glGetError

GLGETERROR(3G)						       GLGETERROR(3G)



NAME
       glGetError - return error information


C SPECIFICATION
       GLenum glGetError( void )


DESCRIPTION
       glGetError returns the value of the error flag.	Each detectable error
       is assigned a numeric code and symbolic name.  When an  error  occurs,
       the  error  flag is set to the appropriate error code value.  No other
       errors are recorded until glGetError is	called,	 the  error  code  is
       returned,  and  the  flag  is  reset  to	 GL_NO_ERROR.	If  a call to
       glGetError returns GL_NO_ERROR, there has  been	no  detectable	error
       since the last call to glGetError, or since the GL was initialized.

       To  allow  for distributed implementations, there may be several error
       flags.  If any single error flag has recorded an error, the  value  of
       that  flag  is  returned	 and  that  flag is reset to GL_NO_ERROR when
       glGetError is called.  If more than one flag has	 recorded  an  error,
       glGetError  returns  and	 clears an arbitrary error flag value.	Thus,
       glGetError should always	 be  called  in	 a  loop,  until  it  returns
       GL_NO_ERROR, if all error flags are to be reset.

       Initially, all error flags are set to GL_NO_ERROR.

       The following errors are currently defined:

       GL_NO_ERROR		     No	 error	has been recorded.  The value
				     of this symbolic constant is  guaranteed
				     to be 0.

       GL_INVALID_ENUM		     An	 unacceptable  value is specified for
				     an enumerated argument.   The  offending
				     command  is  ignored,  and	 has no other
				     side effect than to set the error	flag.

       GL_INVALID_VALUE		     A numeric argument is out of range.  The
				     offending command is ignored, and has no
				     other  side effect than to set the error
				     flag.

       GL_INVALID_OPERATION	     The specified operation is	 not  allowed
				     in	 the  current  state.	The offending
				     command is ignored,  and  has  no	other
				     side  effect than to set the error flag.

       GL_STACK_OVERFLOW	     This command would cause a	 stack	over-
				     flow.  The offending command is ignored,
				     and has no other side effect than to set
				     the error flag.

       GL_STACK_UNDERFLOW	     This  command would cause a stack under-
				     flow.  The offending command is ignored,
				     and has no other side effect than to set
				     the error flag.

       GL_OUT_OF_MEMORY		     There is not enough memory left to	 exe-
				     cute  the	command.  The state of the GL
				     is undefined, except for  the  state  of
				     the  error	 flags,	 after	this error is
				     recorded.

       GL_TABLE_TOO_LARGE	     The specified table exceeds  the  imple-
				     mentation’s   maximum   supported	table
				     size.  The offending command is ignored,
				     and has no other side effect than to set
				     the error flag.

       When an error flag is set, results of a	GL  operation  are  undefined
       only  if	 GL_OUT_OF_MEMORY has occurred.	 In all other cases, the com-
       mand generating the error is ignored and has no effect on the GL state
       or  frame buffer contents.  If the generating command returns a value,
       it returns 0.  If glGetError itself generates an error, it returns  0.

NOTES
       GL_TABLE_TOO_LARGE was introduced in GL version 1.2.

ERRORS
       GL_INVALID_OPERATION  is	 generated  if glGetError is executed between
       the execution of glBegin and the corresponding execution of glEnd.  In
       this case glGetError returns 0.



							       GLGETERROR(3G)