Sprig App - Mandelbrot Viewer

Author: zanderlewis

Diff for: games/Mandelbrot-Viewer.js

@@ -0,0 +1,83 @@
+const maxIter = 64; // Iteration limit for Mandelbrot
+let centerX = -0.5;
+let centerY = 0.0;
+let zoom = 2.0;
+const gridWidth = 256;
+const gridHeight = 256;
+
+const shades = ["0", "1"];
+
+setLegend(
+  ["0", bitmap`
+2222222222222222
+2222222222222222
+2222222222222222
+2222222222222222
+2222222222222222
+2222222222222222
+2222222222222222
+2222222222222222
+2222222222222222
+2222222222222222
+2222222222222222
+2222222222222222
+2222222222222222
+2222222222222222
+2222222222222222
+2222222222222222`],
+  ["1", bitmap`
+0000000000000000
+0000000000000000
+0000000000000000
+0000000000000000
+0000000000000000
+0000000000000000
+0000000000000000
+0000000000000000
+0000000000000000
+0000000000000000
+0000000000000000
+0000000000000000
+0000000000000000
+0000000000000000
+0000000000000000
+0000000000000000`]
+);
+
+function mandelbrot(x, y) {
+  let real = x;
+  let imag = y;
+  let iter = 0;
+  while (real * real + imag * imag <= 4 && iter < maxIter) {
+    let temp = real * real - imag * imag + x;
+    imag = 2 * real * imag + y;
+    real = temp;
+    iter++;
+  }
+  return iter;
+}
+
+function drawMandelbrot() {
+  let level = "";
+  for (let j = 0; j < gridHeight; j++) {
+    for (let i = 0; i < gridWidth; i++) {
+      let x = centerX + (i - gridWidth / 2) * (zoom / gridWidth);
+      let y = centerY + (j - gridHeight / 2) * (zoom / gridHeight);
+      let iter = mandelbrot(x, y);
+      let char = Math.floor(iter / (maxIter / shades.length));
+      level += shades[Math.min(char, shades.length - 1)];
+    }
+    level += "\n";
+  }
+  setMap(map`${level}`);
+}
+
+drawMandelbrot();
+
+onInput("w", () => { centerY -= zoom * 0.1; drawMandelbrot(); });
+onInput("s", () => { centerY += zoom * 0.1; drawMandelbrot(); });
+onInput("a", () => { centerX -= zoom * 0.1; drawMandelbrot(); });
+onInput("d", () => { centerX += zoom * 0.1; drawMandelbrot(); });
+onInput("i", () => { zoom *= 0.8; drawMandelbrot(); });
+onInput("k", () => { zoom *= 1.25; drawMandelbrot(); });
+