Class defines a particle color... how do i redefine the color, dynamically, in Draw?

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spelljamm..

Class defines a particle color... how do i redefine the color, dynamically, in Draw?

in Programming Questions • 1 year ago

I'm fairly new to Processing and programming in general.

So I have a particle class that defines a particle.....

void display() {
stroke(255, lifespan);
fill(255, lifespan);
ellipse(location.x, location.y, 4, 4);
}

...but I want to redefine that color at run time, in Draw. I want the color to change dynamically based on certain variables. Any way I can make this happen? Here is the code, pertaining to the particle system that I have in draw... It works fine, but just calls the particle system with the color already defined in the class.

if (brightness(c) > 160) {
translate(x+cellSize/2, y+cellSize/2);
ps.addParticle();
ps.run();
}

Replies(3)

PhiLho

Re: Class defines a particle color... how do i redefine the color, dynamically, in Draw?

1 year ago

Instead of 255 in the stroke() call, put a variable, like the one you have with lifeSpan.

spelljamm..

Re: Class defines a particle color... how do i redefine the color, dynamically, in Draw?

1 year ago

Ah, I thought about that... but lifeSpan is just declared earlier in the class definition. Not in draw, unfortunately.

PhiLho

Re: Class defines a particle color... how do i redefine the color, dynamically, in Draw?

1 year ago

" lifeSpan is just declared earlier in the class definition. Not in draw, unfortunately."
I don't understand your statement, how it can be problematic.
The particle color, let's call it pc (use a better name!), can be a class field. In this case, it can be set at init time, and changed directly or with a function call (a setter). It can be also a parameter of display(), so you can set it on each call.

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