glGetQueryObject — return parameters of a query object
void glGetQueryObjectiv( | GLuint | id, |
GLenum | pname, | |
GLint * | params) ; |
void glGetQueryObjectuiv( | GLuint | id, |
GLenum | pname, | |
GLuint * | 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
or GL_QUERY_RESULT_AVAILABLE
.
params
Returns the requested data.
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.
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.
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.
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/.