protected override JobHandle OnUpdate(JobHandle lastJobHandle)
{
// Get component data from the GridPlane
var cartesianGridPlane = GetSingleton <CartesianGridOnPlane>();
var rowCount = cartesianGridPlane.Blob.Value.RowCount;
var colCount = cartesianGridPlane.Blob.Value.ColCount;
var targetDirectionsBufferCapacity = ((colCount + 1) / 2) * rowCount;
var gridWalls = (byte *)cartesianGridPlane.Blob.Value.Walls.GetUnsafePtr();
// Initialize the buffer for the target paths with size appropriate to grid.
Entities
.WithName("InitializeTargets")
.WithAll <CartesianGridTarget>()
.WithNone <CartesianGridTargetDirection>()
.WithStructuralChanges()
.ForEach((Entity entity) =>
{
var buffer = EntityManager.AddBuffer <CartesianGridTargetDirection>(entity);
buffer.ResizeUninitialized(targetDirectionsBufferCapacity);
}).Run();
// Rebuild all the paths to the target *only* when the target's grid position changes.
Entities
.WithName("UpdateTargetPaths")
.WithAll <CartesianGridTarget>()
.ForEach((Entity entity, ref CartesianGridTargetCoordinates prevTargetPosition, in CartesianGridCoordinates targetPosition, in DynamicBuffer <CartesianGridTargetDirection> targetDirections) =>
{
if (prevTargetPosition.Equals(targetPosition))
{
return;
}
prevTargetPosition = new CartesianGridTargetCoordinates(targetPosition);
CartesianGridOnPlaneShortestPath.CalculateShortestPathsToTarget(targetDirections.Reinterpret <byte>().AsNativeArray(), rowCount, colCount, targetPosition, gridWalls);
}).Run();
public int WalkPathDistance(CartesianGridCoordinates sourcePosition, CartesianGridCoordinates targetPosition)
{
var directionsRowStride = (ColCount + 1) / 2;
var directionsSize = RowCount * directionsRowStride;
var targetDirections = new NativeArray <byte>(directionsSize, Allocator.Temp);
var sourceDirections = new NativeArray <byte>(directionsSize, Allocator.Temp);
// For testing purposes, recalculate paths every time.
CartesianGridOnPlaneShortestPath.CalculateShortestPathsToTarget(targetDirections, RowCount, ColCount, targetPosition, Walls);
CartesianGridOnPlaneShortestPath.CalculateShortestPathsToTarget(sourceDirections, RowCount, ColCount, sourcePosition, Walls);
// Test distance form source->target is same as target->source
var sourceToTargetDistance = WalkPath(sourcePosition, targetDirections, 0);
var targetToSourceDistance = WalkPath(targetPosition, sourceDirections, 0);
Assert.AreEqual(sourceToTargetDistance, targetToSourceDistance);
var expectedDistance = sourceToTargetDistance;
// Sample path variations (not exhaustive, always follow the variation path option)
for (int i = 1; i < 4; i++)
{
// Test distance form source->target is same as target->source
// Test distance is same for all variations
sourceToTargetDistance = WalkPath(sourcePosition, targetDirections, i);
Assert.AreEqual(expectedDistance, sourceToTargetDistance);
targetToSourceDistance = WalkPath(targetPosition, sourceDirections, i);
Assert.AreEqual(expectedDistance, targetToSourceDistance);
}
targetDirections.Dispose();
sourceDirections.Dispose();
return(expectedDistance);
}