I'm a pretty new programmer working on a project involving classes. I want to create a Tigger-like creature that bounces (using gravity). I haven't gotten that far yet unfortunately. When I run the following code, I get a "expecting IDENT, found ','" error.

Code:

int width=800;
int height=600;
float xpos=400;
float ypos=200;
float headwidth=60;
float headheight=100;
float nosewidth=40;
float noseheight=30;
float noseoffset=30;
float bodywidth=60;
float bodyheight=200;
float bodyoffset=150;
float direction=1;
float speed=4;
float levelofshake=5;
float bounciness=5;
float white=255;
float redness=255;
float greenness=140;
float blueness=0;

Creature tigger;

void setup() {
  size(width,height);
  smooth();
  tigger=new Creature(xpos,ypos,direction,speed);
}

void draw() {
  background(white);
  tigger.display();
  //tigger.bounce(bounciness);
  //tigger.shake(levelofshake);
  //tigger.talk();
}

class Creature {
  Creature(tempXpos,tempYpos,tempDirection,tempSpeed) {
    xpos=tempXpos;
    ypos=tempYpos;
    direction=tempDirection;
    speed=tempSpeed;
  }
}

  void display() {
    fill(redness,greenness,blueness);
    ellipse(xpos-noseoffset,ypos,nosewidth,noseheight); //ellipse for the nose
    ellipse(xpos,ypos,headwidth,headheight); //ellipse for the head
    ellipse(xpos,ypos+bodyoffset,bodywidth,bodyheight); //ellipse for the body
  }
     

I have some questions about this code that I can hopefully get answered here.

I'm wanting to have four customizable attributes of my creature, hence the xpos, ypos, direction and speed found when I initialized my object. I also don't want to have any hard-coded variables, so I put them all at the top of my code. I'll set them as global variables instead of variables within my classes, as I may use some in each of my classes. With this being the case, wouldn't all my attributes be easily customizable, not only the four I mentioned?

I have put my other three user-defined functions (bounce, shake and talk) into comments as I'll worry about those when the time comes. As for now, I just want my creature (so far just a head, nose and body [I'll improve them when the time comes]) to be displayed properly, yet my program isn't even running and I don't know why. No where in the appendix of Daniel Shiffman's book does it mention this area.

May I also know the basic things that are wrong with my code please? I'm only up to ch. 8 (on objects) in Shiffman's book, so I won't be able to fully understand coding from beyond that point. (When I try to make my creature talk, by importing an audio file from somewhere, I'll look ahead and read how to do it).

Thanks very much!  

 

Thanks Giles. Unfortunately when I put my display(); function into my Creature class, it still gives me the same error. Below is the code for my class with the display(); function in it (ignoring the code outside the class).

Code:

class Creature {
  Creature(tempXpos,tempYpos,tempDirection,tempSpeed) {
    xpos=tempXpos;
    ypos=tempYpos;
    direction=tempDirection;
    speed=tempSpeed;
  }

  void display() {
    fill(redness,greenness,blueness);
    ellipse(xpos-noseoffset,ypos,nosewidth,noseheight); //ellipse for the nose
    ellipse(xpos,ypos,headwidth,headheight); //ellipse for the head
    ellipse(xpos,ypos+bodyoffset,bodywidth,bodyheight); //ellipse for the body
  }
} 

I also tried putting the display(); function in with where I defined my variables to each other (xpos=tempXpos, ect), but that gave me the same error.

Thanks again   The answer seems to obvious now that you said it. But I guess that's how it is in programming.

As I said, I'd like to make my Tigger bounce with the gravity effect mentioned in Shiffman's book. I like to think I'm pretty good with making simple objects bounce, yet my Tigger won't be simple (hopefully). Will I have to make every individual part of Tigger bounce, or is there some way around that, where I can make the entire Tigger object bounce? I've read through his chapter on objects several times now and cannot find anything regarding it.

Is it normal to have hard-coded numbers as our function arguments? All the examples in his book give hard-coded numbers, yet my computer professor would like no hard-coded numbers at all. Would I only define the parameters in the class itself? I tried defining all my variables within class and it wouldn't run.

I'm still not certain what variables to put into my class and what to put outside my class. Will the number of variables within my class be greater than the number of parameters the object takes?

And how do I go about have my project make noise? I don't see anything on the reference here regarding importing sound/audio.

When I put all variables besides float white into my class, I get an error saying "Cannot find anything named xpos" on the line where I initialized my object. I assume this is because my argument values aren't hard-coded. Do I need hard-coded values for my arguments?

Code:

tigger=new Creature(xpos,ypos,direction,speed); 

I just downloaded the Mini 2.0.2 full distribution and have to say I am thoroughly confused by it. I found a "groove.mp3" file within the Minim folder and it sounded groovy enough that I'd like it in my project.

Judging from the help given on that site, I would say that something like this:
Code:

import ddf.minim.*;
 
Minim minim;
AudioPlayer song;
 
void setup()
{
  size(100, 100);
 
  minim = new Minim(this);
 
  // this loads mysong.wav from the data folder
  song = minim.loadFile("groove.mp3");
  song.play();
}
 
void draw()
{
  background(0);
}
 
void stop()
{
  song.close();
  minim.stop();
 
  super.stop();
} 

would play that file. Yet, it doesn't, saying that Minim is not defined.

I'm not looking for anything fancy. Just a simple example, that works, that I can run in my own Processing screen, so I can see how to use it. Thanks.

Thank you Plastik, that was helpful for me.

In trying to "start from scratch", I want to apply the gravity effect to just a ball, which will be called Tigger.

I used hard-coded numbers as you suggested. In trying to run the following code, I received an error message I've never seen before:"Syntax error, insert 'AssignmentOperator Expression' to complete Expression." I don't know what I could have done wrong, unless my xpos and ypos only work within the display() function. In which case I would expect a different error message.
Code:

float gravity=.1;

Creature tigger;

void setup() {
  size(800,600);
  smooth();
  tigger=new Creature(10);
}

void draw() {
  background(255);
  tigger.display(400,300);
  tigger.move;
}

class Creature {
  float speed;
  Creature(float tempSpeed) {
    speed=tempSpeed;
  }

  void display(float xpos,float ypos) {
    fill(255,140,0);
    ellipse(xpos,ypos,100,100);
  }

  void move() {
    ypos=ypos+speed;
    speed=speed+gravity;
  }
}
 

Thanks. I should have seen that. I've read in Shiffman's book that when you're frustrated with programming, you should take a break. I didn't do that, and as a consequence failed to see my mistake.

I edited a post further up here regarding the Mimim audio libraries. I'm trying to get a *boing* sound whenever Tigger hits the ground and bounces back up. I can't imagine this would be too hard to do (I say that now).

I've managed to get a picture to be my background image. It looks nice and all but my bouncing object is now very slow. I'm guessing this is due to the background image having to re-draw itself 30 times every second (I put it in my draw(); function). Of course I can't put it in my setup() function or it wouldn't remain. What do I do?  

Thank you! My program has really evolved I feel. I have a background picture imported as well as some text, but I'll leave those out of the following code. I have two questions:

1. How do I make them not jump as high? I tried lowering my speed variable to .0001 yet that barely seems to make a difference.

2. How do I avoid having my creatures get "stuck" on the ground level? Without fail, one of my smilies gets stuck on the second or third bounce, then more get stuck after it. I think it has something to do with my random() functions, yet I can't pinpoint where.
Code:

//I set my global variables
int width=800;
int height=600;

float wbody=200;
float hbody=200;
float woutereye=120;
float houtereye=90;
float winnereye=60;
float hinnereye=45;
float wsmile=120;
float hsmile=80;
float wblink=90;
float hblink=75;
float groundlevel=500;
float mouththickness=12;
float outereyeoffset=50;
float innereyeoffset=50;
float smileoffset=20;
float eyefollowmouse=250;
float slowdowneyemovement=20;
float gravity=.05;
float white=255;
float black=0;
float redness=100;
float greenness=150;
float fontsize=32;
float xposfont=15;
float yposfont=30;

Robots[] robots=new Robots[20];

void setup() {
  size(width,height);
  smooth();
  println("Press 'b' to see the creatures blink.");

  for (int i=0; i<robots.length; i++) {
    robots[i] = new Robots(color(i*2,random(255),random(255)),random(width),random(-1000,-100),.0001);
  }
}

void draw() {
  background(255);

  for (int i=0; i<robots.length; i++) {
    robots[i].display();
    robots[i].move();
    robots[i].sway(PI/4);
    robots[i].blink();
  }
}
 

Class:
Code:

//I begin my class
class Robots {
  color c;
  float xpos;
  float ypos;
  float speed;

  //My class parameters are paired with the Robots class arguments from setup()
  Robots(color tempC, float tempXpos, float tempYpos, float tempSpeed) {
    c=tempC;
    xpos=tempXpos;
    ypos=tempYpos;
    speed=tempSpeed;
  }

  void display() {
    noStroke();
    fill(c);
    ellipse(xpos,ypos,wbody,hbody); //body
    strokeWeight(mouththickness);
    fill(white);
    ellipse(xpos,ypos-outereyeoffset,woutereye,houtereye); //outer eye
    fill(redness,greenness,mouseY);
    ellipse(xpos-(eyefollowmouse-mouseX)/slowdowneyemovement,ypos-innereyeoffset,winnereye,hinnereye); //inner eye
    stroke(white);
    noFill();
    arc(xpos,ypos+smileoffset,wsmile,hsmile,0,PI); //smile
  }

  void move() {
    ypos=ypos+speed;
    speed=speed+gravity;
    if (ypos>groundlevel) {
	speed=speed*-.95; //This achieves the gravity effect. Mulitplying by -.95 decreases the bounce level each bounce.
    }
  }

  /*This allows my robots to have some sort of random movement. I did not include random y-movement as I found the robots often got "stuck"
   on the bottom fo the screen*/
  void sway(float swaylevel) { 
    xpos=xpos+random(-1,1)*swaylevel;
  }

  //If the 'b' button is pressed, the creatures will blink
  void blink() {
    if (keyPressed) {
	if (key=='b'||key=='B') {
	  fill(white);
	  ellipse(xpos,ypos-innereyeoffset,wblink,hblink);
	}
    }
  }
}