Gl.GetFramebufferAttachmentParameterivEXT (gb.opengl)
Static Function GetFramebufferAttachmentParameterivEXT ( Target As Integer, Attachment As Integer, Pname As Integer ) As Integer[]
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
Gl.GetFramebufferAttachmentParameter 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_ATTACHMENT
i,
Gl.DEPTH_ATTACHMENT, Gl.STENCIL_ATTACHMENT, or Gl.DEPTH_STENCIL_ATTACHMENT.
i in Gl.COLOR_ATTACHMENT
i 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
Gl.GetFramebufferAttachmentParameteriv, 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
Gl.GenFramebuffers
Gl.BindFramebuffer