/// <summary>
/// Expands the declaration of a mesh to include tangent and binormal information
/// </summary>
/// <param name="device">The <see cref="Device"/> containing the mesh</param>
/// <param name="mesh">The mesh to be manipulated</param>
/// <param name="hadNormals">Did the original declaration already contain normals?</param>
/// <param name="hadTangents">Did the original declaration already contain tangents?</param>
/// <returns><c>true</c> if the mesh declaration was expanded, <c>false</c> if the declaration didn't need to be changed</returns>
private static bool ExpandDeclaration(Device device, ref Mesh mesh, out bool hadNormals, out bool hadTangents)
{
#region Sanity checks
if (device == null)
{
throw new ArgumentNullException(nameof(device));
}
if (mesh == null)
{
throw new ArgumentNullException(nameof(mesh));
}
#endregion
// Check if vertex declaration of mesh already is already ok
var decl = mesh.GetDeclaration();
if (CompareDecl(PositionNormalBinormalTangentTextured.GetVertexElements(), decl) ||
CompareDecl(PositionNormalMultiTextured.GetVertexElements(), decl))
{
hadNormals = true;
hadTangents = true;
return(false);
}
#region Find existing info
hadNormals = false;
hadTangents = false;
for (int i = 0; i < 6 && i < decl.Length; i++)
{
if (decl[i].Usage == DeclarationUsage.Normal)
{
hadNormals = true;
break;
}
if (decl[i].Usage == DeclarationUsage.Tangent)
{
hadTangents = true;
break;
}
}
#endregion
// Select the appropriate new vertex format
decl = CompareDecl(PositionMultiTextured.GetVertexElements(), decl) ?
PositionNormalMultiTextured.GetVertexElements() : PositionNormalBinormalTangentTextured.GetVertexElements();
// Clone the mesh to change the vertex format
Mesh tempMesh = mesh.Clone(device, mesh.CreationOptions, decl);
mesh.Dispose();
mesh = tempMesh;
return(true);
}
private static PositionMultiTextured[] GenerateVertexes(Size size, float stretchH, float stretchV, ByteGrid heightMap, NibbleGrid textureMap, ByteVector4Grid occlusionIntervalMap)
{
var vertexes = new PositionMultiTextured[size.Width * size.Height];
#if NETFX4
Parallel.For(0, size.Width, x =>
#else
for (int x = 0; x < size.Width; x++)
#endif
{
for (int y = 0; y < size.Height; y++)
{
#region Texture blending
var texWeights = new float[16];
// Perform integer division (texture map has 1/3 of height map accuracy) but keep remainders
int xRemainder;
int xCoord = Math.DivRem(x, 3, out xRemainder);
int yRemainder;
int yCoord = Math.DivRem(y, 3, out yRemainder);
// Use remainders to determine intermediate blending levels for vertexes
switch (xRemainder)
{
case 0:
TextureBlendHelper(textureMap, xCoord, yCoord, texWeights, 0.25f);
TextureBlendHelper(textureMap, xCoord - 1, yCoord, texWeights, 0.25f);
break;
case 1:
TextureBlendHelper(textureMap, xCoord, yCoord, texWeights, 0.5f);
break;
case 2:
TextureBlendHelper(textureMap, xCoord, yCoord, texWeights, 0.25f);
TextureBlendHelper(textureMap, xCoord + 1, yCoord, texWeights, 0.25f);
break;
}
switch (yRemainder)
{
case 0:
TextureBlendHelper(textureMap, xCoord, yCoord, texWeights, 0.25f);
TextureBlendHelper(textureMap, xCoord, yCoord - 1, texWeights, 0.25f);
break;
case 1:
TextureBlendHelper(textureMap, xCoord, yCoord, texWeights, 0.5f);
break;
case 2:
TextureBlendHelper(textureMap, xCoord, yCoord, texWeights, 0.25f);
TextureBlendHelper(textureMap, xCoord, yCoord + 1, texWeights, 0.25f);
break;
}
#endregion
var occlusionIntervals = occlusionIntervalMap?[x, y] ?? new ByteVector4(0, 255, 255, 255);
// Generate vertex using 2D coords, stretch factors (and tex-coords based on them)
// Map X = Engine +X
// Map Y = Engine -Z
// Map height = Engine +Y
vertexes[x + size.Width * y] = new PositionMultiTextured(
new Vector3(x * stretchH, heightMap[x, y] * stretchV, -y * stretchH),
x * stretchH / 500f, y * stretchH / 500f,
occlusionIntervals.ByteToAngle(),
texWeights, Color.White);
}
}
