void keyfun(unsigned char c, int x, int y)
{
/*
* A little game, try to flip an edge when user presses any key.
* Not all edges can be flipped. Boundary edges cannot. Edges also
* cannot be flipped if it will render the mesh invalid.
*/
if(boundary(m, *flipper)) // If this is a boundary edge just drop the idea.
cout << "boundary edge" << endl;
else if(precond_flip_edge(m, *flipper))
{
m.flip_edge(*flipper);
cout << "flipped" << endl;
}
else
cout << "could not flip" << endl;
do
{
++flipper; // Get the next halfedge
// If we have passed the last halfedge, go to the first.
if(flipper==m.halfedges_end())
{
flipper = m.halfedges_begin();
break;
}
}
while(touched[*flipper] == 0); // Only visit halfedges marked '1'
// Function call below informs glut that display should be called to
// show the window again.
glutPostRedisplay();
}
