Add the X10 language (http://x10-lang.org/).

samples/X10/StructSpheres.x10

@@ -0,0 +1,123 @@
+/*
+ *  This file is part of the X10 project (http://x10-lang.org).
+ *
+ *  This file is licensed to You under the Eclipse Public License (EPL);
+ *  You may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *      http://www.opensource.org/licenses/eclipse-1.0.php
+ *
+ *  (C) Copyright IBM Corporation 2006-2014.
+ */
+
+import x10.io.Console;
+import x10.util.Random;
+
+/**
+ * This class represents a real-world problem in graphics engines --
+ * determining which objects in a large sprawling world are close enough to the
+ * camera to be considered for rendering.  
+ *
+ * It illustrates the usage of X10 structs to define new primitive types.
+ * In Native X10, structs are allocated within their containing object/stack frame
+ * and thus using structs instead of classes for Vector3 and WorldObject greatly
+ * improves the memory efficiency of the computation.
+ *
+ * @Author Dave Cunningham
+ * @Author Vijay Saraswat
+ */
+class StructSpheres {
+    static type Real = Float;
+
+    static struct Vector3(x:Real, y:Real, z:Real) {
+        public def getX () = x; 
+        public def getY () = y;
+        public def getZ () = z;
+
+        public def add (other:Vector3)
+            = Vector3(this.x+other.x, this.y+other.y, this.z+other.z);
+
+        public def neg () = Vector3(-this.x, -this.y, -this.z);
+
+        public def sub (other:Vector3) = add(other.neg());
+
+        public def length () = Math.sqrtf(length2());
+
+        public def length2 () = x*x + y*y + z*z;
+    }
+
+
+    static struct WorldObject {
+
+        def this (x:Real, y:Real, z:Real, r:Real) {
+            pos = Vector3(x,y,z);
+            renderingDistance = r;
+        }
+
+        public def intersects (home:Vector3)
+            = home.sub(pos).length2() < renderingDistance*renderingDistance;
+
+        protected val pos:Vector3;
+        protected val renderingDistance:Real;
+    }
+
+
+    public static def compute():boolean {
+
+        val reps = 7500;
+
+        // The following correspond to a modern out-door computer game:
+        val num_objects = 50000;
+        val world_size = 6000;
+        val obj_max_size = 400;
+
+        val ran = new Random(0);
+
+        // the array can go on the heap
+        // but the elements ought to be /*inlined*/ in the array
+        val spheres =
+            new Rail[WorldObject](num_objects, (i:long) => {
+                val x = (ran.nextDouble()*world_size) as Real;
+                val y = (ran.nextDouble()*world_size) as Real;
+                val z = (ran.nextDouble()*world_size) as Real;
+                val r = (ran.nextDouble()*obj_max_size) as Real;
+                return WorldObject(x,y,z,r);
+            });
+
+        val time_start = System.nanoTime();
+
+        var counter : Long = 0;
+
+        // HOT LOOP BEGINS
+        for (c in 1..reps) {
+
+            val x = (ran.nextDouble()*world_size) as Real;
+            val y = (ran.nextDouble()*world_size) as Real;
+            val z = (ran.nextDouble()*world_size) as Real;
+
+            val pos = Vector3(x,y,z);
+
+            for (i in spheres.range()) {
+                if (spheres(i).intersects(pos)) {
+                    counter++;
+                }
+            }
+        }
+        // HOT LOOP ENDS
+
+        val time_taken = System.nanoTime() - time_start;
+        Console.OUT.println("Total time: "+time_taken/1E9);
+
+        val expected = 109702;
+        val ok = counter == expected;
+        if (!ok) {
+            Console.ERR.println("number of intersections: "+counter
+                                +" (expected "+expected+")");
+        }
+        return ok;
+    }
+
+    public static def main (Rail[String]) {
+        compute();
+    }
+
+}