inline SceneZoneCullingState::CullingTestResult SceneCullingState::_test( const T& bounds, Iter zoneIter,
const PlaneF& nearPlane, const PlaneF& farPlane ) const
{
// Defer test of near and far plane until we've hit a zone
// which actually has visible space. This prevents us from
// doing near/far tests on objects that were included in the
// potential render list but aren't actually in any visible
// zone.
bool haveTestedNearAndFar = false;
// Test the culling states of all zones that the object
// is assigned to.
for( ; zoneIter.isValid(); ++ zoneIter )
{
const SceneZoneCullingState& zoneState = getZoneState( *zoneIter );
// Skip zone if there are no positive culling volumes.
if( !zoneState.hasIncluders() )
continue;
// If we haven't tested the near and far plane yet, do so
// now.
if( !haveTestedNearAndFar )
{
// Test near plane.
PlaneF::Side nearSide = nearPlane.whichSide( bounds );
if( nearSide == PlaneF::Back )
return SceneZoneCullingState::CullingTestNegative;
// Test far plane.
PlaneF::Side farSide = farPlane.whichSide( bounds );
if( farSide == PlaneF::Back )
return SceneZoneCullingState::CullingTestNegative;
haveTestedNearAndFar = true;
}
// If the object's world bounds overlaps any of the volumes
// for this zone, it's rendered.
SceneZoneCullingState::CullingTestResult result = zoneState.testVolumes( bounds );
if( result == SceneZoneCullingState::CullingTestPositiveByInclusion )
return result;
else if( result == SceneZoneCullingState::CullingTestPositiveByOcclusion )
return result;
}
return SceneZoneCullingState::CullingTestNegative;
}
ShadowVolumeBSP::SVNode::Side ShadowVolumeBSP::whichSide(SVPoly * poly, const PlaneF & plane) const
{
bool front = false;
bool back = false;
for(U32 i = 0; i < poly->mWindingCount; i++)
{
switch(plane.whichSide(poly->mWinding[i]))
{
case PlaneF::Front:
if(back)
return(SVNode::Split);
front = true;
break;
case PlaneF::Back:
if(front)
return(SVNode::Split);
back = true;
break;
default:
break;
}
}
AssertFatal(!(front && back), "ShadowVolumeBSP::whichSide - failed to classify poly");
if(!front && !back)
return(SVNode::On);
return(front ? SVNode::Front : SVNode::Back);
}
void ShadowVolumeBSP::splitPoly(SVPoly * poly, const PlaneF & plane, SVPoly ** front, SVPoly ** back)
{
PlaneF::Side sides[SVPoly::MaxWinding];
U32 i;
for(i = 0; i < poly->mWindingCount; i++)
sides[i] = plane.whichSide(poly->mWinding[i]);
// create the polys
(*front) = createPoly();
(*back) = createPoly();
// copy the info
(*front)->mWindingCount = (*back)->mWindingCount = 0;
(*front)->mPlane = (*back)->mPlane = poly->mPlane;
(*front)->mTarget = (*back)->mTarget = poly->mTarget;
(*front)->mSurfaceInfo = (*back)->mSurfaceInfo = poly->mSurfaceInfo;
(*front)->mShadowVolume = (*back)->mShadowVolume = poly->mShadowVolume;
//
for(i = 0; i < poly->mWindingCount; i++)
{
U32 j = (i+1) % poly->mWindingCount;
if(sides[i] == PlaneF::On)
{
(*front)->mWinding[(*front)->mWindingCount++] = poly->mWinding[i];
(*back)->mWinding[(*back)->mWindingCount++] = poly->mWinding[i];
}
else if(sides[i] == PlaneF::Front)
{
(*front)->mWinding[(*front)->mWindingCount++] = poly->mWinding[i];
if(sides[j] == PlaneF::Back)
{
const Point3F & a = poly->mWinding[i];
const Point3F & b = poly->mWinding[j];
F32 t = plane.intersect(a, b);
AssertFatal(t >=0 && t <= 1, "ShadowVolumeBSP::splitPoly - bad plane intersection");
Point3F pos;
pos.interpolate(a, b, t);
//
(*front)->mWinding[(*front)->mWindingCount++] =
(*back)->mWinding[(*back)->mWindingCount++] = pos;
}
}
else if(sides[i] == PlaneF::Back)
{
(*back)->mWinding[(*back)->mWindingCount++] = poly->mWinding[i];
if(sides[j] == PlaneF::Front)
{
const Point3F & a = poly->mWinding[i];
const Point3F & b = poly->mWinding[j];
F32 t = plane.intersect(a, b);
AssertFatal(t >=0 && t <= 1, "ShadowVolumeBSP::splitPoly - bad plane intersection");
Point3F pos;
pos.interpolate(a, b, t);
(*front)->mWinding[(*front)->mWindingCount++] =
(*back)->mWinding[(*back)->mWindingCount++] = pos;
}
}
}
AssertFatal((*front)->mWindingCount && (*back)->mWindingCount, "ShadowVolume::split - invalid split");
}
