/**
* @brief
* Clips the polygon against a plane
*/
Polygon Polygon::Clip(const Plane &cPlane) const
{
uint32 nNumOfVertices = m_lstVertices.GetNumOfElements();
Polygon cClipped;
// Loop through all vertices of this polygon
for (uint32 i=0; i<nNumOfVertices; i++) {
// The 2 vertices of an edge
const Vector3 &vA = m_lstVertices[i];
const Vector3 &vB = m_lstVertices[(i+1) % nNumOfVertices];
// Check on which side of the plane the vertices are on
Plane::ESide nSideA = cPlane.GetSide(vA);
Plane::ESide nSideB = cPlane.GetSide(vB);
// Clip
if (nSideA == Plane::InFront || nSideA == Plane::Coinciding) {
cClipped.AddVertex(vA);
if (nSideB == Plane::Behind)
cClipped.AddVertex(cPlane.ClipEdge(vA, vB));
} else if (nSideB == Plane::InFront) {
cClipped.AddVertex(cPlane.ClipEdge(vA, vB));
cClipped.AddVertex(vB);
}
}
// Return the clipped polygon
return cClipped;
}
/**
* @brief
* Checks whether the polygon is completely behind the given plane
*/
bool Polygon::IsBehind(const Plane &cPlane) const
{
for (uint32 i=0; i<m_lstVertices.GetNumOfElements(); i++) {
if (cPlane.GetSide(m_lstVertices[i]) != Plane::Behind)
return false; // Not behind
}
// Behind the given plane
return true;
}
/**
* @brief
* Checks whether the polygon is completely in front of the given plane
*/
bool Polygon::IsInFront(const Plane &cPlane) const
{
for (uint32 i=0; i<m_lstVertices.GetNumOfElements(); i++) {
if (cPlane.GetSide(m_lstVertices[i]) != Plane::InFront)
return false; // Not in front
}
// In front of the given plane
return true;
}
Boole Overlap(const AxisAlignedBox& Box, const Plane& Surface)
{
return ( Plane::S_Both == Surface.GetSide(Box.GetCenter(),Box.GetHalfSize()) );
}