/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_raycasting.c                                    :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: rbousset <marvin@42.fr>                    +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2020/02/14 17:22:57 by rbousset          #+#    #+#             */
/*   Updated: 2020/02/14 17:23:42 by rbousset         ###   ########lyon.fr   */
/*                                                                            */
/* ************************************************************************** */

#include <libft.h>
#include <cub3d.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>

static void
	ft_calc_tex(t_cub *clist)
{
	if (clist->rlist.side == 0)
		clist->rlist.wall_hit_x = (clist->plist.pos_x) +
			clist->rlist.wall_dist * clist->rlist.y_ray_dir;
	else
		clist->rlist.wall_hit_x = (clist->plist.pos_y) +
			clist->rlist.wall_dist * clist->rlist.x_ray_dir;
	clist->rlist.wall_hit_x -= floor(clist->rlist.wall_hit_x);
	clist->tlist[clist->w_side].tex_x = (int)(clist->rlist.wall_hit_x *
			(double)clist->tlist[clist->w_side].img_w);
	if (clist->rlist.side == 0 && clist->rlist.x_ray_dir > 0)
		clist->tlist[clist->w_side].tex_x = clist->tlist[clist->w_side].img_w
			- clist->tlist[clist->w_side].tex_x - 1;
	else if (clist->rlist.side == 1 && clist->rlist.y_ray_dir < 0)
		clist->tlist[clist->w_side].tex_x = clist->tlist[clist->w_side].img_w
			- clist->tlist[clist->w_side].tex_x - 1;
}

static void
	ft_initray(uint16_t i, t_cub *cl)
{
	t_win		*wl;
	t_player	*pl;

	wl = &cl->wlist;
	pl = &cl->plist;
	pl->cam_x = 2 * i / (float)(wl->x_size) - 1;
	cl->rlist.x_ray_pos = pl->pos_y;
	cl->rlist.y_ray_pos = pl->pos_x;
	cl->rlist.x_ray_dir = pl->dir_x + pl->plane_x *
		pl->cam_x;
	cl->rlist.y_ray_dir = pl->dir_y + pl->plane_y *
		pl->cam_x;
	cl->rlist.sqx = (int16_t)cl->rlist.x_ray_pos;
	cl->rlist.sqy = (int16_t)cl->rlist.y_ray_pos;
	ft_detect(cl);
	if (cl->rlist.side == 0)
	{
		cl->rlist.wall_dist = (cl->rlist.sqx - cl->rlist.x_ray_pos +
		(1 - cl->mlist.x_step) / 2) / cl->rlist.x_ray_dir;
	}
	else
	{
		cl->rlist.wall_dist = (cl->rlist.sqy - cl->rlist.y_ray_pos +
		(1 - cl->mlist.y_step) / 2) / cl->rlist.y_ray_dir;
	}
}

static void
	ft_castray_norme(uint16_t i, t_win *wl, t_cub *cl)
{
	ft_initray(i, cl);
	cl->rlist.line_h = (int16_t)(wl->y_size / cl->rlist.wall_dist);
	cl->rlist.wall_t = -cl->rlist.line_h / 2 + wl->y_size / 2;
	if (cl->rlist.wall_t < 0)
		cl->rlist.wall_t = 0;
	cl->rlist.wall_b = cl->rlist.line_h / 2 + wl->y_size / 2;
	if (cl->rlist.wall_b >= (int16_t)wl->y_size)
		cl->rlist.wall_b = wl->y_size - 1;
	cl->rlist.wall_bz[i] = cl->rlist.wall_b;
}

void
	ft_castray(t_cub *cl)
{
	uint16_t	i;
	t_win		*wl;

	wl = &cl->wlist;
	if (!(cl->rlist.wall_dist_tab =
			(float*)malloc(sizeof(float) * cl->wlist.x_size)))
		return ;
	if (!(cl->rlist.wall_bz =
			(int16_t*)malloc(cl->wlist.x_size * sizeof(int16_t))))
		return ;
	i = 0;
	while (i < wl->x_size)
	{
		ft_castray_norme(i, wl, cl);
		ft_choose_tex(cl);
		ft_calc_tex(cl);
		ft_draw_verline(cl, i, cl->rlist.wall_t, cl->rlist.wall_b);
		cl->rlist.wall_dist_tab[i] = cl->rlist.wall_dist;
		i++;
	}
	ft_floor_cast(cl);
	ft_calc_sprite(cl);
	ft_memdel((void**)&cl->rlist.wall_dist_tab);
	ft_memdel((void**)&cl->rlist.wall_bz);
}