Files
linguist/samples/X10/StructSpheres.x10
2015-08-24 13:26:43 -04:00

124 lines
3.6 KiB
Plaintext

/*
* 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();
}
}