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();
}
#include <GLGraphics/gel_glut.h>
#include <CGLA/Vec2d.h>
#include <CGLA/Mat3x3d.h>
#include <CGLA/Mat3x3f.h>
#include <CGLA/Mat4x4f.h>
using namespace std;
using namespace CGLA;
using namespace HMesh;
// The range of the input data.
Vec2d dmin(99e99), dmax(-99e99);
Manifold m; // The triangle mesh data structure.
HalfEdgeIDIterator flipper = m.halfedges_begin(); // The halfedge we try to flip.
HalfEdgeAttributeVector<int> touched;
/*
* Draw the triangle mesh. This function is called from GLUT (a library
* which enables OpenGL drawing in windows.)
*/
void display()
{
// Set up correct OpenGL projection
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(dmin[0], dmax[0], dmin[1], dmax[1]);
glMatrixMode(GL_MODELVIEW);
