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//1. Module name
module laserbolt;

//2. Imports 
import
    arc.scenegraph.all,
    arc.physics.shapes.box,
    arc.sound,
    arc.texture,
    arc.types;

import spacearea;

//3. A laser bolt, fired from the player ship.
class LaserBolt : arc.scenegraph.sprite.Sprite
{
public:
    //4. loads the graphics for the bolt
    static void loadResources()
    {
        // Frame is derived from MultiParentNode, so we will only need
        // to have one instance, which will serve to display the bolt
        // for all instances of LaserBolt
        LaserBolt.beamFrame = new Frame(Texture("astbin/ship/laser.png"));
    }
    
    //5. creates a new laserbolt at a given position, rotation
    // and adds it to the spacearea node.
    static LaserBolt addLaser(inout Point translation, Radians rotation)
    {
        LaserBolt bolt = new LaserBolt(translation, rotation);
        area.addChild(bolt);
        return bolt;
    }
    
private:
    //6. this is serves as a callback to the physics collision handler
    // it is registered in the constructor and will be called whenever
    // there's a new collision between this object and another body
    // 
    // if a laserbolt hits something, remove it
    void onCollideStart(Body a, Body b)
    {
        if(this.parent is area)
            area.removeChild(this);
    }
    
    //7. new laser at position and angle
    this(inout Point translation, Radians rotation)
    {
        // LaserBolt derives from Sprite and can call Sprite's
        // constructor with a Transform and a 'content' node.
        // Since we want the laser bolt to collide with objects, we
        // use one of the physics nodes as a transform:
        
        physics = new Box(beamFrame.frame.size, 10);
        physics.sigCollideStart.connect(&onCollideStart);
        physics.translation = translation;
        physics.rotation = rotation;
        physics.velocity = Point.fromPolar(0.5, rotation - PI/2);
        
        // the 'content' will just be the previously constructed
        // beamFrame - it just draws the beam
        
        super(physics, beamFrame);
    }
        
private:
    //8. Laser bolt vars 
    Body physics;
    static Frame beamFrame;
}