[sdiy] Reverse Sawtooth

[Steven Cook]

> You can actually get away with 90 degrees of a sine wave table. 1/4 the 
> space. It would eat more processor time and the code size MIGHT be worse 
> than the table look up.
>
> Tim Daugard

You can get away with 45 degrees of a sine wave with even more fiddly code.

Or, you could combine sine and cosine tables. To get a 16-bit sine use 4 
8-bit tables: a sine wave, a cosine wave, a 1/256th of a sine and a 1/256th 
of a cosine. Pseudocode: (32-bit phase)

int x = phase >> 24;
int y = (phase >> 16) & 255;sine 
= sinTable1[x]*cosTable2[y] + cosTable1[x]*sinTable2[y];

Regards,

Steven Cook,
http://www.spcplugins.com/