public static unsafe bool GenerateTangentSpace(MikktspaceContext context, float angularThreshold = 180)
{
try
{
// explicitly store the delegates on the stack so they're not collected by the GC during the execution of this function
GetNumFaces _getNumFaces = context.GetNumFaces;
GetNumVerticesOfFace _getNumVerticesOfFace = context.GetNumVerticesOfFace;
GetMeshData _getPosition = context.GetPosition;
GetMeshData _getNormal = context.GetNormal;
GetMeshData _getTexCoord = context.GetTexCoord;
SetTangentSpace _setTangentSpace = context.SetTangentSpace;
SetTangentSpaceBasic _setTangentSpaceBasic = context.SetTangentSpaceBasic;
var mikkInterface = new SMikkTSpaceInterface();
mikkInterface.m_getNumFaces = Marshal.GetFunctionPointerForDelegate(_getNumFaces);
mikkInterface.m_getNumVerticesOfFace = Marshal.GetFunctionPointerForDelegate(_getNumVerticesOfFace);
mikkInterface.m_getPosition = Marshal.GetFunctionPointerForDelegate(_getPosition);
mikkInterface.m_getNormal = Marshal.GetFunctionPointerForDelegate(_getNormal);
mikkInterface.m_getTexCoord = Marshal.GetFunctionPointerForDelegate(_getTexCoord);
if (context.UsesBasicTangentHandler)
{
mikkInterface.m_setTSpaceBasic = Marshal.GetFunctionPointerForDelegate(_setTangentSpaceBasic);
}
else
{
mikkInterface.m_setTSpace = Marshal.GetFunctionPointerForDelegate(_setTangentSpace);
}
var mikkContext = new SMikkTSpaceContext();
mikkContext.m_pInterface = new IntPtr(&mikkInterface);
var pContext = new IntPtr(&mikkContext);
var result = Native.genMikktTangSpace(pContext, angularThreshold);
GC.KeepAlive(context);
GC.KeepAlive(_getNumFaces);
GC.KeepAlive(_getNumVerticesOfFace);
GC.KeepAlive(_getPosition);
GC.KeepAlive(_getNormal);
GC.KeepAlive(_getTexCoord);
GC.KeepAlive(_setTangentSpace);
GC.KeepAlive(_setTangentSpaceBasic);
return(result);
}
finally
{
}
}
public static bool GenerateTangentSpace(int faceCount, VerticesPerFaceHandler getVerticesPerFace,
VertexPositionHandler getPosition, VertexNormalHandler getNormal, VertexUVHandler getUV,
BasicTangentHandler setTangentBasic, float angularThreshold = 180)
{
var context = new MikktspaceContext(faceCount, getVerticesPerFace, getPosition, getNormal, getUV,
setTangentBasic, null);
return(GenerateTangentSpace(context, angularThreshold));
}
