2 // Copyright (c) 2013-2014 The ANGLE Project Authors. All rights reserved.
3 // Use of this source code is governed by a BSD-style license that can be
4 // found in the LICENSE file.
7 // Methods and classes related to uniform layout and packing in GLSL and HLSL.
10 #ifndef COMMON_BLOCKLAYOUT_H_
11 #define COMMON_BLOCKLAYOUT_H_
17 #include <GLSLANG/ShaderLang.h>
21 struct ShaderVariable;
22 struct InterfaceBlockField;
25 struct InterfaceBlock;
27 struct BlockMemberInfo
29 BlockMemberInfo(int offset, int arrayStride, int matrixStride, bool isRowMajorMatrix)
31 arrayStride(arrayStride),
32 matrixStride(matrixStride),
33 isRowMajorMatrix(isRowMajorMatrix)
36 static BlockMemberInfo getDefaultBlockInfo()
38 return BlockMemberInfo(-1, -1, -1, false);
44 bool isRowMajorMatrix;
47 class BlockLayoutEncoder
52 BlockMemberInfo encodeType(GLenum type, unsigned int arraySize, bool isRowMajorMatrix);
54 size_t getBlockSize() const { return mCurrentOffset * BytesPerComponent; }
55 size_t getCurrentRegister() const { return mCurrentOffset / ComponentsPerRegister; }
56 size_t getCurrentElement() const { return mCurrentOffset % ComponentsPerRegister; }
58 virtual void enterAggregateType() = 0;
59 virtual void exitAggregateType() = 0;
61 static const size_t BytesPerComponent = 4u;
62 static const unsigned int ComponentsPerRegister = 4u;
65 size_t mCurrentOffset;
69 virtual void getBlockLayoutInfo(GLenum type, unsigned int arraySize, bool isRowMajorMatrix, int *arrayStrideOut, int *matrixStrideOut) = 0;
70 virtual void advanceOffset(GLenum type, unsigned int arraySize, bool isRowMajorMatrix, int arrayStride, int matrixStride) = 0;
73 // Block layout according to the std140 block layout
74 // See "Standard Uniform Block Layout" in Section 2.11.6 of the OpenGL ES 3.0 specification
76 class Std140BlockEncoder : public BlockLayoutEncoder
81 virtual void enterAggregateType();
82 virtual void exitAggregateType();
85 virtual void getBlockLayoutInfo(GLenum type, unsigned int arraySize, bool isRowMajorMatrix, int *arrayStrideOut, int *matrixStrideOut);
86 virtual void advanceOffset(GLenum type, unsigned int arraySize, bool isRowMajorMatrix, int arrayStride, int matrixStride);
89 // Block layout packed according to the D3D9 or default D3D10+ register packing rules
90 // See http://msdn.microsoft.com/en-us/library/windows/desktop/bb509632(v=vs.85).aspx
91 // The strategy should be ENCODE_LOOSE for D3D9 constant blocks, and ENCODE_PACKED
92 // for everything else (D3D10+ constant blocks and all attributes/varyings).
94 class HLSLBlockEncoder : public BlockLayoutEncoder
97 enum HLSLBlockEncoderStrategy
103 HLSLBlockEncoder(HLSLBlockEncoderStrategy strategy);
105 virtual void enterAggregateType();
106 virtual void exitAggregateType();
107 void skipRegisters(unsigned int numRegisters);
109 bool isPacked() const { return mEncoderStrategy == ENCODE_PACKED; }
111 static HLSLBlockEncoderStrategy GetStrategyFor(ShShaderOutput outputType);
114 virtual void getBlockLayoutInfo(GLenum type, unsigned int arraySize, bool isRowMajorMatrix, int *arrayStrideOut, int *matrixStrideOut);
115 virtual void advanceOffset(GLenum type, unsigned int arraySize, bool isRowMajorMatrix, int arrayStride, int matrixStride);
117 HLSLBlockEncoderStrategy mEncoderStrategy;
120 // This method returns the number of used registers for a ShaderVariable. It is dependent on the HLSLBlockEncoder
121 // class to count the number of used registers in a struct (which are individually packed according to the same rules).
122 unsigned int HLSLVariableRegisterCount(const Varying &variable);
123 unsigned int HLSLVariableRegisterCount(const Uniform &variable, ShShaderOutput outputType);
127 #endif // COMMON_BLOCKLAYOUT_H_