web api instance method
WebGLRenderingContext: getFramebufferAttachmentParameter() method
Available in workers
The
WebGLRenderingContext.getFramebufferAttachmentParameter()
method of the WebGL API returns information
about a framebuffer’s attachment.
Syntax
getFramebufferAttachmentParameter(target, attachment, pname)
Parameters
-
target-
: A
GLenumspecifying the binding point (target). Possible values:gl.FRAMEBUFFER- : Collection buffer data storage of color, alpha, depth and stencil buffers used to render an image.
When using a
WebGL 2 context, the following values are available additionally:gl.DRAW_FRAMEBUFFER- : Equivalent to
gl.FRAMEBUFFER. Used as a destination for drawing, rendering, clearing, and writing operations.
- : Equivalent to
gl.READ_FRAMEBUFFER- : Used as a source for reading operations.
-
-
attachment-
: A
GLenumspecifying the attachment point for thetexture. Possible values:gl.COLOR_ATTACHMENT0: Texture attachment for the framebuffer’s color buffer.gl.DEPTH_ATTACHMENT: Texture attachment for the framebuffer’s depth buffer.gl.STENCIL_ATTACHMENT: Texture attachment for the framebuffer’s stencil buffer.gl.DEPTH_STENCIL_ATTACHMENT: Texture attachment for both, the depth and stencil buffer.
When using a
WebGL 2 context, the following values are available additionally:gl.COLOR_ATTACHMENT1 gl.COLOR_ATTACHMENT2 gl.COLOR_ATTACHMENT3 gl.COLOR_ATTACHMENT4 gl.COLOR_ATTACHMENT5 gl.COLOR_ATTACHMENT6 gl.COLOR_ATTACHMENT7 gl.COLOR_ATTACHMENT8 gl.COLOR_ATTACHMENT9 gl.COLOR_ATTACHMENT10 gl.COLOR_ATTACHMENT11 gl.COLOR_ATTACHMENT12 gl.COLOR_ATTACHMENT13 gl.COLOR_ATTACHMENT14 gl.COLOR_ATTACHMENT15
When using the
WEBGL_draw_buffersextension:ext.COLOR_ATTACHMENT0_WEBGL(same asgl.COLOR_ATTACHMENT0)ext.COLOR_ATTACHMENT1_WEBGL ext.COLOR_ATTACHMENT2_WEBGL ext.COLOR_ATTACHMENT3_WEBGL ext.COLOR_ATTACHMENT4_WEBGL ext.COLOR_ATTACHMENT5_WEBGL ext.COLOR_ATTACHMENT6_WEBGL ext.COLOR_ATTACHMENT7_WEBGL ext.COLOR_ATTACHMENT8_WEBGL ext.COLOR_ATTACHMENT9_WEBGL ext.COLOR_ATTACHMENT10_WEBGL ext.COLOR_ATTACHMENT11_WEBGL ext.COLOR_ATTACHMENT12_WEBGL ext.COLOR_ATTACHMENT13_WEBGL ext.COLOR_ATTACHMENT14_WEBGL ext.COLOR_ATTACHMENT15_WEBGL
-
-
pname-
: A
GLenumspecifying information to query. Possible values:gl.FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE: The type which contains the attached image.gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME: The texture or renderbuffer of the attached image (WebGLRenderbufferorWebGLTexture).gl.FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL: Mipmap level. Default value: 0.gl.FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE: The name of cube-map face of the texture.
When using the
EXT_sRGBextension:ext.FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING_EXT: The framebuffer color encoding.
When using a
WebGL 2 context, the following values are available additionally:gl.FRAMEBUFFER_ATTACHMENT_ALPHA_SIZEgl.FRAMEBUFFER_ATTACHMENT_BLUE_SIZEgl.FRAMEBUFFER_ATTACHMENT_COLOR_ENCODINGgl.FRAMEBUFFER_ATTACHMENT_COMPONENT_TYPEgl.FRAMEBUFFER_ATTACHMENT_DEPTH_SIZEgl.FRAMEBUFFER_ATTACHMENT_GREEN_SIZEgl.FRAMEBUFFER_ATTACHMENT_RED_SIZEgl.FRAMEBUFFER_ATTACHMENT_STENCIL_SIZEgl.FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER
When using the
OVR_multiview2extension:ext.FRAMEBUFFER_ATTACHMENT_TEXTURE_NUM_VIEWS_OVR: the number of views of the framebuffer object attachment.ext.FRAMEBUFFER_ATTACHMENT_TEXTURE_BASE_VIEW_INDEX_OVR: the base view index of the framebuffer object attachment.
-
Return value
Depends on the requested information (as specified with pname). Either a
GLint, a GLenum, a WebGLRenderbuffer, or a
WebGLTexture.
pname parameter |
Return value |
|---|---|
gl.FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE |
A [`GLenum`](/firefox/mdn/api/webgl_api/types/) indicating the
type of the texture. Either gl.RENDERBUFFER,
gl.TEXTURE, or if no image is attached,
gl.NONE.
|
gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME |
The texture ([`WebGLTexture`](/firefox/mdn/api/webgltexture/)) or renderbuffer ([`WebGLRenderbuffer`](/firefox/mdn/api/webglrenderbuffer/)) of the attached image. |
gl.FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL |
A [`GLint`](/firefox/mdn/api/webgl_api/types/) indicating the mipmap level. Default value: 0. |
gl.FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE |
A [`GLenum`](/firefox/mdn/api/webgl_api/types/) indicating the
name of cube-map face of the texture. Possible values:
|
gl.FRAMEBUFFER_ATTACHMENT_ALPHA_SIZE |
A [`GLint`](/firefox/mdn/api/webgl_api/types/) indicating the number of bits in the alpha component of the attachment. |
gl.FRAMEBUFFER_ATTACHMENT_BLUE_SIZE |
A [`GLint`](/firefox/mdn/api/webgl_api/types/) indicating the number of bits in the blue component of the attachment. |
gl.FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING |
A [`GLenum`](/firefox/mdn/api/webgl_api/types/) indicating the
encoding of components of the specified attachment. Either
gl.LINEAR or gl.SRGB.
|
gl.FRAMEBUFFER_ATTACHMENT_COMPONENT_TYPE |
A [`GLenum`](/firefox/mdn/api/webgl_api/types/) indicating the
format of the components of the specified attachment. Either
gl.FLOAT, gl.INT,
gl.UNSIGNED_INT, gl.SIGNED_NORMALIZED, or
gl.UNSIGNED_NORMALIZED.
|
gl.FRAMEBUFFER_ATTACHMENT_DEPTH_SIZE |
A [`GLint`](/firefox/mdn/api/webgl_api/types/) indicating the number of bits in the depth component of the attachment. |
gl.FRAMEBUFFER_ATTACHMENT_GREEN_SIZE |
A [`GLint`](/firefox/mdn/api/webgl_api/types/) indicating the number of bits in the green component of the attachment. |
gl.FRAMEBUFFER_ATTACHMENT_RED_SIZE |
A [`GLint`](/firefox/mdn/api/webgl_api/types/) indicating the number of bits in the red component of the attachment. |
gl.FRAMEBUFFER_ATTACHMENT_STENCIL_SIZE |
A [`GLint`](/firefox/mdn/api/webgl_api/types/) indicating the number of bits in the stencil component of the attachment. |
gl.FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER |
A [`GLint`](/firefox/mdn/api/webgl_api/types/) indicating the number of the texture layer which contains the attached image. |
ext.FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING_EXT |
A [`GLenum`](/firefox/mdn/api/webgl_api/types/) indicating the
framebuffer color encoding. Either gl.LINEAR or
ext.SRGB_EXT.
|
ext.FRAMEBUFFER_ATTACHMENT_TEXTURE_NUM_VIEWS_OVR |
A [`GLsizei`](/firefox/mdn/api/webgl_api/types/) indicating the number of views of the framebuffer object attachment. |
ext.FRAMEBUFFER_ATTACHMENT_TEXTURE_BASE_VIEW_INDEX_OVR
|
A [`GLint`](/firefox/mdn/api/webgl_api/types/) indicating the base view index of the framebuffer object attachment. |
Exceptions
- A
gl.INVALID_ENUMerror is thrown iftargetis notgl.FRAMEBUFFER,gl.DRAW_FRAMEBUFFER,gl.READ_FRAMEBUFFERor ifattachmentis not one of the accepted attachment points.
Examples
gl.getFramebufferAttachmentParameter(
gl.FRAMEBUFFER,
gl.COLOR_ATTACHMENT0,
gl.FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE,
);