| public getDerivedCorner ( int index ) : Vector3 | ||
| index | int | |
| return | Vector3 | |
/// <summary>
/// IsObjectVisible() function for portals.
/// </summary>
/// <remarks>
/// Everything needs to be updated spatially before this function is
/// called including portal corners, frustum planes, etc.
/// </remarks>
/// <param name="portal">
/// The <see cref="Portal"/> to check visibility against.
/// </param>
/// <param name="culledBy">
/// The <see cref="FrustumPlane"/> that the Portal is in.
/// </param>
/// <returns>
/// true if the Portal is visible.
/// </returns>
public bool IsObjectVisible( Portal portal, out FrustumPlane culledBy )
{
culledBy = FrustumPlane.None;
// if portal isn't open, it's not visible
if ( !portal.IsOpen )
{
return false;
}
// check the extra frustum first
if ( !this.extraCullingFrustum.IsObjectVisible( portal ) )
{
return false;
}
// if portal is of type AABB or Sphere, then use simple bound check against planes
if ( portal.Type == PORTAL_TYPE.PORTAL_TYPE_AABB )
{
var aabb = new AxisAlignedBox( portal.getDerivedCorner( 0 ), portal.getDerivedCorner( 1 ) );
return base.IsObjectVisible( aabb, out culledBy );
}
else if ( portal.Type == PORTAL_TYPE.PORTAL_TYPE_SPHERE )
{
return base.IsObjectVisible( portal.getDerivedSphere(), out culledBy );
}
// check if the portal norm is facing the camera
Vector3 cameraToPortal = portal.getDerivedCP() - DerivedPosition;
Vector3 portalDirection = portal.getDerivedDirection();
Real dotProduct = cameraToPortal.Dot( portalDirection );
if ( dotProduct > 0 )
{
// portal is faced away from camera
return false;
}
// check against regular frustum planes
bool visible_flag;
if ( null != CullFrustum )
{
// For each frustum plane, see if all points are on the negative side
// If so, object is not visible
// NOTE: We skip the NEAR plane (plane #0) because Portals need to
// be visible no matter how close you get to them.
for ( int plane = 1; plane < 6; ++plane )
{
// set the visible flag to false
visible_flag = false;
// Skip far plane if infinite view frustum
if ( (FrustumPlane)plane == FrustumPlane.Far && _farDistance == 0 )
{
continue;
}
// we have to check each corner of the portal
for ( int corner = 0; corner < 4; corner++ )
{
PlaneSide side = CullFrustum.FrustumPlanes[ plane ].GetSide( portal.getDerivedCorner( corner ) );
if ( side != PlaneSide.Negative )
{
visible_flag = true;
}
}
// if the visible_flag is still false, then this plane
// culled all the portal points
if ( visible_flag == false )
{
// ALL corners on negative side therefore out of view
if ( culledBy != FrustumPlane.None )
{
culledBy = (FrustumPlane)plane;
}
return false;
}
}
}
else
{
// Make any pending updates to the calculated frustum planes
UpdateFrustumPlanes();
// For each frustum plane, see if all points are on the negative side
// If so, object is not visible
// NOTE: We skip the NEAR plane (plane #0) because Portals need to
// be visible no matter how close you get to them.
// BUGBUG: This can cause a false positive situation when a portal is
// behind the camera but close. This could be fixed by having another
// culling plane at the camera location with normal same as camera direction.
for ( int plane = 1; plane < 6; ++plane )
{
// set the visible flag to false
visible_flag = false;
// Skip far plane if infinite view frustum
if ( (FrustumPlane)plane == FrustumPlane.Far && _farDistance == 0 )
{
continue;
}
// we have to check each corner of the portal
for ( int corner = 0; corner < 4; corner++ )
{
PlaneSide side = _planes[ plane ].GetSide( portal.getDerivedCorner( corner ) );
if ( side != PlaneSide.Negative )
{
visible_flag = true;
}
}
// if the visible_flag is still false, then this plane
// culled all the portal points
if ( visible_flag == false )
{
// ALL corners on negative side therefore out of view
if ( culledBy != FrustumPlane.None )
{
culledBy = (FrustumPlane)plane;
}
return false;
}
}
}
// no plane culled all the portal points and the norm
// was facing the camera, so this portal is visible
return true;
}
/// <summary>
/// IsObjectVisible() function for portals.
/// </summary>
/// <remarks>
/// Everything needs to be updated spatially before this function is
/// called including portal corners, frustum planes, etc.
/// </remarks>
/// <param name="portal">
/// The <see cref="Portal"/> to check visibility against.
/// </param>
/// <returns>
/// true if the Portal is visible.
/// </returns>
public bool IsObjectVisible( Portal portal )
{
// if portal isn't open, it's not visible
if ( !portal.IsOpen )
{
return false;
}
// if the frustum has no planes, just return true
if ( mActiveCullingPlanes.Count == 0 )
{
return true;
}
// check if this portal is already in the list of active culling planes (avoid
// infinite recursion case)
foreach ( PCPlane plane in mActiveCullingPlanes )
{
if ( plane.Portal == portal )
{
return false;
}
}
// if portal is of type AABB or Sphere, then use simple bound check against planes
if ( portal.Type == PORTAL_TYPE.PORTAL_TYPE_AABB )
{
AxisAlignedBox aabb = new AxisAlignedBox();
aabb.SetExtents( portal.getDerivedCorner( 0 ), portal.getDerivedCorner( 1 ) );
return IsObjectVisible( aabb );
}
else if ( portal.Type == PORTAL_TYPE.PORTAL_TYPE_SPHERE )
{
return IsObjectVisible( portal.getDerivedSphere() );
}
// check if the portal norm is facing the frustum
Vector3 frustumToPortal = portal.getDerivedCP() - mOrigin;
Vector3 portalDirection = portal.getDerivedDirection();
Real dotProduct = frustumToPortal.Dot( portalDirection );
if ( dotProduct > 0 )
{
// portal is faced away from Frustum
return false;
}
// check against frustum culling planes
bool visible_flag;
// Check originPlane if told to
if ( mUseOriginPlane )
{
// set the visible flag to false
visible_flag = false;
// we have to check each corner of the portal
for ( int corner = 0; corner < 4; corner++ )
{
PlaneSide side = mOriginPlane.GetSide( portal.getDerivedCorner( corner ) );
if ( side != PlaneSide.Negative )
{
visible_flag = true;
}
}
// if the visible_flag is still false, then the origin plane
// culled all the portal points
if ( visible_flag == false )
{
// ALL corners on negative side therefore out of view
return false;
}
}
// For each active culling plane, see if all portal points are on the negative
// side. If so, the portal is not visible
foreach ( PCPlane plane in mActiveCullingPlanes )
{
visible_flag = false;
// we have to check each corner of the portal
for ( int corner = 0; corner < 4; corner++ )
{
PlaneSide side = plane.GetSide( portal.getDerivedCorner( corner ) );
if ( side != PlaneSide.Negative )
{
visible_flag = true;
}
}
// if the visible_flag is still false, then this plane
// culled all the portal points
if ( visible_flag == false )
{
// ALL corners on negative side therefore out of view
return false;
}
}
// no plane culled all the portal points and the norm
// was facing the frustum, so this portal is visible
return true;
}
// calculate culling planes from portal and frustum
// origin and add to list of culling planes
// NOTE: returns 0 if portal was completely culled by existing planes
// returns > 0 if culling planes are added (# is planes added)
public int AddPortalCullingPlanes( Portal portal )
{
int addedcullingplanes = 0;
// If portal is of type aabb or sphere, add a plane which is same as frustum
// origin plane (ie. redundant). We do this because we need the plane as a flag
// to prevent infinite recursion
if ( portal.Type == PORTAL_TYPE.PORTAL_TYPE_AABB ||
portal.Type == PORTAL_TYPE.PORTAL_TYPE_SPHERE )
{
PCPlane newPlane = GetUnusedCullingPlane();
newPlane.SetFromAxiomPlane( mOriginPlane );
newPlane.Portal = portal;
mActiveCullingPlanes.Add( newPlane );
addedcullingplanes++;
return addedcullingplanes;
}
// For portal Quads: Up to 4 planes can be added by the sides of a portal quad.
// Each plane is created from 2 corners (world space) of the portal and the
// frustum origin (world space).
int i, j;
PlaneSide pt0_side, pt1_side;
bool visible;
for ( i = 0; i < 4; i++ )
{
// first check if both corners are outside of one of the existing planes
j = i + 1;
if ( j > 3 )
{
j = 0;
}
visible = true;
foreach ( PCPlane plane in mActiveCullingPlanes )
{
pt0_side = plane.GetSide( portal.getDerivedCorner( i ) );
pt1_side = plane.GetSide( portal.getDerivedCorner( j ) );
if ( pt0_side == PlaneSide.Negative &&
pt1_side == PlaneSide.Negative )
{
// the portal edge was actually completely culled by one of culling planes
visible = false;
}
}
if ( visible )
{
// add the plane created from the two portal corner points and the frustum location
// to the culling plane
PCPlane newPlane = GetUnusedCullingPlane();
if ( projType == Projection.Orthographic ) // use camera direction if projection is orthographic.
{
newPlane.Redefine( portal.getDerivedCorner( j ) + mOriginPlane.Normal,
portal.getDerivedCorner( j ), portal.getDerivedCorner( i ) );
}
else
{
newPlane.Redefine( mOrigin, portal.getDerivedCorner( j ), portal.getDerivedCorner( i ) );
}
newPlane.Portal = portal;
mActiveCullingPlanes.Add( newPlane );
addedcullingplanes++;
}
}
// if we added ANY planes from the quad portal, we should add the plane of the
// portal itself as an additional culling plane.
if ( addedcullingplanes > 0 )
{
PCPlane newPlane = GetUnusedCullingPlane();
newPlane.Redefine( portal.getDerivedCorner( 2 ), portal.getDerivedCorner( 1 ), portal.getDerivedCorner( 0 ) );
newPlane.Portal = portal;
mActiveCullingPlanes.Add( newPlane );
addedcullingplanes++;
}
return addedcullingplanes;
}
// calculate culling planes from portal and frustum
// origin and add to list of culling planes
// NOTE: returns 0 if portal was completely culled by existing planes
// returns > 0 if culling planes are added (# is planes added)
public int AddPortalCullingPlanes(Portal portal)
{
int addedcullingplanes = 0;
// If portal is of type aabb or sphere, add a plane which is same as frustum
// origin plane (ie. redundant). We do this because we need the plane as a flag
// to prevent infinite recursion
if (portal.Type == PORTAL_TYPE.PORTAL_TYPE_AABB || portal.Type == PORTAL_TYPE.PORTAL_TYPE_SPHERE)
{
PCPlane newPlane = GetUnusedCullingPlane();
newPlane.SetFromAxiomPlane(this.mOriginPlane);
newPlane.Portal = portal;
this.mActiveCullingPlanes.Add(newPlane);
addedcullingplanes++;
return(addedcullingplanes);
}
// For portal Quads: Up to 4 planes can be added by the sides of a portal quad.
// Each plane is created from 2 corners (world space) of the portal and the
// frustum origin (world space).
int i, j;
PlaneSide pt0_side, pt1_side;
bool visible;
for (i = 0; i < 4; i++)
{
// first check if both corners are outside of one of the existing planes
j = i + 1;
if (j > 3)
{
j = 0;
}
visible = true;
foreach (PCPlane plane in this.mActiveCullingPlanes)
{
pt0_side = plane.GetSide(portal.getDerivedCorner(i));
pt1_side = plane.GetSide(portal.getDerivedCorner(j));
if (pt0_side == PlaneSide.Negative && pt1_side == PlaneSide.Negative)
{
// the portal edge was actually completely culled by one of culling planes
visible = false;
}
}
if (visible)
{
// add the plane created from the two portal corner points and the frustum location
// to the culling plane
PCPlane newPlane = GetUnusedCullingPlane();
if (this.projType == Projection.Orthographic) // use camera direction if projection is orthographic.
{
newPlane.Redefine(portal.getDerivedCorner(j) + this.mOriginPlane.Normal, portal.getDerivedCorner(j),
portal.getDerivedCorner(i));
}
else
{
newPlane.Redefine(this.mOrigin, portal.getDerivedCorner(j), portal.getDerivedCorner(i));
}
newPlane.Portal = portal;
this.mActiveCullingPlanes.Add(newPlane);
addedcullingplanes++;
}
}
// if we added ANY planes from the quad portal, we should add the plane of the
// portal itself as an additional culling plane.
if (addedcullingplanes > 0)
{
PCPlane newPlane = GetUnusedCullingPlane();
newPlane.Redefine(portal.getDerivedCorner(2), portal.getDerivedCorner(1), portal.getDerivedCorner(0));
newPlane.Portal = portal;
this.mActiveCullingPlanes.Add(newPlane);
addedcullingplanes++;
}
return(addedcullingplanes);
}
/// <summary>
/// IsObjectVisible() function for portals.
/// </summary>
/// <remarks>
/// Everything needs to be updated spatially before this function is
/// called including portal corners, frustum planes, etc.
/// </remarks>
/// <param name="portal">
/// The <see cref="Portal"/> to check visibility against.
/// </param>
/// <returns>
/// true if the Portal is visible.
/// </returns>
public bool IsObjectVisible(Portal portal)
{
// if portal isn't open, it's not visible
if (!portal.IsOpen)
{
return(false);
}
// if the frustum has no planes, just return true
if (this.mActiveCullingPlanes.Count == 0)
{
return(true);
}
// check if this portal is already in the list of active culling planes (avoid
// infinite recursion case)
foreach (PCPlane plane in this.mActiveCullingPlanes)
{
if (plane.Portal == portal)
{
return(false);
}
}
// if portal is of type AABB or Sphere, then use simple bound check against planes
if (portal.Type == PORTAL_TYPE.PORTAL_TYPE_AABB)
{
var aabb = new AxisAlignedBox();
aabb.SetExtents(portal.getDerivedCorner(0), portal.getDerivedCorner(1));
return(IsObjectVisible(aabb));
}
else if (portal.Type == PORTAL_TYPE.PORTAL_TYPE_SPHERE)
{
return(IsObjectVisible(portal.getDerivedSphere()));
}
// check if the portal norm is facing the frustum
Vector3 frustumToPortal = portal.getDerivedCP() - this.mOrigin;
Vector3 portalDirection = portal.getDerivedDirection();
Real dotProduct = frustumToPortal.Dot(portalDirection);
if (dotProduct > 0)
{
// portal is faced away from Frustum
return(false);
}
// check against frustum culling planes
bool visible_flag;
// Check originPlane if told to
if (this.mUseOriginPlane)
{
// set the visible flag to false
visible_flag = false;
// we have to check each corner of the portal
for (int corner = 0; corner < 4; corner++)
{
PlaneSide side = this.mOriginPlane.GetSide(portal.getDerivedCorner(corner));
if (side != PlaneSide.Negative)
{
visible_flag = true;
}
}
// if the visible_flag is still false, then the origin plane
// culled all the portal points
if (visible_flag == false)
{
// ALL corners on negative side therefore out of view
return(false);
}
}
// For each active culling plane, see if all portal points are on the negative
// side. If so, the portal is not visible
foreach (PCPlane plane in this.mActiveCullingPlanes)
{
visible_flag = false;
// we have to check each corner of the portal
for (int corner = 0; corner < 4; corner++)
{
PlaneSide side = plane.GetSide(portal.getDerivedCorner(corner));
if (side != PlaneSide.Negative)
{
visible_flag = true;
}
}
// if the visible_flag is still false, then this plane
// culled all the portal points
if (visible_flag == false)
{
// ALL corners on negative side therefore out of view
return(false);
}
}
// no plane culled all the portal points and the norm
// was facing the frustum, so this portal is visible
return(true);
}
/* This function check if *this* portal "crossed over" the other portal.
*/
public bool crossedPortal(Portal otherPortal)
{
// Only check if portal is open
if (otherPortal.mOpen)
{
// we model both portals as line swept spheres (mPrevDerivedCP to mDerivedCP).
// intersection test is then between the capsules.
// BUGBUG! This routine needs to check for case where one or both objects
// don't move - resulting in simple sphere tests
// BUGBUG! If one (or both) portals are aabb's this is REALLY not accurate.
Capsule portalCapsule, otherPortalCapsule;
portalCapsule = new Capsule();
portalCapsule.Set(getPrevDerivedCP(), getDerivedCP(), getRadius());
otherPortalCapsule = new Capsule();
otherPortalCapsule.Set(otherPortal.mPrevDerivedCP, otherPortal.mDerivedCP, otherPortal.mRadius);
if (portalCapsule.Intersects(otherPortalCapsule))
{
// the portal intersected the other portal at some time from last frame to this frame.
// Now check if this portal "crossed" the other portal
switch (otherPortal.Type)
{
case PORTAL_TYPE.PORTAL_TYPE_QUAD:
// a crossing occurs if the "side" of the final position of this portal compared
// to the final position of the other portal is negative AND the initial position
// of this portal compared to the initial position of the other portal is non-negative
// NOTE: This function assumes that this portal is the smaller portal potentially crossing
// over the otherPortal which is larger.
if (otherPortal.getDerivedPlane().GetSide(this.mDerivedCP) == PlaneSide.Negative &&
otherPortal.getPrevDerivedPlane().GetSide(this.mPrevDerivedCP) != PlaneSide.Negative)
{
// crossing occurred!
return(true);
}
break;
case PORTAL_TYPE.PORTAL_TYPE_AABB:
{
// for aabb's we check if the center point went from being inside to being outside
// the aabb (or vice versa) for crossing.
var aabb = new AxisAlignedBox(otherPortal.getDerivedCorner(0), otherPortal.getDerivedCorner(1));
//bool previousInside = aabb.contains(mPrevDerivedCP);
bool currentInside = aabb.Contains(this.mDerivedCP);
if (otherPortal.getDerivedDirection() == Vector3.UnitZ)
{
// portal norm is "outward" pointing, look for going from outside to inside
//if (previousInside == false &&
if (currentInside == true)
{
return(true);
}
}
else
{
// portal norm is "inward" pointing, look for going from inside to outside
//if (previousInside == true &&
if (currentInside == false)
{
return(true);
}
}
}
break;
case PORTAL_TYPE.PORTAL_TYPE_SPHERE:
{
// for spheres we check if the center point went from being inside to being outside
// the sphere surface (or vice versa) for crossing.
//Real previousDistance2 = mPrevDerivedCP.squaredDistance(otherPortal->getPrevDerivedCP());
Real currentDistance2 = this.mDerivedCP.DistanceSquared(otherPortal.getDerivedCP());
Real mRadius2 = System.Math.Sqrt(otherPortal.getRadius());
if (otherPortal.getDerivedDirection() == Vector3.UnitZ)
{
// portal norm is "outward" pointing, look for going from outside to inside
//if (previousDistance2 >= mRadius2 &&
if (currentDistance2 < mRadius2)
{
return(true);
}
}
else
{
// portal norm is "inward" pointing, look for going from inside to outside
//if (previousDistance2 < mRadius2 &&
if (currentDistance2 >= mRadius2)
{
return(true);
}
}
}
break;
}
}
}
// there was no crossing of the portal by this portal. It might be touching
// the other portal (but we don't care currently)
return(false);
}
/* This function check if *this* portal "crossed over" the other portal.
*/
public bool crossedPortal( Portal otherPortal )
{
// Only check if portal is open
if ( otherPortal.mOpen )
{
// we model both portals as line swept spheres (mPrevDerivedCP to mDerivedCP).
// intersection test is then between the capsules.
// BUGBUG! This routine needs to check for case where one or both objects
// don't move - resulting in simple sphere tests
// BUGBUG! If one (or both) portals are aabb's this is REALLY not accurate.
Capsule portalCapsule, otherPortalCapsule;
portalCapsule = new Capsule();
portalCapsule.Set( this.getPrevDerivedCP(), this.getDerivedCP(), this.getRadius() );
otherPortalCapsule = new Capsule();
otherPortalCapsule.Set( otherPortal.mPrevDerivedCP,
otherPortal.mDerivedCP,
otherPortal.mRadius );
if ( portalCapsule.Intersects( otherPortalCapsule ) )
{
// the portal intersected the other portal at some time from last frame to this frame.
// Now check if this portal "crossed" the other portal
switch ( otherPortal.Type )
{
case PORTAL_TYPE.PORTAL_TYPE_QUAD:
// a crossing occurs if the "side" of the final position of this portal compared
// to the final position of the other portal is negative AND the initial position
// of this portal compared to the initial position of the other portal is non-negative
// NOTE: This function assumes that this portal is the smaller portal potentially crossing
// over the otherPortal which is larger.
if ( otherPortal.getDerivedPlane().GetSide( mDerivedCP ) == PlaneSide.Negative &&
otherPortal.getPrevDerivedPlane().GetSide( mPrevDerivedCP ) != PlaneSide.Negative )
{
// crossing occurred!
return true;
}
break;
case PORTAL_TYPE.PORTAL_TYPE_AABB:
{
// for aabb's we check if the center point went from being inside to being outside
// the aabb (or vice versa) for crossing.
AxisAlignedBox aabb = new AxisAlignedBox( otherPortal.getDerivedCorner( 0 ), otherPortal.getDerivedCorner( 1 ) );
//bool previousInside = aabb.contains(mPrevDerivedCP);
bool currentInside = aabb.Contains( mDerivedCP );
if ( otherPortal.getDerivedDirection() == Vector3.UnitZ )
{
// portal norm is "outward" pointing, look for going from outside to inside
//if (previousInside == false &&
if ( currentInside == true )
{
return true;
}
}
else
{
// portal norm is "inward" pointing, look for going from inside to outside
//if (previousInside == true &&
if ( currentInside == false )
{
return true;
}
}
}
break;
case PORTAL_TYPE.PORTAL_TYPE_SPHERE:
{
// for spheres we check if the center point went from being inside to being outside
// the sphere surface (or vice versa) for crossing.
//Real previousDistance2 = mPrevDerivedCP.squaredDistance(otherPortal->getPrevDerivedCP());
Real currentDistance2 = mDerivedCP.DistanceSquared( otherPortal.getDerivedCP() );
Real mRadius2 = System.Math.Sqrt( otherPortal.getRadius() );
if ( otherPortal.getDerivedDirection() == Vector3.UnitZ )
{
// portal norm is "outward" pointing, look for going from outside to inside
//if (previousDistance2 >= mRadius2 &&
if ( currentDistance2 < mRadius2 )
{
return true;
}
}
else
{
// portal norm is "inward" pointing, look for going from inside to outside
//if (previousDistance2 < mRadius2 &&
if ( currentDistance2 >= mRadius2 )
{
return true;
}
}
}
break;
}
}
}
// there was no crossing of the portal by this portal. It might be touching
// the other portal (but we don't care currently)
return false;
}
/// <summary>
/// IsObjectVisible() function for portals.
/// </summary>
/// <remarks>
/// Everything needs to be updated spatially before this function is
/// called including portal corners, frustum planes, etc.
/// </remarks>
/// <param name="portal">
/// The <see cref="Portal"/> to check visibility against.
/// </param>
/// <param name="culledBy">
/// The <see cref="FrustumPlane"/> that the Portal is in.
/// </param>
/// <returns>
/// true if the Portal is visible.
/// </returns>
public bool IsObjectVisible(Portal portal, out FrustumPlane culledBy)
{
culledBy = FrustumPlane.None;
// if portal isn't open, it's not visible
if (!portal.IsOpen)
{
return(false);
}
// check the extra frustum first
if (!this.extraCullingFrustum.IsObjectVisible(portal))
{
return(false);
}
// if portal is of type AABB or Sphere, then use simple bound check against planes
if (portal.Type == PORTAL_TYPE.PORTAL_TYPE_AABB)
{
var aabb = new AxisAlignedBox(portal.getDerivedCorner(0), portal.getDerivedCorner(1));
return(base.IsObjectVisible(aabb, out culledBy));
}
else if (portal.Type == PORTAL_TYPE.PORTAL_TYPE_SPHERE)
{
return(base.IsObjectVisible(portal.getDerivedSphere(), out culledBy));
}
// check if the portal norm is facing the camera
Vector3 cameraToPortal = portal.getDerivedCP() - DerivedPosition;
Vector3 portalDirection = portal.getDerivedDirection();
Real dotProduct = cameraToPortal.Dot(portalDirection);
if (dotProduct > 0)
{
// portal is faced away from camera
return(false);
}
// check against regular frustum planes
bool visible_flag;
if (null != CullFrustum)
{
// For each frustum plane, see if all points are on the negative side
// If so, object is not visible
// NOTE: We skip the NEAR plane (plane #0) because Portals need to
// be visible no matter how close you get to them.
for (int plane = 1; plane < 6; ++plane)
{
// set the visible flag to false
visible_flag = false;
// Skip far plane if infinite view frustum
if ((FrustumPlane)plane == FrustumPlane.Far && _farDistance == 0)
{
continue;
}
// we have to check each corner of the portal
for (int corner = 0; corner < 4; corner++)
{
PlaneSide side = CullFrustum.FrustumPlanes[plane].GetSide(portal.getDerivedCorner(corner));
if (side != PlaneSide.Negative)
{
visible_flag = true;
}
}
// if the visible_flag is still false, then this plane
// culled all the portal points
if (visible_flag == false)
{
// ALL corners on negative side therefore out of view
if (culledBy != FrustumPlane.None)
{
culledBy = (FrustumPlane)plane;
}
return(false);
}
}
}
else
{
// Make any pending updates to the calculated frustum planes
UpdateFrustumPlanes();
// For each frustum plane, see if all points are on the negative side
// If so, object is not visible
// NOTE: We skip the NEAR plane (plane #0) because Portals need to
// be visible no matter how close you get to them.
// BUGBUG: This can cause a false positive situation when a portal is
// behind the camera but close. This could be fixed by having another
// culling plane at the camera location with normal same as camera direction.
for (int plane = 1; plane < 6; ++plane)
{
// set the visible flag to false
visible_flag = false;
// Skip far plane if infinite view frustum
if ((FrustumPlane)plane == FrustumPlane.Far && _farDistance == 0)
{
continue;
}
// we have to check each corner of the portal
for (int corner = 0; corner < 4; corner++)
{
PlaneSide side = _planes[plane].GetSide(portal.getDerivedCorner(corner));
if (side != PlaneSide.Negative)
{
visible_flag = true;
}
}
// if the visible_flag is still false, then this plane
// culled all the portal points
if (visible_flag == false)
{
// ALL corners on negative side therefore out of view
if (culledBy != FrustumPlane.None)
{
culledBy = (FrustumPlane)plane;
}
return(false);
}
}
}
// no plane culled all the portal points and the norm
// was facing the camera, so this portal is visible
return(true);
}
