This example shows how to build a custom memory data source.
The geometry is a simple structure containing two triangles only.
int stateId = 1;
int geometryIndex = 0;
int c[] = {0, 1, 2, 2, 3, 4};
std::vector<unsigned int> eltNodes1(c, c+3);
std::vector<unsigned int> eltNodes2(c+3, c+6);
int partId = 1;