Very new to programming; how to establish a background image (with this source code)?
<p>I am very new to all of this and have a general question:</p>

<p>In my pursuit of knowledge, I have decided to create a 2d game using an open source template ("Missile Intercept" ---> <a href="http://www.kirit.com/Missile%20intercept" rel="nofollow">http://www.kirit.com/Missile%20intercept</a>). However, my knowledge is very limited; and hence, I am not sure how I would go about changing the sprites for, say, the missiles or the background itself. Any ideas? (See details below.)</p>

<p>DETAILS:</p>

<p>This code defines the appearance of the missiles within 'Opponent.java' (just small white circles with a trailing white line).</p>

<pre><code>@Override
    public void draw(Canvas c, Layer layer) {
        if ( inuse ) {
            if (layer == Layer.TRAILS) {
                if ( !exploding || fade-- == 8 ) {
                    paint.setColor(0xff808080);
                    c.drawLine(sx, sy, cx, cy, paint);
                } else if ( fade &gt; 0 )  {
                    paint.setColor(0x808080 + fade * 0x02000000 + fade * 0x20000000);
                    c.drawLine(sx, sy, cx, cy, paint);
                    --fade;
                }
            } else if (layer == Layer.MISSILES &amp;&amp; !exploding) {
                paint.setColor(0xffffffff);
                c.drawCircle(cx, cy, 2, paint);
            }
            explosion.draw(c, layer);
        }
    }
</code></pre>

<p>The code defining the background appears to come from separate classes...</p>

<p>As seen in 'Overlay.java':</p>

<pre><code>@Override
public void draw(Canvas c, Layer layer) {
    if ( active ) {
        location.top = 0; location.bottom = view.getHeight();
        location.left = 0; location.right = view.getWidth();
        paint.setColor(Color.BLACK);
        paint.setAlpha(180);
        c.drawRect(location, paint);
        paint.setAlpha(255);

        vibrate.draw(c, layer);
        sound.draw(c, layer);
    }
}
</code></pre>

<p>... and in 'Scene.java':</p>

<pre><code>@Override
protected void onDraw(Canvas c) {
    c.drawARGB(255, 0, 0, 0);
    if ( overlay.tick() )
        if ( !todraw.tick() )
            mintercept.endGame();
    todraw.draw(c, Layer.BACKGROUND);
    todraw.draw(c, Layer.CITIES);
    todraw.draw(c, Layer.TRAILS);
    todraw.draw(c, Layer.EXPLOSIONS);
    todraw.draw(c, Layer.MISSILES);
    todraw.draw(c, Layer.CHROME);
    overlay.draw(c, Layer.CHROME);
}
</code></pre>

<p>Would anyone kindly make sense of this?</p>
