2010 Khronos Group
glGetFramebufferAttachmentParameteriv 3G
glGetFramebufferAttachmentParameteriv retrieve information about attachments of a bound framebuffer object

## C Specification

void `glGetFramebufferAttachmentParameteriv` GLenum target GLenum attachment GLenum pname GLint *params

## Parameters

target

  Specifies the target of the query operation.

attachment

  Specifies the attachment within target

pname

  Specifies the parameter of attachment to query.

params

  Specifies the address of a variable receive the value of pname for attachment.

## Description

`glGetFramebufferAttachmentParameteriv` returns information about attachments of a bound framebuffer object. target specifies the framebuffer binding point and must be `GL_DRAW_FRAMEBUFFER`, `GL_READ_FRAMEBUFFER` or `GL_FRAMEBUFFER`. `GL_FRAMEBUFFER` is equivalent to `GL_DRAW_FRAMEBUFFER`.

If the default framebuffer is bound to target then attachment must be one of `GL_FRONT_LEFT`, `GL_FRONT_RIGHT`, `GL_BACK_LEFT`, or `GL_BACK_RIGHT`, identifying a color buffer, `GL_DEPTH`, identifying the depth buffer, or `GL_STENCIL`, identifying the stencil buffer.

If a framebuffer object is bound, then attachment must be one of `GL_COLOR_ATTACHMENTi`, `GL_DEPTH_ATTACHMENT`, `GL_STENCIL_ATTACHMENT`, or `GL_DEPTH_STENCIL_ATTACHMENT`. i in `GL_COLOR_ATTACHMENTi` must be in the range zero to the value of `GL_MAX_COLOR_ATTACHMENTS` - 1.

If attachment is `GL_DEPTH_STENCIL_ATTACHMENT` and different objects are bound to the depth and stencil attachment points of target the query will fail. If the same object is bound to both attachment points, information about that object will be returned.

Upon successful return from `glGetFramebufferAttachmentParameteriv`, if pname is `GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE`, then params will contain one of `GL_NONE`, `GL_FRAMEBUFFER_DEFAULT`, `GL_TEXTURE`, or `GL_RENDERBUFFER`, identifying the type of object which contains the attached image. Other values accepted for pname depend on the type of object, as described below.

If the value of `GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE` is `GL_NONE`, no framebuffer is bound to target. In this case querying pname `GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME` will return zero, and all other queries will generate an error.

If the value of `GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE` is not `GL_NONE`, these queries apply to all other framebuffer types:

- If pname is `GL_FRAMEBUFFER_ATTACHMENT_RED_SIZE`, `GL_FRAMEBUFFER_ATTACHMENT_GREEN_SIZE`, `GL_FRAMEBUFFER_ATTACHMENT_BLUE_SIZE`, `GL_FRAMEBUFFER_ATTACHMENT_ALPHA_SIZE`, `GL_FRAMEBUFFER_ATTACHMENT_DEPTH_SIZE`, or `GL_FRAMEBUFFER_ATTACHMENT_STENCIL_SIZE`, then params will contain the number of bits in the corresponding red, green, blue, alpha, depth, or stencil component of the specified attachment. Zero is returned if the requested component is not present in attachment.

- If pname is `GL_FRAMEBUFFER_ATTACHMENT_COMPONENT_TYPE`, params will contain the format of components of the specified attachment, one of `GL_FLOAT`, GL_INT, GL_UNSIGNED_INT, GL_SIGNED_NORMALIZED, or GL_UNSIGNED_NORMALIZED for floating-point, signed integer, unsigned integer, signed normalized fixed-point, or unsigned normalized fixed-point components respectively. Only color buffers may have integer components.

- If pname is `GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING`, param will contain the encoding of components of the specified attachment, one of `GL_LINEAR` or `GL_SRGB` for linear or sRGB-encoded components, respectively. Only color buffer components may be sRGB-encoded; such components are treated as described in sections 4.1.7 and 4.1.8. For the default framebuffer, color encoding is determined by the implementation. For framebuffer objects, components are sRGB-encoded if the internal format of a color attachment is one of the color-renderable SRGB formats.

If the value of `GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE` is `GL_RENDERBUFFER`, then:

- If pname is `GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME`, params will contain the name of the renderbuffer object which contains the attached image.

If the value of `GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE` is `GL_TEXTURE`, then:

- If pname is `GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME`, then params will contain the name of the texture object which contains the attached image.

- If pname is `GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL`, then params will contain the mipmap level of the texture object which contains the attached image.

- If pname is `GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE` and the texture object named `GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME` is a cube map texture, then params will contain the cube map face of the cubemap texture object which contains the attached image. Otherwise params will contain the value zero.

- If pname is `GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER` and the texture object named `GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME` is a layer of a three-dimensional texture or a one-or two-dimensional array texture, then params will contain the number of the texture layer which contains the attached image. Otherwise params will contain the value zero.

- If pname is `GL_FRAMEBUFFER_ATTACHMENT_LAYERED`, then params will contain `GL_TRUE` if an entire level of a three-dimesional texture, cube map texture, or one-or two-dimensional array texture is attached. Otherwise, params will contain `GL_FALSE`.

Any combinations of framebuffer type and pname not described above will generate an error.

## Errors

`GL_INVALID_ENUM` is generated if target is not one of the accepted tokens.

`GL_INVALID_ENUM` is generated if pname is not valid for the value of `GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE`.

`GL_INVALID_OPERATION` is generated if attachment is not the accepted values for target.

`GL_INVALID_OPERATION` is generated if attachment is `GL_DEPTH_STENCIL_ATTACHMENT` and different objects are bound to the depth and stencil attachment points of target.

`GL_INVALID_OPERATION` is generated if the value of `GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE` is `GL_NONE` and pname is not `GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME`.

## See Also

glGenFramebuffers, glBindFramebuffer

## Copyright

Copyright 2010-2013 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.