Name MESA_shader_debug Name Strings GL_MESA_shader_debug Contact Brian Paul (brian.paul 'at' tungstengraphics.com) Michal Krol (mjkrol 'at' gmail.com) Status XXX - Not complete yet!!! Version Last Modified Date: July 30, 2006 Author Revision: 0.2 Number TBD Dependencies OpenGL 1.0 is required. The ARB_shader_objects extension is required. The ARB_shading_language_100 extension is required. The extension is written against the OpenGL 1.5 specification. The extension is written against the OpenGL Shading Language 1.10 Specification. Overview This extension introduces a debug object that can be attached to a program object to enable debugging. Vertex and/or fragment shader, during execution, issue diagnostic function calls that are logged to the debug object's log. A separate debug log for each shader type is maintained. A debug object can be attached, detached and queried at any time outside the Begin/End pair. Multiple debug objects can be attached to a single program object. IP Status None Issues None New Procedures and Functions handleARB CreateDebugObjectMESA(void) void ClearDebugLogMESA(handleARB obj, enum logType, enum shaderType) void GetDebugLogMESA(handleARB obj, enum logType, enum shaderType, sizei maxLength, sizei *length, charARB *debugLog) sizei GetDebugLogLengthMESA(handleARB obj, enum logType, enum shaderType) New Types None New Tokens Returned by the parameter of GetObjectParameter{fi}vARB: DEBUG_OBJECT_MESA 0x8759 Accepted by the argument of ClearDebugLogMESA, GetDebugLogLengthMESA and GetDebugLogMESA: DEBUG_PRINT_MESA 0x875A DEBUG_ASSERT_MESA 0x875B Additions to Chapter 2 of the OpenGL 1.5 Specification (OpenGL Operation) None Additions to Chapter 3 of the OpenGL 1.5 Specification (Rasterization) None Additions to Chapter 4 of the OpenGL 1.5 Specification (Per-Fragment Operations and the Frame Buffer) None Additions to Chapter 5 of the OpenGL 1.5 Specification (Special Functions) None Additions to Chapter 6 of the OpenGL 1.5 Specification (State and State Requests) None Additions to Appendix A of the OpenGL 1.5 Specification (Invariance) None Additions to Chapter 1 of the OpenGL Shading Language 1.10 Specification (Introduction) None Additions to Chapter 2 of the OpenGL Shading Language 1.10 Specification (Overview of OpenGL Shading) None Additions to Chapter 3 of the OpenGL Shading Language 1.10 Specification (Basics) None Additions to Chapter 4 of the OpenGL Shading Language 1.10 Specification (Variables and Types) None Additions to Chapter 5 of the OpenGL Shading Language 1.10 Specification (Operators and Expressions) None Additions to Chapter 6 of the OpenGL Shading Language 1.10 Specification (Statements and Structure) None Additions to Chapter 7 of the OpenGL Shading Language 1.10 Specification (Built-in Variables) None Additions to Chapter 8 of the OpenGL Shading Language 1.10 Specification (Built-in Functions) Add a new section 8.10 "Debug Functions": Debug functions are available to both fragment and vertex shaders. They are used to track the execution of a shader by logging passed-in arguments to the debug object's log. Those values can be retrieved by the application for inspection after shader execution is complete. The text, if any, produced by any of these functions is appended to each debug object that is attached to the program object. There are different debug log types Add a new section 8.10.1 "Print Function": The following printMESA prototypes are available. void printMESA(const float value) void printMESA(const int value) void printMESA(const bool value) void printMESA(const vec2 value) void printMESA(const vec3 value) void printMESA(const vec4 value) void printMESA(const ivec2 value) void printMESA(const ivec3 value) void printMESA(const ivec4 value) void printMESA(const bvec2 value) void printMESA(const bvec3 value) void printMESA(const bvec4 value) void printMESA(const mat2 value) void printMESA(const mat3 value) void printMESA(const mat4 value) void printMESA(const sampler1D value) void printMESA(const sampler2D value) void printMESA(const sampler3D value) void printMESA(const samplerCube value) void printMESA(const sampler1DShadow value) void printMESA(const sampler2DShadow value) The printMESA function writes the argument to the "debug print log" (XXX DEBUG_PRINT_MESA?). Each component is written in text format (XXX format!) and is delimited by a white space (XXX 1 or more?). Add a new section 8.10.2 "Assert Function": The following assertMESA prototypes are available. void assertMESA(const bool condition) void assertMESA(const bool condition, const int cookie) void assertMESA(const bool condition, const int cookie, const int file, const int line) The assertMESA function checks if the argument is true or false. If it is true, nothing happens. If it is false, a diagnostic message is written to the "debug assert log". The message contains the argument , , and implementation dependent double-quoted string, each of this delimited by a white space. If the argument is not present, it is meant as if it was of value 0. If the arguments and are not present, they are meant as if they were of values __FILE__ and __LINE__, respectively. The following three calls produce the same output, assuming they were issued from the same file and line. assertMESA (false); assertMESA (false, 0); assertMESA (false, 0, __FILE__, __LINE__); The diagnostic message examples follow. 1 89 0 "" 1 45 333 "all (lessThanEqual (fragColor, vec4 (1.0)))" 1 66 1 "assertion failed in file 1, line 66, cookie 1" Additions to Chapter 9 of the OpenGL Shading Language 1.10 Specification (Shading Language Grammar) None Additions to Chapter 10 of the OpenGL Shading Language 1.10 Specification (Issues) None Additions to the AGL/EGL/GLX/WGL Specifications None GLX Protocol None Errors TBD New State TBD New Implementation Dependent State TBD Sample Code TBD Revision History 29 May 2006 Initial draft. (Michal Krol) 30 July 2006 Add Overview, New Procedures and Functions, New Tokens sections. Add sections 8.10.1, 8.10.2 to GLSL spec.