42_cub3d/algo.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   algo.c                                             :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: greg <greg@student.42.fr>                  +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/10/01 16:24:58 by grobledo          #+#    #+#             */
/*   Updated: 2024/10/03 18:59:06 by greg             ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "algo.h"


static int initalgo(t_ray *ray)
{
	ray->posX = 2;
	ray->posY = 2;
	ray->dirX = -1;
	ray->dirY = 0;
	ray->planeX = 0;
	ray->planeY = 0.66; // FOV de 66 degres
	ray->currtime = 0;
	ray->oldtime = 0;
	ray->movespeed = 0.1;
	ray->rotspeed = 0.1;
	return (0);
}


int algo()
{
	t_ray ray;
	int		x;
	double	width;
	int		height;
	// quelle box sur la map on est
	int		mapX;
	int		mapY;
	// wall hit and if yes in wich direction
	int		hit;
	int		side;

	initalgo(&ray);
	// init image;


	x = 0;
	width = 640;
	height = 480;
	while (x < width)
	{
		// position et direction du rayon
		ray.cameraX = 2 * x / width - 1;
		ray.raydirX = ray.dirX + ray.planeX * ray.cameraX;
		ray.raydirY = ray.dirY + ray.planeY * ray.cameraX;

		mapX = (int)ray.posX;
		mapY = (int)ray.posY;

		ray.deltadistX = (ray.raydirX == 0) ? 1e30 : fabs(1 / ray.raydirX);
		ray.deltadistY = (ray.raydirY == 0) ? 1e30 : fabs(1 / ray.raydirY);

		hit = 0;

			//calculate step and initial sideDist
		if (ray.raydirX < 0)
		{
			ray.stepX = -1;
			ray.sidedistX = (ray.posX - mapX) * ray.deltadistX;
		}
		else
		{
			ray.stepX = 1;
			ray.sidedistX = (mapX + 1.0 - ray.posX) * ray.deltadistX;
		}
		if (ray.raydirY < 0)
		{
			ray.stepY = -1;
			ray.sidedistY = (ray.posY - mapY) * ray.deltadistY;
		}
		else
		{
			ray.stepY = 1;
			ray.sidedistY = (mapY + 1.0 - ray.posY) * ray.deltadistY;
		}
		while(hit == 0)
		{
			//jump to next map square, either in x-direction, or in y-direction
			if(ray.sidedistX < ray.sidedistY)
			{
				ray.sidedistX += ray.deltadistX;
				mapX += ray.stepX;
				side = 0;
			}
			else
			{
				ray.sidedistY += ray.deltadistY;
				mapY += ray.stepY;
				side = 1;
			}
			//Check if ray has hit a wall
			if(worldMap[mapX][mapY] == 1) 
				hit = 1;
		}
		if(side == 0) 
			ray.perpwalldist = (ray.sidedistX - ray.deltadistX);
		else
			ray.perpwalldist = (ray.sidedistY - ray.deltadistY);
		//Calculate height of line to draw on screen
		int lineHeight = (int)(height / ray.perpwalldist);
		lineHeight = (int)(height / ray.perpwalldist);

		//calculate lowest and highest pixel to fill in current stripe
		int	drawStart;
		drawStart = -lineHeight / 2 + height / 2;
		if(drawStart < 0)
			drawStart = 0;
		int drawEnd;
		if(drawEnd >= height)
			drawEnd = height - 1;

		/*mlx fontction color 
		
		give x and y sides different brightness
		if (side == 1) {color = color / 2;}

		//draw the pixels of the stripe as a vertical line
		verLine(x, drawStart, drawEnd, color); */


		//timing for input to dissociate speed from speed processor (same speed on all pc)
		ray.oldtime = ray.currtime;
		ray.currtime = getTicks();
		// put image to window
		// destroy old image


		// hook event

		readKeys();
		//move forward if no wall in front of you
		if (keyDown(move_up))
		{
			if(worldMap[(ray.posX + ray.dirX * ray.movespeed)][(int)(ray.posY)] == 0) 
				ray.posX += ray.dirX * ray.movespeed;
			if(worldMap[(ray.posX)][((int)ray.posY + (int)ray.dirY * (int)ray.movespeed)] == 0) 
				ray.posY += ray.dirY * ray.movespeed;
		}
		//move backwards if no wall behind you
		if (keyDown(moove_down))
		{
			if(worldMap[(ray.posX - ray.dirX * ray.movespeed)][(int)(ray.posY)] == 0)
				ray.posX -= ray.dirX * ray.movespeed;
			if(worldMap[(ray.posX)][((int)ray.posY - (int)ray.dirY * (int)ray.movespeed)] == 0)
				ray.posY -= ray.dirY * ray.movespeed;
		}
		//rotate to the right
		if (keyDown(moove_right))
		{
			//both camera direction and camera plane must be rotated
			ray.oldDirX = ray.dirX;
			ray.dirX = ray.dirX * cos(-ray.rotspeed) - ray.dirY * sin(-ray.rotspeed);
			ray.dirY = ray.oldDirX * sin(-ray.rotspeed) + ray.dirY * cos(-ray.rotspeed);
			ray.oldPlaneX = ray.planeX;
			ray.planeX = ray.planeX * cos(-ray.rotspeed) - ray.planeY * sin(-ray.rotspeed);
			ray.planeY = ray.oldPlaneX * sin(-ray.rotspeed) + ray.planeY * cos(-ray.rotspeed);
		}
		//rotate to the left
		if (keyDown(moove_left))
		{
			//both camera direction and camera plane must be rotated
			ray.oldDirX = ray.dirX;
			ray.dirX = ray.dirX * cos(ray.rotspeed) - ray.dirY * sin(ray.rotspeed);
			ray.dirY = ray.oldDirX * sin(ray.rotspeed) + ray.dirY * cos(ray.rotspeed);
			ray.oldPlaneX = ray.planeX;
			ray.planeX = ray.planeX * cos(ray.rotspeed) - ray.planeY * sin(ray.rotspeed);
			ray.planeY = ray.oldPlaneX * sin(ray.rotspeed) + ray.planeY * cos(ray.rotspeed);
		}
	}
	return (0);

}





// https://github.com/iciamyplant/Cub3d-Linux

// https://lodev.org/cgtutor/raycasting.html

// https://www.youtube.com/watch?v=js7HW65MmNw&list=PL0H9-oZl_QOHM34HvD3DiGmwmj5X7GvTW