85 void box_intersect(box *bx, ray *ry) {  in box_intersect()  argument
92     if (ry->d.x == 0.0) {  in box_intersect()
93         if ((ry->o.x < bx->min.x) || (ry->o.x > bx->max.x))  in box_intersect()
97         tx1 = (bx->min.x - ry->o.x) / ry->d.x;  in box_intersect()
98         tx2 = (bx->max.x - ry->o.x) / ry->d.x;  in box_intersect()
114     if (ry->d.y == 0.0) {  in box_intersect()
115         if ((ry->o.y < bx->min.y) || (ry->o.y > bx->max.y))  in box_intersect()
119         ty1 = (bx->min.y - ry->o.y) / ry->d.y;  in box_intersect()
120         ty2 = (bx->max.y - ry->o.y) / ry->d.y;  in box_intersect()
136     if (ry->d.z == 0.0) {  in box_intersect()
137         if ((ry->o.z < bx->min.z) || (ry->o.z > bx->max.z))  in box_intersect()
141         tz1 = (bx->min.z - ry->o.z) / ry->d.z;  in box_intersect()
142         tz2 = (bx->max.z - ry->o.z) / ry->d.z;  in box_intersect()
158     add_intersection(tnear, (object *)bx, ry);  in box_intersect()
159     add_intersection(tfar, (object *)bx, ry);  in box_intersect()