print out fps

src/main.ts

@@ -107,7 +107,7 @@ function initShaders() {
 }
 
 /** Init an FBO used for the first render pass / perlin noise */
-var perlinNoiseFBO : WebGLFramebuffer | null = null;
+var perlinNoiseFBO: WebGLFramebuffer | null = null;
 var perlinNoiseFBOWidth = 400;
 var ferlinNoiseFBOHeight = 400;
 function initFBO() {
@@ -133,8 +133,21 @@ function initFBO() {
 
 /** Update/Draw function. Targeting 60UPS. */
 var timeSpent = 0.0;
+/** Framerate measurement variables */
+var lastTime = new Date().getTime();
+var counter = 0.0;
+var fps = 0;
 function drawScene(buffer: WebGLBuffer, program: WebGLProgram) {
     timeSpent += 1.0 / 60.0;
+    fps++;
+    let now = new Date();
+    let delta = now.getTime() - lastTime;
+    if ((counter += delta) >= 1000.) {
+        counter = 0;
+        console.log("FPS: " + fps);
+        fps = 0;
+    }
+    lastTime = now.getTime();
     // Two Rendering passes. The first one generates a perlin noise 
     // texture. Second one uses the textur for vertex displacement 
     // of a grid representing the water surface.