Pattern generator for PCD Chicago 2019

ChicagoPCD.pde

import processing.pdf.*;

int paperWidth = 11;
int paperHeight = 17;
int DPI = 300;

int margin = 100;

color[] colorPalette = { color(179, 221, 242),
                         color(255),
                         color(255, 0, 0)
};

void setup() {
  // 11x17 @ 300 DPI
  // processing doesn't let you calculate at this at run time anymore.
  size(3300, 5100, PDF, "filename.pdf");

  ellipseMode (CENTER);
}

void draw() {
  background (255);

  drawGridOfTriangles (20, 4);

  // Exit the program 
  println("Finished.");
  exit();
}



void drawGridOfTriangles (float triangleSize, float triMargin) {

  float superTriangleSize = triangleSize + triMargin;
  float superTriangleHeight = sqrt(3)/2 * superTriangleSize;

  float triRows = (height - 2 * margin - 0.5 * superTriangleHeight) / (superTriangleHeight);
  float triCols = (width - 2 * margin - superTriangleSize) / (superTriangleSize);

  noStroke();

  // draw 2 per grid cell
  for (int r = 0; r < triRows; r++) {
    for (int c = 0; c < triCols; c++) {
      float x1 = margin + c * superTriangleSize;
      float y1 = margin + r * superTriangleHeight;
      float x2 = x1 + 0.5 * superTriangleSize;
      float y2 = y1 + superTriangleHeight;
      float x3 = x1 + superTriangleSize;
      float y3 = y1;

      float m1x = (x1 + x2) / 2;
      float m1y = (y1 + y2) / 2;
      float m2x = (x2 + x3) / 2;
      float m2y = (y2 + y3) / 2;
      float m3x = (x3 + x1) / 2;
      float m3y = (y3 + y1) / 2;

      float cx = (m1x + m2x + m3x) / 3;
      float cy = (m1y + m2y + m3y) / 3;

      pushMatrix();
      translate (cx, cy);
      if (r % 2 == 1) {
        translate (0, (y2 - cy) - (cy - y1));
        rotate (radians(60));
      }

      //triangle (x1 - cx, y1 - cy, x2 - cx, y2 - cy, x3 - cx, y3 - cy);
      scale (triangleSize / superTriangleSize);
      
      int index = int(random(colorPalette.length));
      fill(colorPalette[index]);
      
      triangle (x1 - cx, y1 - cy, x2 - cx, y2 - cy, x3 - cx, y3 - cy);
      popMatrix ();

      pushMatrix ();
      translate (cx + superTriangleSize * 0.5, cy);

      if (r % 2 == 0) {
        translate (0, (y2 - cy) - (cy - y1));
        rotate (radians(-60));
      }

      //triangle (x1 - cx, y1 - cy, x2 - cx, y2 - cy, x3 - cx, y3 - cy);
      scale (triangleSize / superTriangleSize);
      index = int(random(colorPalette.length));
      fill(colorPalette[index]);
      triangle (x1 - cx, y1 - cy, x2 - cx, y2 - cy, x3 - cx, y3 - cy);

      popMatrix();
    }
  }
}