// Given a line segment from vStart to vEnd
// and a list of convex polygons in pSurfInfos and nSurfInfos,
// fill in the list of which polygons the segment intersects.
// Returns the number of intersected surfaces.
static int IntersectSegmentWithSurfInfos(
const Vector &vStart,
const Vector &vEnd,
SurfInfo *pSurfInfos,
const int nSurfInfos,
SurfInfo ** pIntersections,
Vector *pIntersectionPositions,
int nMaxIntersections)
{
if(nMaxIntersections == 0)
return 0;
int nIntersections = 0;
for(int i=0; i < nSurfInfos; i++)
{
SurfInfo *pSurf = &pSurfInfos[i];
// Does it intersect the plane?
float dot1 = pSurf->m_Plane.DistTo(vStart);
float dot2 = pSurf->m_Plane.DistTo(vEnd);
if((dot1 > 0) != (dot2 > 0))
{
float t = dot1 / (dot1 - dot2);
Vector vIntersection = vStart + (vEnd - vStart) * t;
// If the intersection is behind any edge plane, then it's not inside the polygon.
unsigned long iEdge;
for(iEdge=0; iEdge < pSurf->m_nVerts; iEdge++)
{
VPlane edgePlane;
edgePlane.m_Normal = pSurf->m_Plane.m_Normal.Cross(pSurf->m_Verts[iEdge] - pSurf->m_Verts[(iEdge+1)%pSurf->m_nVerts]);
VectorNormalize( edgePlane.m_Normal );
edgePlane.m_Dist = edgePlane.m_Normal.Dot(pSurf->m_Verts[iEdge]);
if(edgePlane.DistTo(vIntersection) < 0.0f)
break;
}
if(iEdge == pSurf->m_nVerts)
{
pIntersections[nIntersections] = pSurf;
pIntersectionPositions[nIntersections] = vIntersection;
++nIntersections;
if(nIntersections >= nMaxIntersections)
break;
}
}
}
return nIntersections;
}
bool CFuncAreaPortalBase::UpdateVisibility( const Vector &vOrigin, float fovDistanceAdjustFactor, bool &bIsOpenOnClient )
{
// NOTE: We leave bIsOpenOnClient alone on purpose here. See the header for a description of why.
if( m_portalNumber == -1 )
return false;
// See if the viewer is on the backside.
VPlane plane;
if( !engine->GetAreaPortalPlane( vOrigin, m_portalNumber, &plane ) )
return true; // leave it open if there's an error here for some reason
bool bOpen = false;
if( plane.DistTo( vOrigin ) + VIEWER_PADDING > 0 )
bOpen = true;
return bOpen;
}
bool CFuncAreaPortalBase::UpdateVisibility( const CUtlVector< Vector > &vecOrigins, float fovDistanceAdjustFactor, bool &bIsOpenOnClient )
{
// NOTE: We leave bIsOpenOnClient alone on purpose here. See the header for a description of why.
if( m_portalNumber == -1 )
return false;
// See if the viewer is on the backside.
for ( int i = 0; i < vecOrigins.Count(); ++i )
{
const Vector &vOrigin = vecOrigins[ i ];
VPlane plane;
if( !engine->GetAreaPortalPlane( vOrigin, m_portalNumber, &plane ) )
return true; // leave it open if there's an error here for some reason
// If either players' origin is on the front, the areaportal is considered opened...
if( plane.DistTo( vOrigin ) + VIEWER_PADDING > 0 )
return true;
}
return false;
}
