(* SRAY -- Sadol RAYtracer 		*)
(* A simple raytracer ;p		*)

(* vector routines *)
fun V:3 : _ ;		(* vector *)

op `+`  : [L[0]+R[0], L[1]+R[1], L[2]+R[2]];
op `-`  : [L[0]-R[0], L[1]-R[1], L[2]-R[2]];
op `*`  : [L[0]*R[0], L[1]*R[1], L[2]*R[2]];
op `/`  : [L[0]/R, L[1]/R, L[2]/R];
op `*.` : [L[0]*R, L[1]*R, L[2]*R];
op `.`  : L[0]*R[0]+L[1]*R[1]+R[2]*R[2];					  (* dot product *)
fun M:1 : (_[0] `.` _[0])^(1/2);							  (* magnitude *)	
fun N:1 : {m=M(_[0]); [_[0][0]/m, _[0][1]/m, _[0][2]/m]};     (* normalize *)

op `<<` : <%[LR%>; 

(* scene:								*)
(*	header: [pixw,pixh, eye]			*)
(*   eye: [x,y,z]						*)
(*	objects: [object, object, ... ]		*)
(*	 object: [type, vec, rgb, ad]		*)
(*	  vec: [x,y,z]						*)
(*	  rgb: [r,g,b]						*)
(*	  ad: additional					*)

s = [	[640,480, [0,0,-5]],
 	 [
		["sph", [0,0,5], [1,0,0], 2],
		["omni", [2,2,2], [1,1,1], 1]
	 ]
    ];

(*raytrace*)    
fun R:1 : {
	s = _[0];
	w = s[0][0];
	h = s[0][1];
	e = s[0][2];
	
	(* pixels to projection plane (x,y) -> vec *)
	fun p:2 : [12/w*_[0]-6, 0-(9/h*_[1]-4.5), 0];
	
	(*trace single ray (ray,depth) -> color *)
	fun t:2 : {
		(* intersection (ray, object) -> (num, num, num, ...) *)
		fun i:2 : {
			o = _[1];
			r = _[0];
			x = <%$0%>;
			if o[0] == "sph" : {
				a = M(r[0]);
				b = 2*(r[0] `.` (o[1] `-` r[1]));
				c = M(o[1] `-` r[1]) * o[3]^2;
				d = b^2 - 2*a*c;
				if (d < 0) : x `<<` -1
				else {
					v = ((0-b)-d^(1/2))/a;
					if v >= 0 : x `<<` v;
					v = ((0-b)+d^(1/2))/a;
					if v >= 0 : x `<<` v
				}
			} else (* TODO: plane *)
				x `<<` -1
			;
			x
		};
		
		out 0 
	};
	
	out 0
}; 



R(s)



(* COMPILED:

~V3_{endf V}
~M1^++*##_00##_00*##_01##_01*##_02##_02/12{endf M}
~N1(2:mM#_0
$3/##_00m/##_01m/##_02m{endlist}{)}{endf N}

:s$2$3,3640,3480$300-05{endlist}{endlist}$2$4"3sph$3005{endlist}$3100{endlist}2{endlist}$4"4omni$3222{endlist}$3111{endlist}1{endlist}{endlist}{endlist}
~R1(7:s#_0
:w##s00
:h##s01
:e##s02
~p2$3-*/,212w#_06-0-*/9h#_1+4.150{endlist}{endf p}
~t2(2~i2(5:o#_1
:r#_0
:x$0
?=#o0"3sph(5:aM#r0
:b*2++*##r00#$3-##o10##r10-##o11##r11-##o12##r12{endlist}0*##r01#$3-##o10##r10-##o11##r11-##o12##r12{endlist}1*#$3-##o10##r10-##o11##r11-##o12##r12{endlist}2#$3-##o10##r10-##o11##r11-##o12##r12{endlist}2
:c*M$3-##o10##r10-##o11##r11-##o12##r12{endlist}^#o32
:d-^b2**2ac
?<d0[x-01{els}(4:v/--0b^d/12a
?|>v0=v0[xv0{endif}
:v/+-0b^d/12a
?|>v0=v0[xv0{endif}{)}{endif}{)}{els}[x-01{endif}
x{)}{endf i}
!0{)}{endf t}
!0{)}{endf R}
Rs

*)