
      virtual void enterAggregateType() = 0;
      virtual void exitAggregateType() = 0;
  
      static const size_t BytesPerComponent = 4u;
      static const unsigned int ComponentsPerRegister = 4u;
  
    protected:
      size_t mCurrentOffset;
  
      void nextRegister();
  
      virtual void getBlockLayoutInfo(GLenum type, unsigned int arraySize, bool isRowMajorMatrix, int *arrayStrideOut, int *matrixStrideOut) = 0;
      virtual void advanceOffset(GLenum type, unsigned int arraySize, bool isRowMajorMatrix, int arrayStride, int matrixStride) = 0;
  };
  
  // Block layout according to the std140 block layout
  // See "Standard Uniform Block Layout" in Section 2.11.6 of the OpenGL ES 3.0 specification
  
  class Std140BlockEncoder : public BlockLayoutEncoder
  {
    public:
      Std140BlockEncoder();
  
      virtual void enterAggregateType();
      virtual void exitAggregateType();
  
    protected:
      virtual void getBlockLayoutInfo(GLenum type, unsigned int arraySize, bool isRowMajorMatrix, int *arrayStrideOut, int *matrixStrideOut);
      virtual void advanceOffset(GLenum type, unsigned int arraySize, bool isRowMajorMatrix, int arrayStride, int matrixStride);
  };
  
  // Block layout packed according to the D3D9 or default D3D10+ register packing rules
  // See http://msdn.microsoft.com/en-us/library/windows/desktop/bb509632(v=vs.85).aspx
  // The strategy should be ENCODE_LOOSE for D3D9 constant blocks, and ENCODE_PACKED
  // for everything else (D3D10+ constant blocks and all attributes/varyings).
  
  class HLSLBlockEncoder : public BlockLayoutEncoder
  {
    public:
      enum HLSLBlockEncoderStrategy
      {
          ENCODE_PACKED,
          ENCODE_LOOSE
      };
  
      HLSLBlockEncoder(HLSLBlockEncoderStrategy strategy);
  
      virtual void enterAggregateType();
      virtual void exitAggregateType();
      void skipRegisters(unsigned int numRegisters);
  
      bool isPacked() const { return mEncoderStrategy == ENCODE_PACKED; }
  
      static HLSLBlockEncoderStrategy GetStrategyFor(ShShaderOutput outputType);
  
    protected:
      virtual void getBlockLayoutInfo(GLenum type, unsigned int arraySize, bool isRowMajorMatrix, int *arrayStrideOut, int *matrixStrideOut);
      virtual void advanceOffset(GLenum type, unsigned int arraySize, bool isRowMajorMatrix, int arrayStride, int matrixStride);
  
      HLSLBlockEncoderStrategy mEncoderStrategy;
  };
  
  // This method returns the number of used registers for a ShaderVariable. It is dependent on the HLSLBlockEncoder
  // class to count the number of used registers in a struct (which are individually packed according to the same rules).
  unsigned int HLSLVariableRegisterCount(const Varying &variable);
  unsigned int HLSLVariableRegisterCount(const Uniform &variable, ShShaderOutput outputType);
  
  }
  
  #endif // COMMON_BLOCKLAYOUT_H_