transform.c, 574..586
if (!(((int) angle) % 90))
{
# (snip) Exact rotation for angles that are multiples of 90.
}
There's a subtle bug here, in that casting to int will eliminate the
full-precision rotation on every range (90*x, 90*x + 1). My C-fu is a
bit weak, but I think that can be fixed by changing the if statement
to:
if ( !( angle % 90.0f ) )
-FunnyMan3595 (Charlie Nolan)
