/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   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_sprite_height(t_cub *cl, t_sprite *sprite)
{
	sprite->spriteheight = abs((int)(cl->wlist->y_size / (sprite->transformy)));
	sprite->drawstarty = -sprite->spriteheight / 2 + cl->wlist->y_size / 2;
	if (sprite->drawstarty < 0)
		sprite->drawstarty = 0;
	sprite->drawendy = sprite->spriteheight / 2 + cl->wlist->y_size / 2;
	if (sprite->drawendy >= (int)cl->wlist->y_size)
		sprite->drawendy = cl->wlist->y_size;
}

void
	ft_sprite_width(t_cub *cl, t_sprite *sprite)
{
	sprite->spritewidth = abs((int)(cl->wlist->x_size / (sprite->transformy)));
	sprite->drawstartx = -sprite->spritewidth / 2 + sprite->spritescreenx;
	if (sprite->drawstartx < 0)
		sprite->drawstartx = 0;
	sprite->drawendx = sprite->spritewidth / 2 + sprite->spritescreenx;
	if (sprite->drawendx >= (int)cl->wlist->x_size)
		sprite->drawendx = cl->wlist->x_size;
}

void
	ft_calc_sprite(t_cub *cl)
{
	t_sprite sprite;

	sprite = cl->sprites;
	sprite.spritex = (sprite.spritex + 1) - cl->plist->pos_x;
	sprite.spritey = (sprite.spritey + 1) - cl->plist->pos_y;
	sprite.invdet = 1.0 / (cl->plist->plane_x *
			cl->plist->dir_y - cl->plist->dir_x * cl->plist->plane_y);
	sprite.transformx = sprite.invdet * (cl->plist->dir_y *
			sprite.spritey - cl->plist->dir_x * sprite.spritex);
	sprite.transformy = sprite.invdet *
		(-cl->plist->plane_y * sprite.spritex + cl->plist->plane_x * sprite.spritey);
	sprite.spritescreenx = (int)((cl->wlist->x_size / 2) *
			(1 + sprite.transformx / sprite.transformy));
	ft_sprite_height(cl, &sprite);
	ft_sprite_width(cl, &sprite);
	ft_draw_sprite(cl, &sprite);
}

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++;
	}
}