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kc3-lang/angle/include/GLSLANG

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  • Author : Zhenyao Mo
    Date : 2013-09-23 14:57:09
    Hash : ac44cd2b
    Message : Add an option in ANGLE shader translator to initialize gl_Position to vec4(0.0, 0.0, 0.0, 1.0). This is to work around driver bugs where shader compile or program link would fail incorrectly if gl_Position is not set in vertex shader. At the moment at least Linux NVIDIA driver has this bug. ANGLEBUG=472 R=alokp@chromium.org, kbr@chromium.org Review URL: https://codereview.appspot.com/13509043

  • ShaderLang.h
  • //
    // 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.
    //
    #ifndef _COMPILER_INTERFACE_INCLUDED_
    #define _COMPILER_INTERFACE_INCLUDED_
    
    #if defined(COMPONENT_BUILD)
    #if defined(_WIN32) || defined(_WIN64)
    
    #if defined(COMPILER_IMPLEMENTATION)
    #define COMPILER_EXPORT __declspec(dllexport)
    #else
    #define COMPILER_EXPORT __declspec(dllimport)
    #endif  // defined(COMPILER_IMPLEMENTATION)
    
    #else  // defined(WIN32)
    #define COMPILER_EXPORT __attribute__((visibility("default")))
    #endif
    
    #else  // defined(COMPONENT_BUILD)
    #define COMPILER_EXPORT
    #endif
    
    #include "KHR/khrplatform.h"
    #include <stddef.h>
    
    //
    // This is the platform independent interface between an OGL driver
    // and the shading language compiler.
    //
    
    #ifdef __cplusplus
    extern "C" {
    #endif
    
    // Version number for shader translation API.
    // It is incremented every time the API changes.
    #define ANGLE_SH_VERSION 122
    
    //
    // The names of the following enums have been derived by replacing GL prefix
    // with SH. For example, SH_INFO_LOG_LENGTH is equivalent to GL_INFO_LOG_LENGTH.
    // The enum values are also equal to the values of their GL counterpart. This
    // is done to make it easier for applications to use the shader library.
    //
    typedef enum {
      SH_FRAGMENT_SHADER = 0x8B30,
      SH_VERTEX_SHADER   = 0x8B31
    } ShShaderType;
    
    typedef enum {
      SH_GLES2_SPEC = 0x8B40,
      SH_WEBGL_SPEC = 0x8B41,
    
      // The CSS Shaders spec is a subset of the WebGL spec.
      //
      // In both CSS vertex and fragment shaders, ANGLE:
      // (1) Reserves the "css_" prefix.
      // (2) Renames the main function to css_main.
      // (3) Disables the gl_MaxDrawBuffers built-in.
      //
      // In CSS fragment shaders, ANGLE:
      // (1) Disables the gl_FragColor built-in.
      // (2) Disables the gl_FragData built-in.
      // (3) Enables the css_MixColor built-in.
      // (4) Enables the css_ColorMatrix built-in.
      //
      // After passing a CSS shader through ANGLE, the browser is expected to append
      // a new main function to it.
      // This new main function will call the css_main function.
      // It may also perform additional operations like varying assignment, texture
      // access, and gl_FragColor assignment in order to implement the CSS Shaders
      // blend modes.
      //
      SH_CSS_SHADERS_SPEC = 0x8B42
    } ShShaderSpec;
    
    typedef enum {
      SH_ESSL_OUTPUT   = 0x8B45,
      SH_GLSL_OUTPUT   = 0x8B46,
      SH_HLSL_OUTPUT   = 0x8B47,
      SH_HLSL9_OUTPUT  = 0x8B47,
      SH_HLSL11_OUTPUT = 0x8B48
    } ShShaderOutput;
    
    typedef enum {
      SH_NONE           = 0,
      SH_INT            = 0x1404,
      SH_UNSIGNED_INT   = 0x1405,
      SH_FLOAT          = 0x1406,
      SH_FLOAT_VEC2     = 0x8B50,
      SH_FLOAT_VEC3     = 0x8B51,
      SH_FLOAT_VEC4     = 0x8B52,
      SH_INT_VEC2       = 0x8B53,
      SH_INT_VEC3       = 0x8B54,
      SH_INT_VEC4       = 0x8B55,
      SH_UNSIGNED_INT_VEC2 = 0x8DC6,
      SH_UNSIGNED_INT_VEC3 = 0x8DC7,
      SH_UNSIGNED_INT_VEC4 = 0x8DC8,
      SH_BOOL           = 0x8B56,
      SH_BOOL_VEC2      = 0x8B57,
      SH_BOOL_VEC3      = 0x8B58,
      SH_BOOL_VEC4      = 0x8B59,
      SH_FLOAT_MAT2     = 0x8B5A,
      SH_FLOAT_MAT3     = 0x8B5B,
      SH_FLOAT_MAT4     = 0x8B5C,
      SH_FLOAT_MAT2x3   = 0x8B65,
      SH_FLOAT_MAT2x4   = 0x8B66,
      SH_FLOAT_MAT3x2   = 0x8B67,
      SH_FLOAT_MAT3x4   = 0x8B68,
      SH_FLOAT_MAT4x2   = 0x8B69,
      SH_FLOAT_MAT4x3   = 0x8B6A,
      SH_SAMPLER_2D     = 0x8B5E,
      SH_SAMPLER_3D     = 0x8B5F,
      SH_SAMPLER_CUBE   = 0x8B60,
      SH_SAMPLER_2D_RECT_ARB = 0x8B63,
      SH_SAMPLER_EXTERNAL_OES = 0x8D66,
      SH_SAMPLER_2D_ARRAY   = 0x8DC1,
      SH_INT_SAMPLER_2D     = 0x8DCA,
      SH_INT_SAMPLER_3D     = 0x8DCB,
      SH_INT_SAMPLER_CUBE   = 0x8DCC,
      SH_INT_SAMPLER_2D_ARRAY = 0x8DCF,
      SH_UNSIGNED_INT_SAMPLER_2D     = 0x8DD2,
      SH_UNSIGNED_INT_SAMPLER_3D     = 0x8DD3,
      SH_UNSIGNED_INT_SAMPLER_CUBE   = 0x8DD4,
      SH_UNSIGNED_INT_SAMPLER_2D_ARRAY = 0x8DD7,
      SH_SAMPLER_2D_SHADOW       = 0x8B62,
      SH_SAMPLER_CUBE_SHADOW     = 0x8DC5,
      SH_SAMPLER_2D_ARRAY_SHADOW = 0x8DC4
    } ShDataType;
    
    typedef enum {
      SH_PRECISION_HIGHP     = 0x5001,
      SH_PRECISION_MEDIUMP   = 0x5002,
      SH_PRECISION_LOWP      = 0x5003,
      SH_PRECISION_UNDEFINED = 0
    } ShPrecisionType;
    
    typedef enum {
      SH_INFO_LOG_LENGTH                = 0x8B84,
      SH_OBJECT_CODE_LENGTH             = 0x8B88,  // GL_SHADER_SOURCE_LENGTH
      SH_ACTIVE_UNIFORMS                = 0x8B86,
      SH_ACTIVE_UNIFORM_MAX_LENGTH      = 0x8B87,
      SH_ACTIVE_ATTRIBUTES              = 0x8B89,
      SH_ACTIVE_ATTRIBUTE_MAX_LENGTH    = 0x8B8A,
      SH_VARYINGS                       = 0x8BBB,
      SH_VARYING_MAX_LENGTH             = 0x8BBC,
      SH_MAPPED_NAME_MAX_LENGTH         = 0x6000,
      SH_NAME_MAX_LENGTH                = 0x6001,
      SH_HASHED_NAME_MAX_LENGTH         = 0x6002,
      SH_HASHED_NAMES_COUNT             = 0x6003,
      SH_ACTIVE_UNIFORMS_ARRAY          = 0x6004,
      SH_SHADER_VERSION                 = 0x6005,
      SH_ACTIVE_INTERFACE_BLOCKS_ARRAY  = 0x6006,
      SH_ACTIVE_OUTPUT_VARIABLES_ARRAY  = 0x6007,
      SH_ACTIVE_ATTRIBUTES_ARRAY        = 0x6008,
      SH_ACTIVE_VARYINGS_ARRAY          = 0x6009,
    } ShShaderInfo;
    
    // Compile options.
    typedef enum {
      SH_VALIDATE                = 0,
      SH_VALIDATE_LOOP_INDEXING  = 0x0001,
      SH_INTERMEDIATE_TREE       = 0x0002,
      SH_OBJECT_CODE             = 0x0004,
      SH_VARIABLES               = 0x0008,
      SH_LINE_DIRECTIVES         = 0x0010,
      SH_SOURCE_PATH             = 0x0020,
      SH_MAP_LONG_VARIABLE_NAMES = 0x0040,
      SH_UNROLL_FOR_LOOP_WITH_INTEGER_INDEX = 0x0080,
    
      // This is needed only as a workaround for certain OpenGL driver bugs.
      SH_EMULATE_BUILT_IN_FUNCTIONS = 0x0100,
    
      // This is an experimental flag to enforce restrictions that aim to prevent 
      // timing attacks.
      // It generates compilation errors for shaders that could expose sensitive
      // texture information via the timing channel.
      // To use this flag, you must compile the shader under the WebGL spec
      // (using the SH_WEBGL_SPEC flag).
      SH_TIMING_RESTRICTIONS = 0x0200,
        
      // This flag prints the dependency graph that is used to enforce timing
      // restrictions on fragment shaders.
      // This flag only has an effect if all of the following are true:
      // - The shader spec is SH_WEBGL_SPEC.
      // - The compile options contain the SH_TIMING_RESTRICTIONS flag.
      // - The shader type is SH_FRAGMENT_SHADER.
      SH_DEPENDENCY_GRAPH = 0x0400,
    
      // Enforce the GLSL 1.017 Appendix A section 7 packing restrictions.
      // This flag only enforces (and can only enforce) the packing
      // restrictions for uniform variables in both vertex and fragment
      // shaders. ShCheckVariablesWithinPackingLimits() lets embedders
      // enforce the packing restrictions for varying variables during
      // program link time.
      SH_ENFORCE_PACKING_RESTRICTIONS = 0x0800,
    
      // This flag ensures all indirect (expression-based) array indexing
      // is clamped to the bounds of the array. This ensures, for example,
      // that you cannot read off the end of a uniform, whether an array
      // vec234, or mat234 type. The ShArrayIndexClampingStrategy enum,
      // specified in the ShBuiltInResources when constructing the
      // compiler, selects the strategy for the clamping implementation.
      SH_CLAMP_INDIRECT_ARRAY_BOUNDS = 0x1000,
    
      // This flag limits the complexity of an expression.
      SH_LIMIT_EXPRESSION_COMPLEXITY = 0x2000,
    
      // This flag limits the depth of the call stack.
      SH_LIMIT_CALL_STACK_DEPTH = 0x4000,
    
      // This flag initializes gl_Position to vec4(0.0, 0.0, 0.0, 1.0) at
      // the beginning of the vertex shader, and has no effect in the
      // fragment shader. It is intended as a workaround for drivers which
      // incorrectly fail to link programs if gl_Position is not written.
      SH_INIT_GL_POSITION = 0x8000,
    } ShCompileOptions;
    
    // Defines alternate strategies for implementing array index clamping.
    typedef enum {
      // Use the clamp intrinsic for array index clamping.
      SH_CLAMP_WITH_CLAMP_INTRINSIC = 1,
    
      // Use a user-defined function for array index clamping.
      SH_CLAMP_WITH_USER_DEFINED_INT_CLAMP_FUNCTION
    } ShArrayIndexClampingStrategy;
    
    //
    // Driver must call this first, once, before doing any other
    // compiler operations.
    // If the function succeeds, the return value is nonzero, else zero.
    //
    COMPILER_EXPORT int ShInitialize();
    //
    // Driver should call this at shutdown.
    // If the function succeeds, the return value is nonzero, else zero.
    //
    COMPILER_EXPORT int ShFinalize();
    
    // The 64 bits hash function. The first parameter is the input string; the
    // second parameter is the string length.
    typedef khronos_uint64_t (*ShHashFunction64)(const char*, size_t);
    
    //
    // Implementation dependent built-in resources (constants and extensions).
    // The names for these resources has been obtained by stripping gl_/GL_.
    //
    typedef struct
    {
        // Constants.
        int MaxVertexAttribs;
        int MaxVertexUniformVectors;
        int MaxVaryingVectors;
        int MaxVertexTextureImageUnits;
        int MaxCombinedTextureImageUnits;
        int MaxTextureImageUnits;
        int MaxFragmentUniformVectors;
        int MaxDrawBuffers;
    
        // Extensions.
        // Set to 1 to enable the extension, else 0.
        int OES_standard_derivatives;
        int OES_EGL_image_external;
        int ARB_texture_rectangle;
        int EXT_draw_buffers;
        int EXT_frag_depth;
    
        // Set to 1 if highp precision is supported in the fragment language.
        // Default is 0.
        int FragmentPrecisionHigh;
    
        // GLSL ES 3.0 constants.
        int MaxVertexOutputVectors;
        int MaxFragmentInputVectors;
        int MinProgramTexelOffset;
        int MaxProgramTexelOffset;
    
        // Name Hashing.
        // Set a 64 bit hash function to enable user-defined name hashing.
        // Default is NULL.
        ShHashFunction64 HashFunction;
    
        // Selects a strategy to use when implementing array index clamping.
        // Default is SH_CLAMP_WITH_CLAMP_INTRINSIC.
        ShArrayIndexClampingStrategy ArrayIndexClampingStrategy;
    
        // The maximum complexity an expression can be.
        int MaxExpressionComplexity;
    
        // The maximum depth a call stack can be.
        int MaxCallStackDepth;
    } ShBuiltInResources;
    
    //
    // Initialize built-in resources with minimum expected values.
    //
    COMPILER_EXPORT void ShInitBuiltInResources(ShBuiltInResources* resources);
    
    //
    // ShHandle held by but opaque to the driver.  It is allocated,
    // managed, and de-allocated by the compiler. It's contents 
    // are defined by and used by the compiler.
    //
    // If handle creation fails, 0 will be returned.
    //
    typedef void* ShHandle;
    
    //
    // Driver calls these to create and destroy compiler objects.
    //
    // Returns the handle of constructed compiler, null if the requested compiler is
    // not supported.
    // Parameters:
    // type: Specifies the type of shader - SH_FRAGMENT_SHADER or SH_VERTEX_SHADER.
    // spec: Specifies the language spec the compiler must conform to -
    //       SH_GLES2_SPEC or SH_WEBGL_SPEC.
    // output: Specifies the output code type - SH_ESSL_OUTPUT, SH_GLSL_OUTPUT,
    //         SH_HLSL9_OUTPUT or SH_HLSL11_OUTPUT.
    // resources: Specifies the built-in resources.
    COMPILER_EXPORT ShHandle ShConstructCompiler(
        ShShaderType type,
        ShShaderSpec spec,
        ShShaderOutput output,
        const ShBuiltInResources* resources);
    COMPILER_EXPORT void ShDestruct(ShHandle handle);
    
    //
    // Compiles the given shader source.
    // If the function succeeds, the return value is nonzero, else zero.
    // Parameters:
    // handle: Specifies the handle of compiler to be used.
    // shaderStrings: Specifies an array of pointers to null-terminated strings
    //                containing the shader source code.
    // numStrings: Specifies the number of elements in shaderStrings array.
    // compileOptions: A mask containing the following parameters:
    // SH_VALIDATE: Validates shader to ensure that it conforms to the spec
    //              specified during compiler construction.
    // SH_VALIDATE_LOOP_INDEXING: Validates loop and indexing in the shader to
    //                            ensure that they do not exceed the minimum
    //                            functionality mandated in GLSL 1.0 spec,
    //                            Appendix A, Section 4 and 5.
    //                            There is no need to specify this parameter when
    //                            compiling for WebGL - it is implied.
    // SH_INTERMEDIATE_TREE: Writes intermediate tree to info log.
    //                       Can be queried by calling ShGetInfoLog().
    // SH_OBJECT_CODE: Translates intermediate tree to glsl or hlsl shader.
    //                 Can be queried by calling ShGetObjectCode().
    // SH_VARIABLES: Extracts attributes, uniforms, and varyings.
    //               Can be queried by calling ShGetVariableInfo().
    //
    COMPILER_EXPORT int ShCompile(
        const ShHandle handle,
        const char* const shaderStrings[],
        size_t numStrings,
        int compileOptions
        );
    
    // Returns a parameter from a compiled shader.
    // Parameters:
    // handle: Specifies the compiler
    // pname: Specifies the parameter to query.
    // The following parameters are defined:
    // SH_INFO_LOG_LENGTH: the number of characters in the information log
    //                     including the null termination character.
    // SH_OBJECT_CODE_LENGTH: the number of characters in the object code
    //                        including the null termination character.
    // SH_ACTIVE_ATTRIBUTES: the number of active attribute variables.
    // SH_ACTIVE_ATTRIBUTE_MAX_LENGTH: the length of the longest active attribute
    //                                 variable name including the null
    //                                 termination character.
    // SH_ACTIVE_UNIFORMS: the number of active uniform variables.
    // SH_ACTIVE_UNIFORM_MAX_LENGTH: the length of the longest active uniform
    //                               variable name including the null
    //                               termination character.
    // SH_VARYINGS: the number of varying variables.
    // SH_VARYING_MAX_LENGTH: the length of the longest varying variable name
    //                        including the null termination character.
    // SH_MAPPED_NAME_MAX_LENGTH: the length of the mapped variable name including
    //                            the null termination character.
    // SH_NAME_MAX_LENGTH: the max length of a user-defined name including the
    //                     null termination character.
    // SH_HASHED_NAME_MAX_LENGTH: the max length of a hashed name including the
    //                            null termination character.
    // SH_HASHED_NAMES_COUNT: the number of hashed names from the latest compile.
    // SH_SHADER_VERSION: the version of the shader language
    //
    // params: Requested parameter
    COMPILER_EXPORT void ShGetInfo(const ShHandle handle,
                                   ShShaderInfo pname,
                                   size_t* params);
    
    // Returns nul-terminated information log for a compiled shader.
    // Parameters:
    // handle: Specifies the compiler
    // infoLog: Specifies an array of characters that is used to return
    //          the information log. It is assumed that infoLog has enough memory
    //          to accomodate the information log. The size of the buffer required
    //          to store the returned information log can be obtained by calling
    //          ShGetInfo with SH_INFO_LOG_LENGTH.
    COMPILER_EXPORT void ShGetInfoLog(const ShHandle handle, char* infoLog);
    
    // Returns null-terminated object code for a compiled shader.
    // Parameters:
    // handle: Specifies the compiler
    // infoLog: Specifies an array of characters that is used to return
    //          the object code. It is assumed that infoLog has enough memory to
    //          accomodate the object code. The size of the buffer required to
    //          store the returned object code can be obtained by calling
    //          ShGetInfo with SH_OBJECT_CODE_LENGTH.
    COMPILER_EXPORT void ShGetObjectCode(const ShHandle handle, char* objCode);
    
    // Returns information about a shader variable.
    // Parameters:
    // handle: Specifies the compiler
    // variableType: Specifies the variable type; options include
    //               SH_ACTIVE_ATTRIBUTES, SH_ACTIVE_UNIFORMS, SH_VARYINGS.
    // index: Specifies the index of the variable to be queried.
    // length: Returns the number of characters actually written in the string
    //         indicated by name (excluding the null terminator) if a value other
    //         than NULL is passed.
    // size: Returns the size of the variable.
    // type: Returns the data type of the variable.
    // precision: Returns the precision of the variable.
    // staticUse: Returns 1 if the variable is accessed in a statement after
    //            pre-processing, whether or not run-time flow of control will
    //            cause that statement to be executed.
    //            Returns 0 otherwise.
    // name: Returns a null terminated string containing the name of the
    //       variable. It is assumed that name has enough memory to accormodate
    //       the variable name. The size of the buffer required to store the
    //       variable name can be obtained by calling ShGetInfo with
    //       SH_ACTIVE_ATTRIBUTE_MAX_LENGTH, SH_ACTIVE_UNIFORM_MAX_LENGTH,
    //       SH_VARYING_MAX_LENGTH.
    // mappedName: Returns a null terminated string containing the mapped name of
    //             the variable, It is assumed that mappedName has enough memory
    //             (SH_MAPPED_NAME_MAX_LENGTH), or NULL if don't care about the
    //             mapped name. If the name is not mapped, then name and mappedName
    //             are the same.
    COMPILER_EXPORT void ShGetVariableInfo(const ShHandle handle,
                                           ShShaderInfo variableType,
                                           int index,
                                           size_t* length,
                                           int* size,
                                           ShDataType* type,
                                           ShPrecisionType* precision,
                                           int* staticUse,
                                           char* name,
                                           char* mappedName);
    
    // Returns information about a name hashing entry from the latest compile.
    // Parameters:
    // handle: Specifies the compiler
    // index: Specifies the index of the name hashing entry to be queried.
    // name: Returns a null terminated string containing the user defined name.
    //       It is assumed that name has enough memory to accomodate the name.
    //       The size of the buffer required to store the user defined name can
    //       be obtained by calling ShGetInfo with SH_NAME_MAX_LENGTH.
    // hashedName: Returns a null terminated string containing the hashed name of
    //             the uniform variable, It is assumed that hashedName has enough
    //             memory to accomodate the name. The size of the buffer required
    //             to store the name can be obtained by calling ShGetInfo with
    //             SH_HASHED_NAME_MAX_LENGTH.
    COMPILER_EXPORT void ShGetNameHashingEntry(const ShHandle handle,
                                               int index,
                                               char* name,
                                               char* hashedName);
    
    // Returns a parameter from a compiled shader.
    // Parameters:
    // handle: Specifies the compiler
    // pname: Specifies the parameter to query.
    // The following parameters are defined:
    // SH_ACTIVE_UNIFORMS_ARRAY: an STL vector of active uniforms. Valid only for
    //                           HLSL output.
    // params: Requested parameter
    COMPILER_EXPORT void ShGetInfoPointer(const ShHandle handle,
                                          ShShaderInfo pname,
                                          void** params);
    
    typedef struct
    {
        ShDataType type;
        int size;
    } ShVariableInfo;
    
    // Returns 1 if the passed in variables pack in maxVectors following
    // the packing rules from the GLSL 1.017 spec, Appendix A, section 7.
    // Returns 0 otherwise. Also look at the SH_ENFORCE_PACKING_RESTRICTIONS
    // flag above.
    // Parameters:
    // maxVectors: the available rows of registers.
    // varInfoArray: an array of variable info (types and sizes).
    // varInfoArraySize: the size of the variable array.
    COMPILER_EXPORT int ShCheckVariablesWithinPackingLimits(
        int maxVectors,
        ShVariableInfo* varInfoArray,
        size_t varInfoArraySize);
    
    #ifdef __cplusplus
    }
    #endif
    
    #endif // _COMPILER_INTERFACE_INCLUDED_