3D-EXP

By Rich Geldreich

May 22nd, 1992


3D-EXP is a little QuickBASIC 4.5 wireframe program I
developed to show people that, yes, it is possible to produce some
cool 3-D animation in a high level language(in this case, QuickBASIC).
Try it out(compiled). I'm sure you'll like it.

So how did you get it so fast, you ask? Easy. Just don't use
any floating point math!! That's the secret. Integer only math is
MUCH quicker than floating point math... This program is an excellent
example. One thing of interest: Did you know that the "/" divide is
actually a floating point divide(even if you are dividing integers)?
Use the "\" divide symbol whenever you don't need a decimal answer...

The program is documented, so I'm not going to explain it
here. Have fun- it's public domain. Just don't distribute a modified
version of it unless you also put your name on it too. Thanks.


Integer math is actually very easy(if you understand
fractions). Lets say you want to multiply a number by .8 The normal
code to do this would be:

B% = A% * .8

That's okay... but there's a much quicker way. Why not this:

B% = (A% * 8) \ 10

At first this statement looks slower because it has an extra
divide. It's not- it's actually MUCH quicker. Why?

The ".8" in the first statement invokes an ultra slow,
mediocre floating point multiply. The second statement, which is
actually:

B% = 8 * A&
--------
10

does not. Clear as mud, right? Have fun figuring out this one...


If you have any questions or ideas, write/call:


Rich Geldreich
410 Market St.
Gloucester City, NJ 08030
(609)-742-8752