org.lwjgl.opengl.ARBTextureBufferObject Maven / Gradle / Ivy
/*
* Copyright LWJGL. All rights reserved.
* License terms: https://www.lwjgl.org/license
* MACHINE GENERATED FILE, DO NOT EDIT
*/
package org.lwjgl.opengl;
import static org.lwjgl.system.Checks.*;
/**
* Native bindings to the ARB_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
* ({@link GL15#glBufferData BufferData}), direct CPU writes ({@link GL15#glMapBuffer 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.
*
* Requires {@link GL20 OpenGL 2.0} and NV_gpu_program4 or EXT_gpu_shader4. Promoted to core in {@link GL31 OpenGL 3.1}.
*/
public class ARBTextureBufferObject {
/**
* Accepted by the {@code target} parameter of BindBuffer, BufferData, BufferSubData, MapBuffer, MapBufferRangeARB, BindTexture, UnmapBuffer,
* GetBufferSubData, GetBufferParameteriv, GetBufferPointerv, and TexBufferARB, and the {@code pname} parameter of GetBooleanv, GetDoublev, GetFloatv, and
* GetIntegerv.
*/
public static final int GL_TEXTURE_BUFFER_ARB = 0x8C2A;
/** Accepted by the {@code pname} parameters of GetBooleanv, GetDoublev, GetFloatv, and GetIntegerv. */
public static final int
GL_MAX_TEXTURE_BUFFER_SIZE_ARB = 0x8C2B,
GL_TEXTURE_BINDING_BUFFER_ARB = 0x8C2C,
GL_TEXTURE_BUFFER_DATA_STORE_BINDING_ARB = 0x8C2D,
GL_TEXTURE_BUFFER_FORMAT_ARB = 0x8C2E;
static { GL.initialize(); }
protected ARBTextureBufferObject() {
throw new UnsupportedOperationException();
}
static boolean isAvailable(GLCapabilities caps) {
return checkFunctions(
caps.glTexBufferARB
);
}
// --- [ glTexBufferARB ] ---
/**
* Attaches the storage for the buffer object named {@code buffer} to the active buffer texture, and specifies an internal format for the texel array found
* in the attached buffer object. If {@code buffer} is zero, any buffer object attached to the buffer texture is detached, and no new buffer object is
* attached. If {@code buffer} is non-zero, but is not the name of an existing buffer object, the error {@link GL11#GL_INVALID_OPERATION INVALID_OPERATION} is generated.
*
* When a buffer object is attached to a buffer texture, the buffer object's data store is taken as the texture's texel array. The number of texels in the
* buffer texture's texel array is given by
*
* floor(buffer_size / (components * sizeof(base_type))
*
* ,
*
* where {@code buffer_size} is the size of the buffer object, in basic machine units and {@code components} and {@code base_type} are the element count
* and base data type for elements. The number of texels in the texel array is then clamped to the implementation-dependent limit
* {@link #GL_MAX_TEXTURE_BUFFER_SIZE_ARB MAX_TEXTURE_BUFFER_SIZE_ARB}. When a buffer texture is accessed in a shader, the results of a texel fetch are undefined if the specified texel number is
* greater than or equal to the clamped number of texels in the texel array.
*
* When a buffer texture is accessed in a shader, an integer is provided to indicate the texel number being accessed. If no buffer object is bound to the
* buffer texture, the results of the texel access are undefined. Otherwise, the attached buffer object's data store is interpreted as an array of elements
* of the GL data type corresponding to {@code internalformat}. Each texel consists of one to four elements that are mapped to texture components
* (R, G, B, A, L, and I). Element {@code m} of the texel numbered {@code n} is taken from element {@code n} * {@code components} + {@code m} of the
* attached buffer object's data store. Elements and texels are both numbered starting with zero. For texture formats with normalized components, the
* extracted values are converted to floating-point values. The components of the texture are then converted to an (R,G,B,A) vector, and returned to the
* shader as a four-component result vector with components of the appropriate data type for the texture's internal format.
*
* @param target the target of the operation. Must be:
{@link #GL_TEXTURE_BUFFER_ARB TEXTURE_BUFFER_ARB}
* @param internalformat the sized internal format of the data in the store belonging to {@code buffer}
* @param buffer the name of the buffer object whose storage to attach to the active buffer texture
*/
public static native void glTexBufferARB(int target, int internalformat, int buffer);
}