                      RasterOps Sources and Objects
	  	        Bill Nowicki October 1982

More thorough documentation is found in /usr/sun/doc/graphics/lib.press.

    Presently, there is NO range checking done on point values given to 
these routines, so the user has to be careful to keep in the 800x1024 region.
That is, YOU have to range check your points.

    The following files are presently in this directory:

line.h		Macros for line drawing
line.c 		Bresenham line drawing routine
bres.s		Assembly code for ultra-fast inner loop of above

text.c		Text draw (paint)er
cmr.c		Font for simple text stuff
gentext.c	More complex text
getsfont.c	Get a font as used by gentext.c

rasterops.h	Include file for raster structures
copy.c		RasterCopy
fill.c		RasterFill
get.c		RasterGet
pattern.c	RasterPattern
put.c		RasterPut
roll.c		RasterRoll

screen.c	Screen operations
decode.c	Debug decoding routines
buf.c		Needed for TD's old IO routines
io.h		Ditto
vectime.c	Test program for different line-drawing algorithms.

---------------------------------------------------------------------------

    The include file "rasterops.h" is needed by and user routine which
invokes a rasterop.  It defines the data structures fb_raster and
mem_raster (a raster in the FB and one in processor memory respectively).
---------------------------------------------------------------------------
Address-probe routines:

GXProbe()

This routine returns the address of the ``first'' frame buffer available,
or 0 to indicate that it found none.

The algorithm used is to see if accessing GXUnit<n>Base gives a bus error,
for n = 6, 5, 4, 3, 2, 1, 0.  If such an access does not result in a bus
error, then it is assumed that a frame buffer is there.

GXUnit7Base is never used, because this would overlap the I/O space.
[source in gxprobe.c; this also calls ProbeAddress in probe.c, which
doesn't really belong here (it should be in libc.a)]
