/*
===========================================================================

Return to Castle Wolfenstein single player GPL Source Code
Copyright (C) 1999-2010 id Software LLC, a ZeniMax Media company. 

This file is part of the Return to Castle Wolfenstein single player GPL Source Code (RTCW SP Source Code).  

RTCW SP Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

RTCW SP Source Code is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with RTCW SP Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the RTCW SP Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the RTCW MP Source Code.  If not, please request a copy in writing from id Software at the address below.

If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.

===========================================================================
*/

#include "tr_local.h"



/*
================
R_CullSurface

Tries to cull surfaces before they are lighted or
added to the sorting list.
================
*/
static qboolean	R_CullSurface( msurface_t *surf ) {
	if ( r_nocull->integer || surf->cullinfo.type == CULLINFO_NONE) {
		return qfalse;
	}

	if ( r_nocurves->integer && *surf->data == SF_GRID ) {
		return qtrue;
	}

	if (surf->cullinfo.type & CULLINFO_PLANE)
	{
		// Only true for SF_FACE, so treat like its own function
		float			d;
		cullType_t ct;

		if ( !r_facePlaneCull->integer ) {
			return qfalse;
		}

		ct = surf->shader->cullType;

		if (ct == CT_TWO_SIDED)
		{
			return qfalse;
		}

		// don't cull for depth shadow
		/*
		if ( tr.viewParms.flags & VPF_DEPTHSHADOW )
		{
			return qfalse;
		}
		*/

		// shadowmaps draw back surfaces
		if ( tr.viewParms.flags & (VPF_SHADOWMAP | VPF_DEPTHSHADOW) )
		{
			if (ct == CT_FRONT_SIDED)
			{
				ct = CT_BACK_SIDED;
			}
			else
			{
				ct = CT_FRONT_SIDED;
			}
		}

		// do proper cull for orthographic projection
		if (tr.viewParms.flags & VPF_ORTHOGRAPHIC) {
			d = DotProduct(tr.viewParms.or.axis[0], surf->cullinfo.plane.normal);
			if ( ct == CT_FRONT_SIDED ) {
				if (d > 0)
					return qtrue;
			} else {
				if (d < 0)
					return qtrue;
			}
			return qfalse;
		}

		d = DotProduct (tr.or.viewOrigin, surf->cullinfo.plane.normal);

		// don't cull exactly on the plane, because there are levels of rounding
		// through the BSP, ICD, and hardware that may cause pixel gaps if an
		// epsilon isn't allowed here 
		if ( ct == CT_FRONT_SIDED ) {
			if ( d < surf->cullinfo.plane.dist - 8 ) {
				return qtrue;
			}
		} else {
			if ( d > surf->cullinfo.plane.dist + 8 ) {
				return qtrue;
			}
		}

		return qfalse;
	}

	if (surf->cullinfo.type & CULLINFO_SPHERE)
	{
		int 	sphereCull;

		if ( tr.currentEntityNum != REFENTITYNUM_WORLD ) {
			sphereCull = R_CullLocalPointAndRadius( surf->cullinfo.localOrigin, surf->cullinfo.radius );
		} else {
			sphereCull = R_CullPointAndRadius( surf->cullinfo.localOrigin, surf->cullinfo.radius );
		}

		if ( sphereCull == CULL_OUT )
		{
			return qtrue;
		}
	}

	if (surf->cullinfo.type & CULLINFO_BOX)
	{
		int boxCull;

		if ( tr.currentEntityNum != REFENTITYNUM_WORLD ) {
			boxCull = R_CullLocalBox( surf->cullinfo.bounds );
		} else {
			boxCull = R_CullBox( surf->cullinfo.bounds );
		}

		if ( boxCull == CULL_OUT )
		{
			return qtrue;
		}
	}

	return qfalse;
}

/*
====================
R_DlightSurface

The given surface is going to be drawn, and it touches a leaf
that is touched by one or more dlights, so try to throw out
more dlights if possible.
====================
*/
static int R_DlightSurface( msurface_t *surf, int dlightBits ) {
	float       d;
	int         i;
	dlight_t    *dl;
	
	if ( surf->cullinfo.type & CULLINFO_PLANE )
	{
		for ( i = 0 ; i < tr.refdef.num_dlights ; i++ ) {
			if ( ! ( dlightBits & ( 1 << i ) ) ) {
				continue;
			}
			dl = &tr.refdef.dlights[i];
			d = DotProduct( dl->origin, surf->cullinfo.plane.normal ) - surf->cullinfo.plane.dist;
			if ( d < -dl->radius || d > dl->radius ) {
				// dlight doesn't reach the plane
				dlightBits &= ~( 1 << i );
			}
		}
	}
	
	if ( surf->cullinfo.type & CULLINFO_BOX )
	{
		for ( i = 0 ; i < tr.refdef.num_dlights ; i++ ) {
			if ( ! ( dlightBits & ( 1 << i ) ) ) {
				continue;
			}
			dl = &tr.refdef.dlights[i];
			if ( dl->origin[0] - dl->radius > surf->cullinfo.bounds[1][0]
				|| dl->origin[0] + dl->radius < surf->cullinfo.bounds[0][0]
				|| dl->origin[1] - dl->radius > surf->cullinfo.bounds[1][1]
				|| dl->origin[1] + dl->radius < surf->cullinfo.bounds[0][1]
				|| dl->origin[2] - dl->radius > surf->cullinfo.bounds[1][2]
				|| dl->origin[2] + dl->radius < surf->cullinfo.bounds[0][2] ) {
				// dlight doesn't reach the bounds
				dlightBits &= ~( 1 << i );
			}
		}
	}

	if ( surf->cullinfo.type & CULLINFO_SPHERE )
	{
		for ( i = 0 ; i < tr.refdef.num_dlights ; i++ ) {
			if ( ! ( dlightBits & ( 1 << i ) ) ) {
				continue;
			}
			dl = &tr.refdef.dlights[i];
			if (!SpheresIntersect(dl->origin, dl->radius, surf->cullinfo.localOrigin, surf->cullinfo.radius))
			{
				// dlight doesn't reach the bounds
				dlightBits &= ~( 1 << i );
			}
		}
	}

	switch(*surf->data)
	{
		case SF_FACE:
		case SF_GRID:
		case SF_TRIANGLES:
			((srfBspSurface_t *)surf->data)->dlightBits = dlightBits;
			break;

		default:
			dlightBits = 0;
			break;
	}

	if ( dlightBits ) {
		tr.pc.c_dlightSurfaces++;
	} else {
		tr.pc.c_dlightSurfacesCulled++;
	}

	return dlightBits;
}

/*
====================
R_PshadowSurface

Just like R_DlightSurface, cull any we can
====================
*/
static int R_PshadowSurface( msurface_t *surf, int pshadowBits ) {
	float       d;
	int         i;
	pshadow_t    *ps;
	
	if ( surf->cullinfo.type & CULLINFO_PLANE )
	{
		for ( i = 0 ; i < tr.refdef.num_pshadows ; i++ ) {
			if ( ! ( pshadowBits & ( 1 << i ) ) ) {
				continue;
			}
			ps = &tr.refdef.pshadows[i];
			d = DotProduct( ps->lightOrigin, surf->cullinfo.plane.normal ) - surf->cullinfo.plane.dist;
			if ( d < -ps->lightRadius || d > ps->lightRadius ) {
				// pshadow doesn't reach the plane
				pshadowBits &= ~( 1 << i );
			}
		}
	}
	
	if ( surf->cullinfo.type & CULLINFO_BOX )
	{
		for ( i = 0 ; i < tr.refdef.num_pshadows ; i++ ) {
			if ( ! ( pshadowBits & ( 1 << i ) ) ) {
				continue;
			}
			ps = &tr.refdef.pshadows[i];
			if ( ps->lightOrigin[0] - ps->lightRadius > surf->cullinfo.bounds[1][0]
				|| ps->lightOrigin[0] + ps->lightRadius < surf->cullinfo.bounds[0][0]
				|| ps->lightOrigin[1] - ps->lightRadius > surf->cullinfo.bounds[1][1]
				|| ps->lightOrigin[1] + ps->lightRadius < surf->cullinfo.bounds[0][1]
				|| ps->lightOrigin[2] - ps->lightRadius > surf->cullinfo.bounds[1][2]
				|| ps->lightOrigin[2] + ps->lightRadius < surf->cullinfo.bounds[0][2] 
				|| BoxOnPlaneSide(surf->cullinfo.bounds[0], surf->cullinfo.bounds[1], &ps->cullPlane) == 2 ) {
				// pshadow doesn't reach the bounds
				pshadowBits &= ~( 1 << i );
			}
		}
	}

	if ( surf->cullinfo.type & CULLINFO_SPHERE )
	{
		for ( i = 0 ; i < tr.refdef.num_pshadows ; i++ ) {
			if ( ! ( pshadowBits & ( 1 << i ) ) ) {
				continue;
			}
			ps = &tr.refdef.pshadows[i];
			if (!SpheresIntersect(ps->viewOrigin, ps->viewRadius, surf->cullinfo.localOrigin, surf->cullinfo.radius)
				|| DotProduct( surf->cullinfo.localOrigin, ps->cullPlane.normal ) - ps->cullPlane.dist < -surf->cullinfo.radius)
			{
				// pshadow doesn't reach the bounds
				pshadowBits &= ~( 1 << i );
			}
		}
	}

	switch(*surf->data)
	{
		case SF_FACE:
		case SF_GRID:
		case SF_TRIANGLES:
			((srfBspSurface_t *)surf->data)->pshadowBits = pshadowBits;
			break;

		default:
			pshadowBits = 0;
			break;
	}

	if ( pshadowBits ) {
		//tr.pc.c_dlightSurfaces++;
	}

	return pshadowBits;
}

/*
======================
R_AddWorldSurface
======================
*/
static void R_AddWorldSurface( msurface_t *surf, int dlightBits, int pshadowBits ) {
	// FIXME: bmodel fog?

	// try to cull before dlighting or adding
	if ( R_CullSurface( surf ) ) {
		return;
	}

	// check for dlighting
	/*if ( dlightBits ) */{
		dlightBits = R_DlightSurface( surf, dlightBits );
		dlightBits = ( dlightBits != 0 );
	}

	// check for pshadows
	/*if ( pshadowBits ) */{
		pshadowBits = R_PshadowSurface( surf, pshadowBits);
		pshadowBits = ( pshadowBits != 0 );
	}

// GR - not tessellated
	R_AddDrawSurf( surf->data, surf->shader, surf->fogIndex, dlightBits, pshadowBits, surf->cubemapIndex, ATI_TESS_NONE );
}

/*
=============================================================

	BRUSH MODELS

=============================================================
*/

//----(SA) added

/*
=================
R_BmodelFogNum

See if a sprite is inside a fog volume
Return positive with /any part/ of the brush falling within a fog volume
=================
*/
int R_BmodelFogNum( trRefEntity_t *re, bmodel_t *bmodel ) {
	int i, j;
	fog_t           *fog;

	for ( i = 1 ; i < tr.world->numfogs ; i++ ) {
		fog = &tr.world->fogs[i];
		for ( j = 0 ; j < 3 ; j++ ) {
			if ( re->e.origin[j] + bmodel->bounds[0][j] > fog->bounds[1][j] ) {
				break;
			}
			if ( re->e.origin[j] + bmodel->bounds[0][j] < fog->bounds[0][j] ) {
				break;
			}
		}
		if ( j == 3 ) {
			return i;
		}
		for ( j = 0 ; j < 3 ; j++ ) {
			if ( re->e.origin[j] + bmodel->bounds[1][j] > fog->bounds[1][j] ) {
				break;
			}
			if ( bmodel->bounds[1][j] < fog->bounds[0][j] ) {
				break;
			}
		}
		if ( j == 3 ) {
			return i;
		}
	}

	return 0;
}

//----(SA) done


/*
=================
R_AddBrushModelSurfaces
=================

void R_AddBrushModelSurfaces( trRefEntity_t *ent ) {
	bmodel_t    *bmodel;
	int clip;
	model_t     *pModel;
	int i;
	int fognum;

	pModel = R_GetModelByHandle( ent->e.hModel );

	bmodel = pModel->bmodel;

	clip = R_CullLocalBox( bmodel->bounds );
	if ( clip == CULL_OUT ) {
		return;
	}

	R_SetupEntityLighting( &tr.refdef, ent );
	R_DlightBmodel( bmodel );

//----(SA) modified
	// determine if in fog
	fognum = R_BmodelFogNum( ent, bmodel );

	for ( i = 0 ; i < bmodel->numSurfaces ; i++ ) {
		( bmodel->firstSurface + i )->fogIndex = fognum;
		// Arnout: custom shader support for brushmodels
		if ( ent->e.customShader ) {
			R_AddWorldSurface( bmodel->firstSurface + i, R_GetShaderByHandle( ent->e.customShader ), tr.currentEntity->needDlights );
		} else {
			R_AddWorldSurface( bmodel->firstSurface + i, ( ( msurface_t * )( bmodel->firstSurface + i ) )->shader, tr.currentEntity->needDlights );
		}
	}
//----(SA) end
}
*/

/*
=================
R_AddBrushModelSurfaces
=================
*/
void R_AddBrushModelSurfaces ( trRefEntity_t *ent ) {
	bmodel_t	*bmodel;
	int			clip;
	model_t		*pModel;
	int			i;
	int fognum;

	pModel = R_GetModelByHandle( ent->e.hModel );

	bmodel = pModel->bmodel;

	clip = R_CullLocalBox( bmodel->bounds );
	if ( clip == CULL_OUT ) {
		return;
	}
	
	R_SetupEntityLighting( &tr.refdef, ent );
	R_DlightBmodel( bmodel );

//----(SA) modified
	// determine if in fog
	fognum = R_BmodelFogNum( ent, bmodel );

	for ( i = 0 ; i < bmodel->numSurfaces ; i++ ) {
		int surf = bmodel->firstSurface + i;

		if (tr.world->surfacesViewCount[surf] != tr.viewCount)
		{
			tr.world->surfacesViewCount[surf] = tr.viewCount;
			tr.world->surfaces[surf].fogIndex = fognum;
			R_AddWorldSurface( tr.world->surfaces + surf, tr.currentEntity->needDlights, 0 );
		}
	}
//----(SA) end
}

/*
=============================================================

	WORLD MODEL

=============================================================
*/


/*
================
R_RecursiveWorldNode
================
*/
static void R_RecursiveWorldNode( mnode_t *node, uint32_t planeBits, uint32_t dlightBits, uint32_t pshadowBits ) {

	do {
		uint32_t newDlights[2];
		uint32_t newPShadows[2];

		// if the node wasn't marked as potentially visible, exit
		// pvs is skipped for depth shadows
		if (!(tr.viewParms.flags & VPF_DEPTHSHADOW) && node->visCounts[tr.visIndex] != tr.visCounts[tr.visIndex]) {
			return;
		}

		// if the bounding volume is outside the frustum, nothing
		// inside can be visible OPTIMIZE: don't do this all the way to leafs?

		if ( !r_nocull->integer ) {
			int		r;

			if ( planeBits & 1 ) {
				r = BoxOnPlaneSide(node->mins, node->maxs, &tr.viewParms.frustum[0]);
				if (r == 2) {
					return;						// culled
				}
				if ( r == 1 ) {
					planeBits &= ~1;			// all descendants will also be in front
				}
			}

			if ( planeBits & 2 ) {
				r = BoxOnPlaneSide(node->mins, node->maxs, &tr.viewParms.frustum[1]);
				if (r == 2) {
					return;						// culled
				}
				if ( r == 1 ) {
					planeBits &= ~2;			// all descendants will also be in front
				}
			}

			if ( planeBits & 4 ) {
				r = BoxOnPlaneSide(node->mins, node->maxs, &tr.viewParms.frustum[2]);
				if (r == 2) {
					return;						// culled
				}
				if ( r == 1 ) {
					planeBits &= ~4;			// all descendants will also be in front
				}
			}

			if ( planeBits & 8 ) {
				r = BoxOnPlaneSide(node->mins, node->maxs, &tr.viewParms.frustum[3]);
				if (r == 2) {
					return;						// culled
				}
				if ( r == 1 ) {
					planeBits &= ~8;			// all descendants will also be in front
				}
			}

			if ( planeBits & 16 ) {
				r = BoxOnPlaneSide(node->mins, node->maxs, &tr.viewParms.frustum[4]);
				if (r == 2) {
					return;						// culled
				}
				if ( r == 1 ) {
					planeBits &= ~16;			// all descendants will also be in front
				}
			}
		}

		if ( node->contents != -1 ) {
			break;
		}

		// node is just a decision point, so go down both sides
		// since we don't care about sort orders, just go positive to negative

		// determine which dlights are needed
		newDlights[0] = 0;
		newDlights[1] = 0;
		if ( dlightBits ) {
			int	i;

			for ( i = 0 ; i < tr.refdef.num_dlights ; i++ ) {
				dlight_t	*dl;
				float		dist;

				if ( dlightBits & ( 1 << i ) ) {
					dl = &tr.refdef.dlights[i];
					dist = DotProduct( dl->origin, node->plane->normal ) - node->plane->dist;
					
					if ( dist > -dl->radius ) {
						newDlights[0] |= ( 1 << i );
					}
					if ( dist < dl->radius ) {
						newDlights[1] |= ( 1 << i );
					}
				}
			}
		}

		newPShadows[0] = 0;
		newPShadows[1] = 0;
		if ( pshadowBits ) {
			int	i;

			for ( i = 0 ; i < tr.refdef.num_pshadows ; i++ ) {
				pshadow_t	*shadow;
				float		dist;

				if ( pshadowBits & ( 1 << i ) ) {
					shadow = &tr.refdef.pshadows[i];
					dist = DotProduct( shadow->lightOrigin, node->plane->normal ) - node->plane->dist;
					
					if ( dist > -shadow->lightRadius ) {
						newPShadows[0] |= ( 1 << i );
					}
					if ( dist < shadow->lightRadius ) {
						newPShadows[1] |= ( 1 << i );
					}
				}
			}
		}

		// recurse down the children, front side first
		R_RecursiveWorldNode (node->children[0], planeBits, newDlights[0], newPShadows[0] );

		// tail recurse
		node = node->children[1];
		dlightBits = newDlights[1];
		pshadowBits = newPShadows[1];
	} while ( 1 );

	{
		// leaf node, so add mark surfaces
		int			c;
		int surf, *view;

		// RF, hack, dlight elimination above is unreliable
		dlightBits = 0xffffffff;

		tr.pc.c_leafs++;

		// add to z buffer bounds
		if ( node->mins[0] < tr.viewParms.visBounds[0][0] ) {
			tr.viewParms.visBounds[0][0] = node->mins[0];
		}
		if ( node->mins[1] < tr.viewParms.visBounds[0][1] ) {
			tr.viewParms.visBounds[0][1] = node->mins[1];
		}
		if ( node->mins[2] < tr.viewParms.visBounds[0][2] ) {
			tr.viewParms.visBounds[0][2] = node->mins[2];
		}

		if ( node->maxs[0] > tr.viewParms.visBounds[1][0] ) {
			tr.viewParms.visBounds[1][0] = node->maxs[0];
		}
		if ( node->maxs[1] > tr.viewParms.visBounds[1][1] ) {
			tr.viewParms.visBounds[1][1] = node->maxs[1];
		}
		if ( node->maxs[2] > tr.viewParms.visBounds[1][2] ) {
			tr.viewParms.visBounds[1][2] = node->maxs[2];
		}

		// add surfaces
		view = tr.world->marksurfaces + node->firstmarksurface;

		c = node->nummarksurfaces;
		while (c--) {
			// just mark it as visible, so we don't jump out of the cache derefencing the surface
			surf = *view;
			if (tr.world->surfacesViewCount[surf] != tr.viewCount)
			{
				tr.world->surfacesViewCount[surf] = tr.viewCount;
				tr.world->surfacesDlightBits[surf] = dlightBits;
				tr.world->surfacesPshadowBits[surf] = pshadowBits;
			}
			else
			{
				tr.world->surfacesDlightBits[surf] |= dlightBits;
				tr.world->surfacesPshadowBits[surf] |= pshadowBits;
			}
			view++;
		}
	}

}


/*
===============
R_PointInLeaf
===============
*/
static mnode_t *R_PointInLeaf( vec3_t p ) {
	mnode_t     *node;
	float d;
	cplane_t    *plane;

	if ( !tr.world ) {
		ri.Error( ERR_DROP, "R_PointInLeaf: bad model" );
	}

	node = tr.world->nodes;
	while ( 1 ) {
		if ( node->contents != -1 ) {
			break;
		}
		plane = node->plane;
		d = DotProduct( p,plane->normal ) - plane->dist;
		if ( d > 0 ) {
			node = node->children[0];
		} else {
			node = node->children[1];
		}
	}

	return node;
}

/*
==============
R_ClusterPVS
==============
*/
static const byte *R_ClusterPVS( int cluster ) {
	if ( !tr.world->vis || cluster < 0 || cluster >= tr.world->numClusters ) {
		return NULL;
	}

	return tr.world->vis + cluster * tr.world->clusterBytes;
}



/*
===============
R_MarkLeaves

Mark the leaves and nodes that are in the PVS for the current
cluster
===============
*/
static void R_MarkLeaves( void ) {
	const byte  *vis;
	mnode_t *leaf, *parent;
	int i;
	int cluster;

	// lockpvs lets designers walk around to determine the
	// extent of the current pvs
	if ( r_lockpvs->integer ) {
		return;
	}

	// current viewcluster
	leaf = R_PointInLeaf( tr.viewParms.pvsOrigin );
	cluster = leaf->cluster;

	// if the cluster is the same and the area visibility matrix
	// hasn't changed, we don't need to mark everything again

	for(i = 0; i < MAX_VISCOUNTS; i++)
	{
		// if the areamask or r_showcluster was modified, invalidate all visclusters
		// this caused doors to open into undrawn areas
		if (tr.refdef.areamaskModified || r_showcluster->modified)
		{
			tr.visClusters[i] = -2;
		}
		else if(tr.visClusters[i] == cluster)
		{
			if(tr.visClusters[i] != tr.visClusters[tr.visIndex] && r_showcluster->integer)
			{
				ri.Printf(PRINT_ALL, "found cluster:%i  area:%i  index:%i\n", cluster, leaf->area, i);
			}
			tr.visIndex = i;
			return;
		}
	}

	tr.visIndex = (tr.visIndex + 1) % MAX_VISCOUNTS;
	tr.visCounts[tr.visIndex]++;
	tr.visClusters[tr.visIndex] = cluster;

	if ( r_showcluster->modified || r_showcluster->integer ) {
		r_showcluster->modified = qfalse;
		if ( r_showcluster->integer ) {
			ri.Printf( PRINT_ALL, "cluster:%i  area:%i\n", cluster, leaf->area );
		}
	}

	vis = R_ClusterPVS(tr.visClusters[tr.visIndex]);

	for ( i = 0,leaf = tr.world->nodes ; i < tr.world->numnodes ; i++, leaf++ ) {
		cluster = leaf->cluster;
		if ( cluster < 0 || cluster >= tr.world->numClusters ) {
			continue;
		}

		// check general pvs
		if ( vis && !(vis[cluster>>3] & (1<<(cluster&7))) ) {
			continue;
		}

		// check for door connection
		if ( ( tr.refdef.areamask[leaf->area >> 3] & ( 1 << ( leaf->area & 7 ) ) ) ) {
			continue;       // not visible
		}

		parent = leaf;
		do {
			if(parent->visCounts[tr.visIndex] == tr.visCounts[tr.visIndex])
				break;
			parent->visCounts[tr.visIndex] = tr.visCounts[tr.visIndex];
			parent = parent->parent;
		} while ( parent );
	}
}


/*
=============
R_AddWorldSurfaces
=============
*/
void R_AddWorldSurfaces( void ) {
	uint32_t planeBits, dlightBits, pshadowBits;

	if ( !r_drawworld->integer ) {
		return;
	}

	if ( tr.refdef.rdflags & RDF_NOWORLDMODEL ) {
		return;
	}

	tr.currentEntityNum = REFENTITYNUM_WORLD;
	tr.shiftedEntityNum = tr.currentEntityNum << QSORT_REFENTITYNUM_SHIFT;

	// determine which leaves are in the PVS / areamask
	if (!(tr.viewParms.flags & VPF_DEPTHSHADOW))
		R_MarkLeaves ();

	// clear out the visible min/max
	ClearBounds( tr.viewParms.visBounds[0], tr.viewParms.visBounds[1] );

	// perform frustum culling and flag all the potentially visible surfaces
	if ( tr.refdef.num_dlights > MAX_DLIGHTS ) {
		tr.refdef.num_dlights = MAX_DLIGHTS ;
	}

	if ( tr.refdef.num_pshadows > MAX_DRAWN_PSHADOWS ) {
		tr.refdef.num_pshadows = MAX_DRAWN_PSHADOWS;
	}

	planeBits = (tr.viewParms.flags & VPF_FARPLANEFRUSTUM) ? 31 : 15;

	if ( tr.viewParms.flags & VPF_DEPTHSHADOW )
	{
		dlightBits = 0;
		pshadowBits = 0;
	}
	else if ( !(tr.viewParms.flags & VPF_SHADOWMAP) )
	{
		dlightBits = ( 1ULL << tr.refdef.num_dlights ) - 1;
		pshadowBits = ( 1ULL << tr.refdef.num_pshadows ) - 1;
	}
	else
	{
		dlightBits = ( 1ULL << tr.refdef.num_dlights ) - 1;
		pshadowBits = 0;
	}

	R_RecursiveWorldNode( tr.world->nodes, planeBits, dlightBits, pshadowBits);

	// now add all the potentially visible surfaces
	// also mask invisible dlights for next frame
	{
		int i;

		tr.refdef.dlightMask = 0;

		for (i = 0; i < tr.world->numWorldSurfaces; i++)
		{
			if (tr.world->surfacesViewCount[i] != tr.viewCount)
				continue;

			R_AddWorldSurface( tr.world->surfaces + i, tr.world->surfacesDlightBits[i], tr.world->surfacesPshadowBits[i] );
			tr.refdef.dlightMask |= tr.world->surfacesDlightBits[i];
		}

		tr.refdef.dlightMask = ~tr.refdef.dlightMask;
	}
}
