HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 195

G glGetError 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 glGetError itself generates an error, it returns 0. 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. Chapter 7 195