how do you make a class variable global?

werdeyo

Trying to use a class variable to specify the new objects parameters but i don't know how. Thanks for the help!

kfrajer

Check this example. I have a button class with multiple variables. I have instantiated an button b1 from this class. The b1 object's parameters are described by the class Button. Can you think of any extra object parameters that could/should be included in the Button class?

This next guide could provide you more details of the main concepts you want to master: https://processing.org/tutorials/objects/

Kf

class Button {
  String label;
  float x;      
  float y;    
  float w;    
  float h;    

  // constructor
  Button(String labelB, float xpos, float ypos, float widthB, float heightB) {
    label = labelB;
    x = xpos;
    y = ypos;
    w = widthB;
    h = heightB;
  }

  void Draw() {
    fill(218);
    stroke(141);
    rect(x, y, w, h, 10);
    textAlign(CENTER, CENTER);
    fill(0);
    text(label, x + (w / 2), y + (h / 2));
  } 

}


Button b1;
void setup() {
  size(600, 400);
  rectMode(CORNER);
  textAlign(CENTER, CENTER);
  b1=new Button("One button", width*0.2, 200, width*0.6, 50);
}

void draw() {
  background(92);
  b1.Draw();
}

werdeyo

Yea I didn't get it I still need help, can someone give a straight answer.

koogs

Not based on the information you've given us, no.

Post some code.

werdeyo

I'M TRYING TO PUT SIZE(THE CLASS VARIABLE) WHERE IT SAYS /HERE/ IN THE SETUP FUNCTION BUT I DON'T KNOW IF IT'S POSSIBLE.

spaceship spaceship1;
spaceship spaceship2;
spaceship spaceship3;
spaceship spaceship4;

void setup() {
  size(500, 400);
  background(0);
  smooth();
  frameRate(30);
  strokeWeight(1);
  ellipseMode(CENTER);
  rectMode(CENTER);
  spaceship1 = new spaceship(mouseX, 125, 1.75, 1.75, random(/*HERE*/, width-/*HERE*/), random(/*HERE*/, height-/*HERE*/), 50);
  spaceship2 = new spaceship(mouseX, 125, -1.75, -1.75, random(/*HERE*/,width-/*HERE*/), random(/*HERE*/, height-/*HERE*/), 75);
  spaceship3 = new spaceship(mouseX, 125, 1.75, 1.75, random(/*HERE*/, width-/*HERE*/), random(/*HERE*/, height-71), 100);
  spaceship4 = new spaceship(mouseX, 125, -1.75, -1.75, random(/*HERE*/, width-/*HERE*/), random(/*HERE*/, height-/*HERE*/), 125);
                          /*(alienX,alienY,velX,  velY,           shipX,                     shipY,                 size)*/
}

void draw() {
  background(0);
  spaceship1.drawSpaceship();
  spaceship2.drawSpaceship();
  spaceship3.drawSpaceship();
  spaceship4.drawSpaceship();
  spaceship1.xBounce();
  spaceship2.xBounce();
  spaceship3.xBounce();
  spaceship4.xBounce();
  spaceship1.yBounce();
  spaceship2.yBounce();
  spaceship3.yBounce();
  spaceship4.yBounce();
  spaceship1.drawFace();
  spaceship2.drawFace();
  spaceship3.drawFace();
  spaceship4.drawFace();
}

class spaceship {
  float centerX;
  float centerY;
  float xVelocity;
  float yVelocity;
  float shipX;
  float shipY;
  float size;

  spaceship(float tempCX, float tempCY, float tempVX, float tempVY, float tempSX, float tempSY, float sSize) {
    centerX = tempCX;
    centerY = tempCY;
    xVelocity = tempVX;
    yVelocity = tempVY;
    shipX = tempSX;
    shipY = tempSY;
    size = sSize;

  }

  void drawSpaceship() { 
  //making the spacship
  stroke(0);//black line color
  fill(255);//inside of shape white 
  ellipse(shipX-0,shipY-(size*.36),(size*.4),(size*.4));//the top dome of the spaceship
  fill(180);//grey color of the body
  ellipse(shipX-0,shipY-(size*.16),size,(size*.4));//the main body of the spaceship
  stroke(0);//black line color
  fill(12, 246,255);
  ellipse(shipX,shipY,(size*.12),(size*.04));//the bottom hole on the spaceship
  noStroke();//no lines/outline of the next shapes
  fill(random(255), random(255), random(255));//random color
  ellipse(shipX-0,shipY-(size*.24), (size*.06), (size*.06));//middle light
  ellipse(shipX+(size*.2),shipY-(size*.24), (size*.06), (size*.06));//middle right
  ellipse(shipX-(size*.2),shipY-(size*.24), (size*.06), (size*.06));//middle left
  ellipse(shipX-(size*.44),shipY-(size*.2), (size*.06), (size*.06));//far left 
  ellipse(shipX+(size*.44),shipY-(size*.2), (size*.06), (size*.06));//far right
  shipX = shipX + xVelocity;//keep moving the x intercept by a value
  shipY = shipY + yVelocity;//keep moving the y intercept by a value
}

  void xBounce() {
    if(shipX > width-(size/2)){
      xVelocity*=-1;
    }
    if(shipX<0+(size/2)){
      xVelocity*=-1; 
    }
  }

  void yBounce() {
    if(shipY<0+(size/2)){
      yVelocity*=-1;
    }
    if(shipY>height){
      yVelocity*=-1;
    }
  }

  void drawFace() {
    centerX = mouseX;
    centerY = mouseY - 40;
    stroke(0);
    fill(28, 221, 50);
    ellipse(centerX, centerY, 40, 80);
    fill(0);
    ellipse(centerX-10 , centerY-10, 10, 30);
    ellipse(centerX+10 , centerY-10, 10, 30);
    line(centerX-5 , centerY+25 ,centerX+5, centerY+25);
}


}

werdeyo

Sorry if i wasn't being clear because i'm a beginner and i don't even know if what i'm even saying even making any sense i'm taking an intro to computer science high school class so i'm very new to all of the concepts.

kfrajer

It is not clear at all what you are asking. The member variable shipX belongs to your class spaceship. When you do this next:

spaceship1 = new spaceship(mouseX, 125, 1.75, 1.75, random(/HERE*/71, width-71), random(/HERE*/71, height-71), 50);

You are assigning the value random(71, width-71) to shipX. The variable shipX cannot be freely access unless you do something like:

println("The value of shipX in spaceship1 is " + spaceship1 .getX);

You need to look into exactly what you want to do.

Kf

werdeyo

I just realized that my question didn't make sense because I was trying to specify some values of variables for my new objects with a variable that I needed to state in the same line. If there is a way around this please let me know, thanks.

werdeyo

I was trying to use the size variable to specify the ships max and minimum x positions when really the starting and ending x was being stated in the same line as size.

werdeyo

Here's the failure piece of code.

I tried making the starting x and y intercepts random and with a minimum if more than half of the ship size and the max the width divided by half of the size also so they wouldn't get stuck on spawning but it didn't work.

  spaceship1 = new spaceship(mouseX, mouseY, 1.75, 1.75, random((spaceship1.size/2), width-(spaceship1.size/2)), random((spaceship1.size/2), height-(spaceship1.size/2)), 50);
  spaceship2 = new spaceship(mouseX, mouseY, -1.75, -1.75, random((spaceship2.size/2), width-(spaceship2.size/2)), random((spaceship2.size/2), height-(spaceship2.size/2)), 75);
  spaceship3 = new spaceship(mouseX, mouseY, 1.75, 1.75, random((spaceship3.size/2), width-(spaceship3.size/2)), random((spaceship3.size/2), height-(spaceship3.size/2)), 100);
  spaceship4 = new spaceship(mouseX, mouseY, -1.75, -1.75, random((spaceship4.size/2), width-(spaceship4.size/2)), random((spaceship4.size/2), height-(spaceship4.size/2)), 125);
                        /*((alienX),(alienY),(velX),(velY),(                       shipX                         ),(                         shipY                       ),size)*/

werdeyo

shipX and shipY = spaceship starting point.(random)

alienX and alienY = alien head starting point.(random)

size = size of spaceship(not random)

velX and velY = steps the ship takes.

Chrisir

is this solved or do you still have a question?

werdeyo

still a question

werdeyo

wanted to know if their was a way of using size to specify shipX one of the parameters even though size was being given a value on the same line.

Chrisir

you can make one var "size" in setup, say its value in setup and pass it to all 4 spaceships

when size is the same for all ships, you can just state it in the class, in line 48, then you don't pass it

werdeyo

so how would I still be able to change the size variable independently throughout the new spaceships?

werdeyo

i still need to be able to change size too

Chrisir

so how would I still be able to change the size variable independently throughout the new spaceships?

when you want different sizes for the ships, you should pass them separately

...a way of using size to specify one of the parameters even though size was being given a value at the same line I was trying to use it.

what you could do is that you calculate size1 in setup separately and then use it in multiple places in the line with "new"

  float size1; 

  size1=50; 
  spaceship1 = new spaceship(mouseX, 125, 1.75, 1.75, random(size1, width-size1), random(size1, height-size1), size1);

(you can use random for size as well)

werdeyo

Thanks, that's a good solution i'll take it. ^:)^

werdeyo

Just a little repetitive but i bet there's no other way.

werdeyo

Thanks!

Chrisir

i still need to be able to change size too

you can change size later with

spaceship1.size--; 

or so

by the way:

spaceship1.drawSpaceship();
  spaceship2.drawSpaceship();
  spaceship3.drawSpaceship();
  spaceship4.drawSpaceship();
  spaceship1.xBounce();
  spaceship2.xBounce();
  spaceship3.xBounce();
  spaceship4.xBounce();
  spaceship1.yBounce();
  spaceship2.yBounce();
  spaceship3.yBounce();
  spaceship4.yBounce();
  spaceship1.drawFace();
  spaceship2.drawFace();
  spaceship3.drawFace();
  spaceship4.drawFace();
}

you call drawSpaceship, xBounce, yBounce, drawFace for all

when you make a function script in the class, this can be shortened:

void script() {
    drawSpaceship(); 
    xBounce(); 
    yBounce(); 
    drawFace();
}

so in draw for each spaceship you put: spaceship1.script();

werdeyo

so script basically means that you want to run every function in the class?

Chrisir

yeah, making your draw() much shorter

the name script can be changed of course

werdeyo

Oh ok i get it now! Thanks again for making my code so much better.Have you seen my actual sketch lol. You could probably duplicate it in a minute. ^:)^

werdeyo

I still don't even know how to use arrays :))

Chrisir

yeah, arrays would be cool

another remark: you can hit ctrl-t to auto-format your code (in processing)

werdeyo

Yea it looks a lot better now thanks!

spaceship spaceship1;
spaceship spaceship2;
spaceship spaceship3;
spaceship spaceship4;

void setup() {
  size(500, 400);
  background(0);
  smooth();
  frameRate(30);
  strokeWeight(1);
  ellipseMode(CENTER);
  rectMode(CENTER);
  float size1 = 50;
  float size2 = 75;
  float size3 = 100;
  float size4 = 125;
  spaceship1 = new spaceship(mouseX, mouseY, 1.75, 1.75, random((size1/2), width-(size1/2)), random((size1/2), height-(size1/2)), size1);
  spaceship2 = new spaceship(mouseX, mouseY, -1.75, -1.75, random((size2/2), width-(size2/2)), random((size2/2), height-(size2/2)), size2);
  spaceship3 = new spaceship(mouseX, mouseY, 1.75, 1.75, random((size3/2), width-(size3/2)), random((size3/2), height-(size3/2)), size3);
  spaceship4 = new spaceship(mouseX, mouseY, -1.75, -1.75, random((size4/2), width-(size4/2)), random((size4/2), height-(size4/2)), size4);
                        /*((alienX),(alienY),(velX),(velY),(             shipX                ),(             shipY              ),size)*/     
}

void draw() {
  background(0);
  spaceship1.fullScript();
  spaceship2.fullScript();
  spaceship3.fullScript();
  spaceship4.fullScript();
}

class spaceship {
  float centerX;
  float centerY;
  float xVelocity;
  float yVelocity;
  float shipX;
  float shipY;
  float size;

  spaceship(float tempCX, float tempCY, float tempVX, float tempVY, float tempSX, float tempSY, float sSize) {
    centerX = tempCX;
    centerY = tempCY;
    xVelocity = tempVX;
    yVelocity = tempVY;
    shipX = tempSX;
    shipY = tempSY;
    size = sSize;

  }

  void drawSpaceship() { 
  //making the spacship
  stroke(0);//black line color
  fill(255);//inside of shape white 
  ellipse(shipX-0,shipY-(size*.36),(size*.4),(size*.4));//the top dome of the spaceship
  fill(180);//grey color of the body
  ellipse(shipX-0,shipY-(size*.16),size,(size*.4));//the main body of the spaceship
  stroke(0);//black line color
  fill(12, 246,255);
  ellipse(shipX,shipY,(size*.12),(size*.04));//the bottom hole on the spaceship
  noStroke();//no lines/outline of the next shapes
  fill(random(255), random(255), random(255));//random color
  ellipse(shipX-0,shipY-(size*.24), (size*.06), (size*.06));//middle light
  ellipse(shipX+(size*.2),shipY-(size*.24), (size*.06), (size*.06));//middle right
  ellipse(shipX-(size*.2),shipY-(size*.24), (size*.06), (size*.06));//middle left
  ellipse(shipX-(size*.44),shipY-(size*.2), (size*.06), (size*.06));//far left 
  ellipse(shipX+(size*.44),shipY-(size*.2), (size*.06), (size*.06));//far right
  shipX = shipX + xVelocity;//keep moving the x intercept by a value
  shipY = shipY + yVelocity;//keep moving the y intercept by a value
}

  void xBounce() {
    if(shipX > width-(size/2)){
      xVelocity*=-1;
    }
    if(shipX<0+(size/2)){
      xVelocity*=-1; 
    }
  }

  void yBounce() {
    if(shipY<0+(size/2)){
      yVelocity*=-1;
    }
    if(shipY>height){
      yVelocity*=-1;
    }
  }

  void drawFace() {
    centerX = mouseX;
    centerY = mouseY - 40;
    stroke(0);
    fill(28, 221, 50);
    ellipse(centerX, centerY, 40, 80);
    fill(0);
    ellipse(centerX-10 , centerY-10, 10, 30);
    ellipse(centerX+10 , centerY-10, 10, 30);
    line(centerX-5 , centerY+25 ,centerX+5, centerY+25);
}

void fullScript() {

  drawSpaceship();
  xBounce();
  yBounce();
  drawFace();

}



}

Chrisir

no use to pass mouseX, mouseY in setup(), they are just 0 there anyway

say centerX = 0; in the constructor

werdeyo

ok got it thanks again =D>

Chrisir

sure!

well done!