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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 overflow.  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 underflow.  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 execute 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 implementation's maximum supported ta-ble table
                                     ble 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 command 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)