WebGLRenderingContext: getFramebufferAttachmentParameter() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

Note: This feature is available in Web Workers.

The WebGLRenderingContext.getFramebufferAttachmentParameter() method of the WebGL API returns information about a framebuffer's attachment.

Syntax

js
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

js
gl.getFramebufferAttachmentParameter(
  gl.FRAMEBUFFER,
  gl.COLOR_ATTACHMENT0,
  gl.FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE,
);

Specifications

Specification
WebGL Specification
# 5.14.6
WebGL 2.0 Specification
# 3.7.4

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
getFramebufferAttachmentParameter

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Full support
Full support

See also