Shortest Ray Tracer In the World (not really)

I saw Andrew Kensler's newest back-of-a-business-card ray tracer. It's some pretty short and simple code to render his initials in reflective spheres. I'm not sure he could find the way to shorten the code even more, without losing any kind of coherence.

This took 2 minutes on my workstation


And here's the code (butchered by my browser)

#include    // card > aek.ppm

#include 

#include 

typedef int i;typedef float f;struct v{

f x,y,z;v operator+(v r){return v(x+r.x

,y+r.y,z+r.z);}v operator*(f r){return

v(x*r,y*r,z*r);}f operator%(v r){return

x*r.x+y*r.y+z*r.z;}v(){}v operator^(v r

){return v(y*r.z-z*r.y,z*r.x-x*r.z,x*r.

y-y*r.x);}v(f a,f b,f c){x=a;y=b;z=c;}v

operator!(){return*this*(1/sqrt(*this%*

this));}};i G[]={247570,280596,280600,

249748,18578,18577,231184,16,16};f R(){

return(f)rand()/RAND_MAX;}i T(v o,v d,f

&t,v&n){t=1e9;i m=0;f p=-o.z/d.z;if(.01

for(i j=9;j--;)if(G[j]&1<,0,-j-4);f b=p%d,c=p%p-1,q=b*b-c;if(q>0

){f s=-b-sqrt(q);if(s.01)t=s,n=!(

p+d*t),m=2;}}return m;}v S(v o,v d){f t

;v n;i m=T(o,d,t,n);if(!m)return v(.7,

.6,1)*pow(1-d.z,4);v h=o+d*t,l=!(v(9+R(

),9+R(),16)+h*-1),r=d+n*(n%d*-2);f b=l%

n;if(b<0||T(h,l,t,n))b=0;f p=pow(l%r*(b

>0),99);if(m&1){h=h*.2;return((i)(ceil(

h.x)+ceil(h.y))&1?v(3,1,1):v(3,3,3))*(b

*.2+.1);}return v(p,p,p)+S(h,r)*.5;}i

main(){printf("P6 512 512 255 ");v g=!v

(-6,-16,0),a=!(v(0,0,1)^g)*.002,b=!(g^a

)*.002,c=(a+b)*-256+g;for(i y=512;y--;)

for(i x=512;x--;){v p(13,13,13);for(i r

=64;r--;){v t=a*(R()-.5)*99+b*(R()-.5)*

99;p=S(v(17,16,8)+t,!(t*-1+(a*(R()+x)+b

*(y+R())+c)*16))*3.5+p;}printf("%c%c%c"

,(i)p.x,(i)p.y,(i)p.z);}}

I'm still waiting for his back-of-a-napkin photon mapper.