fglPrioritizeTexturesEXT(3G) OpenGL Reference fglPrioritizeTexturesEXT(3G)NAME
fglPrioritizeTexturesEXT - set texture residence priority
FORTRAN SPECIFICATION
SUBROUTINE fglPrioritizeTexturesEXT( INTEGER*4 n,
CHARACTER*8 textures,
CHARACTER*8 priorities )
PARAMETERS
n The number of textures to be prioritized.
textures An array containing the names of the textures to be
prioritized.
priorities An array containing the texture priorities. A priority given
in an element of priorities applies to the texture named by
the corresponding element of textures.
DESCRIPTION
fglPrioritizeTexturesEXT assigns the n texture priorities given in
priorities to the n textures named in textures.
On machines with a limited amount of texture memory, OpenGL establishes a
``working set'' of textures that are resident in texture memory. These
textures may be bound to a texture target much more efficiently than
textures that are not resident. By specifying a priority for each
texture, fglPrioritizeTexturesEXT allows applications to guide the OpenGL
implementation in determining which textures should be resident.
The priorities given in priorities are clamped to the range [0.0, 1.0]
before being assigned. Zero indicates the lowest priority, and hence
textures with priority zero are least likely to be resident. One
indicates the highest priority, and hence textures with priority one are
most likely to be resident. However, textures are not guaranteed to be
resident until they are bound.
fglPrioritizeTexturesEXT silently ignores attempts to prioritize texture
zero, or any texture name that does not correspond to an existing
texture.
fglPrioritizeTexturesEXT does not require that any of the textures named
by textures be bound to a texture target. fglTexParameter may also be
used to set a texture's priority, but only if the texture is currently
bound. This is the only way to set the priority of a default texture.
fglPrioritizeTexturesEXT is included in display lists.
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fglPrioritizeTexturesEXT(3G) OpenGL Reference fglPrioritizeTexturesEXT(3G)NOTES
fglPrioritizeTexturesEXT is part of the EXT_texture_object extension.
See fglIntro for more information about using extensions.
ERRORS
GL_INVALID_VALUE is generated if n is negative.
GL_INVALID_OPERATION is generated if fglPrioritizeTexturesEXT is executed
between the execution of fglBegin and the corresponding execution of
fglEnd.
ASSOCIATED GETS
fglGetTexParameter with parameter name GL_TEXTURE_PRIORITY_EXT retrieves
the priority of a currently-bound texture.
SEE ALSO
fglAreTexturesResidentEXT, fglBindTextureEXT, fglTexImage1D,
fglTexImage2D, fglTexImage3DEXT, fglTexParameter.
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