/// <summary>
/// Generate the voxels for the given terrain chunk.
/// </summary>
/// <param name="voxels">The voxels to populate.</param>
/// <param name="surfaceHeights">The height of the surface at each x position.</param>
/// <param name="chunkIndex">The chunk index.</param>
public void Generate(ChunkVoxels voxels, float[] surfaceHeights, Position chunkIndex)
{
int originY = chunkIndex.Y * Chunk.Height;
for (int x = 0; x < Chunk.Width; x++)
{
float surfaceHeightF = surfaceHeights[x];
int surfaceHeightI = (int)Math.Floor(surfaceHeightF);
float deltaHeight = surfaceHeightF - surfaceHeightI;
for (int y = 0; y < Chunk.Height; y++)
{
int height = originY + y;
// Create the voxel at this point
Voxel voxel;
if (height > surfaceHeightI)
{
// This voxel lies above the surface
voxel = Voxel.Air;
}
else
{
// Determine the material
var material = TerrainMaterial.Dirt;
if (height == surfaceHeightI)
{
// This voxel lies on the surface, so scale the density by the noise value
byte density = (byte)(Voxel.DensityMax - (Voxel.DensityMax * deltaHeight));
// The density property stores 2 densities. The 'foreground' density which is that which
// can be dug, and the 'background' density which represents the original density
// Set the foreground and background densities both
density = (byte)((density << 4) | density);
voxel = new Voxel(material, density);
}
else
{
// The voxel lies under the surface
voxel = new Voxel(material, Voxel.DensityMin);
}
}
// Set the voxel
voxels[x, y] = voxel;
}
}
}
/// <summary>
/// Fill the terrain with the given material below the surface and air above.
/// </summary>
/// <param name="chunk">The chunk</param>
/// <param name="chunkIndex">The chunk index.</param>
/// <param name="surfaceHeights">The y value of each surface point.</param>
/// <param name="material">The material to fill below surface.</param>
private void FillAroundSurface(
ChunkVoxels chunk,
Position chunkIndex,
int[] surfaceHeights,
TerrainMaterial material)
{
for (int chunkX = 0; chunkX < Chunk.Width; chunkX++)
{
int surfaceHeight = surfaceHeights[chunkX];
for (int chunkY = 0; chunkY < Chunk.Height; chunkY++)
{
if (chunkY < surfaceHeight)
{
chunk[chunkX, chunkY] = new Voxel(material, Voxel.DensityMin);
}
else if (chunkY > surfaceHeight)
{
chunk[chunkX, chunkY] = new Voxel(TerrainMaterial.Air, Voxel.DensityMax);
}
}
}
}
