glBindTextureEXT(3G) OpenGL Reference glBindTextureEXT(3G)NAME
glBindTextureEXT - bind a named texture to a texturing target
C SPECIFICATION
void glBindTextureEXT( GLenum target,
GLuint texture )
PARAMETERS
target The target to which the texture will be bound. Must be one of
GL_TEXTURE_1D, GL_TEXTURE_2D, GL_DETAIL_TEXTURE_2D_SGIS, or
GL_TEXTURE_3D_EXT.
texture The name of a texture.
DESCRIPTION
glBindTextureEXT is part of the EXT_texture_object extension. This
extension makes it possible to use named 1-, 2-, and 3-dimensional
textures in addition to the usual OpenGL texture targets designated by
GL_TEXTURE_1D, GL_TEXTURE_2D, etc.
Texture names are unsigned integers. The value zero is reserved to
represent the default texture for each texture target. Texture names and
the corresponding texture contents are local to the shared display-list
space (see glXCreateContext) of the current OpenGL rendering context; two
rendering contexts will share texture names only if they also share
display lists.
To create a named texture, simply bind a previously-unused texture name
to one of the texture targets listed above. This can be accomplished by
calling glBindTextureEXT with target set to the appropriate texture
target, and texture set to the name of the new texture. When a texture
is bound to a target, the previous binding for that target is
automatically broken.
Note that glGenTexturesEXT may be used to generate a set of fresh texture
names.
When a texture is first bound it assumes the dimensionality of its
target: A texture first bound to GL_TEXTURE_1D becomes 1-dimensional, a
texture first bound to GL_TEXTURE_2D becomes 2-dimensional, and so on.
The state of a 1-dimensional texture immediately after it is first bound
is equivalent to the state of the default GL_TEXTURE_1D at GL
initialization, and similarly for 2- and 3-dimensional textures. That
is, if the application sets texture parameter values for one texture,
those parameter values are not automatically propagated to the next
texture that the application binds; each newly-created texture receives a
fresh copy of the default texture state. See glTexParameter for more
information about texture parameters and their default values.
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glBindTextureEXT(3G) OpenGL Reference glBindTextureEXT(3G)
While a texture is bound, GL operations on the target to which it is
bound affect the bound texture, and queries of the target to which it is
bound return state from the bound texture. If texture mapping of the
dimensionality of the target to which a texture is bound is active, the
bound texture is used. In effect, the texture targets become aliases for
the textures currently bound to them, and the texture name zero refers to
the default textures that were bound to them at initialization.
A texture binding created with glBindTextureEXT remains active until a
different texture is bound to the same target, or until the bound texture
is deleted with glDeleteTexturesEXT.
Once created, a named texture may be re-bound to the appropriate target
as often as needed. It is usually much faster to bind an existing named
texture to one of the texture targets using glBindTextureEXT than it is
to reload the texture image using glTexImage*. For additional control
over performance, consider using glPrioritizeTexturesEXT.
glBindTextureEXT is included in display lists.
NOTES
See glIntro for more information about using extensions.
ERRORS
GL_INVALID_ENUM is generated if target is not one of the allowable
values.
GL_INVALID_OPERATION is generated if texture has a dimensionality and it
doesn't match that of target.
GL_INVALID_OPERATION is generated if glBindTextureEXT is executed between
the execution of glBegin and the corresponding execution of glEnd.
ASSOCIATED GETS
glGet with parameter names GL_TEXTURE_1D_BINDING_EXT,
GL_TEXTURE_2D_BINDING_EXT, and GL_TEXTURE_3D_BINDING_EXT.
MACHINE DEPENDENCIES
RealityEngine, RealityEngine2, and VTX systems do not support texture
name sharing. Texture names are always local to the rendering context
which was active at the time the names were created.
The implementation on O2 systems uses a minimum of 64K bytes for every
texture object defined.
SEE ALSO
glDeleteTexturesEXT, glGenTexturesEXT, glGet, glGetTexParameter,
glIsTextureEXT, glTexImage1D, glTexImage2D, glTexImage3DEXT,
glTexParameter.
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