tor-browser

ShaderVars.h (12728B)

---

//
// Copyright 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.
//
// ShaderVars.h:
//  Types to represent GL variables (varyings, uniforms, etc)
//

#ifndef GLSLANG_SHADERVARS_H_
#define GLSLANG_SHADERVARS_H_

#include <algorithm>
#include <array>
#include <cstdint>
#include <string>
#include <vector>

namespace sh
{
// GLenum alias
typedef unsigned int GLenum;

// Varying interpolation qualifier, see section 4.3.9 of the ESSL 3.00.4 spec
enum InterpolationType
{
   INTERPOLATION_SMOOTH,
   INTERPOLATION_CENTROID,
   INTERPOLATION_SAMPLE,
   INTERPOLATION_FLAT,
   INTERPOLATION_NOPERSPECTIVE
};

const char *InterpolationTypeToString(InterpolationType type);

// Validate link & SSO consistency of interpolation qualifiers
bool InterpolationTypesMatch(InterpolationType a, InterpolationType b);

// Uniform block layout qualifier, see section 4.3.8.3 of the ESSL 3.00.4 spec
enum BlockLayoutType
{
   BLOCKLAYOUT_STANDARD,
   BLOCKLAYOUT_STD140 = BLOCKLAYOUT_STANDARD,
   BLOCKLAYOUT_STD430,  // Shader storage block layout qualifier
   BLOCKLAYOUT_PACKED,
   BLOCKLAYOUT_SHARED
};

const char *BlockLayoutTypeToString(BlockLayoutType type);

// Interface Blocks, see section 4.3.9 of the ESSL 3.10 spec
enum class BlockType
{
   BLOCK_UNIFORM,
   BLOCK_BUFFER,
};

const char *BlockTypeToString(BlockType type);

// Base class for all variables defined in shaders, including Varyings, Uniforms, etc
// Note: we must override the copy constructor and assignment operator so we can
// work around excessive GCC binary bloating:
// See https://code.google.com/p/angleproject/issues/detail?id=697
struct ShaderVariable
{
   ShaderVariable();
   ShaderVariable(GLenum typeIn);
   ShaderVariable(GLenum typeIn, unsigned int arraySizeIn);
   ~ShaderVariable();
   ShaderVariable(const ShaderVariable &other);
   ShaderVariable &operator=(const ShaderVariable &other);
   bool operator==(const ShaderVariable &other) const;
   bool operator!=(const ShaderVariable &other) const { return !operator==(other); }

   bool isArrayOfArrays() const { return arraySizes.size() >= 2u; }
   bool isArray() const { return !arraySizes.empty(); }
   unsigned int getArraySizeProduct() const;
   // Return the inner array size product.
   // For example, if there's a variable declared as size 3 array of size 4 array of size 5 array
   // of int:
   //   int a[3][4][5];
   // then getInnerArraySizeProduct of a would be 4*5.
   unsigned int getInnerArraySizeProduct() const;

   // Array size 0 means not an array when passed to or returned from these functions.
   // Note that setArraySize() is deprecated and should not be used inside ANGLE.
   unsigned int getOutermostArraySize() const { return isArray() ? arraySizes.back() : 0; }
   void setArraySize(unsigned int size);

   // Turn this ShaderVariable from an array into a specific element in that array. Will update
   // flattenedOffsetInParentArrays.
   void indexIntoArray(unsigned int arrayIndex);

   // Get the nth nested array size from the top. Caller is responsible for range checking
   // arrayNestingIndex.
   unsigned int getNestedArraySize(unsigned int arrayNestingIndex) const;

   // This function should only be used with variables that are of a basic type or an array of a
   // basic type. Shader interface variables that are enumerated according to rules in GLES 3.1
   // spec section 7.3.1.1 page 77 are fine. For those variables the return value should match the
   // ARRAY_SIZE value that can be queried through the API.
   unsigned int getBasicTypeElementCount() const;

   unsigned int getExternalSize() const;

   bool isStruct() const { return !fields.empty(); }
   const std::string &getStructName() const { return structOrBlockName; }
   void setStructName(const std::string &newName) { structOrBlockName = newName; }

   // All of the shader's variables are described using nested data
   // structures. This is needed in order to disambiguate similar looking
   // types, such as two structs containing the same fields, but in
   // different orders. "findInfoByMappedName" provides an easy query for
   // users to dive into the data structure and fetch the unique variable
   // instance corresponding to a dereferencing chain of the top-level
   // variable.
   // Given a mapped name like 'a[0].b.c[0]', return the ShaderVariable
   // that defines 'c' in |leafVar|, and the original name 'A[0].B.C[0]'
   // in |originalName|, based on the assumption that |this| defines 'a'.
   // If no match is found, return false.
   bool findInfoByMappedName(const std::string &mappedFullName,
                             const ShaderVariable **leafVar,
                             std::string *originalFullName) const;

   // Find the child field which matches 'fullName' == var.name + "." + field.name.
   // Return nullptr if not found.
   const sh::ShaderVariable *findField(const std::string &fullName, uint32_t *fieldIndexOut) const;

   bool isBuiltIn() const;
   bool isEmulatedBuiltIn() const;

   // Offset of this variable in parent arrays. In case the parent is an array of arrays, the
   // offset is outerArrayElement * innerArraySize + innerArrayElement.
   // For example, if there's a variable declared as size 3 array of size 4 array of int:
   //   int a[3][4];
   // then the flattenedOffsetInParentArrays of a[2] would be 2.
   // and flattenedOffsetInParentArrays of a[2][1] would be 2*4 + 1 = 9.
   int parentArrayIndex() const
   {
       return hasParentArrayIndex() ? flattenedOffsetInParentArrays : 0;
   }

   int getFlattenedOffsetInParentArrays() const { return flattenedOffsetInParentArrays; }
   void setParentArrayIndex(int indexIn) { flattenedOffsetInParentArrays = indexIn; }

   bool hasParentArrayIndex() const { return flattenedOffsetInParentArrays != -1; }

   void resetEffectiveLocation();
   void updateEffectiveLocation(const sh::ShaderVariable &parent);

   // Decide whether two uniforms are the same at shader link time,
   // assuming they are from consecutive shader stages.
   // GLSL ES Spec 3.00.3, section 4.3.5.
   // GLSL ES Spec 3.10.4, section 4.4.5
   bool isSameUniformAtLinkTime(const ShaderVariable &other) const;

   // InterfaceBlockField
   // Decide whether two InterfaceBlock fields are the same at shader
   // link time, assuming they are from consecutive shader stages.
   // See GLSL ES Spec 3.00.3, sec 4.3.7.
   bool isSameInterfaceBlockFieldAtLinkTime(const ShaderVariable &other) const;

   // Decide whether two varyings are the same at shader link time,
   // assuming they are from consecutive shader stages.
   // Invariance needs to match only in ESSL1. Relevant spec sections:
   // GLSL ES 3.00.4, sections 4.6.1 and 4.3.9.
   // GLSL ES 1.00.17, section 4.6.4.
   bool isSameVaryingAtLinkTime(const ShaderVariable &other, int shaderVersion) const;
   // Deprecated version of isSameVaryingAtLinkTime, which assumes ESSL1.
   bool isSameVaryingAtLinkTime(const ShaderVariable &other) const;

   // Shader I/O blocks may match by block name or instance, based on whether both stages have an
   // instance name or not.
   bool isSameNameAtLinkTime(const ShaderVariable &other) const;

   // NOTE: When adding new members, the following functions also need to be updated:
   // gl::WriteShaderVar(BinaryOutputStream *stream, const sh::ShaderVariable &var)
   // gl::LoadShaderVar(BinaryInputStream *stream, sh::ShaderVariable *var)

   GLenum type;
   GLenum precision;
   std::string name;
   std::string mappedName;

   // Used to make an array type. Outermost array size is stored at the end of the vector.
   std::vector<unsigned int> arraySizes;

   // Static use means that the variable is accessed somewhere in the shader source.
   bool staticUse;
   // A variable is active unless the compiler determined that it is not accessed by the shader.
   // All active variables are statically used, but not all statically used variables are
   // necessarily active. GLES 3.0.5 section 2.12.6. GLES 3.1 section 7.3.1.
   bool active;
   std::vector<ShaderVariable> fields;
   // structOrBlockName is used for:
   // - varyings of struct type, in which case it contains the struct name.
   // - shader I/O blocks, in which case it contains the block name.
   std::string structOrBlockName;
   std::string mappedStructOrBlockName;

   // Only applies to interface block fields. Kept here for simplicity.
   bool isRowMajorLayout;

   // VariableWithLocation
   int location;

   // The location of inputs or outputs without location layout quailifer will be updated to '-1'.
   // GLES Spec 3.1, Section 7.3. PROGRAM OBJECTS
   // Not all active variables are assigned valid locations;
   // the following variables will have an effective location of -1:
   bool hasImplicitLocation;

   // Uniform
   int binding;
   GLenum imageUnitFormat;
   int offset;
   bool rasterOrdered;
   bool readonly;
   bool writeonly;

   // From EXT_shader_framebuffer_fetch / KHR_blend_equation_advanced
   bool isFragmentInOut;

   // OutputVariable
   // From EXT_blend_func_extended.
   int index;

   // From EXT_YUV_target
   bool yuv;

   // Varying
   InterpolationType interpolation;
   bool isInvariant;
   bool isShaderIOBlock;
   bool isPatch;

   // If the variable is a sampler that has ever been statically used with texelFetch
   bool texelFetchStaticUse;

 protected:
   bool isSameVariableAtLinkTime(const ShaderVariable &other,
                                 bool matchPrecision,
                                 bool matchName) const;

   // NOTE: When adding new members, the following functions also need to be updated:
   // gl::WriteShaderVar(BinaryOutputStream *stream, const sh::ShaderVariable &var)
   // gl::LoadShaderVar(BinaryInputStream *stream, sh::ShaderVariable *var)

   int flattenedOffsetInParentArrays;
};

// TODO: anglebug.com/3899
// For backwards compatibility for other codebases (e.g., chromium/src/gpu/command_buffer/service)
using Uniform             = ShaderVariable;
using Attribute           = ShaderVariable;
using OutputVariable      = ShaderVariable;
using InterfaceBlockField = ShaderVariable;
using Varying             = ShaderVariable;

struct InterfaceBlock
{
   InterfaceBlock();
   ~InterfaceBlock();
   InterfaceBlock(const InterfaceBlock &other);
   InterfaceBlock &operator=(const InterfaceBlock &other);

   // Fields from blocks with non-empty instance names are prefixed with the block name.
   std::string fieldPrefix() const;
   std::string fieldMappedPrefix() const;

   // Decide whether two interface blocks are the same at shader link time.
   bool isSameInterfaceBlockAtLinkTime(const InterfaceBlock &other) const;

   bool isBuiltIn() const;

   bool isArray() const { return arraySize > 0; }
   unsigned int elementCount() const { return std::max(1u, arraySize); }

   std::string name;
   std::string mappedName;
   std::string instanceName;
   unsigned int arraySize;
   BlockLayoutType layout;

   // Deprecated. Matrix packing should only be queried from individual fields of the block.
   // TODO(oetuaho): Remove this once it is no longer used in Chromium.
   bool isRowMajorLayout;

   int binding;
   bool staticUse;
   bool active;
   BlockType blockType;
   std::vector<ShaderVariable> fields;
};

struct WorkGroupSize
{
   // Must have a trivial default constructor since it is used in YYSTYPE.
   inline WorkGroupSize() = default;
   inline explicit constexpr WorkGroupSize(int initialSize);

   void fill(int fillValue);
   void setLocalSize(int localSizeX, int localSizeY, int localSizeZ);

   int &operator[](size_t index);
   int operator[](size_t index) const;
   size_t size() const;

   // Checks whether two work group size declarations match.
   // Two work group size declarations are the same if the explicitly specified elements are the
   // same or if one of them is specified as one and the other one is not specified
   bool isWorkGroupSizeMatching(const WorkGroupSize &right) const;

   // Checks whether any of the values are set.
   bool isAnyValueSet() const;

   // Checks whether all of the values are set.
   bool isDeclared() const;

   // Checks whether either all of the values are set, or none of them are.
   bool isLocalSizeValid() const;

   int localSizeQualifiers[3];
};

inline constexpr WorkGroupSize::WorkGroupSize(int initialSize)
   : localSizeQualifiers{initialSize, initialSize, initialSize}
{}

}  // namespace sh

#endif  // GLSLANG_SHADERVARS_H_