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Groovy example source code file (ray.groovy)
The Groovy ray.groovy source code// translated from http://www.ffconsultancy.com/languages/ray_tracer/code/1/ray.java // by Derek Young - Sep 6, 07 class Vec { public double x, y, z; public Vec(double x2, double y2, double z2) { x=x2; y=y2; z=z2; } static Vec add(Vec a, Vec b) { return new Vec(a.x+b.x, a.y+b.y, a.z+b.z); } static Vec sub(Vec a, Vec b) { return new Vec(a.x-b.x, a.y-b.y, a.z-b.z); } static Vec scale(double s, Vec a) { return new Vec(s*a.x, s*a.y, s*a.z); } static double dot(Vec a, Vec b) { return a.x*b.x + a.y*b.y + a.z*b.z; } static Vec unitise(Vec a) { return scale(1 / Math.sqrt(Vec.dot(a, a)), a); } } class Ray { public Vec orig, dir; public Ray(Vec o, Vec d) { orig=o; dir=d; } } class Hit { public double lambda; public Vec normal; public Hit(double l, Vec n) { lambda=l; normal=n; } } abstract class Scene { abstract public Hit intersect(Hit i, Ray ray); } class Sphere extends Scene { static double infinity=Float.POSITIVE_INFINITY; public Vec center; public double radius; public Sphere(Vec c, double r) { center=c; radius=r; } public double ray_sphere(Ray ray) { Vec v = Vec.sub(center, ray.orig); double b = Vec.dot(v, ray.dir), disc = b*b - Vec.dot(v, v) + radius*radius; if (disc < 0) return infinity; double d = Math.sqrt(disc), t2 = b+d; if (t2 < 0) return infinity; double t1 = b-d; return (t1 > 0 ? t1 : t2); } public Hit intersect(Hit i, Ray ray) { double l = ray_sphere(ray); if (l >= i.lambda) return i; Vec n = Vec.add(ray.orig, Vec.sub(Vec.scale(l, ray.dir), center)); return new Hit(l, Vec.unitise(n)); } } class Group extends Scene { public Sphere bound; public ArrayList objs; public Group(Sphere b) { bound = b; objs = new ArrayList(); } public Hit intersect(Hit i, Ray ray) { double l = bound.ray_sphere(ray); if (l >= i.lambda) return i; ListIterator it = objs.listIterator(0); while (it.hasNext()) { Scene scene = (Scene)it.next(); i = scene.intersect(i, ray); } return i; } } class rayMain { double delta=Math.sqrt(Math.ulp(1.0d)), infinity=Float.POSITIVE_INFINITY; double ray_trace(Vec light, Ray ray, Scene scene) { Hit i = scene.intersect(new Hit(infinity, new Vec(0, 0, 0)), ray); if (i.lambda == infinity) return 0; Vec o = Vec.add(ray.orig, Vec.add(Vec.scale(i.lambda, ray.dir), Vec.scale(delta, i.normal))); double g = Vec.dot(i.normal, light); if (g >= 0) return 0.0d; Ray sray = new Ray(o, Vec.scale(-1, light)); Hit si = scene.intersect(new Hit(infinity, new Vec(0, 0, 0)), sray); return (si.lambda == infinity ? -g : 0); } Scene create(int level, Vec c, double r) { Sphere sphere = new Sphere(c, r); if (level == 1) return sphere; Group group = new Group(new Sphere(c, 3*r)); group.objs.add(sphere); double rn = 3*r/Math.sqrt(12); for (int dz in [-1, 1]) { for (int dx in [-1, 1]) { //for (int dx=-1; dx<=1; dx+=2) { Vec c2 = new Vec(c.x+dx*rn, c.y+rn, c.z+dz*rn); group.objs.add(create(level-1, c2, r/2)); } } return group; } void run(int n, int level, int ss) { Scene scene = create(level, new Vec(0, -1, 0), 1); FileOutputStream out = new FileOutputStream("groovyimage.pgm"); out.write(("P5\n"+n+" "+n+"\n255\n").getBytes()); for (int yi in 0..(n-1)) { int y = (n-1) - yi for (int x in 0..(n - 1)) { //print('.'); double g=0; for (int dx in 0..(ss - 1)) { for (int dy in 0..(ss - 1)) { Vec d = new Vec(x+dx*1.0d/ss-n/2.0d, y+dy*1.0d/ss-n/2.0d, n); Ray ray = new Ray(new Vec(0, 0, -4), Vec.unitise(d)); g += ray_trace(Vec.unitise(new Vec(-1, -3, 2)), ray, scene); } } out.write((int)(0.5d+255.0d*g/(ss*ss))); } } out.close(); } } (new rayMain()).run(Integer.parseInt(args[1]), Integer.parseInt(args[0]), 4); Other Groovy examples (source code examples)Here is a short list of links related to this Groovy ray.groovy source code file: |
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