glBindTexture — bind a named texture to a texturing target
void glBindTexture( | GLenum target, |
GLuint texture) ; |
target
Specifies the target of the active texture unit to which the texture is bound. Must be either GL_TEXTURE_2D
or GL_TEXTURE_CUBE_MAP
.
texture
Specifies the name of a texture.
glBindTexture
lets you create or use a named texture. Calling glBindTexture
with target
set to GL_TEXTURE_2D
or GL_TEXTURE_CUBE_MAP
and texture
set to the name of the new texture binds the texture name to the target of the current active texture unit. When a texture is bound to a target, the previous binding for that target is automatically broken.
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 object space of the current GL rendering context.
You may use glGenTextures to generate a set of new texture names.
When a texture is first bound, it assumes the specified target: A texture first bound to GL_TEXTURE_2D
becomes a two-dimensional texture and a texture first bound to GL_TEXTURE_CUBE_MAP
becomes a cube-mapped texture. The state of a two-dimensional texture immediately after it is first bound is equivalent to the state of the default GL_TEXTURE_2D
at GL initialization, and similarly for cube-mapped textures.
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. 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 glBindTexture
remains active until a different texture is bound to the same target, or until the bound texture is deleted with glDeleteTextures.
Once created, a named texture may be re-bound to its same original target as often as needed. It is usually much faster to use glBindTexture
to bind an existing named texture to one of the texture targets than it is to reload the texture image using glTexImage2D.
GL_INVALID_ENUM
is generated if target
is not one of the allowable values.
GL_INVALID_OPERATION
is generated if texture
was previously created with a target that doesn't match that of target
.
// fbo_width and fbo_height are the desired width and height of the FBO. // For Opengl <= 4.4 or if the GL_ARB_texture_non_power_of_two extension // is present, fbo_width and fbo_height can be values other than 2^n for // some integer n. // Build the texture that will serve as the color attachment for the framebuffer. GLuint texture_map; glGenTextures(1, &texture_map); glBindTexture(GL_TEXTURE_2D, texture_map); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, fbo_width, fbo_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL); glBindTexture(GL_TEXTURE_2D, 0); // Build the texture that will serve as the depth attachment for the framebuffer. GLuint depth_texture; glGenTextures(1, &depth_texture); glBindTexture(GL_TEXTURE_2D, depth_texture); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, fbo_width, fbo_height, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, NULL); glBindTexture(GL_TEXTURE_2D, 0); // Build the framebuffer. GLuint framebuffer; glGenFramebuffers(1, &framebuffer); glBindFramebuffer(GL_FRAMEBUFFER, (GLuint)framebuffer); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture_map, 0); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depth_texture, 0); GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER); if (status != GL_FRAMEBUFFER_COMPLETE) // Error glBindFramebuffer(GL_FRAMEBUFFER, 0);
GLuint texture_id; glGenTextures(1, &texture_id); glBindTexture(GL_TEXTURE_2D, texture_id); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); // texture_data is the source data of your texture, in this case // its size is sizeof(unsigned char) * texture_width * texture_height * 4 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texture_width, texture_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, texture_data); glGenerateMipmap(GL_TEXTURE_2D); // Unavailable in OpenGL 2.1, use gluBuild2DMipmaps() instead glBindTexture(GL_TEXTURE_2D, 0);
Sébastien Dominé - Using Texture Compression in OpenGL
Songho - OpenGL Pixel Buffer Object (PBO)
open.gl - Framebuffers
open.gl - Geometry Shaders
open.gl - Textures Objects and Parameters
opengl-tutorial.org - Tutorial 13 : Normal Mapping
opengl-tutorial.org - Tutorial 14 : Render To Texture
opengl-tutorial.org - Tutorial 16 : Shadow mapping
opengl-tutorial.org - Tutorial 5 : A Textured Cube
glDeleteTextures, glGenTextures, glGet, glGetTexParameter, glIsTexture, glTexImage2D, glTexParameter
Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/.