cub3d/src/raycast/walls.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   walls.c                                            :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: kcolin <kcolin@42.fr>                      +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2025/07/31 13:17:39 by kcolin            #+#    #+#             */
/*   Updated: 2025/08/05 14:59:24 by kcolin           ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "../cub3d_data.h"
#include "../consts.h"
#include "ray.h"
#include "../renderer/render.h"

t_cardinal_dir	get_cardinal(t_ray *ray)
{
	if (ray->side == NORTH)
	{
		if (ray->dir_x < 0)
			return (WEST);
		else
			return (EAST);
	}
	else
	{
		if (ray->dir_y > 0)
			return (SOUTH);
		else
			return (NORTH);
	}
}

static int	my_mlx_pixel_get(t_img_data *img, int x, int y)
{
	char	*dst;

	dst = img->addr + (y * img->line_length + x * (img->bits_per_pixel / 8));
	return (*(int *)dst);
}

static int	get_color(t_cub3d_data *data, t_ray *ray, int tex_y)
{
	t_cardinal_dir	dir;
	int				tex_x;
	t_img_data		*texture;

	tex_x = (int)(ray->wall_x * TEXTURE_SIZE);
	if ((ray->side == NORTH && ray->dir_x < 0)
		|| (ray->side == SOUTH && ray->dir_y > 0))
		tex_x = TEXTURE_SIZE - tex_x - 1;
	dir = get_cardinal(ray);
	if (dir == NORTH)
		texture = data->no_texture;
	else if (dir == SOUTH)
		texture = data->so_texture;
	else if (dir == WEST)
		texture = data->we_texture;
	else if (dir == EAST)
		texture = data->ea_texture;
	else
		return (0xff53ff);
	return (my_mlx_pixel_get(texture, tex_x, tex_y));
}

void	render_walls(t_cub3d_data *data, t_ray *ray, int x)
{
	unsigned int	color;
	double			step;
	double			tex_y;
	int				y;

	step = 1.0 * TEXTURE_SIZE / ray->wall_height;
	tex_y = (ray->draw_start - HEIGHT / 2 + ray->wall_height / 2) * step;
	y = 0;
	while (y < ray->draw_start)
	{
		matrix_set(data, x, y, data->map->c_color);
		y++;
	}
	while (y < ray->draw_end - 1)
	{
		tex_y += step;
		color = get_color(data, ray, (int)tex_y);
		matrix_set(data, x, y, color);
		y++;
	}
	while (y < HEIGHT)
	{
		matrix_set(data, x, y, data->map->f_color);
		y++;
	}
}