// Dartmouth CS 2, Winter 2009, Chris Bailey-Kellogg
// Notes 11 | Sketch 4

Ball ball = new Ball();

float shotSpeed=10;
float cannonLength=25;

color shotColor = color(random(255),random(255),random(255),100);

void setup()
{
  size(400,300);
  smooth();
  background(0);
  strokeCap(SQUARE);  // for cannon
}

void draw()
{
  // Erase just the area where the cannon is
  fill(0); stroke(0); strokeWeight(ball.r*2);
  ellipse(0,height,2*cannonLength,2*cannonLength);
 
  // Draw the cannon, pointing toward the mouse 
  stroke(shotColor); 
  strokeWeight(ball.r*2);
  pushMatrix();
  translate(0,height);
  rotate(atan2(mouseY-height, mouseX));
  line(0,0,cannonLength,0);
  popMatrix(); 
  noStroke();

  // Handle the ball
  ball.draw();
  ball.update();
}

void keyPressed()
{
  if (key==' ') { // shoot
    // Compute the position at the end of the cannon by cos and sin
    // Compute the initial velocity the same way
    float angle = atan2(mouseY-height,mouseX);
    ball.shoot(cannonLength*cos(angle), height+cannonLength*sin(angle),
               shotSpeed*cos(angle), shotSpeed*sin(angle),
               shotColor);
  }
  else if (key=='c') // color
    shotColor = color(random(255),random(255),random(255),100);
  else if (key=='s') { // shot speed
    shotSpeed++;
    println("shot speed:"+shotSpeed);
  }
  else if (key=='S') {
    if (shotSpeed>1) shotSpeed--;
    println("shot speed:"+shotSpeed);
  }
  else if (key=='g') { // half as much gravity
    ball.gravity *= 0.5;
    println("gravity:"+ball.gravity);
  }
  else if (key=='G') {
    ball.gravity *= 2;
    println("gravity:"+ball.gravity);
  }
  else if (key=='d') { // half as much drag (measured as 1-d)
    ball.drag = 1 - (1-ball.drag)*0.5;
    println("drag:"+ball.drag);
  }
  else if (key=='D') {
    ball.drag = 1 - (1-ball.drag)*2;
    println("drag:"+ball.drag);
  }
  else if (key=='x') { // half as much damping
    ball.frictX = 1 - (1-ball.frictX)*0.5;
    println("x friction:"+ball.frictX);
  }
  else if (key=='X') {
    ball.frictX = 1 - (1-ball.frictX)*2;
    println("x friction:"+ball.frictX);
  }
  else if (key=='y') { // half as much damping
    ball.frictY = 1 - (1-ball.frictY)*0.5;
    println("y friction:"+ball.frictY);
  }
  else if (key=='Y') {
    ball.frictY = 1 - (1-ball.frictY)*2;
    println("y friction:"+ball.frictY);
  }
}