/// <summary>
/// Build the terrain.
/// </summary>
public void BuildTerrain()
{
if (Heightmap == null) return;
int width = Heightmap.Width;
int depth = Heightmap.Depth;
// Clear the terrain patches.
Patches.Clear();
// Compute the world matrix to place the terrain in the middle of the scene.
// _world = Matrix.Identity;//Matrix.CreateTranslation(width*-0.5f, 0.0f, depth*-0.5f);
// Create the terrain patches.
const int patchWidth = 16;
const int patchDepth = 16;
int patchCountX = width/patchWidth;
int patchCountZ = depth/patchDepth;
PatchRows = patchCountX;
PatchColumns = patchCountZ;
for (int x = 0; x < patchCountX; ++x)
{
for (int z = 0; z < patchCountZ; ++z)
{
// It is necessary to use patch width and depths of +1 otherwise there will be
// gaps between the patches.. [0,15] and [16,31] have a gap of one unit!
var patch = new TerrainPatch(Game, Heightmap, World, patchWidth + 1, patchDepth + 1,
x*patchWidth, z*patchDepth);
// x*(patchWidth - 1), z*(patchDepth - 1));
Patches.Add(patch);
}
}
// Find the minimum bounding box that covers all patches
BoundingBox box = Patches[0].BoundingBox;
foreach (TerrainPatch patch in Patches)
box = BoundingBox.CreateMerged(box, patch.BoundingBox);
BoundingBox = box;
PatchCount = Patches.Count;
_vertexDeclaration = new VertexDeclaration(GraphicsDevice, VertexPositionNormalTexture.VertexElements);
}
private static void PopulatePatch(ICollection<Vector3> trees, TerrainPatch patch)
{
int treeDistanceZ = patch.Depth/1;
int treeDistanceX = patch.Width/1;
for (int z = 0; z < patch.Depth; z += treeDistanceZ)
{
for (int x = 0; x < patch.Width; x += treeDistanceX)
{
int index = z*patch.Width + x;
trees.Add(patch.Geometry[index].Position);
}
}
}