1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/box.cc	Sun Nov 09 13:03:36 2014 +0200
     1.3 @@ -0,0 +1,63 @@
     1.4 +#include "box.h"
     1.5 +
     1.6 +Box::Box()
     1.7 +	: min(-0.5, -0.5, -0.5), max(0.5, 0.5, 0.5)
     1.8 +{
     1.9 +}
    1.10 +
    1.11 +Box::Box(const Vector3 &min_arg, const Vector3 &max_arg)
    1.12 +	: min(min_arg), max(max_arg)
    1.13 +{
    1.14 +}
    1.15 +
    1.16 +bool Box::intersect(const Ray &inray, HitPoint *pt) const
    1.17 +{
    1.18 +	Ray ray = inray.transformed(inv_xform);
    1.19 +
    1.20 +	Vector3 param[2] = {min, max};
    1.21 +	Vector3 inv_dir(1.0 / ray.dir.x, 1.0 / ray.dir.y, 1.0 / ray.dir.z);
    1.22 +	int sign[3] = {inv_dir.x < 0, inv_dir.y < 0, inv_dir.z < 0};
    1.23 +
    1.24 +	float tmin = (param[sign[0]].x - ray.origin.x) * inv_dir.x;
    1.25 +	float tmax = (param[1 - sign[0]].x - ray.origin.x) * inv_dir.x;
    1.26 +	float tymin = (param[sign[1]].y - ray.origin.y) * inv_dir.y;
    1.27 +	float tymax = (param[1 - sign[1]].y - ray.origin.y) * inv_dir.y;
    1.28 +
    1.29 +	pt->normal = Vector3(ray.origin.x > 0.0 ? 1 : -1, 0, 0);
    1.30 +
    1.31 +	if(tmin > tymax || tymin > tmax) {
    1.32 +		return false;
    1.33 +	}
    1.34 +	if(tymin > tmin) {
    1.35 +		pt->normal = Vector3(0, ray.origin.y > 0.0 ? 1 : -1, 0);
    1.36 +		tmin = tymin;
    1.37 +	}
    1.38 +	if(tymax < tmax) {
    1.39 +		tmax = tymax;
    1.40 +	}
    1.41 +
    1.42 +	float tzmin = (param[sign[2]].z - ray.origin.z) * inv_dir.z;
    1.43 +	float tzmax = (param[1 - sign[2]].z - ray.origin.z) * inv_dir.z;
    1.44 +
    1.45 +	if(tmin > tzmax || tzmin > tmax) {
    1.46 +		return false;
    1.47 +	}
    1.48 +	if(tzmin > tmin) {
    1.49 +		pt->normal = Vector3(0, 0, ray.origin.z > 0.0 ? 1 : -1);
    1.50 +		tmin = tzmin;
    1.51 +	}
    1.52 +	if(tzmax < tmax) {
    1.53 +		tmax = tzmax;
    1.54 +	}
    1.55 +
    1.56 +	float t = tmin < 1e-4 ? tmax : tmin;
    1.57 +	if(t >= 1e-4) {
    1.58 +		pt->obj = this;
    1.59 +		pt->dist = t;
    1.60 +		pt->pos = ray.origin + ray.dir * t;
    1.61 +		pt->pos.transform(xform);
    1.62 +		pt->normal.transform(dir_xform);
    1.63 +		return true;
    1.64 +	}
    1.65 +	return false;
    1.66 +}