String title"bombs and birds.";


void setup() {
  size( 640, 480 );
  horizon=  height/3;
  reset();
}
void reset() {
  //// Bird starts at random height, on the left side.
  birdX=  0;
  birdY=  random(20,horizon);
  birdDX=  random(1,10);
  birdDY=0;
  birdR=  random(100,255);
  birdG=  random(200);
  birdB=  random(200);
  birdW=  60 * random(0.5,3.0);
  birdH=  birdW/5;
  //// How many birds?
  numbirds=  int( random(1,10) );
}

/**        Next frame
*/
void draw() {
  background( 200, 220, 255 );
  fill(0);
  text( "q to quit; r to reset; b drops bomb", 20, 30 );
  //++  scene();
  action();
  show();
  tell();
}
void tell() {
  //// Titles, score, etc.
  text( title, width/3, 20 );
}

void show() {
  //// show all objects:  monster, bird, bomb
  // Bird,flapping wing.
  fill( birdR, birdG, birdB );
  flockDraw( numbirds, birdX,birdY, birdW, birdH );
  // Bomb
  if (bombY>0) {
    fill( birdR*2/3, birdG*2/3, birdB*2/3 ); 
    ellipse( bombX, bombY, birdW/10,birdH );
  }
}
void flockDraw( int n, float x, float y, float w, float h ) {
  //// Draw flock of n birds
  float down=0;
  for (int j=0; j<n; j++ ) {
    birdDraw( x,y+down,w,h );
    birdDraw( x,y-down,w,h );
    x=  x - w -20;            // Behind
    down=  down + h;          // Lower
    w=  w * 0.8;
    h=  h * 0.8;
    
  }
}  

void birdDraw( float x, float y, float w, float h ) {
  triangle( x,y, x-w,y-h, x-w,y+h );
  // Wing
  float flap=  2*h;
  if ( frameCount/30 % 2 == 0) flap=  -flap;
  triangle( x-w/3,y, x-w,y, x-w*2/3,y+flap );  
}

void action() {
  //// Bird flies, bomb drops (if visible)
  birdX += birdDX;
  if (birdX > width+200) reset();
  if (bombY>0) {
    bombX += bombDX;
    bombY += bombDY;
    bombDY += gravity / frameRate ;
    if (bombY>height) bombY=0;      // Bomb disappears (Y=0)
  }
  //// Monster Mash
  //-- omitted.
}
 
void keyPressed() {
  if (key == 'q') exit();
  if (key == 'r') reset();
  if (key == 'b') bombDrop();
 
}

void bombDrop() {
  bombX=  birdX - birdW/2;
  bombY=  birdY;
  bombDX=  birdDX * 3/4;
  bombDY=0;
}