/*
	model_brush.c

	model loading and caching

	Copyright (C) 1996-1997  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:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

*/
// models are the only shared resource between a client and server running
// on the same machine.

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

static __attribute__ ((used)) const char rcsid[] = 
	"$Id$";

#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif

#include <math.h>

#include "QF/checksum.h"
#include "QF/cvar.h"
#include "QF/model.h"
#include "QF/qendian.h"
#include "QF/quakefs.h"
#include "QF/render.h"
#include "QF/sys.h"
#include "QF/va.h"

#include "compat.h"

byte        mod_novis[MAX_MAP_LEAFS / 8];

VISIBLE cvar_t		*gl_sky_divide; //FIXME visibility?
VISIBLE int   mod_lightmap_bytes = 1;	//FIXME should this be visible?

VISIBLE mleaf_t *
Mod_PointInLeaf (const vec3_t p, model_t *model)
{
	float       d;
	mnode_t    *node;
	plane_t    *plane;

	if (!model || !model->nodes)
		Sys_Error ("Mod_PointInLeaf: bad model");

	node = model->nodes;
	while (1) {
		if (node->contents < 0)
			return (mleaf_t *) node;
		plane = node->plane;
		d = DotProduct (p, plane->normal) - plane->dist;
		if (d >= 0)
			node = node->children[0];
		else
			node = node->children[1];
	}

	return NULL;						// never reached
}

static inline byte *
Mod_DecompressVis (byte * in, model_t *model)
{
	static byte decompressed[MAX_MAP_LEAFS / 8];
	byte       *out;
	int			row, c;

	row = (model->numleafs + 7) >> 3;
	out = decompressed;

	if (!in) {							// no vis info, so make all visible
		while (row) {
			*out++ = 0xff;
			row--;
		}
		return decompressed;
	}

	do {
		if (*in) {
			*out++ = *in++;
			continue;
		}

		c = in[1];
		in += 2;
		while (c) {
			*out++ = 0;
			c--;
		}
	} while (out - decompressed < row);

	return decompressed;
}

VISIBLE byte *
Mod_LeafPVS (mleaf_t *leaf, model_t *model)
{
	if (leaf == model->leafs)
		return mod_novis;
	return Mod_DecompressVis (leaf->compressed_vis, model);
}

// BRUSHMODEL LOADING =========================================================

//FIXME SLOW! However, it doesn't seem to be a big issue. Leave alone?
static void
mod_unique_miptex_name (texture_t **textures, texture_t *tx, int ind)
{
	char        name[17];
	int         num = 0, i;
	const char *tag;

	strncpy (name, tx->name, 16);
	name[16] = 0;
	do {
		for (i = 0; i < ind; i++)
			if (textures[i] && !strcmp (textures[i]->name, tx->name))
				break;
		if (i == ind)
			break;
		tag = va ("~%x", num++);
		strncpy (tx->name, name, 16);
		if (strlen (name) + strlen (tag) <= 15)
			strcat (tx->name, tag);
		else
			strcpy (tx->name + 15 - strlen (tag), tag);
	} while (1);
}

static void
Mod_LoadTextures (bsp_t *bsp)
{
	dmiptexlump_t  *m;
	int				i, j, pixels, num, max, altmax;
	miptex_t	   *mt;
	texture_t	   *tx, *tx2;
	texture_t	   *anims[10], *altanims[10];

	if (!bsp->texdatasize) {
		loadmodel->textures = NULL;
		return;
	}
	m = (dmiptexlump_t *) bsp->texdata;

	m->nummiptex = LittleLong (m->nummiptex);

	loadmodel->numtextures = m->nummiptex;
	loadmodel->textures = Hunk_AllocName (m->nummiptex * sizeof
										  (*loadmodel->textures), loadname);

	for (i = 0; i < m->nummiptex; i++) {
		m->dataofs[i] = LittleLong (m->dataofs[i]);
		if (m->dataofs[i] == -1)
			continue;
		mt = (miptex_t *) ((byte *) m + m->dataofs[i]);
		mt->width = LittleLong (mt->width);
		mt->height = LittleLong (mt->height);
		for (j = 0; j < MIPLEVELS; j++)
			mt->offsets[j] = LittleLong (mt->offsets[j]);

		if ((mt->width & 15) || (mt->height & 15))
			Sys_Error ("Texture %s is not 16 aligned", mt->name);
		pixels = mt->width * mt->height / 64 * 85;
		tx = Hunk_AllocName (sizeof (texture_t) + pixels, loadname);

		loadmodel->textures[i] = tx;

		memcpy (tx->name, mt->name, sizeof (tx->name));
		mod_unique_miptex_name (loadmodel->textures, tx, i);
		tx->width = mt->width;
		tx->height = mt->height;
		for (j = 0; j < MIPLEVELS; j++)
			tx->offsets[j] =
				mt->offsets[j] + sizeof (texture_t) - sizeof (miptex_t);
		// the pixels immediately follow the structures
		memcpy (tx + 1, mt + 1, pixels);

		if (!strncmp (mt->name, "sky", 3))
			loadmodel->skytexture = tx;
		Mod_ProcessTexture (tx);
	}

	// sequence the animations
	for (i = 0; i < m->nummiptex; i++) {
		tx = loadmodel->textures[i];
		if (!tx || tx->name[0] != '+')
			continue;
		if (tx->anim_next)
			continue;					// already sequenced

		// find the number of frames in the animation
		memset (anims, 0, sizeof (anims));
		memset (altanims, 0, sizeof (altanims));

		max = tx->name[1];
		altmax = 0;
		if (max >= 'a' && max <= 'z')
			max -= 'a' - 'A';
		if (max >= '0' && max <= '9') {
			max -= '0';
			altmax = 0;
			anims[max] = tx;
			max++;
		} else if (max >= 'A' && max <= 'J') {
			altmax = max - 'A';
			max = 0;
			altanims[altmax] = tx;
			altmax++;
		} else
			Sys_Error ("Bad animating texture %s", tx->name);

		for (j = i + 1; j < m->nummiptex; j++) {
			tx2 = loadmodel->textures[j];
			if (!tx2 || tx2->name[0] != '+')
				continue;
			if (strcmp (tx2->name + 2, tx->name + 2))
				continue;

			num = tx2->name[1];
			if (num >= 'a' && num <= 'z')
				num -= 'a' - 'A';
			if (num >= '0' && num <= '9') {
				num -= '0';
				anims[num] = tx2;
				if (num + 1 > max)
					max = num + 1;
			} else if (num >= 'A' && num <= 'J') {
				num = num - 'A';
				altanims[num] = tx2;
				if (num + 1 > altmax)
					altmax = num + 1;
			} else
				Sys_Error ("Bad animating texture %s", tx->name);
		}

#define	ANIM_CYCLE	2
		// link them all together
		for (j = 0; j < max; j++) {
			tx2 = anims[j];
			if (!tx2)
				Sys_Error ("Missing frame %i of %s", j, tx->name);
			tx2->anim_total = max * ANIM_CYCLE;
			tx2->anim_min = j * ANIM_CYCLE;
			tx2->anim_max = (j + 1) * ANIM_CYCLE;
			tx2->anim_next = anims[(j + 1) % max];
			if (altmax)
				tx2->alternate_anims = altanims[0];
		}
		for (j = 0; j < altmax; j++) {
			tx2 = altanims[j];
			if (!tx2)
				Sys_Error ("Missing frame %i of %s", j, tx->name);
			tx2->anim_total = altmax * ANIM_CYCLE;
			tx2->anim_min = j * ANIM_CYCLE;
			tx2->anim_max = (j + 1) * ANIM_CYCLE;
			tx2->anim_next = altanims[(j + 1) % altmax];
			if (max)
				tx2->alternate_anims = anims[0];
		}
	}
}

static void
Mod_LoadVisibility (bsp_t *bsp)
{
	if (!bsp->visdatasize) {
		loadmodel->visdata = NULL;
		return;
	}
	loadmodel->visdata = Hunk_AllocName (bsp->visdatasize, loadname);
	memcpy (loadmodel->visdata, bsp->visdata, bsp->visdatasize);
}

static void
Mod_LoadEntities (bsp_t *bsp)
{
	if (!bsp->entdatasize) {
		loadmodel->entities = NULL;
		return;
	}
	loadmodel->entities = Hunk_AllocName (bsp->entdatasize, loadname);
	memcpy (loadmodel->entities, bsp->entdata, bsp->entdatasize);
}

static void
Mod_LoadVertexes (bsp_t *bsp)
{
	dvertex_t  *in;
	int         count, i;
	mvertex_t  *out;

	in = bsp->vertexes;
	count = bsp->numvertexes;
	out = Hunk_AllocName (count * sizeof (*out), loadname);

	loadmodel->vertexes = out;
	loadmodel->numvertexes = count;

	for (i = 0; i < count; i++, in++, out++) {
		out->position[0] = LittleFloat (in->point[0]);
		out->position[1] = LittleFloat (in->point[1]);
		out->position[2] = LittleFloat (in->point[2]);
	}
}

static void
Mod_LoadSubmodels (bsp_t *bsp)
{
	dmodel_t   *in, *out;
	int         count, i, j;

	in = bsp->models;
	count = bsp->nummodels;
	out = Hunk_AllocName (count * sizeof (*out), loadname);

	loadmodel->submodels = out;
	loadmodel->numsubmodels = count;

	for (i = 0; i < count; i++, in++, out++) {
		for (j = 0; j < 3; j++) {		// spread the mins / maxs by a pixel
			out->mins[j] = LittleFloat (in->mins[j]) - 1;
			out->maxs[j] = LittleFloat (in->maxs[j]) + 1;
			out->origin[j] = LittleFloat (in->origin[j]);
		}
		for (j = 0; j < MAX_MAP_HULLS; j++)
			out->headnode[j] = LittleLong (in->headnode[j]);
		out->visleafs = LittleLong (in->visleafs);
		out->firstface = LittleLong (in->firstface);
		out->numfaces = LittleLong (in->numfaces);
	}

	out = loadmodel->submodels;

	if (out->visleafs > MAX_MAP_LEAFS) {
		Sys_Error ("Mod_LoadSubmodels: too many visleafs (%d, max = %d) in %s",
				   out->visleafs, MAX_MAP_LEAFS, loadmodel->name);
	}

	if (out->visleafs > 8192)
		Sys_MaskPrintf (SYS_WARN,
						"%i visleafs exceeds standard limit of 8192.\n",
						out->visleafs);
}

static void
Mod_LoadEdges (bsp_t *bsp)
{
	dedge_t    *in;
	int         count, i;
	medge_t    *out;

	in = bsp->edges;
	count = bsp->numedges;
	out = Hunk_AllocName ((count + 1) * sizeof (*out), loadname);

	loadmodel->edges = out;
	loadmodel->numedges = count;

	for (i = 0; i < count; i++, in++, out++) {
		out->v[0] = (unsigned short) LittleShort (in->v[0]);
		out->v[1] = (unsigned short) LittleShort (in->v[1]);
	}
}

static void
Mod_LoadTexinfo (bsp_t *bsp)
{
	float       len1, len2;
	int         count, miptex, i, j;
	mtexinfo_t *out;
	texinfo_t  *in;

	in = bsp->texinfo;
	count = bsp->numtexinfo;
	out = Hunk_AllocName (count * sizeof (*out), loadname);

	loadmodel->texinfo = out;
	loadmodel->numtexinfo = count;

	for (i = 0; i < count; i++, in++, out++) {
		for (j = 0; j < 4; j++) {
			out->vecs[0][j] = LittleFloat (in->vecs[0][j]);
			out->vecs[1][j] = LittleFloat (in->vecs[1][j]);
		}
		len1 = VectorLength (out->vecs[0]);
		len2 = VectorLength (out->vecs[1]);

		len1 = (len1 + len2) / 2;
		if (len1 < 0.32)
			out->mipadjust = 4;
		else if (len1 < 0.49)
			out->mipadjust = 3;
		else if (len1 < 0.99)
			out->mipadjust = 2;
		else
			out->mipadjust = 1;

		miptex = LittleLong (in->miptex);
		out->flags = LittleLong (in->flags);

		if (!loadmodel->textures) {
			out->texture = r_notexture_mip;	// checkerboard texture
			out->flags = 0;
		} else {
			if (miptex >= loadmodel->numtextures)
				Sys_Error ("miptex >= loadmodel->numtextures");
			out->texture = loadmodel->textures[miptex];
			if (!out->texture) {
				out->texture = r_notexture_mip;	// texture not found
				out->flags = 0;
			}
		}
	}
}

/*
	CalcSurfaceExtents

	Fills in s->texturemins[] and s->extents[]
*/
static void
CalcSurfaceExtents (msurface_t *s)
{
	float		mins[2], maxs[2], val;
	int			e, i, j;
	int			bmins[2], bmaxs[2];
	mtexinfo_t *tex;
	mvertex_t  *v;

	mins[0] = mins[1] = 999999;
	maxs[0] = maxs[1] = -99999;

	tex = s->texinfo;

	for (i = 0; i < s->numedges; i++) {
		e = loadmodel->surfedges[s->firstedge + i];
		if (e >= 0)
			v = &loadmodel->vertexes[loadmodel->edges[e].v[0]];
		else
			v = &loadmodel->vertexes[loadmodel->edges[-e].v[1]];

		for (j = 0; j < 2; j++) {
			val = v->position[0] * tex->vecs[j][0] +
				v->position[1] * tex->vecs[j][1] +
				v->position[2] * tex->vecs[j][2] + tex->vecs[j][3];
			if (val < mins[j])
				mins[j] = val;
			if (val > maxs[j])
				maxs[j] = val;
		}
	}

	for (i = 0; i < 2; i++) {
		bmins[i] = floor (mins[i] / 16);
		bmaxs[i] = ceil (maxs[i] / 16);

		s->texturemins[i] = bmins[i] * 16;
		s->extents[i] = (bmaxs[i] - bmins[i]) * 16;
		// FIXME even 2000 is really too small, need a saner test
		if (!(tex->flags & TEX_SPECIAL) && s->extents[i] > 2000)
			Sys_Error ("Bad surface extents: %d %x %d %d", i, tex->flags,
					   s->extents[i], LongSwap (s->extents[i]));
	}
}

static void
Mod_LoadFaces (bsp_t *bsp)
{
	dface_t    *in;
	int			count, planenum, side, surfnum, i;
	msurface_t *out;

	in = bsp->faces;
	count = bsp->numfaces;
	out = Hunk_AllocName (count * sizeof (*out), loadname);

	if (count > 32767) {
		Sys_MaskPrintf (SYS_WARN,
						"%i faces exceeds standard limit of 32767.\n", count);
	}

	loadmodel->surfaces = out;
	loadmodel->numsurfaces = count;

	for (surfnum = 0; surfnum < count; surfnum++, in++, out++) {
		out->firstedge = LittleLong (in->firstedge);
		out->numedges = LittleShort (in->numedges);
		out->flags = 0;

		planenum = LittleShort (in->planenum);
		side = LittleShort (in->side);
		if (side)
			out->flags |= SURF_PLANEBACK;

		out->plane = loadmodel->planes + planenum;

		out->texinfo = loadmodel->texinfo + LittleShort (in->texinfo);

		CalcSurfaceExtents (out);

		// lighting info

		for (i = 0; i < MAXLIGHTMAPS; i++)
			out->styles[i] = in->styles[i];
		i = LittleLong (in->lightofs);
		if (i == -1)
			out->samples = NULL;
		else
			out->samples = loadmodel->lightdata + (i * mod_lightmap_bytes);

		// set the drawing flags flag
		if (!out->texinfo->texture || !out->texinfo->texture->name)
			continue;				// avoid crashing on null textures

		if (!strncmp (out->texinfo->texture->name, "sky", 3)) {	// sky
			out->flags |= (SURF_DRAWSKY | SURF_DRAWTILED);
			if (gl_sky_divide && gl_sky_divide->int_val)
				Mod_SubdivideSurface (out);
			continue;
		}

		if (out->texinfo->texture->name[0] == '*') {	// turbulent
			out->flags |= (SURF_DRAWTURB
						   | SURF_DRAWTILED
						   | SURF_LIGHTBOTHSIDES);
			for (i = 0; i < 2; i++) {
				out->extents[i] = 16384;
				out->texturemins[i] = -8192;
			}
			Mod_SubdivideSurface (out);	// cut up polygon for warps
			continue;
		}
	}
}

static void
Mod_SetParent (mnode_t *node, mnode_t *parent)
{
	node->parent = parent;
	if (node->contents < 0)
		return;
	Mod_SetParent (node->children[0], node);
	Mod_SetParent (node->children[1], node);
}

static void
Mod_LoadNodes (bsp_t *bsp)
{
	dnode_t    *in;
	int			count, i, j, p;
	mnode_t    *out;

	in = bsp->nodes;
	count = bsp->numnodes;
	out = Hunk_AllocName (count * sizeof (*out), loadname);

	if (count > 32767) {
		Sys_MaskPrintf (SYS_WARN,
						"%i nodes exceeds standard limit of 32767.\n", count);
	}

	loadmodel->nodes = out;
	loadmodel->numnodes = count;

	for (i = 0; i < count; i++, in++, out++) {
		for (j = 0; j < 3; j++) {
			out->minmaxs[j] = LittleShort (in->mins[j]);
			out->minmaxs[3 + j] = LittleShort (in->maxs[j]);
		}

		p = LittleLong (in->planenum);
		out->plane = loadmodel->planes + p;

		out->firstsurface = LittleShort (in->firstface);
		out->numsurfaces = LittleShort (in->numfaces);

		for (j = 0; j < 2; j++) {
			// handle > 32k nodes. From darkplaces via fitzquake
			p = (unsigned short) LittleShort (in->children[j]);
			if (p < count) {
				out->children[j] = loadmodel->nodes + p;
			} else {
				p = 65535 - p; //NOTE this uses 65535 intentionally, -1 is leaf
				if (p < loadmodel->numleafs) {
					out->children[j] = (mnode_t *) (loadmodel->leafs + p);
				} else {
					Sys_Printf ("Mod_LoadNodes: invalid leaf index %i "
								"(file has only %i leafs)\n", p,
								loadmodel->numleafs);
					//map it to the solid leaf
					out->children[j] = (mnode_t *)(loadmodel->leafs);
				}
			}
		}
	}

	Mod_SetParent (loadmodel->nodes, NULL);	// sets nodes and leafs
}

static void
Mod_LoadLeafs (bsp_t *bsp)
{
	dleaf_t    *in;
	int			count, i, j, p;
	mleaf_t    *out;
	qboolean    isnotmap = true;

	in = bsp->leafs;
	count = bsp->numleafs;
	out = Hunk_AllocName (count * sizeof (*out), loadname);

	if (count > 32767)
		Sys_Error ("%i leafs exceeds limit of 32767.\n", count);

	loadmodel->leafs = out;
	loadmodel->numleafs = count;
//	snprintf(s, sizeof (s), "maps/%s.bsp",
//	Info_ValueForKey(cl.serverinfo,"map"));
	if (!strncmp ("maps/", loadmodel->name, 5))
		isnotmap = false;
	for (i = 0; i < count; i++, in++, out++) {
		for (j = 0; j < 3; j++) {
			out->mins[j] = LittleShort (in->mins[j]);
			out->maxs[j] = LittleShort (in->maxs[j]);
		}

		p = LittleLong (in->contents);
		out->contents = p;

		out->firstmarksurface = loadmodel->marksurfaces +
			(uint16_t) LittleShort (in->firstmarksurface);
		out->nummarksurfaces = (uint16_t) LittleShort (in->nummarksurfaces);

		p = LittleLong (in->visofs);
		if (p == -1)
			out->compressed_vis = NULL;
		else
			out->compressed_vis = loadmodel->visdata + p;
		out->efrags = NULL;

		for (j = 0; j < 4; j++)
			out->ambient_sound_level[j] = in->ambient_level[j];

		// gl underwater warp
		if (out->contents != CONTENTS_EMPTY) {
			for (j = 0; j < out->nummarksurfaces; j++)
				out->firstmarksurface[j]->flags |= SURF_UNDERWATER;
		}
		if (isnotmap) {
			for (j = 0; j < out->nummarksurfaces; j++)
				out->firstmarksurface[j]->flags |= SURF_DONTWARP;
		}
	}
}

static void
Mod_LoadClipnodes (bsp_t *bsp)
{
	dclipnode_t *in;
	mclipnode_t *out;
	hull_t		*hull;
	int			 count, i;

	in = bsp->clipnodes;
	count = bsp->numclipnodes;
	out = Hunk_AllocName (count * sizeof (*out), loadname);

	if (count > 32767) {
		Sys_MaskPrintf (SYS_WARN,
						"%i clilpnodes exceeds standard limit of 32767.\n",
						count);
	}

	loadmodel->clipnodes = out;
	loadmodel->numclipnodes = count;

	hull = &loadmodel->hulls[1];
	loadmodel->hull_list[1] = hull;
	hull->clipnodes = out;
	hull->firstclipnode = 0;
	hull->lastclipnode = count - 1;
	hull->planes = loadmodel->planes;
	hull->clip_mins[0] = -16;
	hull->clip_mins[1] = -16;
	hull->clip_mins[2] = -24;
	hull->clip_maxs[0] = 16;
	hull->clip_maxs[1] = 16;
	hull->clip_maxs[2] = 32;

	hull = &loadmodel->hulls[2];
	loadmodel->hull_list[2] = hull;
	hull->clipnodes = out;
	hull->firstclipnode = 0;
	hull->lastclipnode = count - 1;
	hull->planes = loadmodel->planes;
	hull->clip_mins[0] = -32;
	hull->clip_mins[1] = -32;
	hull->clip_mins[2] = -24;
	hull->clip_maxs[0] = 32;
	hull->clip_maxs[1] = 32;
	hull->clip_maxs[2] = 64;

	for (i = 0; i < count; i++, out++, in++) {
		out->planenum = LittleLong (in->planenum);
		if (out->planenum < 0 || out->planenum >= loadmodel->numplanes)
			Sys_Error ("Mod_LoadClipnodes: planenum out of bounds");
		out->children[0] = (uint16_t) LittleShort (in->children[0]);
		out->children[1] = (uint16_t) LittleShort (in->children[1]);
		if (out->children[0] >= count)
			out->children[0] -= 65536;
		if (out->children[1] >= count)
			out->children[1] -= 65536;
		if ((out->children[0] >= 0
			 && (out->children[0] < hull->firstclipnode
				 || out->children[0] > hull->lastclipnode))
			|| (out->children[1] >= 0
				&& (out->children[1] < hull->firstclipnode
					|| out->children[1] > hull->lastclipnode)))
			Sys_Error ("Mod_LoadClipnodes: bad node number");
	}
}

/*
	Mod_MakeHull0

	Replicate the drawing hull structure as a clipping hull
*/
static void
Mod_MakeHull0 (void)
{
	mclipnode_t *out;
	hull_t		*hull;
	int			 count, i, j;
	mnode_t		*in, *child;

	hull = &loadmodel->hulls[0];
	loadmodel->hull_list[0] = hull;

	in = loadmodel->nodes;
	count = loadmodel->numnodes;
	out = Hunk_AllocName (count * sizeof (*out), loadname);

	hull->clipnodes = out;
	hull->firstclipnode = 0;
	hull->lastclipnode = count - 1;
	hull->planes = loadmodel->planes;

	for (i = 0; i < count; i++, out++, in++) {
		out->planenum = in->plane - loadmodel->planes;
		for (j = 0; j < 2; j++) {
			child = in->children[j];
			if (child->contents < 0)
				out->children[j] = child->contents;
			else
				out->children[j] = child - loadmodel->nodes;
		}
	}
}

static void
Mod_LoadMarksurfaces (bsp_t *bsp)
{
	int			 count, i, j;
	msurface_t **out;
	uint16_t    *in;

	in = bsp->marksurfaces;
	count = bsp->nummarksurfaces;
	out = Hunk_AllocName (count * sizeof (*out), loadname);

	if (count > 32767) {
		Sys_MaskPrintf (SYS_WARN,
						"%i marksurfaces exceeds standard limit of 32767.\n",
						count);
	}

	loadmodel->marksurfaces = out;
	loadmodel->nummarksurfaces = count;

	for (i = 0; i < count; i++) {
		j = (uint16_t) LittleShort (in[i]);
		if (j >= loadmodel->numsurfaces)
			Sys_Error ("Mod_ParseMarksurfaces: bad surface number");
		out[i] = loadmodel->surfaces + j;
	}
}

static void
Mod_LoadSurfedges (bsp_t *bsp)
{
	int          count, i;
	int32_t     *in;
	int         *out;

	in = bsp->surfedges;
	count = bsp->numsurfedges;
	out = Hunk_AllocName (count * sizeof (*out), loadname);

	loadmodel->surfedges = out;
	loadmodel->numsurfedges = count;

	for (i = 0; i < count; i++)
		out[i] = LittleLong (in[i]);
}

static void
Mod_LoadPlanes (bsp_t *bsp)
{
	dplane_t   *in;
	int			bits, count, i, j;
	plane_t    *out;

	in = bsp->planes;
	count = bsp->numplanes;
	out = Hunk_AllocName (count * 2 * sizeof (*out), loadname);

	loadmodel->planes = out;
	loadmodel->numplanes = count;

	for (i = 0; i < count; i++, in++, out++) {
		bits = 0;
		for (j = 0; j < 3; j++) {
			out->normal[j] = LittleFloat (in->normal[j]);
			if (out->normal[j] < 0)
				bits |= 1 << j;
		}

		out->dist = LittleFloat (in->dist);
		out->type = LittleLong (in->type);
		out->signbits = bits;
	}
}

static void
do_checksums (const bsp_t *bsp, void *_mod)
{
	int         i;
	model_t    *mod = (model_t *) _mod;
	byte       *base;

	base = (byte *) bsp->header;

	// checksum all of the map, except for entities
	mod->checksum = 0;
	mod->checksum2 = 0;
	for (i = 0; i < HEADER_LUMPS; i++) {
		lump_t     *lump = bsp->header->lumps + i;
		int         csum;

		if (i == LUMP_ENTITIES)
			continue;
		csum = Com_BlockChecksum (base + lump->fileofs, lump->filelen);
		mod->checksum ^= csum;

		if (i != LUMP_VISIBILITY && i != LUMP_LEAFS && i != LUMP_NODES)
			mod->checksum2 ^= csum;
	}
}

void
Mod_LoadBrushModel (model_t *mod, void *buffer)
{
	dmodel_t   *bm;
	int			i, j;
	bsp_t      *bsp;

	loadmodel->type = mod_brush;

	bsp = LoadBSPMem (buffer, qfs_filesize, do_checksums, mod);

	// load into heap
	Mod_LoadVertexes (bsp);
	Mod_LoadEdges (bsp);
	Mod_LoadSurfedges (bsp);
	Mod_LoadTextures (bsp);
	Mod_LoadLighting (bsp);
	Mod_LoadPlanes (bsp);
	Mod_LoadTexinfo (bsp);
	Mod_LoadFaces (bsp);
	Mod_LoadMarksurfaces (bsp);
	Mod_LoadVisibility (bsp);
	Mod_LoadLeafs (bsp);
	Mod_LoadNodes (bsp);
	Mod_LoadClipnodes (bsp);
	Mod_LoadEntities (bsp);
	Mod_LoadSubmodels (bsp);

	Mod_MakeHull0 ();

	mod->numframes = 2;					// regular and alternate animation

	// set up the submodels (FIXME: this is confusing)
	for (i = 0; i < mod->numsubmodels; i++) {
		bm = &mod->submodels[i];

		mod->hulls[0].firstclipnode = bm->headnode[0];
		mod->hull_list[0] = &mod->hulls[0];
		for (j = 1; j < MAX_MAP_HULLS; j++) {
			mod->hulls[j].firstclipnode = bm->headnode[j];
			mod->hulls[j].lastclipnode = mod->numclipnodes - 1;
			mod->hull_list[j] = &mod->hulls[j];
		}

		mod->firstmodelsurface = bm->firstface;
		mod->nummodelsurfaces = bm->numfaces;

		VectorCopy (bm->maxs, mod->maxs);
		VectorCopy (bm->mins, mod->mins);

		mod->radius = RadiusFromBounds (mod->mins, mod->maxs);

		mod->numleafs = bm->visleafs;

		if (i < mod->numsubmodels - 1) {
			// duplicate the basic information
			char	name[10];

			snprintf (name, sizeof (name), "*%i", i + 1);
			loadmodel = Mod_FindName (name);
			*loadmodel = *mod;
			strcpy (loadmodel->name, name);
			mod = loadmodel;
		}
	}
}