GLAPI/glGetQueryObject

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glGetQueryObject
Core in version 4.4
Core since version 3.3
Core ARB extension ARB_timer_query

glGetQueryObject: return parameters of a query object

Function Definition

 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​);
id
Specifies the name of a query object.
pname
Specifies the symbolic name of a query object parameter. Accepted values are GL_QUERY_RESULT​, GL_QUERY_RESULT_NO_WAIT​​, or GL_QUERY_RESULT_AVAILABLE​.
params
If a buffer is bound to the GL_QUERY_BUFFER​ target, then params​ is treated as an offset to a location within that buffer's data store to receive the result of the query. If no buffer is bound to GL_QUERY_BUFFER​, then params​ is treated as an address in client memory of a variable to receive the resulting 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_NO_WAIT​
If the result of the query is available (that is, a query of GL_QUERY_RESULT_AVAILABLE​ would return non-zero), then params​ returns the value of the query object's passed samples counter, otherwise, the data referred to by params​ is not modified. 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.

GL_QUERY_RESULT_NO_WAIT​ is accepted for pname​ only if the GL version is 4.4 or greater.

The GL_QUERY_BUFFER​ target is available only if the GL version is 4.4 or higher. On earlier versions of the GL, params​ is always an address in client memory.

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 a buffer is currently bound to the GL_QUERY_BUFFER​ target and the command would cause data to be written beyond the bounds of that buffer's data store.

See Also

glBeginQuery, glEndQuery, glGetQuery, glQueryCounter

Copyright

Copyright © 2005 Addison-Wesley. Copyright © 2010-2013 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/.