yquake2remaster/src/refresh/gl_rsurf.c

/*
 * Copyright (C) 1997-2001 Id Software, Inc.
 *
 * This program 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 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

#include <assert.h>
#include "header/local.h"

#define DYNAMIC_LIGHT_WIDTH  128
#define DYNAMIC_LIGHT_HEIGHT 128
#define LIGHTMAP_BYTES 4
#define MAX_LIGHTMAPS 128
#define GL_LIGHTMAP_FORMAT GL_RGBA

int c_visible_lightmaps;
int c_visible_textures;
static vec3_t modelorg;         /* relative to viewpoint */
msurface_t  *r_alpha_surfaces;

typedef struct
{
	int internal_format;
	int current_lightmap_texture;

	msurface_t  *lightmap_surfaces [ MAX_LIGHTMAPS ];

	int allocated [ BLOCK_WIDTH ];

	/* the lightmap texture data needs to be kept in
	   main memory so texsubimage can update properly */
	byte lightmap_buffer [ 4 * BLOCK_WIDTH * BLOCK_HEIGHT ];
} gllightmapstate_t;

static gllightmapstate_t gl_lms;

static void     LM_InitBlock ( void );
static void     LM_UploadBlock ( qboolean dynamic );
static qboolean LM_AllocBlock ( int w, int h, int *x, int *y );

extern void R_SetCacheState ( msurface_t *surf );
extern void R_BuildLightMap ( msurface_t *surf, byte *dest, int stride );

/*
 * Returns the proper texture for a given time and base texture
 */
image_t *
R_TextureAnimation ( mtexinfo_t *tex )
{
	int c;

	if ( !tex->next )
	{
		return ( tex->image );
	}

	c = currententity->frame % tex->numframes;

	while ( c )
	{
		tex = tex->next;
		c--;
	}

	return ( tex->image );
}

void
DrawGLPoly ( glpoly_t *p )
{
	int i;
	float   *v;

	qglBegin( GL_POLYGON );
	v = p->verts [ 0 ];

	for ( i = 0; i < p->numverts; i++, v += VERTEXSIZE )
	{
		qglTexCoord2f( v [ 3 ], v [ 4 ] );
		qglVertex3fv( v );
	}

	qglEnd();
}

void
DrawGLFlowingPoly ( msurface_t *fa )
{
	int i;
	float   *v;
	glpoly_t *p;
	float scroll;

	p = fa->polys;

	scroll = -64 * ( ( r_newrefdef.time / 40.0 ) - (int) ( r_newrefdef.time / 40.0 ) );

	if ( scroll == 0.0 )
	{
		scroll = -64.0;
	}

	qglBegin( GL_POLYGON );
	v = p->verts [ 0 ];

	for ( i = 0; i < p->numverts; i++, v += VERTEXSIZE )
	{
		qglTexCoord2f( ( v [ 3 ] + scroll ), v [ 4 ] );
		qglVertex3fv( v );
	}

	qglEnd();
}

void
R_DrawTriangleOutlines ( void )
{
	int i, j;
	glpoly_t    *p;

	if ( !gl_showtris->value )
	{
		return;
	}

	qglDisable( GL_TEXTURE_2D );
	qglDisable( GL_DEPTH_TEST );
	qglColor4f( 1, 1, 1, 1 );

	for ( i = 0; i < MAX_LIGHTMAPS; i++ )
	{
		msurface_t *surf;

		for ( surf = gl_lms.lightmap_surfaces [ i ]; surf != 0; surf = surf->lightmapchain )
		{
			p = surf->polys;

			for ( ; p; p = p->chain )
			{
				for ( j = 2; j < p->numverts; j++ )
				{
					qglBegin( GL_LINE_STRIP );
					qglVertex3fv( p->verts [ 0 ] );
					qglVertex3fv( p->verts [ j - 1 ] );
					qglVertex3fv( p->verts [ j ] );
					qglVertex3fv( p->verts [ 0 ] );
					qglEnd();
				}
			}
		}
	}

	qglEnable( GL_DEPTH_TEST );
	qglEnable( GL_TEXTURE_2D );
}

void
DrawGLPolyChain ( glpoly_t *p, float soffset, float toffset )
{
	if ( ( soffset == 0 ) && ( toffset == 0 ) )
	{
		for ( ; p != 0; p = p->chain )
		{
			float *v;
			int j;

			v = p->verts [ 0 ];

			if ( v == NULL )
			{
				fprintf( stderr, "BUGFIX: DrawGLPolyChain: v==NULL\n" );
				return;
			}

			qglBegin( GL_POLYGON );

			for ( j = 0; j < p->numverts; j++, v += VERTEXSIZE )
			{
				qglTexCoord2f( v [ 5 ], v [ 6 ] );
				qglVertex3fv( v );
			}

			qglEnd();
		}
	}
	else
	{
		for ( ; p != 0; p = p->chain )
		{
			float *v;
			int j;

			qglBegin( GL_POLYGON );
			v = p->verts [ 0 ];

			for ( j = 0; j < p->numverts; j++, v += VERTEXSIZE )
			{
				qglTexCoord2f( v [ 5 ] - soffset, v [ 6 ] - toffset );
				qglVertex3fv( v );
			}

			qglEnd();
		}
	}
}

/*
* This routine takes all the given light mapped surfaces in the world
* and blends them into the framebuffer.
*/
void
R_BlendLightmaps ( void )
{
	int i;
	msurface_t  *surf, *newdrawsurf = 0;

	/* don't bother if we're set to fullbright */
	if ( r_fullbright->value )
	{
		return;
	}

	if ( !r_worldmodel->lightdata )
	{
		return;
	}

	/* don't bother writing Z */
	qglDepthMask( 0 );

	/* set the appropriate blending mode unless 
	   we're only looking at the lightmaps. */
	if ( !gl_lightmap->value )
	{
		qglEnable( GL_BLEND );

		if ( gl_saturatelighting->value )
		{
			qglBlendFunc( GL_ONE, GL_ONE );
		}
		else
		{
			qglBlendFunc( GL_ZERO, GL_SRC_COLOR );
		}
	}

	if ( currentmodel == r_worldmodel )
	{
		c_visible_lightmaps = 0;
	}

	/* render static lightmaps first */
	for ( i = 1; i < MAX_LIGHTMAPS; i++ )
	{
		if ( gl_lms.lightmap_surfaces [ i ] )
		{
			if ( currentmodel == r_worldmodel )
			{
				c_visible_lightmaps++;
			}

			R_Bind( gl_state.lightmap_textures + i );

			for ( surf = gl_lms.lightmap_surfaces [ i ]; surf != 0; surf = surf->lightmapchain )
			{
				if ( surf->polys )
				{
					DrawGLPolyChain( surf->polys, 0, 0 );
				}
			}
		}
	}

	/* render dynamic lightmaps */
	if ( gl_dynamic->value )
	{
		LM_InitBlock();

		R_Bind( gl_state.lightmap_textures + 0 );

		if ( currentmodel == r_worldmodel )
		{
			c_visible_lightmaps++;
		}

		newdrawsurf = gl_lms.lightmap_surfaces [ 0 ];

		for ( surf = gl_lms.lightmap_surfaces [ 0 ]; surf != 0; surf = surf->lightmapchain )
		{
			int smax, tmax;
			byte    *base;

			smax = ( surf->extents [ 0 ] >> 4 ) + 1;
			tmax = ( surf->extents [ 1 ] >> 4 ) + 1;

			if ( LM_AllocBlock( smax, tmax, &surf->dlight_s, &surf->dlight_t ) )
			{
				base = gl_lms.lightmap_buffer;
				base += ( surf->dlight_t * BLOCK_WIDTH + surf->dlight_s ) * LIGHTMAP_BYTES;

				R_BuildLightMap( surf, base, BLOCK_WIDTH * LIGHTMAP_BYTES );
			}
			else
			{
				msurface_t *drawsurf;

				/* upload what we have so far */
				LM_UploadBlock( true );

				/* draw all surfaces that use this lightmap */
				for ( drawsurf = newdrawsurf; drawsurf != surf; drawsurf = drawsurf->lightmapchain )
				{
					if ( drawsurf->polys )
					{
						DrawGLPolyChain( drawsurf->polys,
								( drawsurf->light_s - drawsurf->dlight_s ) * ( 1.0 / 128.0 ),
								( drawsurf->light_t - drawsurf->dlight_t ) * ( 1.0 / 128.0 ) );
					}
				}

				newdrawsurf = drawsurf;

				/* clear the block */
				LM_InitBlock();

				/* try uploading the block now */
				if ( !LM_AllocBlock( smax, tmax, &surf->dlight_s, &surf->dlight_t ) )
				{
					ri.Sys_Error( ERR_FATAL, "Consecutive calls to LM_AllocBlock(%d,%d) failed (dynamic)\n", smax, tmax );
				}

				base = gl_lms.lightmap_buffer;
				base += ( surf->dlight_t * BLOCK_WIDTH + surf->dlight_s ) * LIGHTMAP_BYTES;

				R_BuildLightMap( surf, base, BLOCK_WIDTH * LIGHTMAP_BYTES );
			}
		}

		/* draw remainder of dynamic lightmaps that haven't been uploaded yet */
		if ( newdrawsurf )
		{
			LM_UploadBlock( true );
		}

		for ( surf = newdrawsurf; surf != 0; surf = surf->lightmapchain )
		{
			if ( surf->polys )
			{
				DrawGLPolyChain( surf->polys, ( surf->light_s - surf->dlight_s ) * ( 1.0 / 128.0 ),
						( surf->light_t - surf->dlight_t ) * ( 1.0 / 128.0 ) );
			}
		}
	}

	/* restore state */
	qglDisable( GL_BLEND );
	qglBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
	qglDepthMask( 1 );
}

void
R_RenderBrushPoly ( msurface_t *fa )
{
	int maps;
	image_t     *image;
	qboolean is_dynamic = false;

	c_brush_polys++;

	image = R_TextureAnimation( fa->texinfo );

	if ( fa->flags & SURF_DRAWTURB )
	{
		R_Bind( image->texnum );

		/* warp texture, no lightmaps */
		R_TexEnv( GL_MODULATE );
		qglColor4f( gl_state.inverse_intensity,
				gl_state.inverse_intensity,
				gl_state.inverse_intensity,
				1.0F );
		EmitWaterPolys( fa );
		R_TexEnv( GL_REPLACE );

		return;
	}
	else
	{
		R_Bind( image->texnum );

		R_TexEnv( GL_REPLACE );
	}

	if ( fa->texinfo->flags & SURF_FLOWING )
	{
		DrawGLFlowingPoly( fa );
	}
	else
	{
		DrawGLPoly( fa->polys );
	}

	/* check for lightmap modification */
	for ( maps = 0; maps < MAXLIGHTMAPS && fa->styles [ maps ] != 255; maps++ )
	{
		if ( r_newrefdef.lightstyles [ fa->styles [ maps ] ].white != fa->cached_light [ maps ] )
		{
			goto dynamic;
		}
	}

	/* dynamic this frame or dynamic previously */
	if ( ( fa->dlightframe == r_framecount ) )
	{
	dynamic:

		if ( gl_dynamic->value )
		{
			if ( !( fa->texinfo->flags & ( SURF_SKY | SURF_TRANS33 | SURF_TRANS66 | SURF_WARP ) ) )
			{
				is_dynamic = true;
			}
		}
	}

	if ( is_dynamic )
	{
		if ( ( ( fa->styles [ maps ] >= 32 ) || ( fa->styles [ maps ] == 0 ) ) && ( fa->dlightframe != r_framecount ) )
		{
			unsigned temp [ 34 * 34 ];
			int smax, tmax;

			smax = ( fa->extents [ 0 ] >> 4 ) + 1;
			tmax = ( fa->extents [ 1 ] >> 4 ) + 1;

			R_BuildLightMap( fa, (void *) temp, smax * 4 );
			R_SetCacheState( fa );

			R_Bind( gl_state.lightmap_textures + fa->lightmaptexturenum );

			qglTexSubImage2D( GL_TEXTURE_2D, 0,
					fa->light_s, fa->light_t,
					smax, tmax,
					GL_LIGHTMAP_FORMAT,
					GL_UNSIGNED_BYTE, temp );

			fa->lightmapchain = gl_lms.lightmap_surfaces [ fa->lightmaptexturenum ];
			gl_lms.lightmap_surfaces [ fa->lightmaptexturenum ] = fa;
		}
		else
		{
			fa->lightmapchain = gl_lms.lightmap_surfaces [ 0 ];
			gl_lms.lightmap_surfaces [ 0 ] = fa;
		}
	}
	else
	{
		fa->lightmapchain = gl_lms.lightmap_surfaces [ fa->lightmaptexturenum ];
		gl_lms.lightmap_surfaces [ fa->lightmaptexturenum ] = fa;
	}
}

/*
 * Draw water surfaces and windows.
 * The BSP tree is waled front to back, so unwinding the chain
 * of alpha_surfaces will draw back to front, giving proper ordering.
 */
void
R_DrawAlphaSurfaces ( void )
{
	msurface_t  *s;
	float intens;

	/* go back to the world matrix */
	qglLoadMatrixf( r_world_matrix );

	qglEnable( GL_BLEND );
	R_TexEnv( GL_MODULATE );

	/* the textures are prescaled up for a better lighting range,
	   so scale it back down */
	intens = gl_state.inverse_intensity;

	for ( s = r_alpha_surfaces; s; s = s->texturechain )
	{
		R_Bind( s->texinfo->image->texnum );
		c_brush_polys++;

		if ( s->texinfo->flags & SURF_TRANS33 )
		{
			qglColor4f( intens, intens, intens, 0.33 );
		}
		else if ( s->texinfo->flags & SURF_TRANS66 )
		{
			qglColor4f( intens, intens, intens, 0.66 );
		}
		else
		{
			qglColor4f( intens, intens, intens, 1 );
		}

		if ( s->flags & SURF_DRAWTURB )
		{
			EmitWaterPolys( s );
		}
		else if ( s->texinfo->flags & SURF_FLOWING )
		{
			DrawGLFlowingPoly( s );
		}
		else
		{
			DrawGLPoly( s->polys );
		}
	}

	R_TexEnv( GL_REPLACE );
	qglColor4f( 1, 1, 1, 1 );
	qglDisable( GL_BLEND );

	r_alpha_surfaces = NULL;
}

void
DrawTextureChains ( void )
{
	int i;
	msurface_t  *s;
	image_t     *image;

	c_visible_textures = 0;

	for ( i = 0, image = gltextures; i < numgltextures; i++, image++ )
	{
		if ( !image->registration_sequence )
		{
			continue;
		}

		s = image->texturechain;

		if ( !s )
		{
			continue;
		}

		c_visible_textures++;

		for ( ; s; s = s->texturechain )
		{
			R_RenderBrushPoly( s );
		}

		image->texturechain = NULL;
	}

	R_TexEnv( GL_REPLACE );
}

void
R_DrawInlineBModel ( void )
{
	int i, k;
	cplane_t    *pplane;
	float dot;
	msurface_t  *psurf;
	dlight_t    *lt;

	/* calculate dynamic lighting for bmodel */
	if ( !gl_flashblend->value )
	{
		lt = r_newrefdef.dlights;

		for ( k = 0; k < r_newrefdef.num_dlights; k++, lt++ )
		{
			R_MarkLights( lt, 1 << k, currentmodel->nodes + currentmodel->firstnode );
		}
	}

	psurf = &currentmodel->surfaces [ currentmodel->firstmodelsurface ];

	if ( currententity->flags & RF_TRANSLUCENT )
	{
		qglEnable( GL_BLEND );
		qglColor4f( 1, 1, 1, 0.25 );
		R_TexEnv( GL_MODULATE );
	}

	/* draw texture */
	for ( i = 0; i < currentmodel->nummodelsurfaces; i++, psurf++ )
	{
		/* find which side of the node we are on */
		pplane = psurf->plane;

		dot = DotProduct( modelorg, pplane->normal ) - pplane->dist;

		/* draw the polygon */
		if ( ( ( psurf->flags & SURF_PLANEBACK ) && ( dot < -BACKFACE_EPSILON ) ) ||
			 ( !( psurf->flags & SURF_PLANEBACK ) && ( dot > BACKFACE_EPSILON ) ) )
		{
			if ( psurf->texinfo->flags & ( SURF_TRANS33 | SURF_TRANS66 ) )
			{   
				/* add to the translucent chain */
				psurf->texturechain = r_alpha_surfaces;
				r_alpha_surfaces = psurf;
			}
			else
			{
				R_RenderBrushPoly( psurf );
			}
		}
	}

	if ( !( currententity->flags & RF_TRANSLUCENT ) )
	{
		R_BlendLightmaps();
	}
	else
	{
		qglDisable( GL_BLEND );
		qglColor4f( 1, 1, 1, 1 );
		R_TexEnv( GL_REPLACE );
	}
}

void
R_DrawBrushModel ( entity_t *e )
{
	vec3_t mins, maxs;
	int i;
	qboolean rotated;

	if ( currentmodel->nummodelsurfaces == 0 )
	{
		return;
	}

	currententity = e;
	gl_state.currenttextures [ 0 ] = gl_state.currenttextures [ 1 ] = -1;

	if ( e->angles [ 0 ] || e->angles [ 1 ] || e->angles [ 2 ] )
	{
		rotated = true;

		for ( i = 0; i < 3; i++ )
		{
			mins [ i ] = e->origin [ i ] - currentmodel->radius;
			maxs [ i ] = e->origin [ i ] + currentmodel->radius;
		}
	}
	else
	{
		rotated = false;
		VectorAdd( e->origin, currentmodel->mins, mins );
		VectorAdd( e->origin, currentmodel->maxs, maxs );
	}

	if ( R_CullBox( mins, maxs ) )
	{
		return;
	}

	qglColor3f( 1, 1, 1 );
	memset( gl_lms.lightmap_surfaces, 0, sizeof ( gl_lms.lightmap_surfaces ) );

	VectorSubtract( r_newrefdef.vieworg, e->origin, modelorg );

	if ( rotated )
	{
		vec3_t temp;
		vec3_t forward, right, up;

		VectorCopy( modelorg, temp );
		AngleVectors( e->angles, forward, right, up );
		modelorg [ 0 ] = DotProduct( temp, forward );
		modelorg [ 1 ] = -DotProduct( temp, right );
		modelorg [ 2 ] = DotProduct( temp, up );
	}

	qglPushMatrix();
	e->angles [ 0 ] = -e->angles [ 0 ];
	e->angles [ 2 ] = -e->angles [ 2 ]; 
	R_RotateForEntity( e );
	e->angles [ 0 ] = -e->angles [ 0 ]; 
	e->angles [ 2 ] = -e->angles [ 2 ];

	R_TexEnv( GL_REPLACE );
	R_TexEnv( GL_MODULATE );

	R_DrawInlineBModel();

	qglPopMatrix();
}

void
R_RecursiveWorldNode ( mnode_t *node )
{
	int c, side, sidebit;
	cplane_t    *plane;
	msurface_t  *surf, **mark;
	mleaf_t     *pleaf;
	float dot;
	image_t     *image;

	if ( node->contents == CONTENTS_SOLID )
	{
		return; /* solid */
	}

	if ( node->visframe != r_visframecount )
	{
		return;
	}

	if ( R_CullBox( node->minmaxs, node->minmaxs + 3 ) )
	{
		return;
	}

	/* if a leaf node, draw stuff */
	if ( node->contents != -1 )
	{
		pleaf = (mleaf_t *) node;

		/* check for door connected areas */
		if ( r_newrefdef.areabits )
		{
			if ( !( r_newrefdef.areabits [ pleaf->area >> 3 ] & ( 1 << ( pleaf->area & 7 ) ) ) )
			{
				return; /* not visible */
			}
		}

		mark = pleaf->firstmarksurface;
		c = pleaf->nummarksurfaces;

		if ( c )
		{
			do
			{
				( *mark )->visframe = r_framecount;
				mark++;
			}
			while ( --c );
		}

		return;
	}

	/* node is just a decision point, so go down the apropriate sides 
	   find which side of the node we are on */
	plane = node->plane;

	switch ( plane->type )
	{
		case PLANE_X:
			dot = modelorg [ 0 ] - plane->dist;
			break;
		case PLANE_Y:
			dot = modelorg [ 1 ] - plane->dist;
			break;
		case PLANE_Z:
			dot = modelorg [ 2 ] - plane->dist;
			break;
		default:
			dot = DotProduct( modelorg, plane->normal ) - plane->dist;
			break;
	}

	if ( dot >= 0 )
	{
		side = 0;
		sidebit = 0;
	}
	else
	{
		side = 1;
		sidebit = SURF_PLANEBACK;
	}

	/* recurse down the children, front side first */
	R_RecursiveWorldNode( node->children [ side ] );

	/* draw stuff */
	for ( c = node->numsurfaces, surf = r_worldmodel->surfaces + node->firstsurface; c; c--, surf++ )
	{
		if ( surf->visframe != r_framecount )
		{
			continue;
		}

		if ( ( surf->flags & SURF_PLANEBACK ) != sidebit )
		{
			continue; /* wrong side */
		}

		if ( surf->texinfo->flags & SURF_SKY )
		{   
			/* just adds to visible sky bounds */
			R_AddSkySurface( surf );
		}
		else if ( surf->texinfo->flags & ( SURF_TRANS33 | SURF_TRANS66 ) )
		{   
			/* add to the translucent chain */
			surf->texturechain = r_alpha_surfaces;
			r_alpha_surfaces = surf;
		}
		else
		{
			/* the polygon is visible, so add it to the texture */
			image = R_TextureAnimation( surf->texinfo );
			surf->texturechain = image->texturechain;
			image->texturechain = surf;
		}
	}

	/* recurse down the back side */
	R_RecursiveWorldNode( node->children [ !side ] );
}

void
R_DrawWorld ( void )
{
	entity_t ent;

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

	if ( r_newrefdef.rdflags & RDF_NOWORLDMODEL )
	{
		return;
	}

	currentmodel = r_worldmodel;

	VectorCopy( r_newrefdef.vieworg, modelorg );

	/* auto cycle the world frame for texture animation */
	memset( &ent, 0, sizeof ( ent ) );
	ent.frame = (int) ( r_newrefdef.time * 2 );
	currententity = &ent;

	gl_state.currenttextures [ 0 ] = gl_state.currenttextures [ 1 ] = -1;

	qglColor3f( 1, 1, 1 );
	memset( gl_lms.lightmap_surfaces, 0, sizeof ( gl_lms.lightmap_surfaces ) );
	R_ClearSkyBox();
	R_RecursiveWorldNode( r_worldmodel->nodes );

	DrawTextureChains();
	R_BlendLightmaps();

	R_DrawSkyBox();

	R_DrawTriangleOutlines();
}

/*
 * Mark the leaves and nodes that are in the PVS for the current
 * cluster
 */
void
R_MarkLeaves ( void )
{
	byte    *vis;
	byte fatvis [ MAX_MAP_LEAFS / 8 ];
	mnode_t *node;
	int i, c;
	mleaf_t *leaf;
	int cluster;

	if ( ( r_oldviewcluster == r_viewcluster ) && ( r_oldviewcluster2 == r_viewcluster2 ) && !r_novis->value &&
		 ( r_viewcluster != -1 ) )
	{
		return;
	}

	/* development aid to let you run around and see exactly where
	   the pvs ends */
	if ( gl_lockpvs->value )
	{
		return;
	}

	r_visframecount++;
	r_oldviewcluster = r_viewcluster;
	r_oldviewcluster2 = r_viewcluster2;

	if ( r_novis->value || ( r_viewcluster == -1 ) || !r_worldmodel->vis )
	{
		/* mark everything */
		for ( i = 0; i < r_worldmodel->numleafs; i++ )
		{
			r_worldmodel->leafs [ i ].visframe = r_visframecount;
		}

		for ( i = 0; i < r_worldmodel->numnodes; i++ )
		{
			r_worldmodel->nodes [ i ].visframe = r_visframecount;
		}

		return;
	}

	vis = Mod_ClusterPVS( r_viewcluster, r_worldmodel );

	/* may have to combine two clusters because of solid water boundaries */
	if ( r_viewcluster2 != r_viewcluster )
	{
		memcpy( fatvis, vis, ( r_worldmodel->numleafs + 7 ) / 8 );
		vis = Mod_ClusterPVS( r_viewcluster2, r_worldmodel );
		c = ( r_worldmodel->numleafs + 31 ) / 32;

		for ( i = 0; i < c; i++ )
		{
			( (int *) fatvis ) [ i ] |= ( (int *) vis ) [ i ];
		}

		vis = fatvis;
	}

	for ( i = 0, leaf = r_worldmodel->leafs; i < r_worldmodel->numleafs; i++, leaf++ )
	{
		cluster = leaf->cluster;

		if ( cluster == -1 )
		{
			continue;
		}

		if ( vis [ cluster >> 3 ] & ( 1 << ( cluster & 7 ) ) )
		{
			node = (mnode_t *) leaf;

			do
			{
				if ( node->visframe == r_visframecount )
				{
					break;
				}

				node->visframe = r_visframecount;
				node = node->parent;
			}
			while ( node );
		}
	}
}

static void
LM_InitBlock ( void )
{
	memset( gl_lms.allocated, 0, sizeof ( gl_lms.allocated ) );
}

static void
LM_UploadBlock ( qboolean dynamic )
{
	int texture;
	int height = 0;

	if ( dynamic )
	{
		texture = 0;
	}
	else
	{
		texture = gl_lms.current_lightmap_texture;
	}

	R_Bind( gl_state.lightmap_textures + texture );
	qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
	qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );

	if ( dynamic )
	{
		int i;

		for ( i = 0; i < BLOCK_WIDTH; i++ )
		{
			if ( gl_lms.allocated [ i ] > height )
			{
				height = gl_lms.allocated [ i ];
			}
		}

		qglTexSubImage2D( GL_TEXTURE_2D,
				0,
				0, 0,
				BLOCK_WIDTH, height,
				GL_LIGHTMAP_FORMAT,
				GL_UNSIGNED_BYTE,
				gl_lms.lightmap_buffer );
	}
	else
	{
		qglTexImage2D( GL_TEXTURE_2D,
				0,
				gl_lms.internal_format,
				BLOCK_WIDTH, BLOCK_HEIGHT,
				0,
				GL_LIGHTMAP_FORMAT,
				GL_UNSIGNED_BYTE,
				gl_lms.lightmap_buffer );

		if ( ++gl_lms.current_lightmap_texture == MAX_LIGHTMAPS )
		{
			ri.Sys_Error( ERR_DROP, "LM_UploadBlock() - MAX_LIGHTMAPS exceeded\n" );
		}
	}
}

/* returns a texture number and the position inside it */
static qboolean
LM_AllocBlock ( int w, int h, int *x, int *y )
{
	int i, j;
	int best, best2;

	best = BLOCK_HEIGHT;

	for ( i = 0; i < BLOCK_WIDTH - w; i++ )
	{
		best2 = 0;

		for ( j = 0; j < w; j++ )
		{
			if ( gl_lms.allocated [ i + j ] >= best )
			{
				break;
			}

			if ( gl_lms.allocated [ i + j ] > best2 )
			{
				best2 = gl_lms.allocated [ i + j ];
			}
		}

		if ( j == w )
		{   
			/* this is a valid spot */
			*x = i;
			*y = best = best2;
		}
	}

	if ( best + h > BLOCK_HEIGHT )
	{
		return ( false );
	}

	for ( i = 0; i < w; i++ )
	{
		gl_lms.allocated [ *x + i ] = best + h;
	}

	return ( true );
}

void
GL_BuildPolygonFromSurface ( msurface_t *fa )
{
	int i, lindex, lnumverts;
	medge_t     *pedges, *r_pedge;
	int vertpage;
	float       *vec;
	float s, t;
	glpoly_t    *poly;
	vec3_t total;

	/* reconstruct the polygon */
	pedges = currentmodel->edges;
	lnumverts = fa->numedges;
	vertpage = 0;

	VectorClear( total );

	/* draw texture */
	poly = Hunk_Alloc( sizeof ( glpoly_t ) + ( lnumverts - 4 ) * VERTEXSIZE * sizeof ( float ) );
	poly->next = fa->polys;
	poly->flags = fa->flags;
	fa->polys = poly;
	poly->numverts = lnumverts;

	for ( i = 0; i < lnumverts; i++ )
	{
		lindex = currentmodel->surfedges [ fa->firstedge + i ];

		if ( lindex > 0 )
		{
			r_pedge = &pedges [ lindex ];
			vec = currentmodel->vertexes [ r_pedge->v [ 0 ] ].position;
		}
		else
		{
			r_pedge = &pedges [ -lindex ];
			vec = currentmodel->vertexes [ r_pedge->v [ 1 ] ].position;
		}

		s = DotProduct( vec, fa->texinfo->vecs [ 0 ] ) + fa->texinfo->vecs [ 0 ] [ 3 ];
		s /= fa->texinfo->image->width;

		t = DotProduct( vec, fa->texinfo->vecs [ 1 ] ) + fa->texinfo->vecs [ 1 ] [ 3 ];
		t /= fa->texinfo->image->height;

		VectorAdd( total, vec, total );
		VectorCopy( vec, poly->verts [ i ] );
		poly->verts [ i ] [ 3 ] = s;
		poly->verts [ i ] [ 4 ] = t;

		/* lightmap texture coordinates */
		s = DotProduct( vec, fa->texinfo->vecs [ 0 ] ) + fa->texinfo->vecs [ 0 ] [ 3 ];
		s -= fa->texturemins [ 0 ];
		s += fa->light_s * 16;
		s += 8;
		s /= BLOCK_WIDTH * 16; /* fa->texinfo->texture->width; */

		t = DotProduct( vec, fa->texinfo->vecs [ 1 ] ) + fa->texinfo->vecs [ 1 ] [ 3 ];
		t -= fa->texturemins [ 1 ];
		t += fa->light_t * 16;
		t += 8;
		t /= BLOCK_HEIGHT * 16; /* fa->texinfo->texture->height; */

		poly->verts [ i ] [ 5 ] = s;
		poly->verts [ i ] [ 6 ] = t;
	}

	poly->numverts = lnumverts;
}

void
GL_CreateSurfaceLightmap ( msurface_t *surf )
{
	int smax, tmax;
	byte    *base;

	if ( surf->flags & ( SURF_DRAWSKY | SURF_DRAWTURB ) )
	{
		return;
	}

	smax = ( surf->extents [ 0 ] >> 4 ) + 1;
	tmax = ( surf->extents [ 1 ] >> 4 ) + 1;

	if ( !LM_AllocBlock( smax, tmax, &surf->light_s, &surf->light_t ) )
	{
		LM_UploadBlock( false );
		LM_InitBlock();

		if ( !LM_AllocBlock( smax, tmax, &surf->light_s, &surf->light_t ) )
		{
			ri.Sys_Error( ERR_FATAL, "Consecutive calls to LM_AllocBlock(%d,%d) failed\n", smax, tmax );
		}
	}

	surf->lightmaptexturenum = gl_lms.current_lightmap_texture;

	base = gl_lms.lightmap_buffer;
	base += ( surf->light_t * BLOCK_WIDTH + surf->light_s ) * LIGHTMAP_BYTES;

	R_SetCacheState( surf );
	R_BuildLightMap( surf, base, BLOCK_WIDTH * LIGHTMAP_BYTES );
}

void
GL_BeginBuildingLightmaps ( model_t *m )
{
	static lightstyle_t lightstyles [ MAX_LIGHTSTYLES ];
	int i;
	unsigned dummy [ 128 * 128 ];

	memset( gl_lms.allocated, 0, sizeof ( gl_lms.allocated ) );

	r_framecount = 1;/* no dlightcache */

	/* setup the base lightstyles so the lightmaps won't have to be regenerated
	   the first time they're seen */
	for ( i = 0; i < MAX_LIGHTSTYLES; i++ )
	{
		lightstyles [ i ].rgb [ 0 ] = 1;
		lightstyles [ i ].rgb [ 1 ] = 1;
		lightstyles [ i ].rgb [ 2 ] = 1;
		lightstyles [ i ].white = 3;
	}

	r_newrefdef.lightstyles = lightstyles;

	if ( !gl_state.lightmap_textures )
	{
		gl_state.lightmap_textures  = TEXNUM_LIGHTMAPS;
	}

	gl_lms.current_lightmap_texture = 1;
	gl_lms.internal_format = gl_tex_solid_format;

	/* initialize the dynamic lightmap texture */
	R_Bind( gl_state.lightmap_textures + 0 );
	qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
	qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
	qglTexImage2D( GL_TEXTURE_2D,
			0,
			gl_lms.internal_format,
			BLOCK_WIDTH, BLOCK_HEIGHT,
			0,
			GL_LIGHTMAP_FORMAT,
			GL_UNSIGNED_BYTE,
			dummy );
}

void
GL_EndBuildingLightmaps ( void )
{
	LM_UploadBlock( false );
}