glGetDebugMessageLog — retrieve messages from the debug message log
GLuint glGetDebugMessageLog( | GLuint count, | 
| GLsizei bufSize, | |
| GLenum *sources, | |
| Glenum *types, | |
| GLuint *ids, | |
| GLenum *severities, | |
| GLsizei *lengths, | |
GLchar *messageLog); | 
countThe number of debug messages to retrieve from the log.
bufSize
                    The size of the buffer whose address is given by messageLog.
                
sourcesThe address of an array of variables to receive the sources of the retrieved messages.
typesThe address of an array of variables to receive the types of the retrieved messages.
idsThe address of an array of unsigned integers to receive the ids of the retrieved messages.
severitiesThe address of an array of variables to receive the severites of the retrieved messages.
lengthsThe address of an array of variables to receive the lengths of the received messages.
messageLogThe address of an array of characters that will receive the messages.
            glGetDebugMessageLog retrieves messages from the debug message log. A maximum of
            count messages are retrieved from the log. If sources
            is not NULL then the source of each message is written into up to count elements
            of the array. If types
            is not NULL then the type of each message is written into up to count elements
            of the array. If id
            is not NULL then the identifier of each message is written into up to count elements
            of the array. If severities
            is not NULL then the severity of each message is written into up to count elements
            of the array. If lengths
            is not NULL then the length of each message is written into up to count elements
            of the array.
        
            messageLog specifies the address of a character array into which the debug messages
            will be written. Each message will be concatenated onto the array starting at the first element of messageLog.
            bufSize specifies the size of the array messageLog. If a message will not
            fit into the remaining space in messageLog then the function terminates and returns the number
            of messages written so far, which may be zero.
        
            If glGetDebugMessageLog returns zero then no messages are present in the debug log, or there
            was not enough space in messageLog to retrieve the first message in the queue. If messageLog
            is NULL then no messages are written and the value of bufSize is ignored.
        
Although debug messages may be enabled in a non-debug context, the quantity and detail of such messages may be substantially inferior to those in a debug context. In particular, a valid implementation of the debug message queue in a non-debug context may produce no messages at all.
            glGet with argument GL_DEBUG_LOGGED_MESSAGES
        
            glGet with argument GL_DEBUG_NEXT_LOGGED_MESSAGE_LENGTH
        
            glGet with argument GL_MAX_DEBUG_MESSAGE_LENGTH
        
            glGet with argument GL_MAX_DEBUG_LOGGED_MESSAGES
        
Copyright © 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/.