/// <summary>
/// Returns the size of the current quadnode, the size is both the length and
/// width as the quadnode is a square.
/// </summary>
/// <returns>The size of the quadnode.</returns>
public static float GetNodeSize(this Quadnode thisNode, float quadtreeSize)
{
// Divide the node size by the amount of levels the node is deep in.
for (int x = 0; x < thisNode.DepthLevel; x++)
{
quadtreeSize = quadtreeSize / 2.0F;
}
// Return the node size.
return(quadtreeSize);
}
public QuadnodeChildren(Quadnode currentNode)
{
ThisNode = currentNode;
if (currentNode.NodeIndices.NodeChild != 0)
{
TopLeftNode = QuadtreeGenerator.QuadNodes[currentNode.NodeIndices.NodeChild + (int)QuadtreePosition.topLeft];
TopRightNode = QuadtreeGenerator.QuadNodes[currentNode.NodeIndices.NodeChild + (int)QuadtreePosition.topRight];
BottomLeftNode = QuadtreeGenerator.QuadNodes[currentNode.NodeIndices.NodeChild + (int)QuadtreePosition.bottomLeft];
BottomRightNode = QuadtreeGenerator.QuadNodes[currentNode.NodeIndices.NodeChild + (int)QuadtreePosition.bottomRight];
}
}
/// <summary>
/// Calculates the bounding box of a supplied quadnode structure.
/// </summary>
/// <returns>A rectangle structure that represents the bounding box of the quadnode.</returns>
public static Rectangle CalculateNodeBoundingBox(this Quadnode thisNode)
{
// Stores the bounding box of the current node.
Rectangle boundingBox = new Rectangle();
// Obtain the size of a node at this specified node depth.
float thisNodeSize = thisNode.GetNodeSize(HeroesHeader.QuadtreeSize);
// Represents the top edge of the quadtree.
float topQuadtreeEdge = HeroesHeader.QuadtreeCenter.Z - (HeroesHeader.QuadtreeSize / 2.0F);
// Represents the left edge of the quadtree.
float leftQuadtreeEdge = HeroesHeader.QuadtreeCenter.X - (HeroesHeader.QuadtreeSize / 2.0F);
// Obtain Horizontal/Vertical Positioning Offset between each node, each increment of this value points to next node.
// e.g. if this is 512, node to the right will have 512 more than the previous node's offset, vertically or horizontally.
int nextNodeOffset = (int)Math.Pow(2, (CollisionGenerator.Properties.BasePower - thisNode.DepthLevel));
// Calculate the amount of nodes offset from the top left node horizontally and vertically.
int nodesRightOfLeftQuadtreeEdge = thisNode.PositioningHorizontalOffset / nextNodeOffset;
int nodesDownOfTopQuadtreeEdge = thisNode.PositioningVerticalOffset / nextNodeOffset;
// Obtain Node Centers
float nodeCenterX = leftQuadtreeEdge + (nodesRightOfLeftQuadtreeEdge * thisNodeSize) + (thisNodeSize / 2.0F);
float nodeCenterY = topQuadtreeEdge + (nodesDownOfTopQuadtreeEdge * thisNodeSize) + (thisNodeSize / 2.0F);
// Set the minimums and maximums.
boundingBox.MinX = nodeCenterX - (thisNodeSize / 2.0F);
boundingBox.MaxX = nodeCenterX + (thisNodeSize / 2.0F);
boundingBox.MinZ = nodeCenterY - (thisNodeSize / 2.0F);
boundingBox.MaxZ = nodeCenterY + (thisNodeSize / 2.0F);
// Account for the node overlap regions set in the properties
boundingBox.MinX -= CollisionGenerator.Properties.NodeOverlapRegion;
boundingBox.MinZ -= CollisionGenerator.Properties.NodeOverlapRegion;
boundingBox.MaxX += CollisionGenerator.Properties.NodeOverlapRegion;
boundingBox.MaxZ += CollisionGenerator.Properties.NodeOverlapRegion;
// Return all of the node rectangle bounding boxes.
return(boundingBox);
}
/// <summary>
/// Finds the intersecting triangles for a suppllied node and its parent node.
/// </summary>
/// <param name="parentNode">The parent node of the current node, for the transfer of the triangle list.</param>
/// <param name="thisNode">The node we are finding the intersecting triangles for.</param>
public static void FindTriangles(ref Quadnode thisNode, Quadnode parentNode)
{
// Allocate memory for this node's triangle list. Approximate 1/4th of parent.
thisNode.TrianglesInNode = new List <HeroesTriangle>(parentNode.TrianglesInNode.Count / 4);
// Retrieve parent's triangle list.
List <HeroesTriangle> parentTriangle = parentNode.TrianglesInNode;
// Retrieve the bounding box for the current node.
Rectangle nodeBoundingBox = thisNode.CalculateNodeBoundingBox();
// Check for collision against parent's triangle list.
foreach (var triangle in parentTriangle)
{
// Index of the individual triangle within the array of triangle boxes.
int triangleIndex = triangle.TriangleIndex;
// Otherwise Compare Triangle-Node intersect Accurately.
if (CollisionChecker.CheckCollision(GeometryData.Triangles[triangleIndex], nodeBoundingBox))
{
thisNode.TrianglesInNode.Add(GeometryData.Triangles[triangleIndex]);
}
}
}