NAME
glGetError
- return error information
C SPECIFICATION
GLenum ggllGGeettEErrrroorr( void )
DESCRIPTION
ggllGGeettEErrrroorr 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 ggllGGeettEErrrroorr is called,
the error code is returned,
and the flag is reset to GGLL__NNOO__EERRRROORR.
If a call to ggllGGeettEErrrroorr returns GGLL__NNOO__EERRRROORR,
there has been no detectable error since the last call to ggllGGeettEErrrroorr,
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 GGLL__NNOO__EERRRROORR
when ggllGGeettEErrrroorr is called.
If more than one flag has recorded an error,
ggllGGeettEErrrroorr returns and clears an arbitrary error flag value.
Thus, ggllGGeettEErrrroorr should always be called in a loop,
until it returns GGLL__NNOO__EERRRROORR,
if all error flags are to be reset.
Initially, all error flags are set to GGLL__NNOO__EERRRROORR.
The following errors are currently defined:
-
GGLL__NNOO__EERRRROORR
-
No error has been recorded.
The value of this symbolic constant is guaranteed to be 0.
-
GGLL__IINNVVAALLIIDD__EENNUUMM
-
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.
-
GGLL__IINNVVAALLIIDD__VVAALLUUEE
-
A numeric argument is out of range.
The offending command is ignored,
and has no other side effect than to set the error flag.
-
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN
-
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.
-
GGLL__SSTTAACCKK__OOVVEERRFFLLOOWW
-
This command would cause a stack overflow.
The offending command is ignored,
and has no other side effect than to set the error flag.
-
GGLL__SSTTAACCKK__UUNNDDEERRFFLLOOWW
-
This command would cause a stack underflow.
The offending command is ignored,
and has no other side effect than to set the error flag.
-
GGLL__OOUUTT__OOFF__MMEEMMOORRYY
-
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.
-
GGLL__TTAABBLLEE__TTOOOO__LLAARRGGEE
-
The specified table exceeds the implementation'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 GGLL__OOUUTT__OOFF__MMEEMMOORRYY
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 ggllGGeettEErrrroorr itself generates an error, it returns 0.
NOTES
GGLL__TTAABBLLEE__TTOOOO__LLAARRGGEE was introduced in GL version 1.2.
ERRORS
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllGGeettEErrrroorr
is executed between the execution of ggllBBeeggiinn
and the corresponding execution of ggllEEnndd.
In this case ggllGGeettEErrrroorr returns 0.