#lang scribble/doc
@(require "common.rkt")

@defclass/title[gl-config% object% ()]{

A @racket[gl-config%] object encapsulates configuration information
 for an OpenGL drawing context. Use a @racket[gl-config%] object as an
 initialization argument for @racket[canvas%] or provide it to
 @racket[make-gl-bitmap].


@defconstructor[()]{

Creates a GL configuration that indicates double buffering, a depth
 buffer of size one, no stencil buffer, no accumulation buffer, no
 multisampling, and not stereo.

}

@defmethod[(get-accum-size)
           (integer-in 0 256)]{

Reports the accumulation-buffer size (for each of red, green, blue,
 and alpha) that the configuration requests, where zero means no
 accumulation buffer is requested.

}

@defmethod[(get-depth-size)
           (integer-in 0 256)]{

Reports the depth-buffer size that the configuration requests, where
 zero means no depth buffer is requested.

}

@defmethod[(get-double-buffered)
           boolean?]{

Reports whether the configuration requests double buffering or not.

}

@defmethod[(get-multisample-size)
           (integer-in 0 256)]{

Reports the multisampling size that the configuration requests, where
 zero means no multisampling is requested.

}

@defmethod[(get-share-context)
           (or/c #f (is-a?/c gl-context<%>))]{

Returns a @racket[gl-context<%>] object that shares certain objects
(textures, display lists, etc.) with newly created OpenGL drawing
contexts, or @racket[#f] is none is set.

See also @method[gl-config% set-share-context].

}
          

@defmethod[(get-stencil-size)
           (integer-in 0 256)]{

Reports the stencil-buffer size that the configuration requests, where
 zero means no stencil buffer is requested.

}

@defmethod[(get-stereo)
           boolean?]{

Reports whether the configuration requests stereo or not.

}

@defmethod[(set-accum-size [on? (integer-in 0 256)])
           void?]{

Adjusts the configuration to request a particular accumulation-buffer
 size for every channel (red, green, blue, and alpha), where zero
 means no accumulation buffer is requested.

}

@defmethod[(set-depth-size [on? (integer-in 0 256)])
           void?]{

Adjusts the configuration to request a particular depth-buffer size,
 where zero means no depth buffer is requested.

}

@defmethod[(set-double-buffered [on? any/c])
           void?]{

Adjusts the configuration to request double buffering or not.

}

@defmethod[(set-multisample-size [on? (integer-in 0 256)])
           void?]{

Adjusts the configuration to request a particular multisample size,
 where zero means no multisampling is requested. If a multisampling
 context is not available, this request will be ignored.

}

@defmethod[(set-share-context [context (or/c #f (is-a?/c gl-context<%>))])
           void?]{

Determines a @racket[gl-context<%>] object that shares certain objects
(textures, display lists, etc.) with newly created OpenGL drawing
contexts, where @racket[#f] indicates
that no sharing should occur.

When a context @racket[_B] shares objects with context @racket[_A], it
is also shares objects with every other context sharing with
@racket[_A], and vice versa.

If an OpenGL implementation does not support sharing, @racket[context]
is effectively ignored when a new context is created.
Sharing should be supported in all versions of Mac OS X.
On Windows and Linux, sharing is provided by the presence of the
@tt{WGL_ARB_create_context} and @tt{GLX_ARB_create_context} extensions,
respectively (and OpenGL 3.2 requires both).

}

@defmethod[(set-stencil-size [on? (integer-in 0 256)])
           void?]{

Adjusts the configuration to request a particular stencil-buffer size,
 where zero means no stencil buffer is requested.

}

@defmethod[(set-stereo [on? any/c])
           void?]{

Adjusts the configuration to request stereo or not.

}}