Re: Jongware -> Building Galaxy Generator in C#

[Jongware] wrote:
> That might be related to the bit-****fting (lrotl, rrotl(?)) in the main 
> generate routine. Older compilers use 16 bit rotations (even in 32 bit 
> mode)

You mean _rotl() and _rotr(), since _lrotl() and _lrotr() work on 
unsigned longs (as their name implies) and are therefore always 32-bit 
rotations (well, as long as you don't have a compiler that uses 64-bit 
longs ;-) ).

> #define SHUFFLEWORD(x,val)   (((x) & 0xffff)<<(val)) | (((x) & 
> 0xffff)>>(16-val))

Actually it should be

#define SHUFFLEWORD(x,val) ((((x)<<(val)) | (((x) & 
0xffff)>>(16-(val)))) & 0xffff)

because the expression ((x) & 0xffff)<<(val)) might still have some bits 
in the upper word set.

But you could just say _rotl instead of SHUFFLEWORD, and then you don't 
have to modify the rest of the source...
well, actually, if there are any spaces between _rotl and the opening 
parenthesis, you have to remove them.
_rotr could be defined in a similar way:

#define _rotr(x,val) (((((x) & 0xffff)>>(val)) | ((x)<<(16-(val)))) & 
0xffff)

-- 
Marcin Grzegorczyk