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    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.
    • 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 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

    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.

    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

    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.

    See also

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     Contributors to this page: fscholz
     Last updated by: fscholz,