gpuray_glsl
annotate src/sphere.cc @ 0:f234630e38ff
initial commit
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Sun, 09 Nov 2014 13:03:36 +0200 |
| parents | |
| children | 297dbc5080c4 |
| rev | line source |
|---|---|
| nuclear@0 | 1 #include <stdio.h> |
| nuclear@0 | 2 #include "sphere.h" |
| nuclear@0 | 3 |
| nuclear@0 | 4 Sphere::Sphere() |
| nuclear@0 | 5 { |
| nuclear@0 | 6 radius = 1.0; |
| nuclear@0 | 7 } |
| nuclear@0 | 8 |
| nuclear@0 | 9 Sphere::Sphere(const Vector3 &pos, float rad) |
| nuclear@0 | 10 { |
| nuclear@0 | 11 radius = rad; |
| nuclear@0 | 12 this->pos = pos; |
| nuclear@0 | 13 } |
| nuclear@0 | 14 |
| nuclear@0 | 15 bool Sphere::intersect(const Ray &inray, HitPoint *pt) const |
| nuclear@0 | 16 { |
| nuclear@0 | 17 Ray ray = inray.transformed(inv_xform); |
| nuclear@0 | 18 |
| nuclear@0 | 19 float a = dot_product(ray.dir, ray.dir); |
| nuclear@0 | 20 float b = 2.0 * ray.dir.x * (ray.origin.x - pos.x) + |
| nuclear@0 | 21 2.0 * ray.dir.y * (ray.origin.y - pos.y) + |
| nuclear@0 | 22 2.0 * ray.dir.z * (ray.origin.z - pos.z); |
| nuclear@0 | 23 float c = dot_product(ray.origin, ray.origin) + dot_product(pos, pos) - |
| nuclear@0 | 24 2.0 * dot_product(ray.origin, pos) - radius * radius; |
| nuclear@0 | 25 |
| nuclear@0 | 26 float discr = b * b - 4.0 * a * c; |
| nuclear@0 | 27 if(discr < 1e-4) |
| nuclear@0 | 28 return false; |
| nuclear@0 | 29 |
| nuclear@0 | 30 float sqrt_discr = sqrt(discr); |
| nuclear@0 | 31 float t0 = (-b + sqrt_discr) / (2.0 * a); |
| nuclear@0 | 32 float t1 = (-b - sqrt_discr) / (2.0 * a); |
| nuclear@0 | 33 |
| nuclear@0 | 34 if(t0 < 1e-4) |
| nuclear@0 | 35 t0 = t1; |
| nuclear@0 | 36 if(t1 < 1e-4) |
| nuclear@0 | 37 t1 = t0; |
| nuclear@0 | 38 |
| nuclear@0 | 39 float t = t0 < t1 ? t0 : t1; |
| nuclear@0 | 40 if(t < 1e-4) |
| nuclear@0 | 41 return false; |
| nuclear@0 | 42 |
| nuclear@0 | 43 // fill the HitPoint structure |
| nuclear@0 | 44 pt->obj = this; |
| nuclear@0 | 45 pt->dist = t; |
| nuclear@0 | 46 pt->pos = ray.origin + ray.dir * t; |
| nuclear@0 | 47 pt->normal = (pt->pos - pos) / radius; |
| nuclear@0 | 48 |
| nuclear@0 | 49 pt->pos.transform(xform); |
| nuclear@0 | 50 pt->normal.transform(dir_xform); |
| nuclear@0 | 51 return true; |
| nuclear@0 | 52 } |