Package org.lwjgl.opengl

Class EXTTextureBufferObject

java.lang.Object

org.lwjgl.opengl.EXTTextureBufferObject

public class EXTTextureBufferObject
extends java.lang.Object

Native bindings to the EXT_texture_buffer_object extension.

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.

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. (Note that this extension only guarantees support for buffer textures with 2^16 texels, but we expect most implementations to exceed that substantially.) 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.

Requires OpenGL 2.0 and EXT_gpu_shader4 or NV_gpu_program4.

Field Summary

Fields

Modifier and Type	Field	Description
static int	GL_MAX_TEXTURE_BUFFER_SIZE_EXT GL_TEXTURE_BINDING_BUFFER_EXT GL_TEXTURE_BUFFER_DATA_STORE_BINDING_EXT	Accepted by the pname parameters of GetBooleanv, GetDoublev, GetFloatv, and GetIntegerv.
static int	GL_TEXTURE_BUFFER_EXT	Accepted by the target parameter of BindBuffer, BufferData, BufferSubData, MapBuffer, BindTexture, UnmapBuffer, GetBufferSubData, GetBufferParameteriv, GetBufferPointerv, and TexBufferEXT, and the pname parameter of GetBooleanv, GetDoublev, GetFloatv, and GetIntegerv.
static int	GL_TEXTURE_BUFFER_FORMAT_EXT	Accepted by the pname parameters of GetBooleanv, GetDoublev, GetFloatv, and GetIntegerv.

Method Summary

Modifier and Type	Method	Description
static void	glTexBufferEXT(int target, int internalformat, int buffer)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

GL_TEXTURE_BUFFER_EXT

Accepted by the target parameter of BindBuffer, BufferData, BufferSubData, MapBuffer, BindTexture, UnmapBuffer, GetBufferSubData, GetBufferParameteriv, GetBufferPointerv, and TexBufferEXT, and the pname parameter of GetBooleanv, GetDoublev, GetFloatv, and GetIntegerv.

GL_MAX_TEXTURE_BUFFER_SIZE_EXT, GL_TEXTURE_BINDING_BUFFER_EXT, GL_TEXTURE_BUFFER_DATA_STORE_BINDING_EXT, GL_TEXTURE_BUFFER_FORMAT_EXT

Accepted by the pname parameters of GetBooleanv, GetDoublev, GetFloatv, and GetIntegerv.

Method Detail

glTexBufferEXT

public static void glTexBufferEXT(int target,
                                  int internalformat,
                                  int buffer)