#include "cube3d.h"

void	ray_intersect(t_game *game, int start_x, int start_y, int *end_x, int *end_y)
{
	int	cell_x;
	int	cell_y;
	int	slope_x;
	int	slope_y;
	int	ray_sign_x;
	int	ray_sign_y;
	int	first_next_x;
	int	first_next_y;
	int	next_x;
	int	next_y;
	int	next_cell_x;
	int	next_cell_y;
	int	ray_step_x;
	int	ray_step_y;
	int	is_x;

	is_x = 0;
	// ray sign
	ray_sign_x = 1;
	if (start_x < *end_x)
		ray_sign_x = -1;
	ray_sign_y = 1;
	if (start_y < *end_y)
		ray_sign_y = -1;
	// cell position of ray
	cell_x = start_x / game->cell;
	cell_y = start_y / game->cell;
	// slope of ray
	slope_x = *end_x - start_x;
	slope_y = *end_y - start_y;
	// direction of next cell
	next_cell_x = -ray_sign_x;
	next_cell_y = -ray_sign_y;
	// ray steps in both axis
	ray_step_x = ft_abs(game->cell * slope_y);
	ray_step_y = ft_abs(game->cell * slope_x);
	// first next time ray cross grid
	first_next_x = start_x % game->cell;
	if (first_next_x && ray_sign_x < 0)
		first_next_x = game->cell - first_next_x;
	if (!first_next_x && ray_sign_x < 0)
		first_next_x = game->cell;
	first_next_y = start_y % game->cell;
	if (first_next_y && ray_sign_y < 0)
		first_next_y = game->cell - first_next_y;
	if (!first_next_y && ray_sign_y < 0)
		first_next_y = game->cell;
	next_x = ft_abs(first_next_x * slope_y);
	next_y = ft_abs(first_next_y * slope_x);
	// loop through grid
if (game->ray_activ == 1) printf("\ncell_x:%i, cell_y:%i, first_next_x:%i, first_next_y:%i\n", cell_x, cell_y, first_next_x, first_next_y);
	while (!is_wall(game, cell_x, cell_y))
	{
if (game->ray_activ == 1) printf("next_x:%-4i, next_y:%-4i, ", next_x, next_y);
		if (next_x > next_y)
		{
			cell_y += next_cell_y;
			next_y += ray_step_y;
			is_x = 0;
		}
		else
		{
			cell_x += next_cell_x;
			next_x += ray_step_x;
			is_x = 1;
		}
if (game->ray_activ == 1) printf("cell_x:%-4i, cell_y:%-4i\n", cell_x, cell_y);
	}
	// end ray position
	double ratio;
	if (is_x)
	{
		*end_x = cell_x * game->cell;
		if (ray_sign_x == 1)
			*end_x += game->cell;
		if (slope_x)
		{
			ratio = (double)(*end_x - start_x) / (double)slope_x;
			*end_y = start_y + (double)slope_y * ratio;
		}
	}
	else
	{
		*end_y = cell_y * game->cell;
		if (ray_sign_y == 1)
			*end_y += game->cell;
		if (slope_y)
		{
			ratio = (double)(*end_y - start_y) / (double)slope_y;
			*end_x = start_x + (double)slope_x * ratio;
		}
	}
}

void	draw_rays(t_game *game)
{
	int	start_x;
	int	start_y;
	int	end_x;
	int	end_y;
	int	i;

	// draw screen size
	start_x = game->screen_size.start_x + game->plr_x;
	start_y = game->screen_size.start_y + game->plr_y;
	rotate(game, &start_x, &start_y);
	end_x = game->screen_size.end_x + game->plr_x;
	end_y = game->screen_size.end_y + game->plr_y;
	rotate(game, &end_x, &end_y);
	draw_line(game, start_x, start_y, end_x, end_y, 0x00FFFFFF);
	// draw rays
	i = 0;
	while (i <= SCREEN_DEF)
	{
		// tmp display one ray with infos
		if (i == game->ray_highlight)
			game->ray_activ = 1;
		// tmp end
		start_x = game->ray.start_x + game->plr_x;
		start_y = game->ray.start_y + game->plr_y;
		end_x = game->ray.end_x + game->plr_x + i * SCREEN_SIZE / SCREEN_DEF;
		end_y = game->ray.end_y + game->plr_y;
		rotate(game, &end_x, &end_y);
		ray_intersect(game, start_x, start_y, &end_x, &end_y);
		draw_line(game, start_x, start_y, end_x, end_y, 0x00FF00FF);
		// tmp display one ray with infos
		if (game->ray_activ == 1)
			draw_line(game, start_x, start_y, end_x, end_y, 0x00FF0000);
		// tmp end
		i++;
		game->ray_activ = 0;
	}
	// draw screen dist
	start_x = game->screen_dist.start_x + game->plr_x;
	start_y = game->screen_dist.start_y + game->plr_y;
	end_x = game->screen_dist.end_x + game->plr_x;
	end_y = game->screen_dist.end_y + game->plr_y;
	rotate(game, &end_x, &end_y);
	draw_line(game, start_x, start_y, end_x, end_y, 0x00FFFFFF);
}

static void	draw_square(t_game *game, int x, int y, int border, int fill, int size, int rotation)
{
	int i;
	int j;
	int new_x;
	int new_y;

	i = 0;
	while (i < size)
	{
		j = 0;
		while (j < size)
		{
			new_x = x + j;
			new_y = y + i;
			if (rotation)
				rotate(game, &new_x, &new_y);
			if (!i || i == size - 1)
				draw_pixel(game, new_x, new_y, border);
			else if (!j || j == size - 1)
				draw_pixel(game, new_x, new_y, border);
			else
				draw_pixel(game, new_x, new_y, fill);
			j++;
		}
		i++;
	}
}

void	draw_map(t_game *game)
{
	int i;
	int j;
	int x;
	int y;

	i = 0;
	x = 0;
	y = 0;
	while ((game->map)[i])
	{
		j = 0;
		while ((game->map)[i][j])
		{
			if ((game->map)[i][j] == '1' )
				draw_square(game, x, y, 0x00999999, 0x00000000, game->cell, 0);
			else
				draw_square(game, x, y, 0x00555555, 0x00333333, game->cell, 0);
			j++;
			x += game->cell;
		}
		i++;
		x = 0;
		y += game->cell;
	}
	draw_square(game, game->plr_x - game->cell / 2, game->plr_y - game->cell / 2, 0x00999900, 0x00330033, game->cell, 1);
}