glGenTextures — generate texture names
void glGenTextures( | GLsizei n, |
GLuint * textures) ; |
n
Specifies the number of texture names to be generated.
textures
Specifies an array in which the generated texture names are stored.
glGenTextures
returns n
texture names in textures
. There is no guarantee that the names form a contiguous set of integers; however, it is guaranteed that none of the returned names was in use immediately before the call to glGenTextures
.
Texture names returned by a call to glGenTextures
are not returned by subsequent calls, unless they are first deleted with glDeleteTextures.
The names returned in textures
are marked as used, for the purposes of glGenTextures
only, but they acquire state and dimensionality only when they are first bound using glBindTexture.
GL_INVALID_VALUE
is generated if n
is negative.
// 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);
open.gl - Framebuffers
opengl-tutorial.org - Tutorial 14 : Render To Texture
opengl-tutorial.org - Tutorial 16 : Shadow mapping
opengl-tutorial.org - Tutorial 5 : A Textured Cube
OpenGL ES API Version | |||
---|---|---|---|
Function Name | 2.0 | 3.0 | 3.1 |
glGenTextures | ✔ | ✔ | ✔ |
glBindTexture, glCopyTexImage2D, glDeleteTextures, glGet, glGetTexParameter, glTexImage2D, glTexImage3D, glTexParameter
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