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engine/r_areaportal.cpp

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+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+// $NoKeywords: $
+//=============================================================================//
+
+#include "render_pch.h"
+#include "client.h"
+#include "debug_leafvis.h"
+#include "con_nprint.h"
+#include "tier0/fasttimer.h"
+#include "r_areaportal.h"
+#include "cmodel_engine.h"
+#include "con_nprint.h"
+
+// memdbgon must be the last include file in a .cpp file!!!
+#include "tier0/memdbgon.h"
+
+ConVar r_ClipAreaPortals( "r_ClipAreaPortals", "1", FCVAR_CHEAT );
+ConVar r_DrawPortals( "r_DrawPortals", "0", FCVAR_CHEAT );
+
+CUtlVector<CPortalRect> g_PortalRects;
+static bool				g_bViewerInSolidSpace = false;
+
+			  
+
+// ------------------------------------------------------------------------------------ //
+// Classes.
+// ------------------------------------------------------------------------------------ //
+
+#define MAX_PORTAL_VERTS	32
+
+
+class CAreaCullInfo
+{
+public:
+	CAreaCullInfo()
+	{
+		m_GlobalCounter = 0;
+		memset( &m_Frustum, 0, sizeof( m_Frustum ) );
+		memset( &m_Rect, 0, sizeof( m_Rect ) );
+	}
+	Frustum_t		m_Frustum;
+	CPortalRect		m_Rect;
+	unsigned short	m_GlobalCounter; // Used to tell if it's been touched yet this frame.
+};
+
+
+
+// ------------------------------------------------------------------------------------ //
+// Globals.
+// ------------------------------------------------------------------------------------ //
+
+// Visible areas from the client DLL + occluded areas using area portals.
+unsigned char g_RenderAreaBits[32];
+
+// Used to prevent it from coming back into portals while flowing through them.
+static unsigned char g_AreaStack[32];
+
+// Frustums for each area for the current frame. Used to cull out leaves.
+static CUtlVector<CAreaCullInfo> g_AreaCullInfo;
+
+// List of areas marked visible this frame.
+static unsigned short g_VisibleAreas[MAX_MAP_AREAS];
+static int g_nVisibleAreas;
+
+// Tied to CAreaCullInfo::m_GlobalCounter.
+static unsigned short g_GlobalCounter = 1;
+
+
+// A copy of the current view setup, but possibly nobbled a bit.
+static CViewSetup g_viewSetup;
+static CPortalRect g_viewWindow;
+// Maps from world space to normalised (-1,1) screen coords.
+static VMatrix g_ScreenFromWorldProjection;
+
+
+// ------------------------------------------------------------------------------------ //
+// Functions.
+// ------------------------------------------------------------------------------------ //
+void R_Areaportal_LevelInit()
+{
+	g_AreaCullInfo.SetCount( host_state.worldbrush->m_nAreas );
+}
+
+void R_Areaportal_LevelShutdown()
+{
+	g_AreaCullInfo.Purge();
+	g_PortalRects.Purge();
+}
+
+static inline void R_SetBit( unsigned char *pBits, int bit )
+{
+	pBits[bit>>3] |= (1 << (bit&7));
+}
+
+static inline void R_ClearBit( unsigned char *pBits, int bit )
+{
+	pBits[bit>>3] &= ~(1 << (bit&7));
+}
+
+static inline unsigned char R_TestBit( unsigned char *pBits, int bit )
+{
+	return pBits[bit>>3] & (1 << (bit&7));
+}
+
+struct portalclip_t
+{
+	portalclip_t()
+	{
+		lists[0] = v0;
+		lists[1] = v1;
+	}
+	Vector v0[MAX_PORTAL_VERTS];
+	Vector v1[MAX_PORTAL_VERTS];
+	Vector *lists[2];
+};
+
+// Transforms and clips the portal's verts to the view frustum. Returns false
+// if the verts lie outside the frustum.
+static inline bool GetPortalScreenExtents( dareaportal_t *pPortal, 
+	portalclip_t * RESTRICT clip, CPortalRect &portalRect , float *pReflectionWaterHeight )
+{
+	portalRect.left = portalRect.bottom = 1e24;
+	portalRect.right = portalRect.top   = -1e24;
+	bool bValidExtents = false;
+	worldbrushdata_t *pBrushData = host_state.worldbrush;
+	
+	int nStartVerts = min( (int)pPortal->m_nClipPortalVerts, MAX_PORTAL_VERTS );
+
+	// NOTE: We need two passes to deal with reflection. We need to compute
+	// the screen extents for both the reflected + non-reflected area portals
+	// and make bounds that surrounds them both.
+	int nPassCount = ( pReflectionWaterHeight != NULL ) ? 2 : 1;
+	for ( int j = 0; j < nPassCount; ++j )
+	{
+		int i;
+		for( i=0; i < nStartVerts; i++ )
+		{
+			clip->v0[i] = pBrushData->m_pClipPortalVerts[pPortal->m_FirstClipPortalVert+i];
+
+			// 2nd pass is to compute the reflected areaportal position
+			if ( j == 1 )
+			{
+				clip->v0[i].z = 2.0f * ( *pReflectionWaterHeight ) - clip->v0[i].z;
+			}
+		}
+
+		int iCurList = 0;
+		bool bAllClipped = false;
+		for( int iPlane=0; iPlane < 4; iPlane++ )
+		{
+			const cplane_t *pPlane = g_Frustum.GetPlane(iPlane);
+
+			Vector *pIn = clip->lists[iCurList];
+			Vector *pOut = clip->lists[!iCurList];
+
+			int nOutVerts = 0;
+			int iPrev = nStartVerts - 1;
+			float flPrevDot = pPlane->normal.Dot( pIn[iPrev] ) - pPlane->dist;
+			for( int iCur=0; iCur < nStartVerts; iCur++ )
+			{
+				float flCurDot = pPlane->normal.Dot( pIn[iCur] ) - pPlane->dist;
+
+				if( (flCurDot > 0) != (flPrevDot > 0) )
+				{
+					if( nOutVerts < MAX_PORTAL_VERTS )
+					{
+						// Add the vert at the intersection.
+						float t = flPrevDot / (flPrevDot - flCurDot);
+						VectorLerp( pIn[iPrev], pIn[iCur], t, pOut[nOutVerts] );
+
+						++nOutVerts;
+					}
+				}
+
+				// Add this vert?
+				if( flCurDot > 0 )
+				{
+					if( nOutVerts < MAX_PORTAL_VERTS )
+					{
+						pOut[nOutVerts] = pIn[iCur];
+						++nOutVerts;
+					}
+				}
+
+				flPrevDot = flCurDot;
+				iPrev = iCur;
+			}
+
+			if( nOutVerts == 0 )
+			{
+				// If they're all behind, then this portal is clipped out.
+				bAllClipped = true;
+				break;
+			}
+
+			nStartVerts = nOutVerts;
+			iCurList = !iCurList;
+		}
+
+		if ( bAllClipped )
+			continue;
+
+		// Project all the verts and figure out the screen extents.
+		Vector screenPos;
+		Assert( iCurList == 0 );
+		for( i=0; i < nStartVerts; i++ )
+		{
+			Vector &point = clip->v0[i];
+
+			g_EngineRenderer->ClipTransformWithProjection ( g_ScreenFromWorldProjection, point, &screenPos );
+
+			portalRect.left   = fpmin( screenPos.x, portalRect.left );
+			portalRect.bottom = fpmin( screenPos.y, portalRect.bottom );
+			portalRect.top    = fpmax( screenPos.y, portalRect.top );
+			portalRect.right  = fpmax( screenPos.x, portalRect.right );
+		}
+		bValidExtents = true;
+	}
+
+	if ( !bValidExtents )
+	{
+		portalRect.left = portalRect.bottom = 0;
+		portalRect.right = portalRect.top   = 0;
+	}
+
+	return bValidExtents;
+}
+
+
+// Fill in the intersection between the two rectangles.
+inline bool GetRectIntersection( CPortalRect const *pRect1, CPortalRect const *pRect2, CPortalRect *pOut )
+{
+	pOut->left  = fpmax( pRect1->left, pRect2->left );
+	pOut->right = fpmin( pRect1->right, pRect2->right );
+	if( pOut->left >= pOut->right )
+		return false;
+
+	pOut->bottom = fpmax( pRect1->bottom, pRect2->bottom );
+	pOut->top    = fpmin( pRect1->top, pRect2->top );
+	if( pOut->bottom >= pOut->top )
+		return false;
+
+	return true;
+}
+
+static void R_FlowThroughArea( int area, const Vector &vecVisOrigin, const CPortalRect *pClipRect, 
+	const VisOverrideData_t* pVisData, float *pReflectionWaterHeight )
+{
+#ifndef SWDS
+	// Update this area's frustum.
+	if( g_AreaCullInfo[area].m_GlobalCounter != g_GlobalCounter )
+	{
+		g_VisibleAreas[g_nVisibleAreas] = area;
+		++g_nVisibleAreas;
+
+		g_AreaCullInfo[area].m_GlobalCounter = g_GlobalCounter;
+		g_AreaCullInfo[area].m_Rect = *pClipRect;
+	}
+	else
+	{
+		// Expand the areaportal's rectangle to include the new cliprect.
+		CPortalRect *pFrustumRect = &g_AreaCullInfo[area].m_Rect;
+		pFrustumRect->left   = fpmin( pFrustumRect->left, pClipRect->left );
+		pFrustumRect->bottom = fpmin( pFrustumRect->bottom, pClipRect->bottom );
+		pFrustumRect->top    = fpmax( pFrustumRect->top, pClipRect->top );
+		pFrustumRect->right  = fpmax( pFrustumRect->right, pClipRect->right );
+	}
+	
+	// Mark this area as visible.
+	R_SetBit( g_RenderAreaBits, area );
+
+	// Set that we're in this area on the stack.
+	R_SetBit( g_AreaStack, area );
+
+	worldbrushdata_t *pBrushData = host_state.worldbrush;
+
+	Assert( area < host_state.worldbrush->m_nAreas );
+	darea_t *pArea = &host_state.worldbrush->m_pAreas[area];
+	// temp buffer for clipping
+	portalclip_t clipTmp;
+
+	// Check all areas that connect to this area.
+	for( int iAreaPortal=0; iAreaPortal < pArea->numareaportals; iAreaPortal++ )
+	{
+		Assert( pArea->firstareaportal + iAreaPortal < pBrushData->m_nAreaPortals );
+		dareaportal_t *pAreaPortal = &pBrushData->m_pAreaPortals[ pArea->firstareaportal + iAreaPortal ];
+
+		// Don't flow back into a portal on the stack.
+		if( R_TestBit( g_AreaStack, pAreaPortal->otherarea ) )
+			continue;
+
+		// If this portal is closed, don't go through it.
+		if ( !R_TestBit( cl.m_chAreaPortalBits, pAreaPortal->m_PortalKey ) )
+			continue;
+
+		// Make sure the viewer is on the right side of the portal to see through it.
+		cplane_t *pPlane = &pBrushData->planes[ pAreaPortal->planenum ];
+		// Use the specified vis origin to test backface culling, or the main view if none was specified
+		float flDist = pPlane->normal.Dot( vecVisOrigin ) - pPlane->dist;
+		if( flDist < -0.1f )
+			continue;
+
+		// If the client doesn't want this area visible, don't try to flow into it.
+		if( !R_TestBit( cl.m_chAreaBits, pAreaPortal->otherarea ) )
+			continue;
+
+		CPortalRect portalRect;
+		bool portalVis = true;
+
+		// don't try to clip portals if the viewer is practically in the plane
+		float fDistTolerance = (pVisData)?(pVisData->m_fDistToAreaPortalTolerance):(0.1f);
+		if ( flDist > fDistTolerance )
+		{
+			portalVis = GetPortalScreenExtents( pAreaPortal, &clipTmp, portalRect, pReflectionWaterHeight );
+		}
+		else
+		{
+			portalRect.left = -1;
+			portalRect.top = 1;
+			portalRect.right = 1;
+			portalRect.bottom = -1;	// note top/bottom reversed!
+			//portalVis=true - not needed, default
+		}
+		if( portalVis )
+		{
+			CPortalRect intersection;
+			if( GetRectIntersection( &portalRect, pClipRect, &intersection ) )
+			{
+#ifdef USE_CONVARS
+				if( r_DrawPortals.GetInt() )
+				{
+					g_PortalRects.AddToTail( intersection );
+				}
+#endif
+
+				// Ok, we can see into this area.
+				R_FlowThroughArea( pAreaPortal->otherarea, vecVisOrigin, &intersection, pVisData, pReflectionWaterHeight );
+			}
+		}
+	}
+	
+	// Mark that we're leaving this area.
+	R_ClearBit( g_AreaStack, area );
+#endif
+}
+
+
+static void IncrementGlobalCounter()
+{
+	if( g_GlobalCounter == 0xFFFF )
+	{
+		for( int i=0; i < g_AreaCullInfo.Count(); i++ )
+			g_AreaCullInfo[i].m_GlobalCounter = 0;
+	
+		g_GlobalCounter = 1;
+	}
+	else
+	{
+		g_GlobalCounter++;
+	}
+}
+
+
+static void R_SetupGlobalFrustum()
+{
+#ifndef SWDS
+
+	// Copy the current view away so that we can play with it if needed.
+	g_viewSetup = g_EngineRenderer->ViewGetCurrent();
+
+	if( g_viewSetup.m_bOrtho )
+	{
+		g_viewWindow.right	= g_viewSetup.m_OrthoRight;
+		g_viewWindow.left		= g_viewSetup.m_OrthoLeft;
+		g_viewWindow.top		= g_viewSetup.m_OrthoTop;
+		g_viewWindow.bottom	= g_viewSetup.m_OrthoBottom;
+	}
+	else
+	{
+		// Assuming a view plane distance of 1, figure out the boundaries of a window
+		// the view would project into given the FOV.
+		float xFOV = g_EngineRenderer->GetFov() * 0.5f;
+		float yFOV = g_EngineRenderer->GetFovY() * 0.5f;
+
+		g_viewWindow.right	= tan( DEG2RAD( xFOV ) );
+		g_viewWindow.left	= -g_viewWindow.right;
+		g_viewWindow.top	= tan( DEG2RAD( yFOV ) );
+		g_viewWindow.bottom	= -g_viewWindow.top;
+
+		if ( g_viewSetup.m_bOffCenter )
+		{
+			// How did this ever work?
+			Assert ( !"test m_bOffCenter frustums with area portals" );
+		}
+		else if ( g_viewSetup.m_bViewToProjectionOverride )
+		{
+			// ...this has been tested and works!
+		}
+
+		// Rather than try to deal with crazy projection matrices (shear, trapezoid, etc), take whatever FOV we're given,
+		// assume it's conservative, and then construct a matching projection matrix for it. Then use that consistent
+		// hallucination throughout, rather than refer back to the engine's actual proj. matrix for anything.
+		VMatrix matrixView;
+		VMatrix matrixProjection;
+		VMatrix matrixWorldToScreen;
+		g_viewSetup.m_bViewToProjectionOverride = false;
+
+		ComputeViewMatrices (
+			&matrixView, 
+			&matrixProjection,
+			&matrixWorldToScreen,
+			g_viewSetup );
+
+		g_ScreenFromWorldProjection = matrixWorldToScreen;
+	}
+
+#endif //#ifndef SWDS
+}
+
+ConVar r_snapportal( "r_snapportal", "-1" );
+extern void CSGFrustum( Frustum_t &frustum );
+
+static void R_SetupVisibleAreaFrustums()
+{
+#ifndef SWDS
+
+	// Now scale the portals as specified in the normalized view frustum (-1,-1,1,1)
+	// into our view window and generate planes out of that.
+	for( int i=0; i < g_nVisibleAreas; i++ )
+	{
+		CAreaCullInfo *pInfo = &g_AreaCullInfo[ g_VisibleAreas[i] ];
+
+		CPortalRect portalWindow;
+		portalWindow.left    = RemapVal( pInfo->m_Rect.left,   -1, 1, g_viewWindow.left,   g_viewWindow.right );
+		portalWindow.right   = RemapVal( pInfo->m_Rect.right,  -1, 1, g_viewWindow.left,   g_viewWindow.right );
+		portalWindow.top     = RemapVal( pInfo->m_Rect.top,    -1, 1, g_viewWindow.bottom, g_viewWindow.top );
+		portalWindow.bottom  = RemapVal( pInfo->m_Rect.bottom, -1, 1, g_viewWindow.bottom, g_viewWindow.top );
+		
+		if( g_viewSetup.m_bOrtho )
+		{
+			// Left and right planes...
+			float orgOffset = DotProduct(CurrentViewOrigin(), CurrentViewRight());
+			pInfo->m_Frustum.SetPlane( FRUSTUM_LEFT, PLANE_ANYZ, CurrentViewRight(), portalWindow.left + orgOffset );
+			pInfo->m_Frustum.SetPlane( FRUSTUM_RIGHT, PLANE_ANYZ, -CurrentViewRight(), -portalWindow.right - orgOffset );
+
+			// Top and bottom planes...
+			orgOffset = DotProduct(CurrentViewOrigin(), CurrentViewUp());
+			pInfo->m_Frustum.SetPlane( FRUSTUM_TOP, PLANE_ANYZ, CurrentViewUp(), portalWindow.top + orgOffset );
+			pInfo->m_Frustum.SetPlane( FRUSTUM_BOTTOM, PLANE_ANYZ, -CurrentViewUp(), -portalWindow.bottom - orgOffset );
+		}
+		else
+		{
+
+			if ( g_viewSetup.m_bOffCenter )
+			{
+				// How did this ever work?
+				Assert ( !"test m_bOffCenter frustums with area portals" );
+			}
+			else if ( g_viewSetup.m_bViewToProjectionOverride )
+			{
+				// ...this has been tested and works!
+			}
+
+			Vector normal;
+			const cplane_t *pTest;
+
+			// right side
+			normal = portalWindow.right * CurrentViewForward() - CurrentViewRight();
+			VectorNormalize(normal); // OPTIMIZE: This is unnecessary for culling
+			pTest = pInfo->m_Frustum.GetPlane( FRUSTUM_RIGHT );
+			pInfo->m_Frustum.SetPlane( FRUSTUM_RIGHT, PLANE_ANYZ, normal, DotProduct(normal,CurrentViewOrigin()) );
+
+			// left side
+			normal = CurrentViewRight() - portalWindow.left * CurrentViewForward();
+			VectorNormalize(normal); // OPTIMIZE: This is unnecessary for culling
+			pTest = pInfo->m_Frustum.GetPlane( FRUSTUM_LEFT );
+			pInfo->m_Frustum.SetPlane( FRUSTUM_LEFT, PLANE_ANYZ, normal, DotProduct(normal,CurrentViewOrigin()) );
+
+			// top
+			normal = portalWindow.top * CurrentViewForward() - CurrentViewUp();
+			VectorNormalize(normal); // OPTIMIZE: This is unnecessary for culling
+			pTest = pInfo->m_Frustum.GetPlane( FRUSTUM_TOP );
+			pInfo->m_Frustum.SetPlane( FRUSTUM_TOP, PLANE_ANYZ, normal, DotProduct(normal,CurrentViewOrigin()) );
+
+			// bottom
+			normal = CurrentViewUp() - portalWindow.bottom * CurrentViewForward();
+			VectorNormalize(normal); // OPTIMIZE: This is unnecessary for culling
+			pTest = pInfo->m_Frustum.GetPlane( FRUSTUM_BOTTOM );
+			pInfo->m_Frustum.SetPlane( FRUSTUM_BOTTOM, PLANE_ANYZ, normal, DotProduct(normal,CurrentViewOrigin()) );
+
+			// farz
+			pInfo->m_Frustum.SetPlane( FRUSTUM_FARZ, PLANE_ANYZ, -CurrentViewForward(), 
+				DotProduct(-CurrentViewForward(), CurrentViewOrigin() + CurrentViewForward()*g_viewSetup.zFar) );
+		}
+
+		// DEBUG: Code to visualize the areaportal frustums in 3D
+		// Useful for debugging
+		extern void CSGFrustum( Frustum_t &frustum );
+		if ( r_snapportal.GetInt() >= 0 )
+		{
+			if ( g_VisibleAreas[i] == r_snapportal.GetInt() )
+			{
+				pInfo->m_Frustum.SetPlane( FRUSTUM_NEARZ, PLANE_ANYZ, CurrentViewForward(), 
+					DotProduct(CurrentViewForward(), CurrentViewOrigin()) );
+				pInfo->m_Frustum.SetPlane( FRUSTUM_FARZ, PLANE_ANYZ, -CurrentViewForward(), 
+					DotProduct(-CurrentViewForward(), CurrentViewOrigin() + CurrentViewForward()*500) );
+				r_snapportal.SetValue( -1 );
+				CSGFrustum( pInfo->m_Frustum );
+			}
+		}
+	}
+#endif
+}
+
+
+
+
+// Intersection of AABB and a frustum. The frustum may contain 0-32 planes
+// (active planes are defined by inClipMask). Returns boolean value indicating
+// whether AABB intersects the view frustum or not.
+// If AABB intersects the frustum, an output clip mask is returned as well
+// (indicating which planes are crossed by the AABB). This information
+// can be used to optimize testing of child nodes or objects inside the
+// nodes (pass value as 'inClipMask').
+inline bool R_CullNodeInternal( mnode_t *pNode, int &nClipMask, const Frustum_t& frustum )
+{
+	int nOutClipMask = nClipMask & FRUSTUM_CLIP_IN_AREA;	// init outclip mask
+
+	float flCenterDotNormal, flHalfDiagDotAbsNormal;
+	if (nClipMask & FRUSTUM_CLIP_RIGHT)
+	{
+		const cplane_t *pPlane = frustum.GetPlane(FRUSTUM_RIGHT);
+		flCenterDotNormal = DotProduct( pNode->m_vecCenter, pPlane->normal ) - pPlane->dist;
+		flHalfDiagDotAbsNormal = DotProduct( pNode->m_vecHalfDiagonal, frustum.GetAbsNormal(FRUSTUM_RIGHT) );
+		if (flCenterDotNormal + flHalfDiagDotAbsNormal < 0.0f)
+			return true;
+		if (flCenterDotNormal - flHalfDiagDotAbsNormal < 0.0f)
+			nOutClipMask |= FRUSTUM_CLIP_RIGHT;	
+	}
+
+	if (nClipMask & FRUSTUM_CLIP_LEFT)
+	{
+		const cplane_t *pPlane = frustum.GetPlane(FRUSTUM_LEFT);
+		flCenterDotNormal = DotProduct( pNode->m_vecCenter, pPlane->normal ) - pPlane->dist;
+		flHalfDiagDotAbsNormal = DotProduct( pNode->m_vecHalfDiagonal, frustum.GetAbsNormal(FRUSTUM_LEFT) );
+		if (flCenterDotNormal + flHalfDiagDotAbsNormal < 0.0f)
+			return true;
+		if (flCenterDotNormal - flHalfDiagDotAbsNormal < 0.0f)
+			nOutClipMask |= FRUSTUM_CLIP_LEFT;	
+	}
+
+	if (nClipMask & FRUSTUM_CLIP_TOP)
+	{
+		const cplane_t *pPlane = frustum.GetPlane(FRUSTUM_TOP);
+		flCenterDotNormal = DotProduct( pNode->m_vecCenter, pPlane->normal ) - pPlane->dist;
+		flHalfDiagDotAbsNormal = DotProduct( pNode->m_vecHalfDiagonal, frustum.GetAbsNormal(FRUSTUM_TOP) );
+		if (flCenterDotNormal + flHalfDiagDotAbsNormal < 0.0f)
+			return true;
+		if (flCenterDotNormal - flHalfDiagDotAbsNormal < 0.0f)
+			nOutClipMask |= FRUSTUM_CLIP_TOP;	
+	}
+
+	if (nClipMask & FRUSTUM_CLIP_BOTTOM)
+	{
+		const cplane_t *pPlane = frustum.GetPlane(FRUSTUM_BOTTOM);
+		flCenterDotNormal = DotProduct( pNode->m_vecCenter, pPlane->normal ) - pPlane->dist;
+		flHalfDiagDotAbsNormal = DotProduct( pNode->m_vecHalfDiagonal, frustum.GetAbsNormal(FRUSTUM_BOTTOM) );
+		if (flCenterDotNormal + flHalfDiagDotAbsNormal < 0.0f)
+			return true;
+		if (flCenterDotNormal - flHalfDiagDotAbsNormal < 0.0f)
+			nOutClipMask |= FRUSTUM_CLIP_BOTTOM;	
+	}
+
+	nClipMask = nOutClipMask;
+	return false;						// AABB intersects frustum
+}
+
+
+bool R_CullNode( Frustum_t *pAreaFrustum, mnode_t *pNode, int& nClipMask )
+{
+	// Now cull to this area's frustum.
+	if (( !g_bViewerInSolidSpace ) && ( pNode->area > 0 ))
+	{
+		// First make sure its whole area is even visible.
+		if( !R_IsAreaVisible( pNode->area ) )
+			return true;
+
+		// This ConVar access causes a huge perf hit in some cases.
+		// If you want to put it back in please cache it's value.
+//#ifdef USE_CONVARS
+//		if( r_ClipAreaPortals.GetInt() )
+//#else
+		if( 1 )
+//#endif
+		{
+			if ((nClipMask & FRUSTUM_CLIP_IN_AREA) == 0)
+			{
+				// In this case, we've never hit this area before and
+				// we need to test all planes again because we just changed the frustum
+				nClipMask = FRUSTUM_CLIP_IN_AREA | FRUSTUM_CLIP_ALL;
+			}
+
+			pAreaFrustum = &g_AreaCullInfo[pNode->area].m_Frustum;
+		}
+	}
+
+	return R_CullNodeInternal( pNode, nClipMask, *pAreaFrustum );
+}
+
+
+static ConVar r_portalscloseall( "r_portalscloseall", "0", FCVAR_CHEAT | FCVAR_DEVELOPMENTONLY );
+static ConVar r_portalsopenall( "r_portalsopenall", "0", FCVAR_CHEAT, "Open all portals" );
+static ConVar r_ShowViewerArea( "r_ShowViewerArea", "0" );
+
+void R_SetupAreaBits( int iForceViewLeaf /* = -1 */, const VisOverrideData_t* pVisData /* = NULL */, float *pWaterReflectionHeight /* = NULL */ )
+{
+	IncrementGlobalCounter();
+
+	g_bViewerInSolidSpace = false;
+
+	// Clear the visible area bits.
+	memset( g_RenderAreaBits, 0, sizeof( g_RenderAreaBits ) );
+	memset( g_AreaStack, 0, sizeof( g_AreaStack ) );
+
+	// Our initial clip rect is the whole screen.
+	CPortalRect rect;
+	rect.left = rect.bottom = -1;
+	rect.top = rect.right = 1;
+
+	// Flow through areas starting at the one we're in.
+	int leaf = iForceViewLeaf;
+	// If view point override wasn't specified, use the current view origin
+	if ( iForceViewLeaf == -1  ) 
+	{
+		leaf = CM_PointLeafnum( g_EngineRenderer->ViewOrigin() );
+	}
+
+	if( r_portalscloseall.GetBool() )
+	{
+		if ( cl.m_bAreaBitsValid )
+		{
+			// Clear the visible area bits.
+			memset( g_RenderAreaBits, 0, sizeof( g_RenderAreaBits ) );
+			int area = host_state.worldbrush->leafs[leaf].area;
+			R_SetBit( g_RenderAreaBits, area );
+			
+			g_VisibleAreas[0] = area;
+			g_nVisibleAreas = 1;
+
+			g_AreaCullInfo[area].m_GlobalCounter = g_GlobalCounter;
+			g_AreaCullInfo[area].m_Rect = rect;
+			
+			R_SetupVisibleAreaFrustums();
+		}
+		else
+		{
+			g_bViewerInSolidSpace = true;
+		}
+
+		return;
+	}
+
+#if defined( REPLAY_ENABLED )
+	if ( host_state.worldbrush->leafs[leaf].contents & CONTENTS_SOLID ||
+		 cl.ishltv || cl.isreplay || !cl.m_bAreaBitsValid || r_portalsopenall.GetBool()  )
+#else
+	if ( host_state.worldbrush->leafs[leaf].contents & CONTENTS_SOLID ||
+		 cl.ishltv || !cl.m_bAreaBitsValid || r_portalsopenall.GetBool()  )
+#endif
+	{
+		// Draw everything if we're in solid space or if r_portalsopenall is true (used for building cubemaps)
+		g_bViewerInSolidSpace = true;
+
+		if ( r_ShowViewerArea.GetInt() )
+			Con_NPrintf( 3, "Viewer area: (solid space)" );
+	}
+	else
+	{
+		int area = host_state.worldbrush->leafs[leaf].area;
+		
+		if ( r_ShowViewerArea.GetInt() )
+			Con_NPrintf( 3, "Viewer area: %d", area );
+
+		g_nVisibleAreas = 0;		
+		Vector vecVisOrigin = (pVisData)?(pVisData->m_vecVisOrigin):(g_EngineRenderer->ViewOrigin());
+		R_SetupGlobalFrustum();
+		R_FlowThroughArea ( area, vecVisOrigin, &rect, pVisData, pWaterReflectionHeight );
+		R_SetupVisibleAreaFrustums();
+	}
+}
+
+
+const Frustum_t* GetAreaFrustum( int area )
+{
+	if ( g_AreaCullInfo[area].m_GlobalCounter == g_GlobalCounter )
+		return &g_AreaCullInfo[area].m_Frustum;
+	else
+		return &g_Frustum;
+}
+
+
+