Well, there's no function for it(see my suggestion thread about onwall3), but the only way to do it is to do something like I did for my lighting script...
PHP Code:
accuracy=.25;
onwall=0;
while (i<dist/accuracy) {
onwall=onwall(x+dx*i,y+dx*i);
if (onwall==1) break;
i+=accuracy;
}
This isn't going to be
too] tax-worthy on CPU, but a lot of baddies doing it might slow it down... but there's no other way.