OctreeCamera::Visibility OctreeCamera::getVisibility( const AxisAlignedBox &bound )
{
// Null boxes always invisible
if ( bound.isNull() )
return NONE;
// Get centre of the box
Vector3 centre = bound.getCenter();
// Get the half-size of the box
Vector3 halfSize = bound.getHalfSize();
bool all_inside = true;
for ( int plane = 0; plane < 6; ++plane )
{
// Skip far plane if infinite view frustum
if (plane == FRUSTUM_PLANE_FAR && mFarDist == 0)
continue;
// This updates frustum planes and deals with cull frustum
Plane::Side side = getFrustumPlane(plane).getSide(centre, halfSize);
if(side == Plane::NEGATIVE_SIDE) return NONE;
// We can't return now as the box could be later on the negative side of a plane.
if(side == Plane::BOTH_SIDE)
all_inside = false;
}
if ( all_inside )
return FULL;
else
return PARTIAL;
}
//---------------------------------------------------------------------()
void Camera::getCameraToViewportBoxVolume(Real screenLeft,
Real screenTop, Real screenRight, Real screenBottom,
PlaneBoundedVolume* outVolume, bool includeFarPlane)
{
outVolume->planes.clear();
if (mProjType == PT_PERSPECTIVE)
{
// Use the corner rays to generate planes
Ray ul = getCameraToViewportRay(screenLeft, screenTop);
Ray ur = getCameraToViewportRay(screenRight, screenTop);
Ray bl = getCameraToViewportRay(screenLeft, screenBottom);
Ray br = getCameraToViewportRay(screenRight, screenBottom);
Vector3 normal;
// top plane
normal = ul.getDirection().crossProduct(ur.getDirection());
normal.normalise();
outVolume->planes.push_back(
Plane(normal, getDerivedPosition()));
// right plane
normal = ur.getDirection().crossProduct(br.getDirection());
normal.normalise();
outVolume->planes.push_back(
Plane(normal, getDerivedPosition()));
// bottom plane
normal = br.getDirection().crossProduct(bl.getDirection());
normal.normalise();
outVolume->planes.push_back(
Plane(normal, getDerivedPosition()));
// left plane
normal = bl.getDirection().crossProduct(ul.getDirection());
normal.normalise();
outVolume->planes.push_back(
Plane(normal, getDerivedPosition()));
}
else
{
// ortho planes are parallel to frustum planes
Ray ul = getCameraToViewportRay(screenLeft, screenTop);
Ray br = getCameraToViewportRay(screenRight, screenBottom);
updateFrustumPlanes();
outVolume->planes.push_back(
Plane(mFrustumPlanes[FRUSTUM_PLANE_TOP].normal, ul.getOrigin()));
outVolume->planes.push_back(
Plane(mFrustumPlanes[FRUSTUM_PLANE_RIGHT].normal, br.getOrigin()));
outVolume->planes.push_back(
Plane(mFrustumPlanes[FRUSTUM_PLANE_BOTTOM].normal, br.getOrigin()));
outVolume->planes.push_back(
Plane(mFrustumPlanes[FRUSTUM_PLANE_LEFT].normal, ul.getOrigin()));
}
// near & far plane applicable to both projection types
outVolume->planes.push_back(getFrustumPlane(FRUSTUM_PLANE_NEAR));
if (includeFarPlane)
outVolume->planes.push_back(getFrustumPlane(FRUSTUM_PLANE_FAR));
}
