Unexpected token Void,

MacrossMike

Hello, I'm having trouble troubleshooting errors in my code. Processing says that there is an "unexpected token: void" but I can't seem to find the problem. It point to line 47 in the following code but I'm not sure why it's a problem.

//First declare objects used for this session
Blocker obstacleBlocktopdown; 
Blocker obstacleBlockacross;
Avatar playerAvatar;
float move = 1;//?? needed?
//Player Avatar;
//Player Seeker; 
boolean upPressed = false;
boolean downPressed = false;
boolean leftPressed = false;
boolean rightPressed = false;


    void setup(){
      size(1300, 900); 
      //Initialize object here
      obstacleBlocktopdown = new Blocker(width/2, 1, 20, 20, 0, 2); 
      obstacleBlockacross = new Blocker(1, height/2, 20, 20, 3, .4);
      playerAvatar = new Avatar(0, 0, 15, 15);  
      //Avatar = new Player(color(255,0,0),10,100,2);
      //Seeker = new Player(color(0,0,255),100,10,1);
    } 

    void draw(){ 

      if (upPressed) {// playerAvatar moves up 1 pixel
       playerAvatar.movesup();
      }
      if (downPressed) {//playerAvatar moves down 1 pixel
       playerAvatar.movesdown();
      }
      if (leftPressed) {//playerAvatar moves to the left 1 pixel
       playerAvatar.movesleft();
      }
      if (rightPressed) {//playerAvatar moves to the right 1 pixel
       playerAvatar.movesright();
      }

      background(255); 
      //obstacleBlocktopdown.display();
      //obstacleBlockacross.display(); 
      obstacleBlocktopdown.run(); 
      obstacleBlockacross.run();
      playerAvatar.display(); 

        //enacts the movement of desired object
        void keyPressed (KeyEvent e) { 
      if (key == CODED) {
        if (keyCode == UP) {
          upPressed = true;
        }
        else if (keyCode == DOWN) {
          downPressed = true;
        }
        else if (keyCode == LEFT) {
          leftPressed = true;
        }
        else if (keyCode == RIGHT) {
          rightPressed = true;
        }
      }
    }

         // stops movement once key(s) are released 
    void keyReleased(KeyEvent e) {
      if (key == CODED) {
        if (keyCode == UP) {
          upPressed = false;
        }
        else if (keyCode == DOWN) {
          downPressed = false;
        }
        else if (keyCode == LEFT) {
          leftPressed = false;
        }
        else if (keyCode == RIGHT) {
          rightPressed = false;
        }
      }
    } 
     /* Avatar.drive();
      Avatar.display();
      Seeker.drive();
      Seeker.display();*/
    }

//I don't think my other classes are creating the problem but here they are for reference.

class Avatar {
  float x; 
  float y; 
  float a;
  float b; 

  //constructors 
  Avatar(){
  }

  Avatar (float _x, float _y, float _a, float _b) {
    x = _x;
    y = _y; 
    a = _a;
    b = _b; 
  }

  //Functions 
  void display () {
    stroke(0); 
    fill(83, 125, 243);
    ellipse(x, y, a, b);
  }

  void movesup(){
   y = y - 1; 
  playerAvatar.display(); 
  }
  void movesdown() {
    y = y + 1; 
    playerAvatar.display(); 
  }
  void movesleft() {
    x = x - 1; 
    playerAvatar.display(); 
  }
  void movesright() {
    x = x + 1; 
    playerAvatar.display(); 
  }

}

// ANOTHER CLASS

class Blocker {
  //Global variables
  float x = 0;
  float y = 0;
  float a = 0;
  float b = 0;
  float speedX = 0;
  float speedY = 0;

  //Constructors
  Blocker() {
  }

  Blocker(float _x, float _y, float _a, float _b, float _c, float _d) {
    x=_x;
    y=_y;
    a=_a;
    b=_b;
   // speedX = random(-4, 4);
    //speedY = random(-4, 4);
   speedX = _c;
   speedY = _d; 
  }

  //Functions
  void display () {
    ellipse (x, y, a, b);
  }

  void movement(float spX, float spY) {//make blockers move in basic motions

    x = x + speedX;
    y = y + speedY;
  }

  void bounce() {
    if (x > width) {
      speedX = speedX * -1;
    }
    if (x < 0) {
      speedX = speedX * -1;
    }
    if (y > height) {
      speedY = speedY * -1;
    }
    if (y < 0) {
      speedY = speedY * -1;
    }
  }

  void run() {
    //display();
    obstacleBlocktopdown.movement(0, 2);
    obstacleBlockacross.movement(3, .4);
    bounce();
    obstacleBlocktopdown.display();
    obstacleBlockacross.display();
    }

}

Any help will be appreciated.

TfGuy44

Ctrl-t

Where does your draw() function end?

bilmor

KeyPressed and KeyReleased should be outside of the draw() function.

MacrossMike

Yes that works. Those methods shouldn't be in my draw() function. Thank you

MacrossMike

One more question though, I'm trying to make constraints for the playerAvatar object so it doesn't go off screen. Here is the code I implemented. I hope I'm using the constrain method correctly...

//First declare objects used for this session
Blocker obstacleBlocktopdown; 
Blocker obstacleBlockacross;
Avatar playerAvatar;
boolean upPressed = false;
boolean downPressed = false;
boolean leftPressed = false;
boolean rightPressed = false;


void setup(){
  size(1300, 900); 
  //Initialize object here
  obstacleBlocktopdown = new Blocker(width/2, 1, 20, 20, 0, 2); 
  obstacleBlockacross = new Blocker(1, height/2, 20, 20, 3, .4);
  playerAvatar = new Avatar(11, 11, 15, 15);  
} 

void draw(){ 
   playerAvatar.constrain(playerAvatar.y, 10, height-10);
   playerAvatar.constrain(playerAvatar.x, 10, width-10);

  if (upPressed) {// playerAvatar moves up 1 pixel
   playerAvatar.movesup();
  }
  if (downPressed) {//playerAvatar moves down 1 pixel
   playerAvatar.movesdown();
  }
  if (leftPressed) {//playerAvatar moves to the left 1 pixel
   playerAvatar.movesleft();
  }
  if (rightPressed) {//playerAvatar moves to the right 1 pixel
   playerAvatar.movesright();
  }

  background(255); 
  obstacleBlocktopdown.run(); 
  obstacleBlockacross.run();
  playerAvatar.display(); 

}

  //enacts the movement of desired object
    void keyPressed (KeyEvent e) { 
  if (key == CODED) {
    if (keyCode == UP) {
      upPressed = true;
    }
    else if (keyCode == DOWN) {
      downPressed = true;
    }
    else if (keyCode == LEFT) {
      leftPressed = true;
    }
    else if (keyCode == RIGHT) {
      rightPressed = true;
    }
  }
}

     // stops movement once key(s) are released 
void keyReleased(KeyEvent e) {
  if (key == CODED) {
    if (keyCode == UP) {
      upPressed = false;
    }
    else if (keyCode == DOWN) {
      downPressed = false;
    }
    else if (keyCode == LEFT) {
      leftPressed = false;
    }
    else if (keyCode == RIGHT) {
      rightPressed = false;
    }
  }
} 

I get an error saying "The function constrain(float, int, int) does not exist. I'm really new at this so it doesn't make much sense to me. I thought the syntax for the constrain() function was constrain(amt, low, high) where the amt refers to the value to be constrained? And it can return an int or float?

GoToLoop

When we use the dot . operator, Java considers its right operand as a member of the left operand's object:
https://processing.org/reference/dot.html

• So at playerAvatar.constrain(playerAvatar.x, 10, width-10);
• playerAvatar is the left operand of the dot . access operator and represents the object.
• While constrain() is the right operand and it is assumed to be a member of playerAvatar.
• Since variable playerAvatar is of type Avatar, the search's gonna happen inside that class.
• And since there's no member called constrain() there, it's gonna display it doesn't exist!
• Same thing for playerAvatar.x. Only diff. is that the member x actually exists there!
• However, if you had just used Processing API's constrain(), it'd surely be found!

https://processing.org/reference/constrain_.html

GoToLoop

Much probably what you meant was assigning the result of constrain() back to field x: ;;)
playerAvatar.x = constrain(playerAvatar.x, 10, width-10);

It'd be much better if that was an Avatar's method instead: *-:)

void constrainToScreen() {
  x = constrain(x, a/2.0, width  - a/2.0);
  y = constrain(x, b/2.0, height - b/2.0);
}

GoToLoop

Also take a look at my online example below:
http://studio.processingtogether.com/sp/pad/export/ro.91tcpPtI9LrXp/

The class Player there also relies on constrain() @ its member method move()! :bz

MacrossMike

Hi, "GoToLoop", there is a slight problem with the constrainToScreen method. It makes the left and right buttons make the playerAvatar go on a diagonal and the moveup() and movedown() methods don't work. I'm trying to tweak it but I'm still running into problems.

And on an unrelated note, I can't control the color of some objects. I wanted to change the color of the Avatar object but it changed the color of all objects on screen. Why is that? The code is below...

class Avatar {
  float x; 
  float y; 
  float a;
  float b; 

  //constructors 
  Avatar(){
  }

  Avatar (float _x, float _y, float _a, float _b) {
    x = _x;
    y = _y; 
    a = _a;
    b = _b; 
  }

  //Functions 
  void display () {
    stroke(0); 
    fill(83, 125, 243);
    ellipse(x, y, a, b);
  }

  void movesup(){// MAY NEED IF ELSE STATEMENTS 
    constrain(y, 10, height-10);
   y = y - 1; 
  playerAvatar.display(); 
  }
  void movesdown() {
    constrain(y, 10, height-10);
    y = y + 1; 
    playerAvatar.display(); 
  }
  void movesleft() {
    constrain(x, 10, width-10);
    x = x - 1; 
    playerAvatar.display(); 
  }
  void movesright() {
    constrain(x, 10, width-10);
    x = x + 1; 
    playerAvatar.display(); 
  }

  void constrainToScreen() {
  x = constrain(x, a/2.0, width  - a/2.0);
  y = constrain(x, b/2.0, height - b/2.0);
}

}

// THE BLOCKER CLASS

class Blocker {
  //Global variables
  float x = 0;
  float y = 0;
  float a = 0;
  float b = 0;
  float speedX = 0;
  float speedY = 0;

  //Constructors
  Blocker() {
  }

  Blocker(float _x, float _y, float _a, float _b, float _c, float _d) {
    x=_x;
    y=_y;
    a=_a;
    b=_b;
   // speedX = random(-4, 4);
    //speedY = random(-4, 4);
   speedX = _c;
   speedY = _d; 
  }

  //Functions
  void display () {
    ellipse (x, y, a, b);
  }

  void movement(float spX, float spY) {//make blockers move in basic motions

    x = x + speedX;
    y = y + speedY;
  }

  void bounce() {
    if (x > width) {
      speedX = speedX * -1;
    }
    if (x < 0) {
      speedX = speedX * -1;
    }
    if (y > height) {
      speedY = speedY * -1;
    }
    if (y < 0) {
      speedY = speedY * -1;
    }
  }

  void run() {
    //display();
    obstacleBlocktopdown.movement(0, 2);
    obstacleBlockacross.movement(3, .4);
    bounce();
    obstacleBlocktopdown.display();
    obstacleBlockacross.display();
    }

}

// SETUP AND DRAW FUNCTIONS.

//First declare objects used for this session
Blocker obstacleBlocktopdown; 
Blocker obstacleBlockacross;
Avatar playerAvatar;
boolean upPressed = false;
boolean downPressed = false;
boolean leftPressed = false;
boolean rightPressed = false;


void setup(){
  size(1300, 900); 
  //Initialize object here
  obstacleBlocktopdown = new Blocker(width/2, 1, 20, 20, 0, 2); 
  obstacleBlockacross = new Blocker(1, height/2, 20, 20, 3, .4);
  playerAvatar = new Avatar(11, 11, 15, 15);  
} 

void draw(){ 
  // playerAvatar.constrain(playerAvatar.y, 10, height-10);
  // playerAvatar.constrain(playerAvatar.x, 10, width-10);
  playerAvatar.constrainToScreen(); 


  if (upPressed) {// playerAvatar moves up 1 pixel
   playerAvatar.movesup();
  }
  if (downPressed) {//playerAvatar moves down 1 pixel
   playerAvatar.movesdown();
  }
  if (leftPressed) {//playerAvatar moves to the left 1 pixel
   playerAvatar.movesleft();
  }
  if (rightPressed) {//playerAvatar moves to the right 1 pixel
   playerAvatar.movesright();
  }

  background(255); 
  obstacleBlocktopdown.run(); 
  obstacleBlockacross.run();
  playerAvatar.display(); 
}

  //enacts the movement of desired object
    void keyPressed (KeyEvent e) { 
  if (key == CODED) {
    if (keyCode == UP) {
      upPressed = true;
    }
    else if (keyCode == DOWN) {
      downPressed = true;
    }
    else if (keyCode == LEFT) {
      leftPressed = true;
    }
    else if (keyCode == RIGHT) {
      rightPressed = true;
    }
  }
}

     // stops movement once key(s) are released 
void keyReleased(KeyEvent e) {
  if (key == CODED) {
    if (keyCode == UP) {
      upPressed = false;
    }
    else if (keyCode == DOWN) {
      downPressed = false;
    }
    else if (keyCode == LEFT) {
      leftPressed = false;
    }
    else if (keyCode == RIGHT) {
      rightPressed = false;
    }
  }
} 

Why do all my objects change color?

MacrossMike

Ok so I fixed the problem with the diagonal movement. (it turned out to be really simple, but I can't seem to get the colors right. Why do all my objects change to the same color?

GoToLoop

Why do all my objects change to the same color?

• B/c fill(), stroke(), etc. alter the whole canvas' foreground color!
• Anything drawn after any of them obeys the latest chosen color.
• In short, those functions control the sketch's canvas properties.
• And therefore they're global configs, affecting everywhere!

I see that inside Avatar's display() method both stroke() & fill() are issued:

void display () {
  stroke(0);
  fill(83, 125, 243);
  ellipse(x, y, a, b);
}

• Of course that's gonna affect Blocker's display() too and anything else! :-\"
• Either issue fill() before calling Blocker's own display() or have that inside it as well! *-:)

---

• I see that you define a fixed color for Avatar. So it's a constant!
• In my online example, Player's colors are defined inside it as constant fields:

static final color INK = #008000, OUTLINE = 0;

• In your case that'd translate as:

static final color INK = #537DF3, OUTLINE = 0;

void display () {
  stroke(OUTLINE);
  fill(INK);
  ellipse(x, y, a, b);
}

• Do the same for the Blocker class if all of them have the same color properties.
• In case each Blocker got its own color, you're gonna need regular color fields to store it.
• That is, in the same way we store the other instance properties like coordinates, dimensions, etc.

---

• One final tip: upPressed, downPressed, leftPressed & rightPressed would be better fit as Avatar's fields rather than sketch's! :>
• Again take a look at how the online sketch tackles it:

void keyPressed() {
  p.setMove(keyCode, true);
}

void keyReleased() {
  p.setMove(keyCode, false);
}

• It invokes Player's setMove() method, which either sets or resets its boolean fields.
• Then Player's move() method calculates the movement based on those 4 boolean fields.
• Of course you do almost the same but inside sketch's draw()! O:-)