Core Functions

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Initialization Functions

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fractol_init()

void fractol_init(t_fractol *fractol);

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Implementation Details

void fractol_init(t_fractol *fractol)
{
    fractol->mlx_connection = mlx_init();
    if (fractol->mlx_connection == NULL)
        malloc_error();
    fractol->mlx_window = mlx_new_window(fractol->mlx_connection,
            WIDTH, HEIGHT, fractol->name);
    if (fractol->mlx_window == NULL)
    {
        mlx_destroy_display(fractol->mlx_connection);
        free(fractol->mlx_connection);
        malloc_error();
    }
    fractol->img.img_ptr = mlx_new_image(fractol->mlx_connection,
            WIDTH, HEIGHT);
    if (fractol->img.img_ptr == NULL)
    {
        mlx_destroy_window(fractol->mlx_connection, fractol->mlx_window);
        mlx_destroy_display(fractol->mlx_connection);
        free(fractol->mlx_connection);
        malloc_error();
    }
    fractol->img.pixel_ptr = mlx_get_data_addr(fractol->img.img_ptr,
            &fractol->img.bpp, &fractol->img.line_length, &fractol->img.endian);
    events_init(fractol);
    data_init(fractol);
}

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Behavior

1. MLX Connection: Calls mlx_init() to establish connection to X server
2. Window Creation: Creates 2000x1500 window with fractal name as title
3. Image Buffer: Allocates image buffer matching window dimensions
4. Pixel Data: Retrieves direct memory address for pixel manipulation
5. Event Registration: Calls events_init() to hook keyboard/mouse handlers
6. Data Initialization: Calls data_init() to set default parameters

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data_init()

void data_init(t_fractol *fractol);

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Implementation

void data_init(t_fractol *fractol)
{
    fractol->escape_value = 4;
    fractol->iterations_definition = 30;
    fractol->shift_x = 0.0;
    fractol->shift_y = 0.0;
    fractol->zoom = 1;
}

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Default Values

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Rendering Functions

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fractol_render()

void fractol_render(t_fractol *fractol);

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Implementation

void fractol_render(t_fractol *fractol)
{
    int x;
    int y;

    y = 0;
    while (y < HEIGHT)
    {
        x = 0;
        while (x < WIDTH)
        {
            handle_pixel(x, y, fractol);
            x++;
        }
        y++;
    }
    mlx_put_image_to_window(fractol->mlx_connection, fractol->mlx_window,
        fractol->img.img_ptr, 0, 0);
}

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Behavior

1. Iterates through all 2000×1500 = 3,000,000 pixels
2. Calls handle_pixel() for each coordinate
3. After all pixels are calculated, displays image buffer to window via mlx_put_image_to_window()

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handle_pixel()

void handle_pixel(int x, int y, t_fractol *fractol);

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Implementation

void handle_pixel(int x, int y, t_fractol *fractol)
{
    t_complex z;
    t_complex c;
    int       i;
    int       color;

    i = 0;
    z.x = (map(x, -2, +2, WIDTH) * fractol->zoom) + fractol->shift_x;
    z.y = (map(y, +2, -2, HEIGHT) * fractol->zoom) + fractol->shift_y;
    mandel_vs_julia(&z, &c, fractol);
    while (i < fractol->iterations_definition)
    {
        z = sum_complex(sqare_complex(z), c);
        if ((z.x * z.x) + (z.y * z.y) > fractol->escape_value)
        {
            color = map(i, PSYCHEDELIC_LIME, PSYCHEDELIC_MINT,
                    fractol->iterations_definition);
            my_pixel_put(x, y, &fractol->img, color);
            return;
        }
        i++;
    }
    my_pixel_put(x, y, &fractol->img, WHITE);
}

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Algorithm Steps

1. Coordinate Mapping: Convert screen pixel to complex plane coordinates
   • X maps from [0, WIDTH] to [-2, +2]
   • Y maps from [0, HEIGHT] to [+2, -2] (inverted for screen coordinates)
   • Apply zoom and shift transformations
2. Fractal Selection: mandel_vs_julia() sets initial conditions
   • Julia: c = constant (julia_x, julia_y), z = pixel coordinate
   • Mandelbrot: c = pixel coordinate, z = (0, 0) implicitly
3. Iteration Loop: Apply formula z = z² + c up to iterations_definition
4. Escape Check: If |z|² > escape_value, point escapes
   • Color mapped from iteration count to gradient (LIME → MINT)
   • Early return after pixel write
5. In-Set Points: If max iterations reached without escape, color WHITE

static void mandel_vs_julia(t_complex *z, t_complex *c, t_fractol *fractol)
{
    if (!ft_strncmp(fractol->name, "Julia"))
    {
        c->x = fractol->julia_x;
        c->y = fractol->julia_y;
    }
    else
    {
        c->x = z->x;
        c->y = z->y;
    }
}

static void my_pixel_put(int x, int y, t_img *img, int color)
{
    int offset;

    offset = (y * img->line_length) + (x * (img->bpp / 8));
    *(unsigned int *)(img->pixel_ptr + offset) = color;
}

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Event Handlers

static void events_init(t_fractol *fractol)
{
    mlx_hook(fractol->mlx_window, KeyPress, KeyPressMask,
        key_handler, fractol);
    mlx_hook(fractol->mlx_window, ButtonPress,
        ButtonPressMask, mouse_handler, fractol);
    mlx_hook(fractol->mlx_window, DestroyNotify, StructureNotifyMask,
        close_handler, fractol);
}

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key_handler()

int key_handler(int keysym, t_fractol *fractol);

• ESC: Exit program via close_handler()
• Left/A: Pan left (decrease shift_x)
• Right/D: Pan right (increase shift_x)
• Up/W: Pan up (increase shift_y)
• Down/S: Pan down (decrease shift_y)
• +: Increase iterations by 5
• -: Decrease iterations by 5

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mouse_handler()

int mouse_handler(int button, int x, int y, t_fractol *fractol);

• Button4 (scroll up): Zoom in (multiply zoom by 0.95)
• Button5 (scroll down): Zoom out (multiply zoom by 1.05)

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close_handler()

int close_handler(t_fractol *fractol);

1. Destroy image buffer
2. Destroy window
3. Destroy display connection
4. Free MLX connection
5. Exit with EXIT_SUCCESS