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intersections.c
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intersections.c
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/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* intersections.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: okupin <[email protected]> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2018/06/08 18:32:10 by okupin #+# #+# */
/* Updated: 2018/06/08 18:32:10 by okupin ### ########.fr */
/* */
/* ************************************************************************** */
#include "rtv1.h"
float sphere_intersect(t_world *e, t_v3 eye, t_v3 dir)
{
t_sphere *this;
float dabc[4];
float t1;
float t2;
t_v3 centerdist;
this = e->geometry;
centerdist = v_diff(eye, this->c);
dabc[1] = v_dot(dir, dir);
dabc[2] = 2 * v_dot(dir, centerdist);
dabc[3] = v_dot(centerdist, centerdist) - SQR(this->r);
dabc[0] = SQR(dabc[2]) - 4 * dabc[1] * dabc[3];
if (dabc[0] < 0)
return (INFIN);
t1 = (-dabc[2] - sqrt(dabc[0])) / (2 * dabc[1]);
if (t1 > 0 && t1 < INFIN)
{
e->temp_normal = v_norm(v_diff(v_add(eye,
v_scale(dir, t1)), this->c));
return (t1);
}
else if (t1 < 0)
{
t2 = (-dabc[2] + sqrt(dabc[0])) / (2 * dabc[1]);
if (t2 > 0 && t2 < INFIN)
{
e->temp_normal = v_norm(v_diff(v_add(eye,
v_scale(dir, t2)), this->c));
return (t2);
}
}
return (INFIN);
}
float plane_intersect(t_world *e, t_v3 eye, t_v3 dir)
{
t_plane *this;
float temp;
float t;
this = e->geometry;
this->n = v_norm(this->n);
temp = v_dot(dir, this->n);
if (temp == 0.0f)
return (INFIN);
t = v_dot(v_diff(this->p, eye), this->n) / temp;
if (t > 0 && t < INFIN)
{
e->temp_normal = this->n;
return (t);
}
return (INFIN);
}
float cylinder_intersect(t_world *e, t_v3 eye, t_v3 dir)
{
t_cylinder *this;
float dabc[4];
float t;
float d;
float d2;
t_v3 temp;
this = e->geometry;
temp = v_diff(eye, this->c);
d = v_dot(dir, this->rot);
d2 = v_dot(temp, this->rot);
dabc[1] = v_dot(dir, dir) - d * d;
dabc[2] = 2 * (v_dot(dir, temp) -
(d * d2));
dabc[3] = v_dot(temp, temp) - (d2 * d2) - (SQR(this->r));
dabc[0] = (SQR(dabc[2])) - 4 * dabc[1] * dabc[3];
if (dabc[0] < 0)
return (INFIN);
t = (-dabc[2] - sqrt(dabc[0])) / (2 * dabc[1]);
if (t > 0 && t < INFIN)
{
cylinder_get_normal(e, this, t);
return (t);
}
return (INFIN);
}
// float triangle_intersect(t_world *e)
// {
// t_triangle *this;
// float t1;
// this = e->geometry;
// }
float cone_intersect(t_world *e, t_v3 eye, t_v3 dir)
{
t_cone *this;
float dabc[4];
float t;
float k;
t_v3 temp;
this = e->geometry;
temp = v_diff(eye, this->c);
k = tan(this->angle);
dabc[1] = v_dot(dir, dir)
- (1 + k * k) * (SQR(v_dot(dir, this->rot)));
dabc[2] = 2 * (v_dot(dir, temp) - (1 + (SQR(k)))
* v_dot(dir, this->rot) * v_dot(temp, this->rot));
dabc[3] = v_dot(temp, temp)
- (1 + (SQR(k))) * (SQR(v_dot(temp, this->rot)));
dabc[0] = (SQR(dabc[2])) - (4 * dabc[1] * dabc[3]);
if (dabc[0] <= 0)
return (INFIN);
t = (-dabc[2] - sqrt(dabc[0])) / (2 * dabc[1]);
if (t > 0 && t < INFIN)
{
cone_get_normal(e, this, t);
return (t);
}
return (INFIN);
}