2005 Sams Publishing glGetQueryObject 3G glGetQueryObject return parameters of a query object C Specification void glGetQueryObjectiv GLuint id GLenum pname GLint * params void glGetQueryObjectuiv GLuint id GLenum pname GLuint * params Parameters id Specifies the name of a query object. pname Specifies the symbolic name of a query object parameter. Accepted values are GL_QUERY_RESULT or GL_QUERY_RESULT_AVAILABLE. params Returns the requested data. Description glGetQueryObject returns in params a selected parameter of the query object specified by id. pname names a specific query object parameter. pname can be as follows: GL_QUERY_RESULT params returns the value of the query object's passed samples counter. The initial value is 0. GL_QUERY_RESULT_AVAILABLE params returns whether the passed samples counter is immediately available. If a delay would occur waiting for the query result, GL_FALSE is returned. Otherwise, GL_TRUE is returned, which also indicates that the results of all previous queries are available as well. Notes If an error is generated, no change is made to the contents of params. glGetQueryObject implicitly flushes the GL pipeline so that any incomplete rendering delimited by the occlusion query completes in finite time. If multiple queries are issued using the same query object id before calling glGetQueryObject, the results of the most recent query will be returned. In this case, when issuing a new query, the results of the previous query are discarded. glGetQueryObject is available only if the GL version is 1.5 or greater. Errors GL_INVALID_ENUM is generated if pname is not an accepted value. GL_INVALID_OPERATION is generated if id is not the name of a query object. GL_INVALID_OPERATION is generated if id is the name of a currently active query object. GL_INVALID_OPERATION is generated if glGetQueryObject is executed between the execution of glBegin and the corresponding execution of glEnd. See Also glBeginQuery, glEndQuery, glGetQueryiv, glIsQuery Copyright Copyright 2005 Addison-Wesley. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.