Modify a text file: $/old/eyesfollow.txt

$/old/eyesfollow.txt

// Cat chases mouse; bombs drop from blimp.
// bam:  '1A21
// bam:  '2222    Watch the cat:  add eyes that follow

// Cat chases mouse; bombs drop from blimp.
// bam:  '1A21

//// GLOABAL VARIABLES ////
int score=0;                   // Score increases by 10 for each rat eaten.
int eaten=0;                   // Number of rats eaten.
int hits=0;                    // Number of bombs hitting cat.
int countdown=0;               // Countdown for cat eating rat.

float xCat=100, yCat=200;      // Position of the cat.
float xRat=50, yRat=50;        // Position of the mouse ("rat").
float xBomb=300, yBomb=0;  // Blimp & bomb are halfway across the screen.
float vBomb=0;                 // Velocity of bomb (downward) -- increases with acceleration of gravity.
// float frameRate=30.0; 
float gravity= 9.81 / frameRate;            // Acceleration of gravity is 9.81 meters per second.

boolean hitCat=false;
boolean nearCat=false;

void setup() {  
  //Big screen, initialize.
  size(640, 888);
  rectMode(CENTER);
  ellipseMode(CENTER);
  //frameRate=1;
}

void draw() {
  // Move cat, mouse, bomb; check hits; draw everything.
  background( 127, 255, 127 );                          // A grassy field.
  fill( 255,0,255);
  
  updateScore( score );

////  1.  Blimp and bomb.
  updateBomb();
 
  //// 2.  Cat.
  updateCat();

// 3.  Rat.
  updateRat( mouseX, mouseY );        // Rat follows mouse.

}

boolean isOver( float x1, float y1, float x2, float y2, float margin ) {
  // Return true if 1 is over 2.

return   (abs(x1-x2) < margin)     &&    (abs(y1-y2) < margin );
  
  
/*  
  boolean result;
  result =   (abs(x1-x2) < margin)     &&    (abs(y1-y2) < margin ));
  return result;
*/

/*
  if (abs(x1-x2) < margin 
    && abs(y1-y2) < margin ) {
      return true;        // True if within this margin.
  } else {
    return false;
  }
*/

}

void keyPressed() {
  yBomb=1;              // Bomb starts dropping when y>0;
  vBomb=0;
  xBomb= random( 0.1*width, 0.9*width );  // Random bomb position.
}

///////////////   MOVINDG & DRAWING  METHODS    //////////////

void updateScore( int n ) {
    text( "Press any key to drop bomb", 400, 10);
    fill(0);
    if (score < 0) fill(255,0,0);
    if (score != 0) text( "SCORE:  " + score, 400, 30);   // Display the score (if > 10);
}

void updateBomb() {        // Handle the blimp and bomb,
  // xBomb=width/2;
 // First, draw blimp and accelerate the bomb.
  drawBlimp( xBomb, yBomb );    // Draw blimp (containin the bomb).
  moveBomb();                   // Accelerate the bomb.
  drawBomb( xBomb, yBomb );     // Draw bomb, unless it is off the screen.
  //--  drawBomb( 100, 100 );     // debugging:  dislay static bomb
}
void drawBlimp(float x, float y) {
  fill( 0, 255, 255 );
  rect( xBomb, 20, 100, 40);
}
void moveBomb() {
  // Make the bomb fall.  (Acceleration of gravity is 10 m/s.  Let 1o pixels = 10 meters.
  if (yBomb < height) {      // Accelerate bomb, unless it is off the screen.
    vBomb=  vBomb + gravity;
    yBomb = yBomb + vBomb;
  }
}
void drawBomb(float x, float y) {
  if (y < height) {        // Draw bomb, unless it is off the screen.
  fill( 0, 127, 127 );
  rect( x, y, 30, 65);
  fill( 255 );
  text( "B\nO\nM\nB", x,y-20);
  fill( 0 );
  text( ""+key, x,y+45);
  fill( 255 );
  if (y<height) text( vBomb, 400,60);
  }
}

void updateCat() {        // Handle the cat.
  if (hitCat) {                // Cat was previously by bomb -- move it off screen.
    xCat=  -20; yCat=  -20;    // Move cat offscreen.
    score -= 20;               // Cat loses 20 points.
    hits++;
  }
  moveCat();                                            // Chase the rat.
  nearCat=  isOver( xBomb, yBomb, xCat,yCat, 150);      // Check if bomb is near or hit the cat!
  hitCat=  isOver( xBomb, yBomb, xCat,yCat, 75);        // Check if cat was actually hit.
  drawCat( xCat, yCat );      // Draw cat.
}
void moveCat() {
  // Cat chases mouse.
  float xFar= xRat-xCat;
  float yFar= yRat-yCat;
  xCat=  xCat + xFar/60;      // Close the distance by half!
  yCat=  yCat + yFar/60;      // Close the distance by half!
}
void drawCat(float x, float y) {
  // Check if bomb is over the cat -- if so, then shock the cat by changing its colors.
  if (hitCat) {                // BOMB HIT CAT!   Make cat blue (this frame).
    fill( 0,0,255 );
  } else if (nearCat) {        // BOMB is near -- cat is scared.
    fill( 255,255,0 );         //   Make the scaredy-cat yellow (and harmless).
  } else {                      
    int darker=  10 * hits;    // Cat gets darker with hits, but lighter with eating.
    int lighter= 10 * eaten;
    fill( 200+lighter, 100-darker, 100-darker );
  }
  // Now, draw a cat at x,y
  noStroke();
  rect( x, y, 80-hits, 40-hits);    // Body
  rect( x+40, y-20, 40, 30);        // Head
  triangle( x+20, y-30, x+25,y-45, x+35, y-30);  
  triangle( x+25, y-30, x+30,y-45, x+40, y-35);  
  //// Eyes and mouth
  eyeFollow( x+35,y-25, xRat, yRat);
  fill(255,0,0);
  triangle( x+35,y-12, x+60,y-17, x+60,y-3 );
  //// Show teeth, based on x coordinate / 10
  int teeth=  (int) x /10;
  if (teeth % 5  > 0) 
  {
    //--  text( x%10, x+50,y );
    fill(255);
    triangle( x+40,y-10, x+60,y-15, x+60,y-5 );
  }
  //// Hits text.
  fill(0);
  text( "CAT \n  # " + hits, x-20, y );
}

void updateRat( float x, float y) {
  xRat= x; yRat=y;                    // Move rat to new x,y.
  if (mousePressed) xRat += 50;         // Rat jumops to right, on click.
  // Check if rat is eaten, else draw it.
  if ( ! nearCat && isOver( xCat,yCat, xRat,yRat, 50)) {    // Use a mouse radius of 50.
    eatRat();
    if (countdown<=0) countdown=20;    // Cat eats rat -- start countdown.
    countdown--;
    if (countdown==0) {          // Countdown finished.
        xCat=  -20; yCat=  -20;            // Move cat off-screen.
        score += 10;
        eaten++;
    }
    fill( 0, 127, 0 );
    drawRat( xRat-10+countdown, yRat-10+countdown );      // Draw "mouse (rat).
  } else {
    fill( 0, 255, 0 );
    drawRat( xRat, yRat );      // Draw "mouse (rat).
  }  
  eyeFollow( xRat-10,yRat-40, xCat, yCat);
  eyeFollow( xRat+10,yRat-40, xCat, yCat);
}
void eyeFollow( float x1, float y1,   float x2, float y2 ) {
  //// Add an eye at (x1,y1) that follows (x2,y2)
  stroke(0);
  fill(255);
  ellipseMode(CENTER);
  ellipse(x1,y1, 20,25);
  noStroke();
  //// Make the pupil follow X2,y2
  float right,down;      //// How far right/left?  down/up?
  right=  (x2-x1) / width;      // Fraction amount right/left
  down=  (y2-y1) / height;
  fill(0,0,100);
  ellipse(x1+20*right, y1+20*down, 5,5);
}
void drawRat(float x, float y) {
  int smaller= (2 * eaten) % 10;    // Mouse gets smaller (and lighter) after being eating.
  if (countdown>0) smaller= -2 * countdown;
  rect( x-20,y-20, 60-smaller,30-smaller/2);
  rect( x-60,y-30, 20,5);
  fill(255,0,0);
  text( "RAT \n  # " + eaten, x-40, y-20 );
}
void eatRat() {                        // Rat was eaten!  update scores, etc.
    background(127,127,127, 200);      // Flash the background.
    text( "CAT EATS THE RAT!!!!!", mouseX+10, mouseY-40);
}