glAreTexturesResident
- determine if textures are loaded in texture memory
C SPECIFICATION
GLboolean glAreTexturesResident(
GLsizei n,
const GLuint *textures,
GLboolean *residences )
PARAMETERS
n
Specifies the number of textures to be queried.
textures
Specifies an array containing the names of the textures to be queried.
residences
Specifies an array in which the texture residence status is returned.
The residence status of a texture named by an element of textures is
returned in the corresponding element of residences.
DESCRIPTION
GL establishes
a ``working set'' of textures that are resident in texture memory.
These textures can be bound to a texture target much more efficiently
than textures that are not resident.
glAreTexturesResident queries the texture residence status of the n textures named by
the elements of textures.
If all the named textures are resident,
glAreTexturesResident returns GL_TRUE,
and the contents of residences are undisturbed.
If not all the named textures are resident, glAreTexturesResident returns GL_FALSE,
and detailed status is returned in the n elements of residences.
If an element of residences is GL_TRUE, then the texture named by
the corresponding element of textures is resident.
The residence status of a single bound texture may also be queried
by calling
glGetTexParameter with the target argument set to the
target to which the texture is bound, and the pname argument
set to GL_TEXTURE_RESIDENT.
This is the only way that the residence status of a default texture can be
queried.
NOTES
glAreTexturesResident is available only if the GL version is 1.1 or greater.
glAreTexturesResident returns the residency status of the textures at the time of
invocation. It does not guarantee that the textures will remain
resident at any other time.
If textures reside in virtual memory (there is no texture memory), they
are considered always resident.
Some implementations may not load a texture until the first use of
that texture.
ERRORS
GL_INVALID_VALUE is generated if n is negative.
GL_INVALID_VALUE is generated if any element in textures
is 0 or does not name a texture. In that case, the function returns
GL_FALSE and the contents of residences is indeterminate.
GL_INVALID_OPERATION is generated if glAreTexturesResident is executed
between the execution of glBegin and the corresponding
execution of glEnd.
ASSOCIATED GETS
glGetTexParameter with parameter name GL_TEXTURE_RESIDENT
retrieves the residence status of a currently bound texture.
