[comp.graphics] integer vs. floating point math

alex@umbc3.UMD.EDU (Alex S. Crain) (12/15/87)

	Hiya!

	I've started to draw things on my 3b1, and life bodes well except
that there is no floating point hardware available for the machine. Since
I'm partial to both ray tracing & mandelbrot sets, I've gotten used to 
starting the program and then going to bed. It occures to me that what I'm
doing is fairly restrictive in its range, and fixed-point numbers would
work well here with a significant speed increase. At this point I step into
a gray area of my experiance however, So I'm looking for algoriths. 

	If anyone can point me at a source of general purpose graphics 
algorithms that use integer/fixed-point math to calculate line slopes,
angles, circles, etc. I would greatly appreciate it.

	Also, the machine supports basic bit map functions for AND OR & XORing
of bit patterns. What are the rules of thumb for generating gray-scales?
What are the affects of different patterns, and how do you predict them?
What relationship do gray scale patters have to color? Where do I look for
answers to these and other questions?

		ThanX in advance...
						:alex.


alex@umbc3.umd.edu

jwhitnel@csi.UUCP (Jerry Whitnell) (12/17/87)

In article <642@umbc3.UMD.EDU> alex@umbc3.UMD.EDU (Alex S. Crain) writes:
>	If anyone can point me at a source of general purpose graphics 
>algorithms that use integer/fixed-point math to calculate line slopes,
>angles, circles, etc. I would greatly appreciate it.

You might also want to look at limited precisison floating point packages.
I know of a couple that use only 32 bits that are resonably fast.  I
used these for generating Mandlebrot on my Mac Plus.  Details on request.

>						:alex.

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