Name

glFramebufferTexture2D — attach a texture image to a framebuffer object

C Specification

void glFramebufferTexture2D(GLenum target,
 GLenum attachment,
 GLenum textarget,
 GLuint texture,
 GLint level);
 

Parameters

target

Specifies the framebuffer target. The symbolic constant must be GL_FRAMEBUFFER.

attachment

Specifies the attachment point to which an image from texture should be attached. Must be one of the following symbolic constants: GL_COLOR_ATTACHMENT0, GL_DEPTH_ATTACHMENT, or GL_STENCIL_ATTACHMENT.

textarget

Specifies the texture target. Must be one of the following symbolic constants: GL_TEXTURE_2D, GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z, or GL_TEXTURE_CUBE_MAP_NEGATIVE_Z.

texture

Specifies the texture object whose image is to be attached.

level

Specifies the mipmap level of the texture image to be attached, which must be 0.

Description

glFramebufferTexture2D attaches the texture image specified by texture and level as one of the logical buffers of the currently bound framebuffer object. attachment specifies whether the texture image should be attached to the framebuffer object's color, depth, or stencil buffer. A texture image may not be attached to the default framebuffer object name 0.

If texture is not 0, the value of GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE for the specified attachment point is set to GL_TEXTURE, the value of GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME is set to texture, and the value of GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL is set to level. If texture is a cube map texture, the value of GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE is set to textarget; otherwise it is set to the default value GL_TEXTURE_CUBE_MAP_POSITIVE_X. Any previous attachment to the attachment logical buffer of the currently bound framebuffer object is broken.

If texture is 0, the current image, if any, attached to the attachment logical buffer of the currently bound framebuffer object is detached. The value of GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE is set to GL_NONE. The value of GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME is set to 0. GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL and GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE are set to the default values 0 and GL_TEXTURE_CUBE_MAP_POSITIVE_X, respectively.

Notes

Special precautions need to be taken to avoid attaching a texture image to the currently bound framebuffer while the texture object is currently bound and potentially sampled by the current vertex or fragment shader. Doing so could lead to the creation of a "feedback loop" between the writing of pixels by rendering operations and the simultaneous reading of those same pixels when used as texels in the currently bound texture. In this scenario, the framebuffer will be considered framebuffer complete, but the values of fragments rendered while in this state will be undefined. The values of texture samples may be undefined as well.

If a texture object is deleted while its image is attached to the currently bound framebuffer, then it is as if glFramebufferTexture2D had been called with a texture of 0 for the attachment point to which this image was attached in the currently bound framebuffer object. In other words, the texture image is detached from the currently bound framebuffer. Note that the texture image is specifically not detached from any non-bound framebuffers. Detaching the image from any non-bound framebuffers is the responsibility of the application.

Errors

GL_INVALID_ENUM is generated if target is not GL_FRAMEBUFFER.

GL_INVALID_ENUM is generated if textarget is not an accepted texture target and texture is not 0.

GL_INVALID_ENUM is generated if attachment is not an accepted attachment point.

GL_INVALID_VALUE is generated if level is not 0 and texture is not 0.

GL_INVALID_OPERATION is generated if the default framebuffer object name 0 is bound.

GL_INVALID_OPERATION is generated if texture is neither 0 nor the name of an existing texture object.

GL_INVALID_OPERATION is generated if texture is the name of an existing two-dimensional texture object but textarget is not GL_TEXTURE_2D or if texture is the name of an existing cube map texture object but textarget is GL_TEXTURE_2D.

Associated Gets

glGetFramebufferAttachmentParameteriv

See Also

glBindFramebuffer, glBindTexture, glCheckFramebufferStatus, glDeleteFramebuffers, glDeleteTextures, glFramebufferRenderbuffer, glGenerateMipmap, glGetFramebufferAttachmentParameteriv, glTexImage2D

Copyright

Copyright © 2008 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.