C (902 byte)
This doesn't use trigonometric functions (like the original perl version), so it's quite ``bloated''. Anyway, here is my first code-golf submission:
#define V(r) (4*r*r+6*r+3)
#define F for(i=0;ie)*p=h[0];E(j>m)*p=h[1];E(j>s)*p=h[2];else*p=h[3];p++;}
if(i+1==r){h="7654";m--;e--;}E(i==r){s--;}E(i>r){s--;e++;}
else{s++;e--;}p++;}for(p=f+V(r)/2-1,i=0;i=x&&i
also, the #defines look rather ugly, but they save about 200 bytes so I kept them in, anyway. It is valid ANSI C89/C90 and compiles with very few warnings (two about atoi and puts and two about crippled form of main).