Fdf

Status: done

Grade: 125

FdF school42

Wireframe model. This project is about representing a landscape as a 3D object in which all surfaces are outlined in lines.

launch MacOS

git clone https://github.com/MariaKorshunova/FdF.git
cd FdF
git clone https://github.com/MariaKorshunova/libft.git
git clone https://github.com/MariaKorshunova/get_next_line.git
make bonus
./fdf 21.fdf

Project execution steps

Step 1. Parsing maps and error management

• Invalid number of arguments: only one argument with the name of file with map.
• Invalid file extension: extension of file has to ne .fdf .
• Define the number of rows and columns of a map.
• Invalid map in case of the numbers of columns it the rows don't match.
• Invalid map in case of empty file
• Allocate memory for two-dimensional arrays for altitudes and colors.
• Fill this arrays. If there isn't value for color, cell is filled by defoult.
• Invalid map in case of altitude: empty string, not integer
• Invalid map in case of colors: not hex RGB if not empty.

It is two ways for reading map:

• Open map file at first time and define number of rows anf columns. And then open file one more time for filling arrays .
• Use lists for define columns with opening map file only once.

At this step don't forget about leaks management, including protection of the malloc function.

leaks --atExit -- filename.fdf

You can check yourself at the end of this step with the function whis prints two-dimensional arrays for altitudes and colors:

void	ft_print_int_array(int **arr, int row, int column, int base)
{
	int	i;
	int	j;

	i = 0;
	while (i < row)
	{
		j = 0;
		while (j < column)
		{
			if (base == 10)
				printf("%2d ", arr[i][j]);
			if (base == 16)
				printf("%6x ", arr[i][j]);
			j++;
		}
		printf("\n");
		i++;
	}
}

Step 2. Color definition based on altitude

• Define max and min altitude value
• Define value of [R, G, B] in RGB: r = LOW_R + coeff_minimax_normalization_altitude * (HIGH_R - LOW_R)
• Define value in color use BitShifting
• Check maps colors in case where one value altitude for all maps points

Step 3. Include MinilibX

• Connection login to the graphical server
• Create a pointer to the window
• Initialize the image
• Calculate the memory offset using the line length set by mlx_get_data_addr
• Put image to window
• Memory leak protection for minilibx fubctions
• Destroy image for protect memory leaks

Useful source: https://harm-smits.github.io/42docs/libs/minilibx/getting_started.html

man /usr/share/man/man3/mlx.1

A simple example use Minilibx:

//cc -I /usr/local/include main.c  -L /usr/local/lib/ -lmlx -framework OpenGL -framework APPKit

void	ft_putchar(char c)
{
	write(1, &c, 1);
}	

int	deal_key(void)
{
	ft_putchar('X');
	return (0);
}

int	main(void)
{
	void	*mlx_ptr;
	void	*win_ptr;

	// connection login to the graphical server
	mlx_ptr = mlx_init();
	//man /usr/share/man/man3/mlx_new_window.1
	win_ptr = mlx_new_window(mlx_ptr, 500, 500, "mlx-42");
	// write 'X' in terminal when press a key in window
	mlx_key_hook(win_ptr, deal_key, (void *)0);
	mlx_loop(mlx_ptr);
}

Step 4. Draw a line

• Draw a line of a define colore
• Draw a line with a gradient of colors

• Bresenham's line algorithm - https://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm

• Xiaolin Wu's line algorithm - https://en.wikipedia.org/wiki/Xiaolin_Wu%27s_line_algorithm

    void	ft_line(t_img *img, t_coord p0, t_coord p1, int color)
    {
    	int		error;
    	int		d_error;
    	t_coord	step;
    	t_coord	diff;
  
    	ft_define_step_diff(&p0, &p1, &step, &diff);
    	error = diff.x + diff.y;
    	while ((p0.x != p1.x) || (p0.y != p1.y))
    	{
    		ft_mlx_pixel_put_img(img, p0.x, p0.y, color);
    		d_error = 2 * error;
    		if (d_error >= diff.y && p0.x != p1.x)
    		{
    			error += diff.y;
    			p0.x += step.x;
    		}
    		if (d_error <= diff.x && p0.y != p1.y)
    		{
    			error += diff.x;
    			p0.y += step.y;
    		}
    	}
    	ft_mlx_pixel_put_img(img, p1.x, p1.y, color);
    }
  

Checking draw line function with ft_asterisk:

void	ft_asterisk(t_img *img, t_coord center, int r, int color)
{
	t_coord	p;
	double	alpha;
	int		i;

	alpha = 0;
	i = 0;
	while (i < 12)
	{
		p.x = (int)(center.x + r * cos(alpha));
		p.y = (int)(center.y + r * sin(alpha));
		ft_line(img, center, p, color);
		alpha += M_PI / 6;
		i++;
	}
}

Step 5. Draw map in 2d-representation

• Define zoom depending on map size
• Fixed segmentation fault in case out-of-bounds image
• Align map to the center of image
• Connect map points (x, y) with lines

The loop algorithm for connectiom points:

0 -> 0 -> 0 -> 0 -> 0
|    |    |    |    |
0 -> 0 -> 0 -> 0 -> 0
|    |    |    |    |
0 -> 0 -> 0 -> 0 -> 0
|    |    |    |    |
0 -> 0 -> 0 -> 0 -> 0
|    |    |    |    |
0 -> 0 -> 0 -> 0 -> 0

Step 6. Isometric transformatiom

• Function multiply 2 matriсes 3 * 3
• Define matrix rotate x
• Define matrix rotate y
• Define matrix rotate z
• Rotate map in isometric proection: 1) rotate; 2) scale; 3) translation.
• Zoom in case large altitude changes

Useful source:

• https://habr.com/ru/post/497808/
• https://ru.wikipedia.org/wiki/Матрица_перехода
• https://ru.wikipedia.org/wiki/Матрица_поворота

Step 7. Graphic management

• Your program has to display the image in a window

• Pressing ESC must close the window and quit the program in a clean way

• Clicking on the cross on the window’s frame must close the window and quit the program in a clean way

  void mlx_hook(mlx_win_list_t *win_ptr, int x_event, int x_mask, int (*f)(), void *param)

Step 8. Bonus part

• Include one extra projection (such as parallel or conic)!
• Zoom in and out.
• Translate your model.
• Rotate your model.
• Text tips
• Zoom altitude