Sketch 8, Terra Firma

app/8/index.js

@@ -0,0 +1,210 @@
+new p5(sketch => {
+  sketch.disableFriendlyErrors = true;
+  // reused dimensions and a seed
+  let seed, width, height, noiseResolution, overdraw, blurQuality;
+  const layers = {}; // offscreen layers
+  const shaders = {}; // shaders
+  const lib = {}; // libraries
+  const assets = {}; // fonts, images, sound files
+
+  sketch.preload = () => {
+    shaders.whiteNoise = sketch.loadShader(
+      "../shaders/base.vert",
+      "../shaders/white-noise.frag"
+    );
+    assets.stroke = sketch.loadImage("./brush-100x30.png");
+  };
+
+  sketch.setup = () => {
+    filenamePrefix = "seigler-p5-8-terra-firma-";
+    overdraw = 0.1;
+    width = Math.floor(sketch.windowWidth * (1 + overdraw));
+    height = Math.floor(sketch.windowHeight * (1 + overdraw));
+    noiseResolution = [0.2, 0.1, 0.05, 2];
+    blurQuality = 2;
+
+    window.onhashchange = () => {
+      seed = window.location.hash.substr(1);
+      generate();
+    };
+
+    seed = window.location.hash.substr(1);
+    sketch.colorMode(sketch.HSL, 1);
+
+    sketch.createCanvas(sketch.windowWidth, sketch.windowHeight);
+
+    layers.contours = sketch.createGraphics(width, height);
+    layers.contours.colorMode(sketch.HSL, 1);
+
+    layers.noise = sketch.createGraphics(width, height, sketch.WEBGL);
+
+    // layers.blur1 = sketch.createGraphics(width, height, sketch.WEBGL);
+    // layers.blur2 = sketch.createGraphics(width, height, sketch.WEBGL);
+
+    generate();
+  };
+
+  sketch.draw = () => {};
+
+  sketch.keyReleased = () => {
+    if (sketch.key == " ") {
+      seed = null;
+      generate();
+    } else if (sketch.key == "s") {
+      sketch.saveCanvas(filenamePrefix + seed + ".jpg", "jpg");
+    }
+  };
+
+  sketch.doubleClicked = () => {
+    seed = null;
+    generate();
+  };
+
+  let resizeTimer;
+  sketch.windowResized = () => {
+    clearTimeout(resizeTimer);
+    resizeTimer = setTimeout(() => {
+      window.location.reload();
+    }, 100);
+  };
+
+  function generate() {
+    if (seed) {
+      sketch.randomSeed(seed);
+    } else {
+      const seed = Math.floor(sketch.random(1000000000000));
+      window.location.hash = seed;
+      sketch.randomSeed(seed);
+    }
+
+    sketch.noiseSeed(sketch.random(0, 1000000000));
+    lib.simplex = new SimplexNoise(sketch.random(0, 1000000000));
+
+    layers.contours.clear();
+    drawContours(layers.contours);
+
+    sketch.blendMode(sketch.BLEND);
+    sketch.background(0);
+    layers.noise.shader(shaders.whiteNoise);
+    shaders.whiteNoise.setUniform("u_resolution", [width, height]);
+    shaders.whiteNoise.setUniform("u_alpha", 0.05);
+    layers.noise.rect(0, 0, width, height);
+    sketch.image(
+      layers.contours,
+      Math.round((-width * overdraw) / 2),
+      Math.round((-height * overdraw) / 2)
+    );
+    sketch.blendMode(sketch.OVERLAY);
+    sketch.image(layers.noise, 0, 0);
+  }
+
+  function drawContours(layer) {
+    const noiseScale = 3 / (width + height);
+    const quant = Math.round(Math.sqrt(width * height) / 1440 * 100); // 100 at 1920*1080
+    layers.contours.imageMode(sketch.CENTER);
+
+    const dots = buildGrid(0, 0, width, height, 15 * quant);
+    layer.noStroke();
+    dots.forEach(({x, y}) => {
+      const {noise, angle} = noisePlus(x, y, noiseScale);
+      if (noise < 0.5) { // water
+        layer.tint(218/360, 0.8, 0.1 + sketch.random(0.05) + noise * 2 * 0.2);
+      } else { // land
+        layer.tint(119/360, 0.8, 0.1 + sketch.random(0.05) + (noise - 0.5) * 2 * 0.2);
+      }
+      const size = 200;
+      layer.translate(x, y);
+      layer.rotate(angle + (noise < 0.5 ? sketch.HALF_PI : 0));
+      layer.image(assets.stroke, 0, 0, size, size / 3);
+      layer.resetMatrix();
+    });
+
+    const trails = buildGrid(0, 0, width, height, 5 * quant);
+    layer.noTint();
+    layer.strokeCap(sketch.SQUARE);
+    trails.forEach((point) => {
+      const x = point.x + sketch.random(-50, 50);
+      const y = point.y + sketch.random(-50, 50);
+      const noise = fractalNoise(x, y, noiseScale);
+      for (let i = 0, max = quant/2, aX = x, aY = y; i < max; i++) {
+        const {angle} = noisePlus(aX, aY, noiseScale);
+        const dX = Math.cos(angle + sketch.HALF_PI) * 4;
+        const dY = Math.sin(angle + sketch.HALF_PI) * 4;
+        if (noise > 0.5) {
+          layer.stroke(0, 0.8);
+        } else {
+          layer.stroke(1, 0.5);
+        }
+        layer.strokeWeight(Math.sin(i/max*Math.PI)); // smooth 0 to 1 to 0
+        layer.line(aX, aY, aX + dX, aY + dY);
+        aX += dX;
+        aY += dY;
+      }
+    });
+  }
+
+  function buildGrid(minX, minY, maxX, maxY, approxPoints) {
+    const width = maxX - minX;
+    const height = maxY - minY;
+    const unit = Math.sqrt(width * height / Math.sin(Math.PI / 3) / approxPoints);
+    const rows =
+      Math.max(1, Math.round(height / unit / Math.sin(Math.PI / 3))) + 1;
+    const cols = Math.max(1, Math.round(width / unit)) + 1;
+    const grid = [];
+    for (let index = 0; index < rows * cols; index++) {
+      const col = index % cols;
+      const row = Math.floor(index / cols);
+      grid.push({
+        x: minX + (width / (cols - 1)) * col + (((row % 2) - 0.5) * unit) / 2,
+        y: minY + (height / (rows - 1)) * row
+      });
+    }
+    return grid;
+  }
+
+  function noisePlus(x, y, noiseScale = 2 / (width + height), noiseOffset = 0) {
+    const noise = fractalNoise(x, y, noiseScale, noiseOffset);
+    const dX = fractalNoise(x + 1, y, noiseScale, noiseOffset) - noise;
+    const dY = fractalNoise(x, y + 1, noiseScale, noiseOffset) - noise;
+    const angle = Math.atan2(dY, dX);
+    const length = sketch.dist(0, 0, dX, dY);
+    return ({noise, angle, length});
+  }
+
+  function fractalNoise(x, y, noiseScale = 2 / (width + height), noiseOffset = 0) {
+    return 0.5 + 0.5 * (
+      lib.simplex.noise2D(
+        noiseOffset + noiseScale * x,
+        noiseOffset + noiseScale * y
+      ) + 
+      0.5 * lib.simplex.noise2D(
+        noiseOffset + 2 * noiseScale * x,
+        noiseOffset + 2 * noiseScale * y
+      ) +
+      0.25 * lib.simplex.noise2D(
+        noiseOffset + 4 * noiseScale * x,
+        noiseOffset + 4 * noiseScale * y
+      )
+    ) / 1.75;
+  }
+
+  // give normally distributed values from 0-1 a uniform distribution
+  function flattenDistribution(x) {
+    return (
+      23.8615 * Math.pow(x, 5) -
+      59.6041 * Math.pow(x, 4) +
+      47.2472 * Math.pow(x, 3) -
+      11.3053 * Math.pow(x, 2) +
+      0.806219 * x -
+      0.00259101
+    );
+  }
+
+  // returns abs angle from a to b to c
+  function three_point_angle(A, B, C) {
+    const AB = Math.sqrt(Math.pow(B.x - A.x, 2) + Math.pow(B.y - A.y, 2));
+    const BC = Math.sqrt(Math.pow(B.x - C.x, 2) + Math.pow(B.y - C.y, 2));
+    const AC = Math.sqrt(Math.pow(C.x - A.x, 2) + Math.pow(C.y - A.y, 2));
+    return Math.acos((BC * BC + AB * AB - AC * AC) / (2 * BC * AB));
+  }
+});

app/8/index.static.hbs

@@ -0,0 +1,7 @@
+---
+title: Terra Firma
+created: 2019-11-18
+index: 8
+_options:
+  layout: app/layouts/sketch.hbs
+---

app/index.static.hbs

@@ -14,6 +14,12 @@ _options:
   <body>
     <main>
       <h1>P5.js generative art</h1>
+      {{> preview
+        index="8"
+        date="2019-11-18"
+        title="Terra Firma"
+        alt="a brush stroked map of sea and land, with breezy black and white contour lines marking the elevation"
+      }}
       {{> preview
         index="7"
         date="2019-11-16"

app/layouts/sketch.hbs

@@ -19,6 +19,7 @@
   <body>
     <script src="../modules/p5.min.js"></script>
     <script src="../modules/rhill-voronoi-core.min.js"></script>
+    <script src="../modules/simplex-noise.js"></script>
     <script src="DIGEST(../app.js)"></script>
     <footer><a href="../">Back</a> | <code>Space</code> or double click for a new one. <code>S</code> to save.</footer>
   </body>

brunch-config.js

@@ -21,7 +21,8 @@ exports.plugins = {
     modules: [
       'node_modules/p5/lib/p5.min.js',
       'node_modules/p5/lib/addons/p5.sound.min.js',
-      'node_modules/voronoi/rhill-voronoi-core.min.js'
+      'node_modules/voronoi/rhill-voronoi-core.min.js',
+      'node_modules/simplex-noise/simplex-noise.js'
     ],
     verbose : true,
     onlyChanged: true

package-lock.json

@@ -3338,9 +3338,9 @@
             "dev": true
         },
         "handlebars": {
-            "version": "4.5.1",
+            "version": "4.5.2",
-            "resolved": "https://registry.npmjs.org/handlebars/-/handlebars-4.5.1.tgz",
+            "resolved": "https://registry.npmjs.org/handlebars/-/handlebars-4.5.2.tgz",
-            "integrity": "sha512-C29UoFzHe9yM61lOsIlCE5/mQVGrnIOrOq7maQl76L7tYPCgC1og0Ajt6uWnX4ZTxBPnjw+CUvawphwCfJgUnA==",
+            "integrity": "sha512-29Zxv/cynYB7mkT1rVWQnV7mGX6v7H/miQ6dbEpYTKq5eJBN7PsRB+ViYJlcT6JINTSu4dVB9kOqEun78h6Exg==",
             "dev": true,
             "requires": {
                 "neo-async": "^2.6.0",
@@ -3363,9 +3363,9 @@
                     "dev": true
                 },
                 "uglify-js": {
-                    "version": "3.6.8",
+                    "version": "3.6.9",
-                    "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.6.8.tgz",
+                    "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.6.9.tgz",
-                    "integrity": "sha512-XhHJ3S3ZyMwP8kY1Gkugqx3CJh2C3O0y8NPiSxtm1tyD/pktLAkFZsFGpuNfTZddKDQ/bbDBLAd2YyA1pbi8HQ==",
+                    "integrity": "sha512-pcnnhaoG6RtrvHJ1dFncAe8Od6Nuy30oaJ82ts6//sGSXOP5UjBMEthiProjXmMNHOfd93sqlkztifFMcb+4yw==",
                     "dev": true,
                     "optional": true,
                     "requires": {
@@ -5500,6 +5500,11 @@
                 "safe-buffer": "^5.0.1"
             }
         },
+        "simplex-noise": {
+            "version": "2.4.0",
+            "resolved": "https://registry.npmjs.org/simplex-noise/-/simplex-noise-2.4.0.tgz",
+            "integrity": "sha512-OjyDWm/QZjVbMrPxDVi9b2as+SeNn9EBXlrWVRlFW+TSyWMSXouDryXkQN0vf5YP+QZKobrmkvx1eQYPLtuqfw=="
+        },
         "since-app-start": {
             "version": "0.3.3",
             "resolved": "https://registry.npmjs.org/since-app-start/-/since-app-start-0.3.3.tgz",

package.json

@@ -12,6 +12,7 @@
     "version": "1.0.0",
     "dependencies": {
         "p5": "^0.10.2",
+        "simplex-noise": "^2.4.0",
         "voronoi": "^1.0.0"
     },
     "devDependencies": {
@@ -23,7 +24,7 @@
         "copycat-brunch": "^1.1.1",
         "digest-brunch": "^1.6.0",
         "git-directory-deploy": "^1.5.1",
-        "handlebars": "^4.5.1",
+        "handlebars": "^4.5.2",
         "html-brunch-static": "^1.4.1",
         "uglify-js-brunch": "^2.10.0"
     }