erebus: liberebus/src/bvol.cc annotate

erebus

helpful comment

author	John Tsiombikas <nuclear@member.fsf.org>
date	Fri, 18 Sep 2015 06:47:41 +0300
parents	4abdce1361b9
children	c4d48a21bc4a

rev	line source
nuclear@2	1 #include "bvol.h"
nuclear@2	2
nuclear@2	3 bool AABox::intersect(const Ray &ray) const
nuclear@2	4 {
nuclear@2	5 Vector3 param[2] = {vmin, vmax};
nuclear@2	6 Vector3 inv_dir(1.0 / ray.dir.x, 1.0 / ray.dir.y, 1.0 / ray.dir.z);
nuclear@2	7 int sign[3] = {inv_dir.x < 0, inv_dir.y < 0, inv_dir.z < 0};
nuclear@2	8
nuclear@2	9 float tmin = (param[sign[0]].x - ray.origin.x) * inv_dir.x;
nuclear@2	10 float tmax = (param[1 - sign[0]].x - ray.origin.x) * inv_dir.x;
nuclear@2	11 float tymin = (param[sign[1]].y - ray.origin.y) * inv_dir.y;
nuclear@2	12 float tymax = (param[1 - sign[1]].y - ray.origin.y) * inv_dir.y;
nuclear@2	13
nuclear@2	14 if(tmin > tymax \|\| tymin > tmax) {
nuclear@2	15 return false;
nuclear@2	16 }
nuclear@2	17 if(tymin > tmin) {
nuclear@2	18 tmin = tymin;
nuclear@2	19 }
nuclear@2	20 if(tymax < tmax) {
nuclear@2	21 tmax = tymax;
nuclear@2	22 }
nuclear@2	23
nuclear@2	24 float tzmin = (param[sign[2]].z - ray.origin.z) * inv_dir.z;
nuclear@2	25 float tzmax = (param[1 - sign[2]].z - ray.origin.z) * inv_dir.z;
nuclear@2	26
nuclear@2	27 if(tmin > tzmax \|\| tzmin > tmax) {
nuclear@2	28 return false;
nuclear@2	29 }
nuclear@2	30 if(tzmin > tmin) {
nuclear@2	31 tmin = tzmin;
nuclear@2	32 }
nuclear@2	33 if(tzmax < tmax) {
nuclear@2	34 tmax = tzmax;
nuclear@2	35 }
nuclear@2	36
nuclear@2	37 return true;
nuclear@2	38 }