private bool IsDetailedEnough(ChunkedLodTreeFactory.ChunkedLodTreeNode node)
{
var nodeCenter = new Vector3d(node.Bounds.Center.X, node.Bounds.Center.Y, 0);
var distanceToCamera = (nodeCenter - _cameraPosition).Length;
var screenSpaceError = (node.GeometricError / distanceToCamera) * _k;
return(screenSpaceError <= _allowedScreenSpaceError);
}
public Terrain()
{
_tree = CreateTree();
_chunkedLod = new ChunkedLod();
_simpleMaterial = new SimpleMaterial();
_simpleMaterial.Create();
_normalDebugProgram = new NormalDebugProgram();
_normalDebugProgram.Create();
_cache = new TerrainChunkCache(new TerrainChunkFactory(), new ResourceAllocator(new OpenGlResourceFactory()));
}
public Terrain(IChunkedLod chunkedLod)
{
_tree = CreateTree();
_chunkedLod = chunkedLod;
_simpleMaterial = new SimpleMaterial();
_simpleMaterial.Create();
_normalDebugProgram = new NormalDebugProgram();
_normalDebugProgram.Create();
_cache = new TerrainChunkCache(new TerrainChunkFactory(), new ResourceAllocator(new OpenGlResourceFactory()));
}
public void Does_not_request_child_unless_all_children_are_cached()
{
var parent = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), null, 0);
var firstChild = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), parent, 0);
var secondChild = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), parent, 0);
CacheNode(parent);
CacheNode(firstChild);
var cache = GetCache();
var result = LODCache.getNodesToDrawAndCache(cache, new[] { firstChild, secondChild });
CollectionAssert.AreEqual(new[] { parent }, result.Item1);
CollectionAssert.AreEqual(new[] { secondChild }, result.Item2);
}
public void All_nodes_are_requested_when_all_are_cached()
{
var node0 = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), null, 0);
var node1 = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), node0, 0);
var node2 = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), node1, 0);
var node3 = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), null, 0);
CacheNodes(node0, node1, node2, node3);
var cache = GetCache();
var result = LODCache.getNodesToDrawAndCache(cache, new[] { node0, node1, node2, node3 });
CollectionAssert.AreEqual(new[] { node0, node1, node2, node3 }, result.Item1);
Assert.IsEmpty(result.Item2);
}
public void Do_not_request_descendants_when_the_ancestor_is_also_requested()
{
var level0 = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), null, 0);
var level10 = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), level0, 0);
var level11 = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), level0, 0);
var level20 = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), level10, 0);
CacheNode(level0);
var cache = GetCache();
var result = LODCache.getNodesToDrawAndCache(cache, new[] { level11, level20 });
CollectionAssert.AreEqual(new[] { level0 }, result.Item1);
CollectionAssert.AreEqual(new[] { level11, level20 }, result.Item2);
}
private bool IsVisible(ChunkedLodTreeFactory.ChunkedLodTreeNode node)
{
var center = new Vector3d(node.Bounds.Center.X, node.Bounds.Center.Y, 0);
var delta = node.Bounds.Max - node.Bounds.Min;
var side = Math.Max(delta.X, delta.Y);
var radius = Math.Sqrt(side * side + side * side);
for (var i = 0; i < _frustumPlanes.Length; i++)
{
var sphereIsOutsideOfPlane = PlaneDistance(_frustumPlanes[i], center) < -radius;
if (sphereIsOutsideOfPlane)
{
return(false);
}
}
return(true);
}
private void CalculateVisibleNodes(ChunkedLodTreeFactory.ChunkedLodTreeNode node)
{
if (!IsVisible(node))
{
return;
}
if (IsDetailedEnough(node) || node.IsLeaf())
{
_visibleNodes.Add(node);
return;
}
foreach (var child in node.Nodes)
{
CalculateVisibleNodes(child);
}
}
public List <ChunkedLodTreeFactory.ChunkedLodTreeNode> Calculate(
ChunkedLodTreeFactory.ChunkedLodTreeNode root,
double viewportWidth,
double horizontalFieldOfView,
Vector3d cameraPosition,
double allowedScreenSpaceError,
Vector4d[] frustumPlanes)
{
_frustumPlanes = frustumPlanes;
_allowedScreenSpaceError = allowedScreenSpaceError;
_cameraPosition = cameraPosition;
_visibleNodes = new List <ChunkedLodTreeFactory.ChunkedLodTreeNode>();
_k = viewportWidth / (Math.Tan(horizontalFieldOfView / 2));
CalculateVisibleNodes(root);
return(_visibleNodes);
}
public void No_nodes_are_requested_if_the_root_is_not_cached()
{
var root = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), null, 0);
var cache = GetCache();
var result = LODCache.getNodesToDrawAndCache(cache, new ChunkedLodTreeFactory.ChunkedLodTreeNode[] { root });
Assert.IsEmpty(result.Item1);
CollectionAssert.AreEqual(new[] { root }, result.Item2);
}
public void Requests_nodes_parent_if_originally_requested_node_is_not_cached_but_when_parent_is()
{
var parent = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), null, 0);
var child = new ChunkedLodTreeFactory.ChunkedLodTreeNode(new Bounds2D(), parent, 0);
CacheNode(parent);
var cache = GetCache();
var result = LODCache.getNodesToDrawAndCache(cache, new[] { child });
CollectionAssert.AreEqual(new[] { parent }, result.Item1);
CollectionAssert.AreEqual(new[] { child }, result.Item2);
}
