void GLMesh::fillBuffers(const std::vector<Eigen::Vector3f>& colors)
{
vertices.resize(3*(mesh.faces.size() - mesh.boundaries.size()));
for (FaceCIter f = mesh.faces.begin(); f != mesh.faces.end(); f++) {
if (!f->isBoundary()) {
int i = 0;
int fIdx = 3*f->index;
HalfEdgeCIter h = f->he;
do {
VertexCIter v = h->vertex;
// set vertex
vertices[fIdx+i].position = v->position.cast<float>();
vertices[fIdx+i].normal = v->normal().cast<float>();
vertices[fIdx+i].color = colors[f->index];
vertices[fIdx+i].uv = v->uv.cast<float>();
i++;
h = h->next;
} while (h != f->he);
// set barycenters
vertices[fIdx+0].barycenter = Eigen::Vector3f(1.0, 0.0, 0.0);
vertices[fIdx+1].barycenter = Eigen::Vector3f(0.0, 1.0, 0.0);
vertices[fIdx+2].barycenter = Eigen::Vector3f(0.0, 0.0, 1.0);
}
}
}
Vector3D Vertex::normal( void ) const
// TODO Returns an approximate unit normal at this vertex, computed by
// TODO taking the area-weighted average of the normals of neighboring
// TODO triangles, then normalizing.
{
// TODO Compute and return the area-weighted unit normal.
//no boundary polygon
HalfedgeCIter h = this->halfedge();
Vector3D nrm(0, 0, 0);
double totalarea = 0;
do
{
h = h->twin();
FaceCIter f = h->face();
if(!f->isBoundary())
{
VertexCIter v1 = h->vertex();
VertexCIter v2 = h->next()->twin()->vertex();
Vector3D out = cross(v1->position - position, v2->position - position);
nrm += out;
totalarea += out.norm();
}
h = h->next();
}
while(h != this->halfedge());
nrm /= totalarea;
nrm.normalize();
return nrm;
}
void Viewer :: drawPolygons( void )
{
for (FaceCIter f = mesh->faces.begin();
f != mesh->faces.end();
f ++ )
{
bool onBoundary = f->isBoundary();
if( onBoundary )
continue;
glBegin( GL_POLYGON );
if( renderWireframe )
{
Vector3D N = f->normal();
glNormal3dv( &N[0] );
}
HalfEdgeCIter he = f->he;
do
{
if( not renderWireframe )
{
Vector3D N = he->vertex->normal();
glNormal3dv( &N[0] );
}
glVertex3dv( &he->vertex->position[0] );
he = he->next;
}
while( he != f->he );
glEnd();
}
}
void GLMesh::fillPickBuffers()
{
int tris = (int)(mesh.faces.size() - mesh.boundaries.size());
// add faces
int i = 0;
pickVertices.resize(3*tris);
for (FaceCIter f = mesh.faces.begin(); f != mesh.faces.end(); f++) {
if (!f->isBoundary()) {
int j = 0;
Eigen::Vector3f color = elementColor(f->index);
HalfEdgeCIter h = f->he;
do {
// set vertex
pickVertices[3*i+j].position = h->vertex->position.cast<float>();
pickVertices[3*i+j].color = color;
j++;
h = h->next;
} while (h != f->he);
i++;
}
}
// add vertex faces
int verts = 0;
for (VertexCIter v = mesh.vertices.begin(); v != mesh.vertices.end(); v++) {
verts += v->degree();
if (v->isBoundary()) verts -= 1;
}
pickVertices.resize(3*(tris + verts));
for (VertexCIter v = mesh.vertices.begin(); v != mesh.vertices.end(); v++) {
Eigen::Vector3d n = 0.0015*v->normal();
Eigen::Vector3f p1 = (v->position + n).cast<float>();
Eigen::Vector3f color = elementColor(tris + v->index);
HalfEdgeCIter h = v->he;
do {
if (!h->onBoundary) {
Eigen::Vector3f p2 = (h->next->vertex->position + n).cast<float>();
Eigen::Vector3f p3 = (h->next->next->vertex->position + n).cast<float>();
pickVertices[3*i+0].position = p1;
pickVertices[3*i+1].position = p1 + 0.125*(p2 - p1);
pickVertices[3*i+2].position = p1 + 0.125*(p3 - p1);
pickVertices[3*i+0].color = pickVertices[3*i+1].color = pickVertices[3*i+2].color = color;
i++;
}
h = h->flip->next;
} while (h != v->he);
}
}
void drawFaces()
{
glColor4f(0.0, 0.0, 1.0, 0.6);
for (FaceCIter f = mesh.faces.begin(); f != mesh.faces.end(); f++) {
if (f->isBoundary()) continue;
glBegin(GL_LINE_LOOP);
HalfEdgeCIter he = f->he;
do {
glVertex3d(he->vertex->position.x(), he->vertex->position.y(), he->vertex->position.z());
he = he->next;
} while (he != f->he);
glEnd();
}
}
void Viewer :: drawVectorField( void )
{
shader.disable();
glPushAttrib( GL_ALL_ATTRIB_BITS );
double h = 0.25*mesh.meanEdgeLength();
glDisable( GL_LIGHTING );
glColor3f( 0., 0., 0. );
glLineWidth( 2.0 );
for( FaceCIter f = mesh.faces.begin();
f != mesh.faces.end();
f ++ )
{
if( f->isBoundary() ) continue;
Vector a = f->barycenter();
Vector b = a + h*f->vector;
Vector n = f->normal();
Vector v = b - a;
Vector v90 = cross(n, v);
Vector p0 = b;
Vector p1 = p0 - 0.2 * v - 0.1 * v90;
Vector p2 = p0 - 0.2 * v + 0.1 * v90;
glBegin( GL_LINES );
glVertex3dv( &a[0] );
glVertex3dv( &b[0] );
glEnd();
glBegin(GL_TRIANGLES);
glVertex3dv( &p0[0] );
glVertex3dv( &p1[0] );
glVertex3dv( &p2[0] );
glEnd();
}
glPopAttrib();
}
void Viewer :: drawPolygons( void )
{
glEnable(GL_COLOR_MATERIAL);
for( FaceCIter f = mesh.faces.begin();
f != mesh.faces.end();
f ++ )
{
if( f->isBoundary() ) continue;
glBegin( GL_POLYGON );
if( renderWireframe )
{
Vector N = f->normal();
glNormal3dv( &N[0] );
}
HalfEdgeCIter he = f->he;
do
{
if( not renderWireframe )
{
Vector N = he->vertex->normal();
glNormal3dv( &N[0] );
}
double alpha = he->vertex->distance / maxDistance;
glColor4f( alpha, alpha, alpha, 1. );
glVertex3dv( &he->vertex->position[0] );
he = he->next;
}
while( he != f->he );
glEnd();
}
glDisable(GL_COLOR_MATERIAL);
}
