public QuadTreeNode(GraphicsDevice graphicsDevice, HeightProvider heightProvider, NodeType nodeType, QuadTreeNode parentNode, float edgeLengthFlat, Vector3Double originPositionFlat, Vector3 upDirectionFlat, Vector3 rightDirectionFlat, float radiusSphere)
{
_graphicsDevice = graphicsDevice;
_heightProvider = heightProvider;
_nodeType = nodeType;
_parentNode = parentNode;
_edgeLengthFlat = edgeLengthFlat;
_halfEdgeLengthFlat = _edgeLengthFlat / 2;
_quarterEdgeLengthFlat = _edgeLengthFlat / 4;
_originPositionFlat = originPositionFlat;
_upDirectionFlat = upDirectionFlat;
_rightDirectionFlat = rightDirectionFlat;
_radiusSphere = radiusSphere;
Vector3 originPositionSphereNormal = Vector3Double.Normalize(_originPositionFlat);
Vector3Double originPositionSpherePosition = new Vector3Double(_radiusSphere * originPositionSphereNormal);
OriginPositionSphere = originPositionSpherePosition + _heightProvider.GetHeight(originPositionSpherePosition) * originPositionSphereNormal;
IndexBuffer = _indexBuffers[IndexBufferSelection.Base];
}
private void CalculateContents()
{
float vertexSpacingFlat = _edgeLengthFlat / (VerticesPerEdge - 1);
Vector3 min = new Vector3(float.MaxValue, float.MaxValue, float.MaxValue);
Vector3 max = new Vector3(float.MinValue, float.MinValue, float.MinValue);
// We're adding a border of 1 extra vertex for smooth normal calculations
List <TerrainVertexInterstitial> interstitialVertices = new List <TerrainVertexInterstitial>();
for (int y = -1; y < VerticesPerEdge + 1; y++)
{
for (int x = -1; x < VerticesPerEdge + 1; x++)
{
Vector3Double positionWorldFlat = _originPositionFlat + (x * vertexSpacingFlat - _halfEdgeLengthFlat) * _rightDirectionFlat + (y * vertexSpacingFlat - _halfEdgeLengthFlat) * _upDirectionFlat;
Vector3 positionWorldSphereNormal = Vector3Double.Normalize(positionWorldFlat);
Vector3Double positionWorldSpherePosition = new Vector3Double(_radiusSphere * positionWorldSphereNormal);
float positionWorldSphereHeight = _heightProvider.GetHeight(positionWorldSpherePosition);
Vector3Double positionWorldSphere = positionWorldSpherePosition + positionWorldSphereHeight * positionWorldSphereNormal;
Vector3 position = (positionWorldSphere - OriginPositionSphere).ToVector3();
bool includeInMesh = y > -1 && y <VerticesPerEdge && x> -1 && x < VerticesPerEdge;
TerrainVertexInterstitial vertex = new TerrainVertexInterstitial(position, includeInMesh);
if (includeInMesh)
{
float baseColourValue = Globals.CosineInterpolate(0.7f, 0.9f, (positionWorldSphereHeight - 50) / (500 - 50));
vertex.BaseColour = new Color(baseColourValue, baseColourValue, baseColourValue);
min = Vector3.Min(min, vertex.Position);
max = Vector3.Max(max, vertex.Position);
}
interstitialVertices.Add(vertex);
}
}
BoundingBox = new BoundingBox(min, max);
// Accumulate normals
for (int i = 0; i < _normalCalculationIndices.Length; i += 3)
{
TerrainVertexInterstitial vertex1 = interstitialVertices.ElementAt(_normalCalculationIndices[i]);
TerrainVertexInterstitial vertex2 = interstitialVertices.ElementAt(_normalCalculationIndices[i + 1]);
TerrainVertexInterstitial vertex3 = interstitialVertices.ElementAt(_normalCalculationIndices[i + 2]);
Vector3 side1 = vertex1.Position - vertex3.Position;
Vector3 side2 = vertex1.Position - vertex2.Position;
Vector3 normal = Vector3.Cross(side1, side2);
vertex1.Normal += normal;
vertex2.Normal += normal;
vertex3.Normal += normal;
}
List <TerrainVertexInterstitial> interstitialVerticesForBuffer = interstitialVertices.Where(v => v.IncludeInBuffer).ToList();
// Normalise normals
foreach (TerrainVertexInterstitial vertex in interstitialVerticesForBuffer)
{
vertex.Normal = Vector3.Normalize(vertex.Normal);
}
TerrainVertex[] resultVerticesData = interstitialVerticesForBuffer.Select(v => v.ToTerrainVertex()).ToArray();
VertexBuffer = new VertexBuffer(_graphicsDevice, TerrainVertex.VertexDeclaration, resultVerticesData.Length, BufferUsage.WriteOnly);
VertexBuffer.SetData(resultVerticesData);
}