The WebGLRenderingContext.getFramebufferAttachmentParameter()
method of the WebGL API returns information about a framebuffer's attachment.
Syntax
any gl.getFramebufferAttachmentParameter(target, attachment, pname);
Parameters
- target
- A
GLenum
specifying 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 togl.FRAMEBUFFER
. Used as a destination for drawing, rendering, clearing, and writing operations.gl.READ_FRAMEBUFFER
: Used as a source for reading operations.
- attachment
- A
GLenum
specifying 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.- When using a WebGL 2 context, the following values are available additionally:
gl.DEPTH_STENCIL_ATTACHMENT
: Texture attachment for both, the depth and stencil buffer.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_buffers
extension: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
GLenum
specifying 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 (WebGLRenderbuffer
orWebGLTexture
).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_sRGB
extension: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_SIZE
gl.FRAMEBUFFER_ATTACHMENT_BLUE_SIZE
gl.FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING
gl.FRAMEBUFFER_ATTACHMENT_COMPONENT_TYPE
gl.FRAMEBUFFER_ATTACHMENT_DEPTH_SIZE
gl.FRAMEBUFFER_ATTACHMENT_GREEN_SIZE
gl.FRAMEBUFFER_ATTACHMENT_RED_SIZE
gl.FRAMEBUFFER_ATTACHMENT_STENCIL_SIZE
gl.FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER
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 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 ) or renderbuffer (WebGLRenderbuffer ) of the attached image. |
gl.FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL |
A GLint indicating the mipmap level. Default value: 0. |
gl.FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE |
A GLenum indicating the name of cube-map face of the texture. Possible values:
|
gl.FRAMEBUFFER_ATTACHMENT_ALPHA_SIZE |
A GLint indicating the number of bits in the alpha component of the attachment. |
gl.FRAMEBUFFER_ATTACHMENT_BLUE_SIZE |
A GLint indicating the number of bits in the blue component of the attachment. |
gl.FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING |
A GLenum indicating the encoding of components of the specified attachment. Either gl.LINEAR or gl.SRGB . |
gl.FRAMEBUFFER_ATTACHMENT_COMPONENT_TYPE |
A GLenum 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 indicating the number of bits in the depth component of the attachment. |
gl.FRAMEBUFFER_ATTACHMENT_GREEN_SIZE |
A GLint indicating the number of bits in the green component of the attachment. |
gl.FRAMEBUFFER_ATTACHMENT_RED_SIZE |
A GLint indicating the number of bits in the red component of the attachment. |
gl.FRAMEBUFFER_ATTACHMENT_STENCIL_SIZE |
A GLint indicating the number of bits in the stencil component of the attachment. |
gl.FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER |
A GLint indicating the number of the texture layer which contains the attached image. |
ext.FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING_EXT |
A GLenum indicating the framebuffer color encoding. Either gl.LINEAR or ext.SRGB_EXT . |
Exceptions
- A
gl.INVALID_ENUM
error is thrown iftarget
is notgl.FRAMEBUFFER
,gl.DRAW_FRAMEBUFFER
,gl.READ_FRAMEBUFFER
or ifattachment
is not one of the accepted attachment points.
Examples
gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE);
Specifications
Specification | Status | Comment |
---|---|---|
WebGL 1.0 The definition of 'getFramebufferAttachmentParameter' in that specification. |
Recommendation | Initial definition for WebGL. |
OpenGL ES 2.0 The definition of 'glGetFramebufferAttachmentParameteriv' in that specification. |
Standard | Man page of the (similar) OpenGL API. |
WebGL 2.0 The definition of 'getFramebufferAttachmentParameter' in that specification. |
Editor's Draft | Updated definition for WebGL 2. |
OpenGL ES 3.0 The definition of 'glGetFramebufferAttachmentParameteriv' in that specification. |
Standard | Man page of the (similar) OpenGL ES 3 API. |
Browser compatibility
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | 9 | 12 | 4.0 (2.0) | 11 | 12 | 5.1 |
WebGL 2 | No support [2] | No support | Nightly build [1] | No support | No support | No support |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | Firefox OS | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|
Basic support | ? | 25 | 4.0 (2.0) | 1.0 | ? | 12 | 8.0 |
WebGL 2 | No support | No support | No support | No support | No support | No support | No support |
[1] WebGL 2 is enabled by default in Firefox Nightly. To enable it in a release version of Firefox, set the preference webgl.enable-prototype-webgl2
to true
in about:config.
[2] To use an experimental implementation of WebGL 2 in Chrome, you have to start Chrome with the runtime flag --enable-unsafe-es3-apis
.