class/objects for novice

Programming Questions

hibohi

in Programming Questions • 2 years ago

hi I recently started learning processing..
I'm having some trouble making my program run
Could anyone tell me how I would make it run properly..basically trying to generate a randomly colored circle that follows the mouse.
thanks in advance.

void setup(){
size(200,200);
myCreation = new Creation();
}

class Creation {
colour r;
int xpos;
int ypos;

Creation() {
    r = random(colour(255));
    xpos = mouseX;
    ypos = mouseY;
}

    void display() {
      fill(r);
      ellipse(xpos, ypos, 20, 10);
    }
}
//end class

//making and using class
Creation myCreation;          //declare variable to hold creation object
void start() {
    myCreation = new Creation();   //make new creation object
}

void draw() {
    myCreation.display();
}

Replies(2)

tfguy44

Re: class/objects for novice

2 years ago

I neatened up your code. I made the following changes:

- Turned calls to colour() into calls to color()

- Fixed the way that the color was being randomly generated in the constructor.

- Added an update function to your class. This way the position of the object always updates to the location of the mouse, and isn't always fixed at where the mouse was (probably (0,0)) when the object was created.

- Added a call to background(), so you always start drawing with a blank background.

- Removed start(). You already had setup() - this is the correct place to create your object.

- Shuffled things about a bit.

Protip of the day: Ctrl+t is awesome.

class Creation {

color r;

int xpos;

int ypos;

Creation() {

r = color(random(255));

xpos = mouseX;

ypos = mouseY;

}

void update(){

xpos = mouseX;

ypos = mouseY;

}

void display() {

fill(r);

ellipse(xpos, ypos, 20, 10);

}

} // End of class Creation.

Creation myCreation; //declare variable to hold creation object

void setup(){

size(200,200);

myCreation = new Creation(); // Creates new object.

}

void draw() {

background(0); // Clear the drawing area.

myCreation.update(); // Update the Creation's position so it is at the mouse.

myCreation.display();

}

hibohi

Re: Re: class/objects for novice

2 years ago

thanks so much mate :)

appreciate the help

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