// 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;
}
VMatrix SetupMatrixReflection(const VPlane &thePlane)
{
VMatrix mReflect, mBack, mForward;
Vector vOrigin, N;
N = thePlane.m_Normal;
mReflect.Init(
-2.0f*N.x*N.x + 1.0f, -2.0f*N.x*N.y, -2.0f*N.x*N.z, 0.0f,
-2.0f*N.y*N.x, -2.0f*N.y*N.y + 1.0f, -2.0f*N.y*N.z, 0.0f,
-2.0f*N.z*N.x, -2.0f*N.z*N.y, -2.0f*N.z*N.z + 1.0f, 0.0f,
0.0f, 0.0f, 0.0f, 1.0f
);
vOrigin = thePlane.GetPointOnPlane();
mBack.Identity();
mBack.SetTranslation(-vOrigin);
mForward.Identity();
mForward.SetTranslation(vOrigin);
// (multiplied in reverse order, so it translates to the origin point,
// reflects, and translates back).
return mForward * mReflect * mBack;
}
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;
}
//-----------------------------------------------------------------------------
// Purpose:
//-----------------------------------------------------------------------------
void C_FireSmoke::FindClipPlane( void )
{
m_bClipTested = true;
m_flClipPerc = 1.0f;
trace_t tr;
Vector end( 0.0f, 0.0f, SMOKE_RISE_RATE*SMOKE_LIFETIME );
UTIL_TraceLine( GetAbsOrigin(), GetAbsOrigin()+end, MASK_SOLID_BRUSHONLY, NULL, COLLISION_GROUP_NONE, &tr );
//If the ceiling is too close, reject smoke
if ( tr.fraction < 0.5f )
{
m_nFlags &= ~bitsFIRESMOKE_SMOKE;
return;
}
if ( tr.fraction < 1.0f )
{
m_planeClip.Init( tr.plane.normal, tr.plane.dist );
m_nFlags |= bitsFIRESMOKE_SMOKE_COLLISION;
m_flClipPerc = tr.fraction * 0.5f;
}
}
