Shared PVector values in Classes

Processing Coding Questions
1

I have created a new Class, “Polygon” that uses a PVector to store the position on the screen that a shape is displayed. However, whenever I update the position of one the Polygons it updates the position of all the others, effectively making all Polygons centred around the same position. I know this has something to do with PVectors calling on the same object or something but I don’t properly understand it. Is there anyway around this problem or should I just store the x and y position as 2 separate floats?

2

Processing.org/reference/PVector_set_.html

class Polygon {
  final PVector vec = new PVector();

  Polygon(final PVector v) {
    vec.set(v);
  }
}
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3

What does ‘final’ do? I’ve done ‘vec = v;’ rather than using ‘vec.set(v)’ because for some reason ‘vec.set(v)’ causes an error for some reason, but that shouldn’t make a difference right? But my issue is that when something like this is run:

PVector position = new PVector(200, 200); Polygon square = new Polygon(position); Polygon pentagon = new Polygon(position); pentagon.vec.x = 400; println(square.vec.x);
This prints 400 because line 4 updates the x position for all Polygons. When I want it to print 200.

4 
void setup() {
  final PVector pos = new PVector(200, 200);

  final Polygon square = new Polygon(pos); 
  final Polygon pentagon = new Polygon(pos);

  pentagon.vec.x = 400; 
  println(square.vec.x); // 200.0

  exit();
}

class Polygon {
  final PVector vec = new PVector();

  Polygon(final PVector v) {
    vec.set(v);
  }
}
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