[net.micro.amiga] SPF routines speed up math?

rick1@sbcs.UUCP (Guest account) (11/13/85)

Bobp of AMIGA posted  a very   informative  program a couple of weeks ago. It
showed how to use the FFP  routines  rather than  the compiler generated ieee
floating point math. The posting was  extremely  helpful to me (and should be
to you) since the manual set  (V1.0) talks  about  the assemply language int-
erface but not the C language interface (for  the routines bobp illustrated).

Is there a difference between using  ieee  or ffp  floats? Bobp said that the
speed differential would be approximately 10 times in favor of ffp. Well,   I
was writting an animation demo  which,  in its digital scene generation, used
floating point heavily. Factor of ten? Definately.

I can render three-d smooth shaded  objects  at a very comfortable rate where
using ieee format math, my  grandmother could  grow some lemons and then make
them into lemonade in the time it took to render objects.

The routines are tricky to get used  to. One thing that threw me for a little
while was the order  of operands for  routines which are not operand commuta-
tive (like division).

My advice is to learn how to use the ffp routines asap if you are to use much
floating point in your work.

Bobp: could you post a sumary of the routines and there operand ordering?

Anyone: could someone write a subroutine to generate the sound of steel balls
	(like pinballs) colliding? I need it badly to add the finishing touch
	to my demo and without a sound editor I'm pretty much lost. I'll pass
	you a boolean flag describing which side I want the sound to come out
	on. I am not using sound otherwise.

I'll post the demo after someone helps me out with the sound. Thanks.