Circle Pack Push in GameMaker

// Circle pack-push in GameMaker by oliver @pixelchipcode

// obj_packer: Create Event
circles = [];
path_points = [];
is_drawing = false;
max_radius = 20;
min_radius = 2;
spawn_interval = 10;
last_spawn_x = 0;
last_spawn_y = 0;

// Physics constants - tweaked for smoother motion with arrays
spring_strength = .4;
damping = 0.8;
min_push_distance = 0.1;

// obj_packer: Step Event
// Handle mouse input and drawing
if (mouse_check_button_pressed(mb_left)) {
    is_drawing = true;
    circles = [];  // Clear arrays
    path_points = [];
    array_push(path_points, [mouse_x, mouse_y]);
    last_spawn_x = mouse_x;
    last_spawn_y = mouse_y;
}

if (mouse_check_button(mb_left) && is_drawing) {
    // Add new mouse position if moved
    var path_len = array_length(path_points);
    var last_point = path_points[path_len - 1];
    if (point_distance(mouse_x, mouse_y, last_point[0], last_point[1]) > 5) {
        array_push(path_points, [mouse_x, mouse_y]);
    }

    // Spawn new circles along the line
    var dist = point_distance(last_spawn_x, last_spawn_y, mouse_x, mouse_y);

    if (dist >= spawn_interval) {
        var dir = point_direction(last_spawn_x, last_spawn_y, mouse_x, mouse_y);
        var steps = floor(dist / spawn_interval);

        for (var i = 0; i < steps; i++) {
            var spawn_x = last_spawn_x + lengthdir_x(spawn_interval * (i + 1), dir);
            var spawn_y = last_spawn_y + lengthdir_y(spawn_interval * (i + 1), dir);

            // [x, y, vx, vy, radius, target_radius, growing, hue]
            array_push(circles, [
                spawn_x,                    // x
                spawn_y,                    // y
                0,                          // vx
                0,                          // vy
                1,                          // radius
                random_range(min_radius, max_radius), // target_radius
                1,                          // growing (1 = true, 0 = false)
                (point_distance(spawn_x, spawn_y, room_width/2, room_height/2) /
                 point_distance(0, 0, room_width/2, room_height/2)) * 255 // hue
            ]);
        }

        last_spawn_x = spawn_x;
        last_spawn_y = spawn_y;
    }
}

if (mouse_check_button_released(mb_left)) {
    is_drawing = false;
}

// Update circles with physics
var circle_count = array_length(circles);
for (var i = 0; i < circle_count; i++) {
    var circle = circles[i];

    // Grow circles
    if (circle[6] && circle[4] < circle[5]) {  // if growing and radius < target_radius
        circle[4] += 0.5;  // increase radius
        if (circle[4] >= circle[5]) {
            circle[4] = circle[5];
            circle[6] = 0;  // stop growing
        }
    }

    // Calculate spring forces between circles
    var total_force_x = 0;
    var total_force_y = 0;

    for (var j = 0; j < circle_count; j++) {
        if (i == j) continue;

        var o = circles[j];
        var dist = point_distance(circle[0], circle[1], o[0], o[1]);
        var min_dist = circle[4] + o[4];  // sum of radii

        if (dist < min_dist && dist > 0) {
            var overlap = min_dist - dist;
            var angle = point_direction(o[0], o[1], circle[0], circle[1]);

            // Calculate spring force
            var force = overlap * spring_strength;
            total_force_x += lengthdir_x(force, angle);
            total_force_y += lengthdir_y(force, angle);
        }
    }

    // Apply forces and update velocity
    circle[2] += total_force_x;  // vx
    circle[3] += total_force_y;  // vy

    // Apply damping
    circle[2] *= damping;
    circle[3] *= damping;

    // Update position if movement is significant
    if (abs(circle[2]) > min_push_distance || abs(circle[3]) > min_push_distance) {
        circle[0] += circle[2];  // x += vx
        circle[1] += circle[3];  // y += vy
    }
}

// Draw circles with gradient effect
var circle_count = array_length(circles);
for (var i = 0; i < circle_count; i++) {
    var circle = circles[i];
    if(circle[4] < 5){
            draw_circle(circle[0], circle[1], circle[4],false)
    } else{
    draw_circle(circle[0], circle[1], circle[4],true)
    }
}