--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/trunk/tests/ChipmunkDemos/samples/OneWay.d	Sat Dec 04 02:02:29 2010 +0100
@@ -0,0 +1,112 @@
+
+// written in the D programming language
+
+module samples.OneWay;
+
+import chipmunkd.chipmunk;
+
+import samples.ChipmunkDemo;
+
+static cpSpace *space;
+
+struct OneWayPlatform {
+	cpVect n; // direction objects may pass through
+	cpArray *passThruList; // list of objects passing through
+}
+
+static OneWayPlatform platformInstance;
+
+static cpBool
+preSolve(cpArbiter *arb, cpSpace *space, void *ignore)
+{
+	mixin(CP_ARBITER_GET_SHAPES!("arb", "a", "b"));
+	OneWayPlatform *platform = cast(OneWayPlatform *)a.data;
+		
+	if(cpvdot(cpArbiterGetNormal(arb, 0), platform.n) < 0){
+		cpArbiterIgnore(arb);
+		return cpFalse;
+	}
+	
+	return cpTrue;
+}
+
+static void
+update(int ticks)
+{
+	int steps = 1;
+	cpFloat dt = 1.0f/60.0f/cast(cpFloat)steps;
+	
+	for(int i=0; i<steps; i++){
+		cpSpaceStep(space, dt);
+	}
+}
+
+static cpSpace *
+init()
+{
+	cpResetShapeIdCounter();
+	
+	space = cpSpaceNew();
+	space.iterations = 10;
+	space.gravity = cpv(0, -100);
+
+	cpBody *_body;
+	cpBody *staticBody = &space.staticBody;
+	cpShape *shape;
+
+	// Create segments around the edge of the screen.
+	shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-320,-240), cpv(-320,240), 0.0f));
+	shape.e = 1.0f; shape.u = 1.0f;
+	shape.layers = NOT_GRABABLE_MASK;
+
+	shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(320,-240), cpv(320,240), 0.0f));
+	shape.e = 1.0f; shape.u = 1.0f;
+	shape.layers = NOT_GRABABLE_MASK;
+
+	shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-320,-240), cpv(320,-240), 0.0f));
+	shape.e = 1.0f; shape.u = 1.0f;
+	shape.layers = NOT_GRABABLE_MASK;
+	
+	// Add our one way segment
+	shape = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-160,-100), cpv(160,-100), 10.0f));
+	shape.e = 1.0f; shape.u = 1.0f;
+	shape.collision_type = 1;
+	shape.layers = NOT_GRABABLE_MASK;
+	
+	// We'll use the data pointer for the OneWayPlatform struct
+	platformInstance.n = cpv(0, 1); // let objects pass upwards
+	platformInstance.passThruList = cpArrayNew(0);
+	shape.data = &platformInstance;
+	
+	
+	// Add a ball to make things more interesting
+	cpFloat radius = 15.0f;
+	_body = cpSpaceAddBody(space, cpBodyNew(10.0f, cpMomentForCircle(10.0f, 0.0f, radius, cpvzero)));
+	_body.p = cpv(0, -200);
+	_body.v = cpv(0, 170);
+
+	shape = cpSpaceAddShape(space, cpCircleShapeNew(_body, radius, cpvzero));
+	shape.e = 0.0f; shape.u = 0.9f;
+	shape.collision_type = 2;
+	
+	cpSpaceAddCollisionHandler(space, 1, 2, null, &preSolve, null, null, null);
+	
+	return space;
+}
+
+static void
+destroy()
+{
+	cpSpaceFreeChildren(space);
+	cpSpaceFree(space);
+	
+	cpArrayFree(platformInstance.passThruList);
+}
+
+chipmunkDemo OneWay = {
+	"One Way Platforms",
+	null,
+	&init,
+	&update,
+	&destroy,
+};