Gl.GetError (gb.opengl)

Return error information.

Description

Gl.GetError 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 Gl.GetError is called, the error code is returned, and the flag is reset to Gl.NO_ERROR. If a call to Gl.GetError returns Gl.NO_ERROR, there has been no detectable error since the last call to Gl.GetError, 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 Gl.GetError is called. If more than one flag has recorded an error, Gl.GetError returns and clears an arbitrary error flag value. Thus, Gl.GetError 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.INVALID_FRAMEBUFFER_OPERATION

The framebuffer object is not complete. 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.

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 Gl.GetError itself generates an error, it returns 0.

See original documentation on OpenGL website