/// <summary>
/// warning: cache thrashes
/// </summary>
/// <param name="mesh"></param>
/// <param name="vertexes"></param>
public static void ConvertMeshToVertList(Vector3[,] mesh, ref VertexPositionTexture[] vertexes)
{
int index = 0;
for (int x = 0; x < mesh.GetLength(0) - 1; x++) {
for (int z = 0; z < mesh.GetLength(1) - 1; z++) {
vertexes[index].Position = mesh[x, z];
vertexes[index + 1].Position = mesh[x, z + 1];
vertexes[index + 2].Position = mesh[x + 1, z + 1];
vertexes[index + 3].Position = mesh[x + 1, z];
index += 4;
}
}
}
public static void ConvertMeshToVertList(Vector3[,] mesh, Vector3[,] normals, ref VertexPositionNormalTexture[] verticies)
{
//convert from 2d array to 1d
int index = 0;
for (int x = 0; x < mesh.GetLength(0) - 1; x++){
for (int z = 0; z < mesh.GetLength(1) - 1; z++){
verticies[index].Position = mesh[x, z];
verticies[index].Normal = normals[x, z];
verticies[index + 1].Position = mesh[x, z + 1];
verticies[index + 1].Normal = normals[x, z + 1];
verticies[index + 2].Position = mesh[x + 1, z + 1];
verticies[index + 2].Normal = normals[x + 1, z + 1];
verticies[index + 3].Position = mesh[x + 1, z];
verticies[index + 3].Normal = normals[x + 1, z];
index += 4;
}
}
}
public static VertexPositionNormalTexture[] ConvertMeshToVertList(Vector3[,] mesh, Vector3[,] normals)
{
var vertLi = new VertexPositionNormalTexture[(mesh.GetLength(0) - 1) * (mesh.GetLength(1) - 1) * 4];
//convert from 2d array to 1d
int index = 0;
for (int x = 0; x < mesh.GetLength(0) - 1; x++) {
for (int z = 0; z < mesh.GetLength(1) - 1; z++) {
vertLi[index].Position = mesh[x, z];
vertLi[index].Normal = normals[x, z];
vertLi[index + 1].Position = mesh[x, z + 1];
vertLi[index + 1].Normal = normals[x, z + 1];
vertLi[index + 2].Position = mesh[x + 1, z + 1];
vertLi[index + 2].Normal = normals[x + 1, z + 1];
vertLi[index + 3].Position = mesh[x + 1, z];
vertLi[index + 3].Normal = normals[x + 1, z];
index += 4;
}
}
return vertLi;
}
public static Vector3[,] GenerateMeshNormals(Vector3[,] mesh)
{
var normals = new Vector3[mesh.GetLength(0), mesh.GetLength(1)];
for (int vertX = 0; vertX < mesh.GetLength(0) - 1; vertX++) {
for (int vertZ = 0; vertZ < mesh.GetLength(1) - 1; vertZ++) {
var crossSum = new Vector3();
var s1 = mesh[vertX + 1, vertZ] - mesh[vertX, vertZ];
var s2 = mesh[vertX, vertZ + 1] - mesh[vertX, vertZ];
var s3 = mesh[vertX + 1, vertZ + 1] - mesh[vertX, vertZ];
crossSum += Vector3.Cross(s1, s3);
crossSum += Vector3.Cross(s3, s2);
normals[vertX, vertZ] += crossSum;
if (crossSum != Vector3.Zero) {
normals[vertX, vertZ].Normalize();
}
}
}
for (int vertX = 1; vertX < mesh.GetLength(0); vertX++) {
for (int vertZ = 1; vertZ < mesh.GetLength(1); vertZ++) {
var crossSum = new Vector3();
var s1 = mesh[vertX - 1, vertZ] - mesh[vertX, vertZ];
var s2 = mesh[vertX, vertZ - 1] - mesh[vertX, vertZ];
var s3 = mesh[vertX - 1, vertZ - 1] - mesh[vertX, vertZ];
crossSum += Vector3.Cross(s1, s3);
crossSum += Vector3.Cross(s3, s2);
normals[vertX, vertZ] += crossSum;
normals[vertX, vertZ].Normalize();
}
}
return normals;
}
