squares & circles

squaresCircles.pde

int[][] result;
float t, c;

float ease(float p) {
  return 3*p*p - 2*p*p*p;
}

float ease(float p, float g) {
  if (p < 0.5) 
    return 0.5 * pow(2*p, g);
  else
    return 1 - 0.5 * pow(2*(1 - p), g);
}

float mn = .5*sqrt(3), ia = atan(sqrt(.5));

void push() {
  pushMatrix();
  pushStyle();
}

void pop() {
  popStyle();
  popMatrix();
}

float c01(float g) {
  return constrain(g, 0, 1);
}

void draw() {

  if (!recording) {
    t = mouseX*1.0/width;
    c = mouseY*1.0/height;
    if (mousePressed)
      println(c);
    draw_();
  } else {
    for (int i=0; i<width*height; i++)
      for (int a=0; a<3; a++)
        result[i][a] = 0;

    c = 0;
    for (int sa=0; sa<samplesPerFrame; sa++) {
      t = map(frameCount-1 + sa*shutterAngle/samplesPerFrame, 0, numFrames, 0, 1);
      draw_();
      loadPixels();
      for (int i=0; i<pixels.length; i++) {
        result[i][0] += pixels[i] >> 16 & 0xff;
        result[i][1] += pixels[i] >> 8 & 0xff;
        result[i][2] += pixels[i] & 0xff;
      }
    }

    loadPixels();
    for (int i=0; i<pixels.length; i++)
      pixels[i] = 0xff << 24 | 
        int(result[i][0]*1.0/samplesPerFrame) << 16 | 
        int(result[i][1]*1.0/samplesPerFrame) << 8 | 
        int(result[i][2]*1.0/samplesPerFrame);
    updatePixels();

    saveFrame("f###.gif");
    if (frameCount==numFrames)
      exit();
  }
}

//////////////////////////////////////////////////////////////////////////////

int samplesPerFrame = 4;
int numFrames = 400;        
float shutterAngle = 1;

boolean recording = false;

void setup() {
  size(720, 720, P3D);
  pixelDensity(recording ? 1 : 2);
  smooth(8);
  result = new int[width*height][3];
  rectMode(CENTER);
  noStroke();
}

float x, y, z, tt;
int N = 32;
float th, qq, R = 31, sp = 3*R;

void cap(float q) {
  beginShape();
  for (int i=0; i<N; i++) {
    qq = i/float(N);
    th = lerp(-QUARTER_PI, QUARTER_PI, qq);
    x = R*(sin(th));
    y = R*(cos(th)-cos(QUARTER_PI))*(1-q);
    vertex(x, y);
  }

  for (int i=0; i<N; i++) {
    qq = i/float(N);
    th = lerp(-QUARTER_PI, QUARTER_PI, qq);
    x = -R*(sin(th));
    y = -R*(cos(th)-cos(QUARTER_PI))*q;
    vertex(x, y);
  }
  endShape(CLOSE);
}

color RED = #c83131, BLUE = #1b3181;
float grow = 1.175;

void draw_() {
  background(248, 240, 234); 
  push();
  translate(width/2, height/2);
  for (int a=-5; a<6; a++) {
    for (int b=-5; b<6; b++) {
      tt = map(cos(TWO_PI*t - 0.16*dist(a, b, 0, 0)), 1, -1, 0, 1);
      tt = ease(tt, 3);
      
      push();
      translate(a*sp, b*sp);

      fill((a+b)%2 == 0 ? RED : BLUE);

      push();
      if ((a+b)%2 == 0)
        scale(pow(grow, tt));
      else
        scale(pow(grow, 1-tt));
      rect(0, 0, R*sqrt(2), R*sqrt(2));
      pop();

      if ((a+b)%2 == 0) {
        fill(lerpColor(RED, BLUE, ease(tt)));
        for (int i=0; i<4; i++) {
          push();
          rotate(HALF_PI*i);
          translate(0, R*cos(QUARTER_PI) + (sp-R*sqrt(2))*tt);
          cap(tt);
          pop();
        }
      }
      pop();
    }
  }

  pop();
}