== Description

Xtypes provides scheme bindings for common datatypes used in xlib
programming.  This egg is meant to be used mainly in conjunction with the
xlib egg, as a convenience, because it exposes these various datatypes as
high level scheme objects rather than opaque c-pointers.  Objects created
by the make-* constructors here all have finalizers for automatic garbage
collecting.

This library has been developed on an as-needed basis, rather than a
methodical one.  There are possibly many more datatypes that would be the
proper domain of this library to handle, and those can be added as they
are reported to me, or as need arises in my own work with xlib.

=== Datatypes

* XGlyphInfo
* XRectangle
* XRenderColor


== Authors

* John J Foerch


== Requirements
=== Chicken eggs

* [[foreigners]]

=== C headers

* X11 development headers (libx11-dev)
* XRender development headers (libxrender-dev)


== API
=== XRectangle

<procedure>(make-xrectangle x y width height)</procedure>
<procedure>(xrectangle-x rect)</procedure>
<procedure>(xrectangle-y rect)</procedure>
<procedure>(xrectangle-width rect)</procedure>
<procedure>(xrectangle-height rect)</procedure>
<procedure>(xrectangle-x-set! rect x)</procedure>
<procedure>(xrectangle-y-set! rect y)</procedure>
<procedure>(xrectangle-width-set! rect width)</procedure>
<procedure>(xrectangle-height-set! rect height)</procedure>
<procedure>(xrectangle->string rect)</procedure>

Some of these procedures have the same names as procedures in the xlib
egg, so if you are using xtypes and xlib together, you should change your
xlib import form to look like this:

<enscript highlight="scheme">
(use
 (except xlib make-xrectangle
              xrectangle-x xrectangle-y
              xrectangle-width xrectangle-height)
 xtypes)
</enscript>


=== XGlyphInfo

<procedure>(make-xglyphinfo)</procedure>
<procedure>(xglyphinfo-x xginfo)</procedure>
<procedure>(xglyphinfo-y xginfo)</procedure>
<procedure>(xglyphinfo-width xginfo)</procedure>
<procedure>(xglyphinfo-height xginfo)</procedure>
<procedure>(xglyphinfo-xoff xginfo)</procedure>
<procedure>(xglyphinfo-yoff xginfo)</procedure>


=== XRenderColor

The channel values of an xrendercolor are all normalized to a decimal
number between 0.0 and 1.0.

<procedure>(make-xrendercolor r g b [a])</procedure>
<procedure>(xrendercolor-red color)</procedure>
<procedure>(xrendercolor-green color)</procedure>
<procedure>(xrendercolor-blue color)</procedure>
<procedure>(xrendercolor-alpha color)</procedure>


== Examples




== License

BSD


== Version History

* 0.1a (January 2, 2012) initial release
* 0.1a2 (February 7, 2013) added xrectangle->string