How to create nested polygon

Processing Coding Questions
10

Here’s the finished, working effect:

int numVertices=int(random(4, 10));
float[] curtX;
float[] curtY;
float[] nextX;
float[] nextY;
float[] angles;

void setup() {
  size(600,600);
  curtX = new float[numVertices];
  curtY = new float[numVertices];
  nextX = new float[numVertices];
  nextY = new float[numVertices];
  angles = new float[numVertices];
  // Pick initial random angles.
  for (int i=0; i<numVertices; i++) {
    angles[i] = random(TWO_PI);
  }
  // Sort the angles.
  angles = sort(angles);
}

void draw() {
  background(0);
  stroke(255);
  noFill();
  translate(width/2, height/2);
  float radius=280;
  ellipse(0,0,2*radius, 2*radius);
  // Convert the random angles to (x,y) positions.
  for (int i = 0; i < numVertices; i++) {
    curtX[i] = cos(angles[i]) * radius;
    curtY[i] = sin(angles[i]) * radius;
  }
  for( int t = 0; t < 20; t++){
    draw_polygon();
    next_gen();
    copy_back();
  }
  noLoop();
}

void draw_polygon() {
  beginShape();
  for (int i = 0; i<numVertices; i++) {
      vertex(curtX[i], curtY[i]);
  }
  endShape(CLOSE);
}

void next_gen(){
  for( int i = 0; i < numVertices; i++){
    nextX[i] = ( curtX[i] + curtX[(i+1)%numVertices] ) / 2.0;
    nextY[i] = ( curtY[i] + curtY[(i+1)%numVertices] ) / 2.0;
  }
}

void copy_back(){
  for( int i = 0; i < numVertices; i++){
    curtX[i] = nextX[i];
    curtY[i] = nextY[i];
  }
}

Make sure you study this - line by line, function by function, one loop at a time - in detail so you understand how it works.

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