void cFrustum::UpdateSphere()
{
// calculate the radius of the frustum sphere
float fViewLen = mfFarPlane - mfNearPlane;
float fHeight = fViewLen * tan(mfFOV * 0.5f);
float fWidth = fHeight * mfAspect;
// halfway point between near/far planes starting at the origin and extending along the z axis
cVector3f P(0.0f, 0.0f, mfNearPlane + fViewLen * 0.5f);
// the calculate far corner of the frustum
cVector3f Q(fWidth, fHeight, fViewLen);
// the vector between P and Q
cVector3f vDiff = P - Q;
// the radius becomes the length of this vector
float fRadius = vDiff.Length();
// get the look vector of the camera from the view matrix
cVector3f vLookVector = m_mtxModelView.GetForward() * -1;
// calculate the center of the sphere
cVector3f vCenter = (mvOrigin) + (vLookVector * (fViewLen * 0.5f + mfNearPlane));
mBoundingSphere = cSpheref(vCenter,fRadius);
}
void cFrustum::UpdateSphere()
{
float fViewLen = m_fFarPlane - m_fNearPlane;
float fHeight = fViewLen * tan(m_fFOV * 0.5f);
float fWidth = fHeight * m_fAspect;
cVector3f P(0.0f, 0.0f, m_fNearPlane + fViewLen * 0.5f);
cVector3f Q(fWidth, fHeight, fViewLen);
cVector3f vDiff = P - Q;
float fRadius = vDiff.Length();
cVector3f vLookVector = m_mtxModelView.GetForward() * -1;
cVector3f vCenter = (m_vOrigin) + (vLookVector * (fViewLen * 0.5f + m_fNearPlane));
m_BoundingSphere = cSpheref(vCenter, fRadius);
}
