Create donut.js

Javascript Algorithms/donut.js

@@ -0,0 +1,52 @@
+//https://www.a1k0n.net/2011/07/20/donut-math.html
+
+const sin = Math.sin;
+const cos = Math.cos;
+
+let A = 0, B = 0;
+const renderDonut = () => {
+    const b = [];
+    const z = [];
+    for (let k = 0; k < 1760; k++) {
+        b[k] = ' ';
+        z[k] = 0;
+    }
+
+    for (let j = 0; j < 6.28; j += 0.07) {
+        for (let i = 0; i < 6.28; i += 0.02) {
+            const c = sin(i),
+                  d = cos(j),
+                  e = sin(A),
+                  f = sin(j),
+                  g = cos(A),
+                  h = d + 2,
+                  D = 1 / (c * h * e + f * g + 5),
+                  l = cos(i),
+                  m = cos(B),
+                  n = sin(B),
+                  t = c * h * g - f * e;
+
+            const x = Math.floor(40 + 30 * D * (l * h * m - t * n));
+            const y = Math.floor(12 + 15 * D * (l * h * n + t * m));
+            const o = x + 80 * y;
+            const N = Math.floor(8 * ((f * e - c * d * g) * m - c * d * e - f * g - l * d * n));
+
+            if (y > 0 && y < 22 && x > 0 && x < 80 && D > z[o]) {
+                z[o] = D;
+                b[o] = ".,-~:;=!*#$@"[N > 0 ? N : 0];
+            }
+        }
+    }
+
+    console.clear();
+    let output = '';
+    for (let k = 0; k < 1760; k++) {
+        output += k % 80 ? b[k] : '\n';
+    }
+    console.log(output);
+
+    A += 0.04;
+    B += 0.02;
+};
+
+setInterval(renderDonut, 120);