cannon

    Cannon c;
    Mover mov;
    Ground ground;

    void setup() {
        size(640,360);
        int num = 1;
        c = new Cannon();
        ground = new Ground();
        mov = new Mover();
        mov.location.x = c.cbase;
    }

    void draw() {
        background(0);

        ground.display();
        pushMatrix();
        translate(90,height-90);
        rotate(5.7);
        if(mov.location.x < c.end){
            PVector blast = new PVector(0.009,0.0);
            mov.applyForce(blast);
        }
        if(mov.location.x > c.end){
            PVector gravity = new PVector(0,0.03);
            gravity.mult(mov.mass);
            mov.applyForce(gravity);

            // now apply friction
            PVector friction = mov.velocity.get();
            friction.normalize();

            float c = -0.01;
            friction.mult(c);
            mov.applyForce(friction);

        }
        mov.update();
        fill(255);
        stroke(0);
        stroke(255);
        strokeWeight(5);
        //draw_bits();
        c.display();
        mov.display();
        popMatrix();
        mov.checkEdges();
        noFill();
        stroke(255);
        strokeWeight(6);
        rectMode(CORNER);
        rect(0,0,width,height);

    }

    class Ground{
        Ground(){

        }
        void display(){
            rectMode(CORNER);
            fill(#A34719);
            noStroke();
            rect(0,height-25,width,30);
        }

    }
    class Cannon {

        float len;
        float wid;
        float cbase;
        float end;
        Cannon(){
            len = 200;
            wid = 80;
            cbase = -len/2;
            end = len/2;
        }


        void display(){
            fill(100,255,70,90);
            pushMatrix();
            noStroke();
            rectMode(CENTER);
            rect(0,0,len,wid);
            fill(255);
            //rect(0,0,20,20);

            popMatrix();
        }
    }

    void draw_bits(){

        fill(255,120);
        stroke(255,120);
        float dd = c.cbase;
        line(dd,0,100,0);
        ellipseMode(CENTER);
        ellipse(dd+30/2,0,30,30);
    }


    class Mover {

        PVector location;
        PVector velocity;
        PVector acceleration;
        float mass;

        float angle = 0;
        float aVelocity = 0;
        float aAcceleration = 0;

        Mover() {
            location = new PVector(0,0);
            velocity = new PVector(0,0);
            acceleration = new PVector(0,0);
            mass = 1;
        }

        void applyForce(PVector force) {
            // Newtons 2nd law with mass
            PVector f = PVector.div(force,mass);
            acceleration.add(f);
        }

        void update() {
            velocity.add(acceleration);
            location.add(velocity);

            aAcceleration = acceleration.x / 10.0;
            aVelocity += aAcceleration;
            aVelocity = constrain(aVelocity, -0.1,0.1);
            angle += aVelocity;

            acceleration.mult(0);
        }

        void display() {
            stroke(0);
            strokeWeight(2);
            noStroke();
            fill(200);
            pushMatrix();
            translate(location.x,location.y);
            rotate(angle);
            fill(255,24,90);
            rect(0,0,mass*20,mass*20);
            popMatrix();
        }

        void checkEdges() {

            if (location.x > width) {
                location.x = width;
                velocity.x *= -1;
            } else if (location.x < 0) {
                velocity.x *= -1;
                location.x = 0;
            }

            if (location.y > height) {
                velocity.y *= -1;
                location.y = height;
            }
}

}