Modifying the main function

The final modifications will be to initialization that happens in the main function. We will need to create new objects for the camera, render_manager, and locator pointers we defined earlier:

camera = new Camera(CANVAS_WIDTH, CANVAS_HEIGHT);
render_manager = new RenderManager();
locator = new Locator();

In the previous version of our code, we had seven calls to new Asteroid and used asteroid_list.push_back to push those seven new asteroids into our list of asteroids. We will now need to create far more asteroids than seven, so, instead of doing them as individual calls, we will be using a double for loop to create and spread out our asteroids all over the gameplay area. To do this, we will first need to remove all of those earlier calls to create and push asteroids:

asteroid_list.push_back( new Asteroid(
                            200, 50, 0.05, 
                            DEG_TO_RAD(10) ) );
asteroid_list.push_back( new Asteroid(
                            600, 150, 0.03, 
                            DEG_TO_RAD(350) ) );
asteroid_list.push_back( new Asteroid(
                            150, 500, 0.05, 
                            DEG_TO_RAD(260) ) );
asteroid_list.push_back( new Asteroid(
                            450, 350, 0.01, 
                            DEG_TO_RAD(295) ) );
asteroid_list.push_back( new Asteroid(
                            350, 300, 0.08, 
                            DEG_TO_RAD(245) ) );
asteroid_list.push_back( new Asteroid(
                            700, 300, 0.09, 
                            DEG_TO_RAD(280) ) );
asteroid_list.push_back( new Asteroid(
                            200, 450, 0.03, 
                            DEG_TO_RAD(40) ) );

Once you have removed all of the preceding code, we will add the following code to create our new asteroids and space them semi-randomly throughout the gameplay area:

int asteroid_x = 0;
int asteroid_y = 0;
int angle = 0;

// SCREEN 1
for( int i_y = 0; i_y < 8; i_y++ ) {
    asteroid_y += 100;
    asteroid_y += rand() % 400;
    asteroid_x = 0;

    for( int i_x = 0; i_x < 12; i_x++ ) {
        asteroid_x += 66;
        asteroid_x += rand() % 400;
        int y_save = asteroid_y;
        asteroid_y += rand() % 400 - 200;
        angle = rand() % 359;
        asteroid_list.push_back( new Asteroid(
                        asteroid_x, asteroid_y,
                        get_random_float(0.5, 1.0),
                        DEG_TO_RAD(angle) ) );
        asteroid_y = y_save;
    }
}