diff --git a/src/net/minecraft/client/GameWindow.js b/src/net/minecraft/client/GameWindow.js
index 83bc970..582c130 100644
--- a/src/net/minecraft/client/GameWindow.js
+++ b/src/net/minecraft/client/GameWindow.js
@@ -13,11 +13,11 @@ window.GameWindow = class {
         document.getElementById(this.canvasWrapperId).appendChild(canvas);
 
         // Init
-        this.initialize();
+        this.onResize();
 
         // On resize
         let scope = this;
-        window.addEventListener('resize', _ => scope.initialize(), false);
+        window.addEventListener('resize', _ => scope.onResize(), false);
 
         // Request focus
         canvas.onclick = function () {
@@ -29,12 +29,12 @@ window.GameWindow = class {
 
         // Mouse motion
         document.addEventListener('mousemove', event => this.onMouseMove(event), false);
-    }
 
-    initialize() {
         // Create keyboard
         Keyboard.create();
+    }
 
+    onResize() {
         // Get canvas size
         let canvasElement = document.getElementById(this.canvasWrapperId);
         this.canvasWidth = canvasElement.offsetWidth;
diff --git a/src/net/minecraft/client/world/World.js b/src/net/minecraft/client/world/World.js
index 0236cfb..e3d31f9 100644
--- a/src/net/minecraft/client/world/World.js
+++ b/src/net/minecraft/client/world/World.js
@@ -23,12 +23,12 @@ window.World = class {
     getCollisionBoxes(aabb) {
         let boundingBoxList = [];
 
-        let minX = Math.floor(aabb.minX) - 1;
-        let maxX = Math.ceil(aabb.maxX) + 1;
-        let minY = Math.floor(aabb.minY) - 1;
-        let maxY = Math.ceil(aabb.maxY) + 1;
-        let minZ = Math.floor(aabb.minZ) - 1;
-        let maxZ = Math.ceil(aabb.maxZ) + 1;
+        let minX = MathHelper.floor_double(aabb.minX);
+        let maxX = MathHelper.floor_double(aabb.maxX + 1.0);
+        let minY = MathHelper.floor_double(aabb.minY);
+        let maxY = MathHelper.floor_double(aabb.maxY + 1.0);
+        let minZ = MathHelper.floor_double(aabb.minZ);
+        let maxZ = MathHelper.floor_double(aabb.maxZ + 1.0);
 
         for (let x = minX; x < maxX; x++) {
             for (let y = minY; y < maxY; y++) {
diff --git a/src/net/minecraft/util/Keyboard.js b/src/net/minecraft/util/Keyboard.js
index 1651882..2b42028 100644
--- a/src/net/minecraft/util/Keyboard.js
+++ b/src/net/minecraft/util/Keyboard.js
@@ -3,8 +3,14 @@ window.Keyboard = class {
     static state = {};
 
     static create() {
-        window.addEventListener('keyup', (e) => Keyboard.state[e.code] = false);
-        window.addEventListener('keydown', (e) => Keyboard.state[e.code] = true);
+        window.addEventListener('keydown', function (event) {
+            Keyboard.state[event.code] = true;
+            //console.log("Key " + event.code + " down");
+        });
+        window.addEventListener('keyup', function (event) {
+            delete Keyboard.state[event.code];
+            //console.log("Key " + event.code + " up");
+        });
     };
 
     static isKeyDown(key) {
diff --git a/src/net/minecraft/util/MathHelper.js b/src/net/minecraft/util/MathHelper.js
new file mode 100644
index 0000000..796f7c9
--- /dev/null
+++ b/src/net/minecraft/util/MathHelper.js
@@ -0,0 +1,11 @@
+window.MathHelper = class {
+
+    /**
+     * Returns the greatest integer less than or equal to the double argument
+     */
+    static floor_double(value) {
+        let i = parseInt(value);
+        return value < i ? i - 1 : i;
+    }
+
+}
\ No newline at end of file
diff --git a/src/start.js b/src/start.js
index 02c90e7..dad6e6d 100644
--- a/src/start.js
+++ b/src/start.js
@@ -48,6 +48,7 @@ loadScripts([
 
     // Minecraft Source
     "src/net/minecraft/util/Timer.js",
+    "src/net/minecraft/util/MathHelper.js",
     "src/net/minecraft/util/BoundingBox.js",
     "src/net/minecraft/util/Keyboard.js",
     "src/net/minecraft/client/GameWindow.js",