/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   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>

void
	ft_calc_sprite(t_cub *cl)
{
	cl->sprites.s_x = cl->sprites.s_pos_x - cl->plist->pos_x;
	cl->sprites.s_y = cl->sprites.s_pos_y - cl->plist->pos_y;
	cl->sprites.inv_c_m = 1.0 / (cl->plist->plane_x * cl->plist->dir_y
								- cl->plist->dir_x * cl->plist->plane_y);
	cl->sprites.sprite_transform_x = cl->sprites.inv_c_m
		* (cl->plist->dir_y * cl->sprites.s_x
		- cl->plist->dir_x * cl->sprites.s_y);
	cl->sprites.sprite_transform_y = cl->sprites.inv_c_m
		* (-cl->plist->plane_y * cl->sprites.s_x
		+ cl->plist->plane_x * cl->sprites.s_y);
	cl->sprites.s_screen_x = (int)((cl->wlist->x_size / 2)
		* (1 + cl->sprites.sprite_transform_x
		/ cl->sprites.sprite_transform_y));
	cl->sprites.s_h =
		abs((int)(cl->wlist->y_size * cl->sprites.sprite_transform_y));
	ft_calc_sprite_norme(cl);
}

void
	ft_calc_sprite_norme(t_cub *cl)
{
	cl->sprites.s_start_y = -cl->sprites.s_h / 2 + cl->wlist->y_size / 2;
	if (cl->sprites.s_start_y < 0)
		cl->sprites.s_start_y = 0;
	cl->sprites.s_end_y = cl->sprites.s_h / 2 + cl->wlist->y_size / 2;
	if (cl->sprites.s_end_y > (int)cl->wlist->y_size)
		cl->sprites.s_end_y = cl->wlist->y_size - 1;
	cl->sprites.s_w = abs((int)(cl->wlist->y_size
		/ cl->sprites.sprite_transform_y)); /*sprite width*/
	cl->sprites.s_start_x = -cl->sprites.s_w / 2 + cl->sprites.s_screen_x;
	if (cl->sprites.s_start_x < 0)
		cl->sprites.s_start_x = 0;
	cl->sprites.s_end_x = cl->sprites.s_w / 2 + cl->sprites.s_screen_x;
	printf("%d\n", cl->sprites.s_w);
	if (cl->sprites.s_end_x > (int)cl->wlist->x_size)
		cl->sprites.s_end_x = cl->wlist->x_size - 1;
	/*ft_printf("start x: %d\nend   x : %d\n", cl->sprites.s_start_x, cl->sprites.s_end_x);*/
	/*ft_printf("start y: %d\nend   y : %d\n", cl->sprites.s_start_y, cl->sprites.s_end_y);*/
	/*ft_draw_sprite(cl);*/
}


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(t_cub *cl, uint16_t i)
{
	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;
}

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

	i = 0;
	wl = cl->wlist;
	while (i < wl->x_size)
	{
		ft_initray(cl, i);
		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 >= (float)wl->y_size)
			cl->rlist.wall_b = wl->y_size - 1;
		ft_choose_tex(cl);
		ft_calc_tex(cl);
		ft_draw_verline(cl, i, cl->rlist.wall_t, cl->rlist.wall_b);
		i++;
	}
}