float DIST = 50; // between blocks
float LINE_LENGTH = 50; // size of a block

int BLOCKS_W = 17;
int BLOCKS_H = 17;
void setup() {
  size(850, 850);

}

void draw() {
  background(0);
  //translate(DIST, DIST);

  strokeWeight(2);

  for (int x = 0; x < BLOCKS_W; x++) {
    for (int y = 0; y < BLOCKS_H; y++) {
      float distCenter = abs(sqrt(pow((floor(BLOCKS_W/2.0)) - x, 2.0) * pow((floor(BLOCKS_H/2.0)) - y, 2.0)));
      float distCenterPercent = 1.0 + ((distCenter / BLOCKS_W) * 3.0);
      float offsetMul = (sin(millis()/10000.0 + distCenterPercent)+1.0)/2.0;
      stroke(255*(0.5 + (offsetMul/2.0)));
      translate((LINE_LENGTH * (1.0-offsetMul)) / 2.0, (LINE_LENGTH * (1.0-offsetMul)) / 2.0);
      if (x >= BLOCKS_W/2 && y >= BLOCKS_H/2) {
        // bottom right
        line(
          x * DIST,
          y * DIST,
          x * DIST + LINE_LENGTH * offsetMul,
          y * DIST
         );

        line(
          x * DIST,
          y * DIST,
          x * DIST,
          y * DIST + LINE_LENGTH * offsetMul
         );
      }
      if (x <= BLOCKS_W/2 && y >= BLOCKS_H/2) {
        // bottom left
        line(
          x * DIST + LINE_LENGTH * offsetMul,
          y * DIST,
          x * DIST,
          y * DIST
         );

        line(
          x * DIST + LINE_LENGTH * offsetMul,
          y * DIST,
          x * DIST + LINE_LENGTH * offsetMul,
          y * DIST + LINE_LENGTH * offsetMul
         );
      }
      if (x >= BLOCKS_W/2 && y <= BLOCKS_H/2) {
        // top right
        line(
          x * DIST + LINE_LENGTH * offsetMul,
          y * DIST + LINE_LENGTH * offsetMul,
          x * DIST,
          y * DIST + LINE_LENGTH * offsetMul
         );

        line(
          x * DIST,
          y * DIST,
          x * DIST,
          y * DIST + LINE_LENGTH * offsetMul
         );
      }
      if (x <= BLOCKS_W/2 && y <= BLOCKS_H/2) {
        // top left
        line(
          x * DIST,
          y * DIST + LINE_LENGTH * offsetMul,
          x * DIST + LINE_LENGTH * offsetMul,
          y * DIST + LINE_LENGTH * offsetMul
         );

        line(
          x * DIST + LINE_LENGTH * offsetMul,
          y * DIST,
          x * DIST + LINE_LENGTH * offsetMul,
          y * DIST + LINE_LENGTH * offsetMul
         );
      }
      translate(-(LINE_LENGTH * (1.0-offsetMul)) / 2.0, -(LINE_LENGTH * (1.0-offsetMul)) / 2.0);
    }
  }
  // save frames for .mov output
  //saveFrame("output/lines_####.png");
}