miniRT/render_normal.c at master · fv99/miniRT · GitHub

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/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   render_normal.c                                    :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: khlavaty <khlavaty@student.42.fr>          +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/09/09 12:40:21 by fvonsovs          #+#    #+#             */
/*   Updated: 2024/09/12 21:28:48 by khlavaty         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "minirt.h"

t_float_3	sphere_normal(t_trace *inter)
{
	t_float_3	normal;
	t_sp		*sphere;

	sphere = (t_sp *)inter->hit_object.object;
	normal = vec_sub(inter->hit_point, sphere->pos);
	return (normal);
}

t_float_3	cylinder_normal(t_trace *inter, t_ray ray)
{
	t_cy		*cylinder;
	t_float_3	hit_point;
	t_float_3	v;
	t_float_3	projection;

	cylinder = (t_cy *)inter->hit_object.object;
	hit_point = vec_add(ray.orig, vec_mul(ray.dir, inter->t));
	v = vec_sub(hit_point, cylinder->pos);
	projection = vec_mul(cylinder->vec,
			vec_dot(v, vec_normalize(cylinder->vec)));
	return (vec_normalize(vec_sub(v, projection)));
}

t_float_3	plane_normal(t_trace *inter, t_ray ray)
{
	t_float_3	normal;
	t_pl		*plane;

	plane = (t_pl *)inter->hit_object.object;
	normal = plane->vec;
	if (vec_dot(ray.dir, normal) > 0)
		normal = vec_negate(normal);
	return (vec_normalize(normal));
}

t_float_3	shape_normal(t_trace *inter, t_ray ray)
{
	if (inter->hit_object.type == PLANE)
		return (plane_normal(inter, ray));
	else if (inter->hit_object.type == SPHERE)
		return (sphere_normal(inter));
	else
		return (cylinder_normal(inter, ray));
}