different rectangles different movements

pelibuu

Hello everyone! I need urgent help for my project. I need 10 rectangles at the bottom of the canvas, when I click them they should go up but they all should have different jumps. For example, rectangle1 jumps 10px while rectangle5 jumps 50, rectangle10 jumps 100px when I click on them. Appreciate your help!

TfGuy44

Okay, so each rectangle is going to have a few properies that are different. For one, since they are all along the bottom of the screen, they are all going to have different X positions. But they all HAVE x positions! So we can start writing a class to define a Rectangle object with different starting X positions:

class JumpingRect {
  float x;
  // ...
}

Now we need to be able to pass a different value in when we create one of these objects. So we will need a parameter for this in the constructor function. let's add that.

Jumpingrect( float ix ){
  x = ix;
}

Now we can try creating some of these objects. We can store them easily in an array.

JumpingRect[] jrects = new JumpingRect[10];

And we can create them with a loop:

for( int i = 0; i < 10; i++) jrects[i] = new JumpingRect( 10 * i );

Now you need to write some code... Your JumpingRect object needs a draw function! Where is it? Can you draw it there? You will also need to write a loop that draws all the objects in the jrects array... do this in draw().

Attempt this now. Once you have, you should a running sketch. Post this - or your attempt at it - for more help.

TfGuy44

Once you have rectangles that have different X positions, you can give them OTHER different properties too... like... color... Or... HOW HIGH THEY JUMP...

pelibuu

Hello TfGuy44, Thank you for your quick answer! Unfortunately as a beginner I am struggling with those stuff. so I have some questions :) You've said "constructor function" do you mean setup draw() ? and should I add this to JumpingRect class or main code? do I need variables for location of the rectangles? If I do, where should I add it, to class or main code? Thanks a lot!!

TfGuy44

A constructor function is a function without a return type that is inside a class, and has the same name as the class.

class FancyObjectType {
  FancyObjectType() { // <--- This is this object's constructor function.

  }
}

The constructor is what you call when you create a new instance of an object:

FancyObjectType anFancyThing = new FancyObjectType();

Your code should take the following format:

// Your rectangle class:
class JumpingRect {
  // Properties each rectangle has, for example:
  float x, y;
  color c;
  float howHighItJumps;
  // Constructor
  JumpingRect( ... ) { // Might want some parameters in here!
    // .. what happens when you create one of these?
  }
  // Other functions this object might have:
  void render() { // Draws this object
    // Drawing happens in here.
  }
} // End of class

// Now back at the global level, you can have global variables...
JumpingRect jr0;

// Next, setup() and draw():
void setup(){
  //...
}

void draw(){
  //...
}

Attempt to fill in the blanks and POST THE ATTEMPT, PLEASE.

jeremydouglass

@pelibuu -- in order to make this approach work for you, you must use classes and objects. If you don't know what those are, start with the Objects Tutorial:

• https://processing.org/tutorials/objects/

The awkward beginner way of doing the same thing without classes is to create a global variable for every property of each object. So instead of this:

class JumpingRect {
  // Properties each rectangle has, for example:
  float x, y;
  color c;
  float howHighItJumps;
  [...]

You have this in your header:

float r1x;
float r1y;
color r1c;
float r1jump;

float r2x;
float r2y;
color r2c;
float r2jump;

float r3x;
float r3y;
color r3c;
float r3jump;

Already with four rectangles you can see how messy the "simple" way gets! Imagine 16 rectangles, or 50! A class JumpingRect allows you to create a single object "r1" and it comes with a group of properties all built-in: r1.x, r1.y, r1.c, r1.jump ....