47 lines
1.5 KiB
C
47 lines
1.5 KiB
C
/* ************************************************************************** */
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/* */
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/* ::: :::::::: */
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/* maths_sphere.c :+: :+: :+: */
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/* +:+ +:+ +:+ */
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/* By: gbrochar <marvin@42.fr> +#+ +:+ +#+ */
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/* +#+#+#+#+#+ +#+ */
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/* Created: 2019/02/08 14:43:58 by gbrochar #+# #+# */
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/* Updated: 2019/02/11 14:15:57 by gbrochar ### ########.fr */
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/* */
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/* ************************************************************************** */
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#include "rtv1.h"
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double intersect_sphere(void *obj, t_ray r)
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{
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t_sphere *s;
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double roots[2];
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double params[3];
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s = (t_sphere *)obj;
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params[0] = 1;
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params[1] = (double)2 * dot_product(r.d, vec_sub(r.o, s->o));
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params[2] = dot_product(vec_sub(r.o, s->o), vec_sub(r.o, s->o))
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- s->r * s->r;
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if (SUCCESS == solve_quadratic(params, roots))
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{
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if (roots[0] > 0)
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return (roots[0] - E);
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else if (roots[1] > 0)
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return (roots[1] - E);
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}
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return (FAILURE);
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}
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t_vec normal_sphere(void *obj, t_ray r, double t)
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{
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t_sphere *s;
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t_vec p;
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s = (t_sphere *)obj;
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p = vec_add(r.o, vec_mul(r.d, t));
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p = vec_sub(p, s->o);
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normalize(&p);
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return (p);
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}
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