int score=0;
float horizon;
float heroX=20, heroY=300, heroDX=0, heroDY=0;
float monsterX=500, monsterY=200, monsterDX=4, monsterDY=3;
float birdsX=10, birdsY=100, birdsDX=6, birdsDY=0;
float targetX=-20, targetY=-20;    // (off-screen)

void setup() {
  //// Init.
  size( 800, 600 );
  horizon=  height/3;
}

void draw() {
  //// Next frame
  if (key == '?') {
    help();
  } else {
    scene();
    action();
    scoring();
  }
}
void help() {
  int x=width/2, y=height/2;
  textSize(12);
  text( "Click to start hero moving.", x,y );
  y +=15;
  text( "Lose 10 points, when monster hits hero.", x,y );
  y +=15;
  text( "Gain 5 points, when birds finish a flight.", x,y );
}

void action() {
  //// Move & draw creatures.
  hero();
  monsters();
  //// Check collisions
  if ( dist( heroX,heroY, monsterX,monsterY ) < 50 ) {
    background( 0 );
    score -= 10;
    monsterX=  width-20;      // Move monster to left side, random height.
    monsterX=  random( horizon, height);
  }
}

void hero() {
  //// Move & draw hero
  if (heroX<20 || heroX> width-20) heroDX *= -1;    // Bounce
  if (heroY<horizon || heroY> height-20) heroDY *= -1;
  heroX += heroDX;
  heroY += heroDY;
  rectMode( CENTER );
  fill( 0, 255, 255 );
  rect( heroX, heroY, 50, 80);  
  fill( 255, 255, 255 );
  ellipse( heroX, heroY-60, 40,40 );  
  //// Arms
  float y= heroY-40;
  for (int j=0; j<8; j++) {
    line( heroX-25, y, heroX-45, y );
    line( heroX+25, y, heroX+45, y );
    y += 10;
  }
}  
void monsters() {
  //// Move & draw monster
  if (monsterX<20 || monsterX> width-20) monsterDX *= -1;
  if (monsterY<horizon || monsterY> height-20) monsterDY *= -1;
  monsterX += monsterDX;
  monsterY += monsterDY;
  fill( 255, 0, 0 );
  ellipse( monsterX, monsterY, 50, 80);  
}
void scene() {
  //// sky, grass, etc.
  background( 200,200,255 );
  //// Grass
  fill( 100,g,100 );
  rectMode( CORNERS );
  rect( 0,horizon, width,height );
  //// Flowers
  fill( 200, 200, 0 );
  float x=  20, y=height-50;
  while (x < width-20) {
    ellipse( x, y, 30,30);
    line( x, y+15, x, y+40 );
    x+=  50;
  }
  //// Titles, etc.
  textSize( 20 );
  fill( 0,0,200 );
  text( title, width/3, 40 );
  textSize( 14 );
  text( author, 20, height-100 );
}
void scoring() {
  //// Scoreboard
  text( "Score is "+score, width-100, 50 );
}
  
void keyPressed() {
  //// Event handler for keyboard
  if (key == 'q') {
    exit();
  }  else if (key == '+') {
    heroDX *= 1.1 ;         // 10% speedup
    heroDY *= 1.1 ; 
  }  else if (key == '-') {
    heroDX *= 0.9 ; 
    heroDY *= 0.9 ; 
  }
}

void mousePressed() {
  //// Move hero toward mouse-click.
  //--  if (mouseX>heroX) heroDX=  +2;    
  //--  else heroDX=  -2;
  //--  heroDY= (mouseY>heroY) ? +1.5 : -1.5 ;
  heroDX=  (mouseX-heroX) / 60;
  heroDY=  (mouseY-heroY) / 60;

  //  heroDY= (mouseY>heroY) ? +1.5 : -1.5 ;
  background( 255 );
}