Mercurial > projects > ldc
view demos/ray.cpp @ 1064:f0b6549055ab
Make LDC work with LLVM trunk (s/LinkOnceLinkage/LinkOnceOdrLinkage/)
Also moved the #defines for linkage types into a separate header instead of
mars.h so we can #include revisions.h without having to rebuild the entire
frontend every time we update.
(I'm using revisions.h to get the LLVM revision for use in preprocessor
conditionals. It should work with LLVM release 2.5, old trunk and new trunk)
author | Frits van Bommel <fvbommel wxs.nl> |
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date | Sun, 08 Mar 2009 16:13:10 +0100 |
parents | 90522b72128a |
children |
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#include <list> #include <iostream> #include <limits> #include <cmath> #include <cstdlib> using namespace std; numeric_limits<double> real; double delta = sqrt(real.epsilon()), infinity = real.infinity(); struct Vec { double x, y, z; Vec(double x2, double y2, double z2) : x(x2), y(y2), z(z2) {} }; Vec operator+(const Vec &a, const Vec &b) { return Vec(a.x+b.x, a.y+b.y, a.z+b.z); } Vec operator-(const Vec &a, const Vec &b) { return Vec(a.x-b.x, a.y-b.y, a.z-b.z); } Vec operator*(double a, const Vec &b) { return Vec(a*b.x, a*b.y, a*b.z); } double dot(const Vec &a, const Vec &b) { return a.x*b.x + a.y*b.y + a.z*b.z; } Vec unitise(const Vec &a) { return (1 / sqrt(dot(a, a))) * a; } typedef pair<double, Vec> Hit; struct Ray { Vec orig, dir; Ray(const Vec &o, const Vec &d) : orig(o), dir(d) {} }; struct Scene { virtual ~Scene() {}; virtual void intersect(Hit &, const Ray &) const = 0; }; struct Sphere : public Scene { Vec center; double radius; Sphere(Vec c, double r) : center(c), radius(r) {} ~Sphere() {} double ray_sphere(const Ray &ray) const { Vec v = center - ray.orig; double b = dot(v, ray.dir), disc = b*b - dot(v, v) + radius * radius; if (disc < 0) return infinity; double d = sqrt(disc), t2 = b + d; if (t2 < 0) return infinity; double t1 = b - d; return (t1 > 0 ? t1 : t2); } void intersect(Hit &hit, const Ray &ray) const { double lambda = ray_sphere(ray); if (lambda >= hit.first) return; hit = Hit(lambda, unitise(ray.orig + lambda*ray.dir - center)); } }; typedef list<Scene *> Scenes; struct Group : public Scene { Sphere bound; Scenes child; Group(Sphere b, Scenes c) : bound(b), child(c) {} ~Group() { for (Scenes::const_iterator it=child.begin(); it!=child.end(); ++it) delete *it; } void intersect(Hit &hit, const Ray &ray) const { double l = bound.ray_sphere(ray); if (l < hit.first) for (Scenes::const_iterator it=child.begin(); it!=child.end(); ++it) (*it)->intersect(hit, ray); } }; Hit intersect(const Ray &ray, const Scene &s) { Hit res = Hit(infinity, Vec(0, 0, 0)); s.intersect(res, ray); return res; } double ray_trace(const Vec &light, const Ray &ray, const Scene &s) { Hit hit = intersect(ray, s); if (hit.first == infinity) return 0; double g = dot(hit.second, light); if (g >= 0) return 0.; Vec p = ray.orig + hit.first*ray.dir + delta*hit.second; return (intersect(Ray(p, -1. * light), s).first < infinity ? 0 : -g); } Scene *create(int level, const Vec &c, double r) { Scene *s = new Sphere(c, r); if (level == 1) return s; Scenes child; child.push_back(s); double rn = 3*r/sqrt(12.); for (int dz=-1; dz<=1; dz+=2) for (int dx=-1; dx<=1; dx+=2) child.push_back(create(level-1, c + rn*Vec(dx, 1, dz), r/2)); return new Group(Sphere(c, 3*r), child); } int main(int argc, char *argv[]) { int level = 6, n = 512, ss = 4; if (argc == 2) level = atoi(argv[1]); Vec light = unitise(Vec(-1, -3, 2)); Scene *s(create(level, Vec(0, -1, 0), 1)); cout << "P5\n" << n << " " << n << "\n255\n"; for (int y=n-1; y>=0; --y) for (int x=0; x<n; ++x) { double g=0; for (int dx=0; dx<ss; ++dx) for (int dy=0; dy<ss; ++dy) { Vec dir(unitise(Vec(x+dx*1./ss-n/2., y+dy*1./ss-n/2., n))); g += ray_trace(light, Ray(Vec(0, 0, -4), dir), *s); } cout << char(int(.5 + 255. * g / (ss*ss))); } delete s; return 0; }