--- a/demos/ray.d	Mon Nov 12 06:32:46 2007 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,96 +0,0 @@
-//import std.stdio, std.math, std.string;
-//import tools.base;
-
-double delta;
-static this() { delta=sqrt(real.epsilon); }
-
-struct Vec {
-  double x, y, z;
-  Vec opAdd(ref Vec other) { return Vec(x+other.x, y+other.y, z+other.z); }
-  Vec opSub(ref Vec other) { return Vec(x-other.x, y-other.y, z-other.z); }
-  Vec opMul(double a) { return Vec(x*a, y*a, z*a); }
-  double dot(ref Vec other) { return x*other.x+y*other.y+z*other.z; }
-  Vec unitise() { return opMul(1.0/sqrt(dot(*this))); }
-}
-
-struct Pair(T, U) { T first; U second; }
-typedef Pair!(double, Vec) Hit;
-
-struct Ray { Vec orig, dir; }
-
-class Scene {
-  abstract void intersect(ref Hit, ref Ray);
-}
-
-class Sphere : Scene {
-  Vec center;
-  double radius;
-  this(ref Vec c, double r)
-  {
-    center = c;
-    radius = r;
-  }
-  double ray_sphere(ref Ray ray) {
-    auto v = center - ray.orig, b = v.dot(ray.dir), disc=b*b - v.dot(v) + radius*radius;
-    if (disc < 0) return double.infinity;
-    auto d = sqrt(disc), t2 = b + d;
-    if (t2 < 0) return double.infinity;
-    auto t1 = b - d;
-    return (t1 > 0 ? t1 : t2);
-  }
-  void intersect(ref Hit hit, ref Ray ray) {
-    auto lambda = ray_sphere(ray);
-    if (lambda < hit.first)
-      hit = Hit(lambda, (ray.orig + lambda*ray.dir - center).unitise);
-  }
-}
-
-class Group : Scene {
-  Sphere bound;
-  Scene[] children;
-  mixin This!("bound, children");
-  void intersect(ref Hit hit, ref Ray ray) {
-    auto l = bound.ray_sphere(ray);
-    if (l < hit.first) foreach (child; children) child.intersect(hit, ray);
-  }
-}
-
-double ray_trace(ref Vec light, ref Ray ray, Scene s) {
-  auto hit=Hit(double.infinity, Vec(0, 0, 0));
-  s.intersect(hit, ray);
-  if (hit.first == double.infinity) return 0.0;
-  auto g = hit.second.dot(light);
-  if (g >= 0) return 0.0;
-  auto p = ray.orig + ray.dir*hit.first + hit.second*delta;
-  auto hit2=Hit(double.infinity, Vec(0, 0, 0));
-  s.intersect(hit2, Ray(p, light*-1.0));
-  return (hit2.first < double.infinity ? 0 : -g);
-}
-
-Scene create(int level, ref Vec c, double r) {
-  auto s = new Sphere(c, r);
-  if (level == 1) return s;
-  Scene[] children=[s];
-  double rn = 3*r/sqrt(12.0);
-  for (int dz=-1; dz<=1; dz+=2)
-    for (int dx=-1; dx<=1; dx+=2)
-      children~=create(level-1, c + Vec(dx, 1, dz)*rn, r/2);
-  return new Group(new Sphere(c, 3*r), children);
-}
-
-void main(string[] args) {
-  int level = (args.length==3 ? args[1].atoi() : 9),
-    n = (args.length==3 ? args[2].atoi() : 512), ss = 4;
-  auto light = Vec(-1, -3, 2).unitise();
-  auto s=create(level, Vec(0, -1, 0), 1);
-  writefln("P5\n", n, " ", n, "\n255");
-  for (int y=n-1; y>=0; --y)
-    for (int x=0; x<n; ++x) {
-      double g=0;
-      for (int d=0; d<ss*ss; ++d) {
-        auto dir=Vec(x+(d%ss)*1.0/ss-n/2.0, y+(d/ss)*1.0/ss-n/2.0, n).unitise();
-    g += ray_trace(light, Ray(Vec(0, 0, -4), dir), s);
-      }
-      printf("%c", cast(ubyte)(0.5 + 255.0 * g / (ss*ss)));
-    }
-}