gldebugmessagecallback(3g) [centos man page]
GLDEBUGMESSAGECALLBA(3G) OpenGL Manual GLDEBUGMESSAGECALLBA(3G) NAME
glDebugMessageCallback - specify a callback to receive debugging messages from the GL C SPECIFICATION
void glDebugMessageCallback(DEBUGPROC callback, void * userParam); PARAMETERS
callback The address of a callback function that will be called when a debug message is generated. userParam A user supplied pointer that will be passed on each invocation of callback. DESCRIPTION
glDebugMessageInsert sets the current debug output callback function to the function whose address is given in callback. The callback function should have the following prototype (in C), or be otherwise compatible with such a prototype: typedef void (APIENTRY *DEBUGPROC)(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar* message, void* userParam); This function is defined to have the same calling convention as the GL API functions. In most cases this is defined as APIENTRY, although it will vary depending on platform, language and compiler. Each time a debug message is generated the debug callback function will be invoked with source, type, id, and severity associated with the message, and length set to the length of debug message whose character string is in the array pointed to by messageuserParam will be set to the value passed in the userParam parameter to the most recent call to glDebugMessageInsert. NOTES
When the GL is in use remotely, the server may not be able to call functions in the client's address space. In such cases, the callback function may not be invoked and the user should retrieve debug messages from the context's debug message log by calling glGetDebugMessageLog(). SEE ALSO
glDebugMessageControl(), glDebugMessageInsert(), glGetDebugMessageLog(). COPYRIGHT
Copyright (C) 2012 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/. AUTHORS
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GLUNURBSCALLBACK(3G) OpenGL Manual GLUNURBSCALLBACK(3G) NAME
gluNurbsCallback - define a callback for a NURBS object C SPECIFICATION
void gluNurbsCallback(GLUnurbs* nurb, GLenum which, _GLUfuncptr CallBackFunc); PARAMETERS
nurb Specifies the NURBS object (created with gluNewNurbsRenderer()). which Specifies the callback being defined. Valid values are GLU_NURBS_BEGIN, GLU_NURBS_VERTEX, GLU_NURBS_NORMAL, GLU_NURBS_COLOR, GLU_NURBS_TEXTURE_COORD, GLU_NURBS_END, GLU_NURBS_BEGIN_DATA, GLU_NURBS_VERTEX_DATA, GLU_NURBS_NORMAL_DATA, GLU_NURBS_COLOR_DATA, GLU_NURBS_TEXTURE_COORD_DATA, GLU_NURBS_END_DATA, and GLU_NURBS_ERROR. CallBackFunc Specifies the function that the callback calls. DESCRIPTION
gluNurbsCallback is used to define a callback to be used by a NURBS object. If the specified callback is already defined, then it is replaced. If CallBackFunc is NULL, then this callback will not get invoked and the related data, if any, will be lost. Except the error callback, these callbacks are used by NURBS tessellator (when GLU_NURBS_MODE is set to be GLU_NURBS_TESSELLATOR) to return back the OpenGL polygon primitives resulting from the tessellation. Note that there are two versions of each callback: one with a user data pointer and one without. If both versions for a particular callback are specified then the callback with the user data pointer will be used. Note that ``userData'' is a copy of the pointer that was specified at the last call to gluNurbsCallbackData. The error callback function is effective no matter which value that GLU_NURBS_MODE is set to. All other callback functions are effective only when GLU_NURBS_MODE is set to GLU_NURBS_TESSELLATOR. The legal callbacks are as follows: GLU_NURBS_BEGIN The begin callback indicates the start of a primitive. The function takes a single argument of type GLenum, which can be one of GLU_LINES, GLU_LINE_STRIP, GLU_TRIANGLE_FAN, GLU_TRIANGLE_STRIP, GLU_TRIANGLES, or GLU_QUAD_STRIP. The default begin callback function is NULL. The function prototype for this callback looks like: void begin( GLenum type ); GLU_NURBS_BEGIN_DATA The same as the GLU_NURBS_BEGIN callback except that it takes an additional pointer argument. This pointer is a copy of the pointer that was specified at the last call to gluNurbsCallbackData. The default callback function is NULL. The function prototype for this callback function looks like: void beginData(GLenum type, void *userData); GLU_NURBS_VERTEX The vertex callback indicates a vertex of the primitive. The coordinates of the vertex are stored in the parameter ``vertex''. All the generated vertices have dimension 3; that is, homogeneous coordinates have been transformed into affine coordinates. The default vertex callback function is NULL. The function prototype for this callback function looks like: void vertex( GLfloat *vertex ); GLU_NURBS_VERTEX_DATA This is the same as the GLU_NURBS_VERTEX callback, except that it takes an additional pointer argument. This pointer is a copy of the pointer that was specified at the last call to gluNurbsCallbackData. The default callback function is NULL. The function prototype for this callback function looks like: void vertexData( GLfloat *vertex, void *userData ); GLU_NURBS_NORMAL The normal callback is invoked as the vertex normal is generated. The components of the normal are stored in the parameter ``normal.'' In the case of a NURBS curve, the callback function is effective only when the user provides a normal map (GLU_MAP1_NORMAL). In the case of a NURBS surface, if a normal map (GLU_MAP2_NORMAL) is provided, then the generated normal is computed from the normal map. If a normal map is not provided, then a surface normal is computed in a manner similar to that described for evaluators when GLU_AUTO_NORMAL is enabled. The default normal callback function is NULL. The function prototype for this callback function looks like: void normal( GLfloat *normal ); GLU_NURBS_NORMAL_DATA The same as the GLU_NURBS_NORMAL callback except that it takes an additional pointer argument. This pointer is a copy of the pointer that was specified at the last call to gluNurbsCallbackData. The default callback function is NULL. The function prototype for this callback function looks like: void normalData( GLfloat *normal, void *userData ); GLU_NURBS_COLOR The color callback is invoked as the color of a vertex is generated. The components of the color are stored in the parameter ``color.'' This callback is effective only when the user provides a color map (GLU_MAP1_COLOR_4 or GLU_MAP2_COLOR_4). ``color'' contains four components: R, G, B, A. The default color callback function is NULL. The prototype for this callback function looks like: void color( GLfloat *color ); GLU_NURBS_COLOR_DATA The same as the GLU_NURBS_COLOR callback except that it takes an additional pointer argument. This pointer is a copy of the pointer that was specified at the last call to gluNurbsCallbackData. The default callback function is NULL. The function prototype for this callback function looks like: void colorData( GLfloat *color, void *userData ); GLU_NURBS_TEXTURE_COORD The texture callback is invoked as the texture coordinates of a vertex are generated. These coordinates are stored in the parameter ``texCoord.'' The number of texture coordinates can be 1, 2, 3, or 4 depending on which type of texture map is specified (GLU_MAP1_TEXTURE_COORD_1, GLU_MAP1_TEXTURE_COORD_2, GLU_MAP1_TEXTURE_COORD_3, GLU_MAP1_TEXTURE_COORD_4, GLU_MAP2_TEXTURE_COORD_1, GLU_MAP2_TEXTURE_COORD_2, GLU_MAP2_TEXTURE_COORD_3, GLU_MAP2_TEXTURE_COORD_4). If no texture map is specified, this callback function will not be called. The default texture callback function is NULL. The function prototype for this callback function looks like: void texCoord( GLfloat *texCoord ); GLU_NURBS_TEXTURE_COORD_DATA This is the same as the GLU_NURBS_TEXTURE_COORD callback, except that it takes an additional pointer argument. This pointer is a copy of the pointer that was specified at the last call to gluNurbsCallbackData. The default callback function is NULL. The function prototype for this callback function looks like: void texCoordData( GLfloat *texCoord, void *userData ); GLU_NURBS_END The end callback is invoked at the end of a primitive. The default end callback function is NULL. The function prototype for this callback function looks like: void end( void ); GLU_NURBS_END_DATA This is the same as the GLU_NURBS_END callback, except that it takes an additional pointer argument. This pointer is a copy of the pointer that was specified at the last call to gluNurbsCallbackData. The default callback function is NULL. The function prototype for this callback function looks like: void endData( void *userData ); GLU_NURBS_ERROR The error function is called when an error is encountered. Its single argument is of type GLenum, and it indicates the specific error that occurred. There are 37 errors unique to NURBS, named GLU_NURBS_ERROR1 through GLU_NURBS_ERROR37. Character strings describing these errors can be retrieved with gluErrorString(). NOTES
gluNurbsCallback is available only if the GLU version is 1.2 or greater. GLU version 1.2 supports only the GLU_ERROR parameter for which. The GLU_ERROR value is deprecated in GLU version 1.3 in favor of GLU_NURBS_ERROR. All other accepted values for CallBackFunc are available only if the GLU version is 1.3 or greater. SEE ALSO
gluErrorString(), gluNewNurbsRenderer(), gluNurbsCallbackData, gluNurbsProperty() COPYRIGHT
Copyright (C) 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/. AUTHORS
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