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glbeginconditionalrender(3g) [osx man page]

GLBEGINCONDITIONALRE(3G)					    OpenGL 3.3						  GLBEGINCONDITIONALRE(3G)

NAME
glBeginConditionalRender - start conditional rendering C SPECIFICATION
void glBeginConditionalRender(GLuint id, GLenum mode); PARAMETERS
id Specifies the name of an occlusion query object whose results are used to determine if the rendering commands are discarded. mode Specifies how glBeginConditionalRender interprets the results of the occlusion query. C SPECIFICATION
void glEndConditionalRender(void); DESCRIPTION
Conditional rendering is started using glBeginConditionalRender and ended using glEndConditionalRender. During conditional rendering, all vertex array commands, as well as glClear() and glClearBuffer() have no effect if the (GL_SAMPLES_PASSED) result of the query object id is zero, or if the (GL_ANY_SAMPLES_PASSED) result is GL_FALSE. The results of commands setting the current vertex state, such as glVertexAttrib() are undefined. If the (GL_SAMPLES_PASSED) result is non-zero or if the (GL_ANY_SAMPLES_PASSED) result is GL_TRUE, such commands are not discarded. The id parameter to glBeginConditionalRender must be the name of a query object previously returned from a call to glGenQueries(). mode specifies how the results of the query object are to be interpreted. If mode is GL_QUERY_WAIT, the GL waits for the results of the query to be available and then uses the results to determine if subsequent rendering commands are discarded. If mode is GL_QUERY_NO_WAIT, the GL may choose to unconditionally execute the subsequent rendering commands without waiting for the query to complete. If mode is GL_QUERY_BY_REGION_WAIT, the GL will also wait for occlusion query results and discard rendering commands if the result of the occlusion query is zero. If the query result is non-zero, subsequent rendering commands are executed, but the GL may discard the results of the commands for any region of the framebuffer that did not contribute to the sample count in the specified occlusion query. Any such discarding is done in an implementation-dependent manner, but the rendering command results may not be discarded for any samples that contributed to the occlusion query sample count. If mode is GL_QUERY_BY_REGION_NO_WAIT, the GL operates as in GL_QUERY_BY_REGION_WAIT, but may choose to unconditionally execute the subsequent rendering commands without waiting for the query to complete. NOTES
glBeginConditionalRender and glEndConditionalRender are available only if the GL version is 3.0 or greater. The GL_ANY_SAMPLES_PASSED query result is available only if the GL version is 3.3 or greater. ERRORS
GL_INVALID_VALUE is generated if id is not the name of an existing query object. GL_INVALID_ENUM is generated if mode is not one of the accepted tokens. GL_INVALID_OPERATION is generated if glBeginConditionalRender is called while conditional rendering is active, or if glEndConditionalRender is called while conditional rendering is inactive. GL_INVALID_OPERATION is generated if id is the name of a query object with a target other than GL_SAMPLES_PASSED or GL_ANY_SAMPLES_PASSED. GL_INVALID_OPERATION is generated if id is the name of a query currently in progress. SEE ALSO
glGenQueries(), glDeleteQueries(), glBeginQuery() COPYRIGHT
Copyright (C) 2009 Khronos Group. 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/. OpenGL 3.3 03/08/2011 GLBEGINCONDITIONALRE(3G)

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GLGETQUERYOBJECT(3G)						    OpenGL 3.3						      GLGETQUERYOBJECT(3G)

NAME
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); void glGetQueryObjecti64v(GLuint id, GLenum pname, GLint64 * params); void glGetQueryObjectui64v(GLuint id, GLenum pname, GLuint64 * 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. glGetQueryObjecti64v and glGetQueryObjectui64v are available only if the GL version is 3.3 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. SEE ALSO
glBeginQuery(), glEndQuery(), glGetQueryiv(), glIsQuery(), glQueryCounter() COPYRIGHT
Copyright (C) 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/. OpenGL 3.3 03/08/2011 GLGETQUERYOBJECT(3G)
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