新增ninja adventure例子

source/src/Math/SubpixelFloat.ts

@@ -0,0 +1,32 @@
+module es {
+    /**
+     * 它存储值，直到累计的总数大于1。一旦超过1，该值将在调用update时添加到amount中
+     * 一般用法如下:
+     *
+     *  let deltaMove = this.velocity * es.Time.deltaTime;
+     *  deltaMove.x = this._x.update(deltaMove.x);
+     *  deltaMove.y = this._y.update(deltaMove.y);
+     */
+    export class SubpixelFloat {
+        public remainder: number = 0;
+
+        /**
+         * 以amount递增余数，将值截断，存储新的余数并将amount设置为当前值
+         * @param amount
+         */
+        public update(amount: number){
+            this.remainder += amount;
+            let motion = Math.trunc(this.remainder);
+            this.remainder -= motion;
+            amount = motion;
+            return amount;
+        }
+
+        /**
+         * 将余数重置为0
+         */
+        public reset(){
+            this.remainder = 0;
+        }
+    }
+}