void ConvexClipper<Real>::GetTriangles (std::vector<int>& indices,
std::vector<Plane3<Real> >& planes)
{
const int numFaces = (int)mFaces.size();
for (int f = 0; f < numFaces; ++f)
{
Face& face = mFaces[f];
if (face.Visible)
{
const int numEdges = (int)face.Edges.size();
assertion(numEdges >= 3, "Unexpected condition.\n");
std::vector<int> vOrdered(numEdges + 1);
OrderVertices(face, vOrdered);
int v0 = vOrdered[0];
int v2 = vOrdered[numEdges - 1];
int v1 = vOrdered[(numEdges - 1) >> 1];
Vector3<Real> diff1 = mVertices[v1].Point - mVertices[v0].Point;
Vector3<Real> diff2 = mVertices[v2].Point - mVertices[v0].Point;
Real sgnVolume = face.Plane.Normal.Dot(diff1.Cross(diff2));
if (sgnVolume > (Real)0)
{
// Clockwise, need to swap.
for (int i = 1; i + 1 < numEdges; ++i)
{
indices.push_back(v0);
indices.push_back(vOrdered[i + 1]);
indices.push_back(vOrdered[i]);
planes.push_back(face.Plane);
}
}
else
{
// Counterclockwise.
for (int i = 1; i + 1 < numEdges; ++i)
{
indices.push_back(v0);
indices.push_back(vOrdered[i]);
indices.push_back(vOrdered[i + 1]);
planes.push_back(face.Plane);
}
}
}
}
}
bool ClipMesh::getTriangles( std::vector<int>& indices ) {
const size_t numFaces = _faces.size();
for( size_t currFace = 0; currFace < numFaces; ++currFace ) {
CFace& face = _faces[currFace];
if( !face.visible ) {
continue;
}
const size_t numEdges = face.edges.size();
//assert(numEdges >= 3); // unexpected condition
if( numEdges < 3 ) {
return false;
}
std::vector<int> vOrdered(numEdges+1);
if( !orderVertices(face, vOrdered) ) {
return false;
}
const int v0 = vOrdered[0];
const int v2 = vOrdered[numEdges - 1];
const int v1 = vOrdered[(numEdges - 1) >> 1];
const cc::Vec3f diff1 = _vertices[v1].point - _vertices[v0].point;
const cc::Vec3f diff2 = _vertices[v2].point - _vertices[v0].point;
const float sgnVolume = face.normal.dot(diff1.cross(diff2));
if( sgnVolume < 0.0f ) { // feel free to invert this test
// clockwise, need to swap
for( unsigned int i = 1; i + 1 < numEdges; ++i ) {
indices.push_back(v0);
indices.push_back(vOrdered[i + 1]);
indices.push_back(vOrdered[i]);
}
} else {
// counterclockwise
for( unsigned int i = 1; i + 1 < numEdges; ++i ) {
indices.push_back(v0);
indices.push_back(vOrdered[i]);
indices.push_back(vOrdered[i + 1]);
}
}
}
return true;
}
