OpenGL extension EXT.texture_buffer_object
This module customises the behaviour of the
OpenGL.raw.GL.EXT.texture_buffer_object to provide a more
Overview (from the spec)
This extension provides a new texture type, called a buffer texture.
Buffer textures are one-dimensional arrays of texels whose storage comes
from an attached buffer object. When a buffer object is bound to a buffer
texture, a format is specified, and the data in the buffer object is
treated as an array of texels of the specified format.
The use of a buffer object to provide storage allows the texture data to
be specified in a number of different ways: via buffer object loads
(BufferData), direct CPU writes (MapBuffer), framebuffer readbacks
(EXT_pixel_buffer_object extension). A buffer object can also be loaded
by transform feedback (NV_transform_feedback extension), which captures
selected transformed attributes of vertices processed by the GL. Several
of these mechanisms do not require an extra data copy, which would be
required when using conventional TexImage-like entry points.
Buffer textures do not support mipmapping, texture lookups with normalized
floating-point texture coordinates, and texture filtering of any sort, and
may not be used in fixed-function fragment processing. They can be
accessed via single texel fetch operations in programmable shaders. For
assembly shaders (NV_gpu_program4), the TXF instruction is used. For GLSL
(EXT_gpu_shader4), a new sampler type and texel fetch function are used.
While buffer textures can be substantially larger than equivalent
one-dimensional textures; the maximum texture size supported for buffer
textures in the initial implementation of this extension is 2^27 texels,
versus 2^13 (8192) texels for otherwise equivalent one-dimensional
textures. When a buffer object is attached to a buffer texture, a size is
not specified; rather, the number of texels in the texture is taken by
dividing the size of the buffer object by the size of each texel.
The official definition of this extension is available here:
|EXTENSION_NAME = 'GL_EXT_texture_buffer_object'|
GL_MAX_TEXTURE_BUFFER_SIZE_EXT = GL_MAX_TEXTURE_BUFFER_SIZE_EXT
GL_TEXTURE_BINDING_BUFFER_EXT = GL_TEXTURE_BINDING_BUFFER_EXT
GL_TEXTURE_BUFFER_DATA_STORE_BINDING_EXT = GL_TEXTURE_BUFFER_DATA_STORE_BINDING_EXT
GL_TEXTURE_BUFFER_EXT = GL_TEXTURE_BUFFER_EXT
GL_TEXTURE_BUFFER_FORMAT_EXT = GL_TEXTURE_BUFFER_FORMAT_EXT
__file__ = '/home/mcfletch/pylive/OpenGL/GL/EXT/texture_buffer_object.pyc'
__name__ = 'OpenGL.GL.EXT.texture_buffer_object'
__package__ = 'OpenGL.GL.EXT'
glTexBufferEXT = <OpenGL.platform.baseplatform.glTexBufferEXT object at 0x76f1610>