public static void AddFaceToVao(WorldServer world, Vector3i blockPos, int x, int y, int z, Block block, BlockFace face, BlockModel.FaceData data, VertexArrayObject vao, Matrix4 transform)
{
var faceId = (int)face - 1;
var indicesOffset = vao.VertexCount;
//var transform = Matrix4.CreateScale()//Matrix4.Identity;//block.GetTransform(world, blockPos, face);
var texture = data.LoadedTexture; //block.GetTexture(world, blockPos, face);
//var overlayTexture = block.GetOverlayTexture(world, blockPos, face);
var texCoords = data.GetTexCoords(); //block.GetTexCoords(world, blockPos, face) ?? FaceTexCoords;
//var overlayTexCoords = block.GetOverlayTexCoords(world, blockPos, face) ?? FaceTexCoords;
var color = data.TintIndex == -1 ? new Vector4(1) : block.GetTintColor(world, blockPos, data.TintIndex).ToVector4();
var normal = face.GetNormal();
if (texCoords.Length != 4)
{
throw new Exception($"\"{block}\" invalid texture coords array length!");
}
var vPositions = new Vector3[4];
var vTexCoords = new Vector4[4];
var vOverlayTexCoords = new Vector4[4]; //TODO: Remove
var vBrightness = new Vector3[4];
for (var j = 0; j < 4; j++)
{
var vertexPosition = FacePositions[faceId * 4 + j];
var position = (new Vector4(vertexPosition, 1) * transform).Xyz + new Vector3(x, y, z);
//tex coords are -1 if texture is null
var texCoord = texture == null ? new Vector4(-1) : new Vector4(texCoords[j])
{
//texCoord z = texId, w = textureArrayId
Z = texture.TextureId,
W = texture.ArrayId
};
//per vertex light value interpolation (smooth lighting + free ambient occlusion)
var brightness = CalculateBrightness(world, block, blockPos, face, vertexPosition);
//TODO: transform normals
vPositions[j] = position;
vTexCoords[j] = texCoord;
vOverlayTexCoords[j] = new Vector4(-1);
vBrightness[j] = brightness;
}
//Flip faces to fix ambient occlusion anisotrophy
//https://0fps.net/2013/07/03/ambient-occlusion-for-minecraft-like-worlds/
for (var j = 0; j < 4; j++)
{
vao.Add(vPositions[j], vTexCoords[j], new Vector4(normal), color.Xyz, vBrightness[j]);
}
var newIndices = new uint[FaceIndices.Length];
if ((vBrightness[0] + vBrightness[3]).LengthSquared > (vBrightness[1] + vBrightness[2]).LengthSquared)
{
for (var j = 0; j < newIndices.Length; j++)
{
newIndices[j] = (uint)(FlippedFaceIndices[j] + indicesOffset);
}
}
else
{
for (var j = 0; j < newIndices.Length; j++)
{
newIndices[j] = (uint)(FaceIndices[j] + indicesOffset);
}
}
//Calculate face middle for transparency sorting
var faceMiddle = Vector3.Zero;
if (vao is SortedVertexArrayObject)
{
faceMiddle = vPositions.Aggregate(faceMiddle, (current, pos) => current + pos);
faceMiddle = faceMiddle / vPositions.Length + blockPos.ToVector3() - new Vector3(x, y, z);
}
vao.AddFace(newIndices, faceMiddle);
}