let curr_col, col_dir, lag, maxLag;

let grid_active;

let paused = false;

let monochrome;

let colors, colorIndex;

let bg;

let o;

let bg_gfx;

​

function keyPressed() {

  if (key == " ") paused = !paused;

}

function setup() {

  createCanvas(1000, 1000);

  pixelDensity(1);

  bg_gfx = createGraphics(width, height);

  o = width * 0.01;

  angleMode(RADIANS);

​

  monochrome = true;

  // dt06 - chromotome

  colors = [color(204, 43, 28), color(231, 206, 181)];

  colorIndex = 0;

​

  grid_active = false;

  col_dir = false;

​

  lag = 0;

  maxLag = 250;

​

  if (monochrome) {

    bg = color(20);

    curr_col = 220;

  } else {

    bg = color(39, 31, 71);

    curr_col = colors[colorIndex];

    lag = maxLag;

  }

​

  let numPoints = random(10, 50);

  let offset = width / numPoints;

​

  pts = [];

  let off = offset;

  for (let i = 0; i < numPoints; i++) {

    let step = random([32, 64, 128, 256, 512, 1024]); //,2048,5096]);

    pts.push({

      theta: i,

      step: TWO_PI / step,

      r: int(width / 3),

      orig_r: int(width / 3),

    });

    off += offset;

  }

​

  bg_gfx.background(bg);

  dither(bg_gfx);

  image(bg_gfx,0,0);

  frameRate(60);

}

​

function draw() {

  if (!paused) {

    translate(width / 2, height / 2);

    // background(0);

    drawShadow(4, null);

​

    stroke(color(curr_col));

​

    strokeWeight(0.5);

    beginShape(LINES);

    for (let i = 0; i < pts.length; i++) {

      let x = pts[i].r * cos(pts[i].theta);

      let y = pts[i].r * sin(pts[i].theta);

      vertex(x, y);

      pts[i].theta += pts[i].step;

​

      if (grid_active) {

        pts[i].r += random(-12, 12); // crazy?

        pts[i].r = constrain(pts[i].r, 1, width / 2 + width / 4);

      } else {

        if (pts[i].r > pts[i].orig_r) pts[i].r--;

        if (pts[i].r < pts[i].orig_r) pts[i].r++;

      }

    }

    endShape();

​

    if (lag == 0) {

      if (monochrome) {

        if (col_dir) {

          curr_col++;

          if (curr_col >= 255) {

            curr_col = 255;

            col_dir = false;

            lag = maxLag;

          }

        } else {

          curr_col--;

          if (curr_col <= 0) {

            curr_col = 0;

            col_dir = true;

            lag = maxLag;

          }

        }

      } else {

        colorIndex++;

        if (colorIndex > colors.length - 1) colorIndex = 0;

        curr_col = colors[colorIndex];

        lag = maxLag;

      }

    } else {

      // console.log(lag);

      lag--;

      if (lag <= 0) lag = 0;

    }

​

    if (frameCount % 500 == 0) grid_active = !grid_active;

​

    push();

    translate(-width/2,-height/2);

    noStroke();

    drawShadow(0, null);

    fill(0);

    rect(0,0,width,o);

    rect(0,0,o,height);

    rect(width-o,0,o,height);

    rect(0,height-o,width,o);

    pop();

  }

}

​

function drawShadow(b, g) {

  if (g == null) {

    if (b == 0) {

      drawingContext.shadowOffsetX = 0;

      drawingContext.shadowOffsetY = 0;

      drawingContext.shadowBlur = 0;

      drawingContext.shadowColor = color(0); //"black";

    } else {

      drawingContext.shadowOffsetX = 3;

      drawingContext.shadowOffsetY = 3;

      drawingContext.shadowBlur = b;

      drawingContext.shadowColor = color(0); //"black";

    }

  } else {

    if (b == 0) {

      g.drawingContext.shadowOffsetX = 0;

      g.drawingContext.shadowOffsetY = 0;

      g.drawingContext.shadowBlur = 0;

      g.drawingContext.shadowColor = color(0); //"black";

    } else {

      g.drawingContext.shadowOffsetX = 3;

      g.drawingContext.shadowOffsetY = 3;

      g.drawingContext.shadowBlur = b;

      g.drawingContext.shadowColor = color(0); //"black";

    }

  }

}

​

function index(g, x, y) {

  if (g == null) return (x + y * width) * 4;

  else return (x + y * g.width) * 4;

}

​

function dither(g) {

  if (g != null) {

    g.loadPixels();

    for (let y = 0; y < height - 1; y++) {

      for (let x = 1; x < width - 1; x++) {

        let oldr = g.pixels[index(g, x, y)];

        let oldg = g.pixels[index(g, x, y) + 1];

        let oldb = g.pixels[index(g, x, y) + 2];

​

        let factor = 1.0;

        let newr = round((factor * oldr) / 255) * (255 / factor);

        let newg = round((factor * oldg) / 255) * (255 / factor);

        let newb = round((factor * oldb) / 255) * (255 / factor);

​

        g.pixels[index(g, x, y)] = newr;

        g.pixels[index(g, x, y) + 1] = newg;

        g.pixels[index(g, x, y) + 2] = newb;

​

        g.pixels[index(g, x + 1, y)] += ((oldr - newr) * 7) / 16.0;

        g.pixels[index(g, x + 1, y) + 1] += ((oldr - newr) * 7) / 16.0;

        g.pixels[index(g, x + 1, y) + 2] += ((oldr - newr) * 7) / 16.0;

​

        g.pixels[index(g, x - 1, y + 1)] += ((oldr - newr) * 3) / 16.0;

        g.pixels[index(g, x - 1, y + 1) + 1] += ((oldr - newr) * 3) / 16.0;

        g.pixels[index(g, x - 1, y + 1) + 2] += ((oldr - newr) * 3) / 16.0;

​

        g.pixels[index(g, x, y + 1)] += ((oldr - newr) * 5) / 16.0;

        g.pixels[index(g, x, y + 1) + 1] += ((oldr - newr) * 5) / 16.0;

        g.pixels[index(g, x, y + 1) + 2] += ((oldr - newr) * 5) / 16.0;

​

        g.pixels[index(g, x + 1, y + 1)] += ((oldr - newr) * 1) / 16.0;

        g.pixels[index(g, x + 1, y + 1) + 1] += ((oldr - newr) * 1) / 16.0;

        g.pixels[index(g, x + 1, y + 1) + 2] += ((oldr - newr) * 1) / 16.0;

      }

    }

    g.updatePixels();

  } else {

    g = null;

    loadPixels();

    for (let y = 0; y < height - 1; y++) {

      for (let x = 1; x < width - 1; x++) {

        let oldr = pixels[index(g, x, y)];

        let oldg = pixels[index(g, x, y) + 1];

        let oldb = pixels[index(g, x, y) + 2];

​

        let factor = 1.0;

        let newr = round((factor * oldr) / 255) * (255 / factor);

        let newg = round((factor * oldg) / 255) * (255 / factor);

        let newb = round((factor * oldb) / 255) * (255 / factor);

​

        pixels[index(g, x, y)] = newr;

        pixels[index(g, x, y) + 1] = newg;

        pixels[index(g, x, y) + 2] = newb;

​

        pixels[index(g, x + 1, y)] += ((oldr - newr) * 7) / 16.0;

        pixels[index(g, x + 1, y) + 1] += ((oldr - newr) * 7) / 16.0;

        pixels[index(g, x + 1, y) + 2] += ((oldr - newr) * 7) / 16.0;

​

        pixels[index(g, x - 1, y + 1)] += ((oldr - newr) * 3) / 16.0;

        pixels[index(g, x - 1, y + 1) + 1] += ((oldr - newr) * 3) / 16.0;

        pixels[index(g, x - 1, y + 1) + 2] += ((oldr - newr) * 3) / 16.0;

​

        pixels[index(g, x, y + 1)] += ((oldr - newr) * 5) / 16.0;

        pixels[index(g, x, y + 1) + 1] += ((oldr - newr) * 5) / 16.0;

        pixels[index(g, x, y + 1) + 2] += ((oldr - newr) * 5) / 16.0;

​

        pixels[index(g, x + 1, y + 1)] += ((oldr - newr) * 1) / 16.0;

        pixels[index(g, x + 1, y + 1) + 1] += ((oldr - newr) * 1) / 16.0;

        pixels[index(g, x + 1, y + 1) + 2] += ((oldr - newr) * 1) / 16.0;

      }

    }

    updatePixels();

  }

}

​