WebGLRenderingContext.getFramebufferAttachmentParameter()

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 to gl.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 the texture. 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_buffers extension:
- ext.COLOR_ATTACHMENT0_WEBGL (same as gl.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 or WebGLTexture).
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
When using the OVR_multiview2 extension:
- 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` 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.TEXTURE_CUBE_MAP_POSITIVE_X`: Image for the positive X face of the cube. `gl.TEXTURE_CUBE_MAP_NEGATIVE_X`: Image for the negative X face of the cube. `gl.TEXTURE_CUBE_MAP_POSITIVE_Y`: Image for the positive Y face of the cube. `gl.TEXTURE_CUBE_MAP_NEGATIVE_Y`: Image for the negative Y face of the cube. `gl.TEXTURE_CUBE_MAP_POSITIVE_Z`: Image for the positive Z face of the cube. `gl.TEXTURE_CUBE_MAP_NEGATIVE_Z`: Image for the negative Z face of the cube.
`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`.
`ext.FRAMEBUFFER_ATTACHMENT_TEXTURE_NUM_VIEWS_OVR`	A `GLsizei` indicating the number of views of the framebuffer object attachment.
`ext.FRAMEBUFFER_ATTACHMENT_TEXTURE_BASE_VIEW_INDEX_OVR`	A `GLint` indicating the base view index of the framebuffer object attachment.

Exceptions

A gl.INVALID_ENUM error is thrown if target is not gl.FRAMEBUFFER, gl.DRAW_FRAMEBUFFER, gl.READ_FRAMEBUFFER or if attachment 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

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`getFramebufferAttachmentParameter`	Chrome Full support 9	Edge Full support 12	Firefox Full support 4	IE Full support 11	Opera Full support 12	Safari Full support 5.1	WebView Android Full support Yes	Chrome Android Full support 25	Firefox Android Full support Yes	Opera Android Full support 12	Safari iOS Full support 8	Samsung Internet Android Full support 1.5
`WebGL2`	Chrome Full support 56	Edge Full support 79	Firefox Full support 51	IE No support No	Opera Full support 43	Safari No support No	WebView Android Full support 58	Chrome Android Full support 58	Firefox Android Full support 51	Opera Android Full support 43	Safari iOS No support No	Samsung Internet Android Full support 7.0

Legend

Full support: Full support
No support: No support