use canvas instead of txt

3 years ago · e36fb20761
parent bef70f4482
commit e36fb20761
2 changed files with 68 additions and 4 deletions
--- a/index.html
+++ b/index.html
@ -18,7 +18,7 @@
    </style>
  </head>
  <body>
-    <pre id="game-of-life-canvas"></pre>
+    <canvas id="game-of-life-canvas"></canvas>
    <script src="./bootstrap.js"></script>
  </body>
 </html>
--- a/index.js
+++ b/index.js
@ -1,12 +1,76 @@
-import { Universe } from "wasm-game-of-life";
+import { Universe, Cell } from "wasm-game-of-life";
+// Import wasm memory
+import { memory } from "wasm-game-of-life/wasm_game_of_life_bg";
+
+const CELL_SIZE = 5;
+const GRID_COLOR = "#CCCCCC";
+const DEAD_COLOR = "#FFFFFF";
+const ALIVE_COLOR = "#000000";

-const pre = document.getElementById("game-of-life-canvas");
 const universe = Universe.new();
+const width = universe.width();
+const height = universe.height();
+
+const canvas = document.getElementById("game-of-life-canvas");
+canvas.height = (CELL_SIZE + 1) * height + 1;
+canvas.width = (CELL_SIZE + 1) * width + 1;
+
+const ctx = canvas.getContext('2d');

 const renderLoop = () => {
-  pre.textContent = universe.render();
+  drawGrid();
+  drawCells();
+
  universe.tick();
+
  requestAnimationFrame(renderLoop);
 };

+const drawGrid = () => {
+  ctx.beginPath();
+  ctx.strokeStyle = GRID_COLOR;
+
+  for (let i = 0; i <= width; i++) {
+    ctx.moveTo(i * (CELL_SIZE + 1) + 1, 0);
+    ctx.lineTo(i * (CELL_SIZE + 1) + 1, (CELL_SIZE + 1) * height + 1);
+  }
+
+  for (let j = 0; j <= height; j++) {
+    ctx.moveTo(0,                           j * (CELL_SIZE + 1) + 1);
+    ctx.lineTo((CELL_SIZE + 1) * width + 1, j * (CELL_SIZE + 1) + 1);
+  }
+
+  ctx.stroke();
+}
+
+const getIndex = (row, column) => {
+  return row * width + column;
+}
+
+const drawCells = () => {
+  const cellsPtr = universe.cells();
+  const cells = new Uint8Array(memory.buffer, cellsPtr, width * height);
+
+  ctx.beginPath();
+
+  for (let row = 0; row < height; row++) {
+    for (let col = 0; col < width; col++) {
+      const i = getIndex(row, col);
+
+      ctx.fillStyle = cells[i] === Cell.Dead
+        ? DEAD_COLOR
+        : ALIVE_COLOR;
+
+      ctx.fillRect(
+        col * (CELL_SIZE + 1) + 1,
+        row * (CELL_SIZE + 1) + 1,
+        CELL_SIZE,
+        CELL_SIZE
+      );
+    }
+  }
+
+  ctx.stroke();
+}
+
 requestAnimationFrame(renderLoop);