Xr - Rendering for X

Description
-----------
Xr provides anti-aliased vector-based rendering for X. Paths consist
of line segments and cubic splines and can be rendered at any width
with various join and cap styles. All colors may be specified with
optional translucence (opacity/alpha) throught the extended
Porter/Duff compositing algebra as found in the X Render Extension.

Dependencies
------------
Xr currently requires the following supporting libraries:

	Xc
	Xft
	fontconfig

Usage
-----
Xr exports a stateful rendering API similar in spirit to the path
construction, text, and painting operators of PostScript, (with the
significant addition of translucence in the imaging model). The API
was carefully designed to be easily understood with as little
additional explanation as possible. All functions take a minimal
number of arguments so that the number and order of arguments should
be easy to remember without the need to continually consult reference
documentation while developing with Xr.

Documentation
-------------
As mentioned above, we hope that users of Xr will be productive
without having to consult the documentation often. Ideally, a simple
glance at the Xr.h header file will provide enough information for the
programmer.

We'll see if we've been successful in our goal, since for the moment
the Xr.h header file is the only documentation that currently exists.

History
-------
Xr was developed by Carl Worth <cworth@isi.edu> and Keith Packard
<keithp@keithp.com>. Many thanks are due to Lyle Ramshaw without whose
patient help our ignorance would be much more apparent.