#include "quakedef.h"

#ifdef TERRAIN
#include "glquake.h"
#include "shader.h"

#include "pr_common.h"

//#define STRICTEDGES	//strict (ugly) grid
#define TERRAINTHICKNESS 16
#define TERRAINACTIVESECTIONS 1000

/*
a note on networking:
By default terrain is NOT networked. This means content is loaded without networking delays.
If you wish to edit the terrain collaboratively, you can enable the mod_terrain_networked cvar.
When set, changes on the server will notify clients that a section has changed, and the client will reload it as needed.
Changes on the client WILL NOT notify the server, and will get clobbered if the change is also made on the server.
This means for editing purposes, you MUST funnel it via ssqc with your own permission checks.
It also means for explosions and local stuff, the server will merely restate changes from impacts if you do them early. BUT DO NOT CALL THE EDIT FUNCTION IF THE SERVER HAS ALREADY APPLIED THE CHANGE.
*/
cvar_t mod_terrain_networked = CVARD("mod_terrain_networked", "0", "Terrain edits are networked. Clients will download sections on demand, and servers will notify clients of changes.");

//heightmaps work thusly:
//there is one raw heightmap file
//the file is split to 4*4 sections.
//each section is textured independantly (remember banshees are capped at 256*256 pixels)
//it's built into 16 seperate display lists, these display lists are individually culled, but the drivers are expected to optimise them too.
//Tei claims 14x speedup with a single display list. hopefully we can achieve the same speed by culling per-section.
//we get 20->130
//perhaps we should build it with multitexture? (no - slower on ati)

int Surf_NewLightmaps(int count, int width, int height, qboolean deluxe);

#define MAXSECTIONS 64	//this many sections max in each direction
#define SECTTEXSIZE 64	//this many texture samples per section
#define SECTHEIGHTSIZE 17 //this many height samples per section

//each section is this many sections higher in world space, to keep the middle centered at '0 0'
#define CHUNKBIAS	(MAXSECTIONS*MAXSECTIONS/2)
#define CHUNKLIMIT	(MAXSECTIONS*MAXSECTIONS)

#define LMCHUNKS 2

#define HMLMSTRIDE (LMCHUNKS*SECTTEXSIZE)

#define SECTION_MAGIC (*(int*)"HMMS")
#define SECTION_VER	1
/*simple version history:
ver=0
	SECTHEIGHTSIZE=16
*/

enum
{
	//these flags can be found on disk
	TSF_HASWATER	= 1u<<0,
	TSF_HASCOLOURS	= 1u<<1,

	//these flags should not be found on disk
	TSF_NOTIFY		= 1u<<28,	//modified on server, waiting for clients to be told about the change.
	TSF_RELIGHT		= 1u<<29,	//height edited, needs relighting.
	TSF_DIRTY		= 1u<<30,	//its heightmap has changed, the mesh needs rebuilding
	TSF_EDITED		= 1u<<31	//says it needs to be written if saved

#define TSF_INTERNAL	(TSF_RELIGHT|TSF_DIRTY|TSF_EDITED|TSF_NOTIFY)
};

typedef struct
{
	int size;
	vec3_t axisorg[4];
	float scale;
	int reserved3;
	int reserved2;
	int reserved1;
	//char modelname[1+];
} dsmesh_t;
typedef struct
{
	int magic;
	int ver;
	unsigned int flags;
	char texname[4][32];
	unsigned int texmap[SECTTEXSIZE][SECTTEXSIZE];
	float heights[SECTHEIGHTSIZE*SECTHEIGHTSIZE];
	unsigned short holes;
	float waterheight;
	float minh;
	float maxh;
	int ents_num;
	int reserved1;
	int reserved4;
	int reserved3;
	int reserved2;
} dsection_t;

typedef struct hmpolyset_s
{
	struct hmpolyset_s *next;
	shader_t *shader;
	mesh_t mesh;
	mesh_t *amesh;
	vbo_t vbo;
} hmpolyset_t;
typedef struct
{
	link_t recycle;
	int sx, sy;

	float heights[SECTHEIGHTSIZE*SECTHEIGHTSIZE];
	unsigned short holes;
	unsigned int flags;
	float waterheight;
	float minh, maxh;
	struct heightmap_s *hmmod;

#ifndef SERVERONLY
	vec4_t colours[SECTHEIGHTSIZE*SECTHEIGHTSIZE];
	char texname[4][32];
	int lightmap;
	int lmx, lmy;

	texnums_t textures;
	vbo_t vbo;
	mesh_t mesh;
	mesh_t *amesh;

	int numents;
	int maxents;
	entity_t *ents;

	hmpolyset_t *polys;
#endif
} hmsection_t;
typedef struct
{
	hmsection_t *section[MAXSECTIONS*MAXSECTIONS];
} hmcluster_t;
typedef struct heightmap_s
{
	char path[MAX_QPATH];
	int firstsegx, firstsegy;
	int maxsegx, maxsegy; //tex/cull sections
	float sectionsize;	//each section is this big, in world coords
	hmcluster_t *cluster[MAXSECTIONS*MAXSECTIONS];
	shader_t *skyshader;
	shader_t *shader;
	shader_t *watershader;
	mesh_t skymesh;
	mesh_t *askymesh;
	unsigned int exteriorcontents;
	int tiled;
	int tilecount[2];
	int tilepixcount[2];

	int activesections;
	link_t recycle;

#ifndef SERVERONLY
	struct lmsect_s
	{
		struct lmsect_s *next;
		int lm, x, y;
	} *unusedlmsects;
#endif

#ifndef SERVERONLY
	//I'm putting this here because we might have some quite expensive lighting routines going on
	//and that'll make editing the terrain jerky as fook, so relighting it a few texels at a time will help maintain a framerate while editing
	hmsection_t *relight;
	unsigned int relightidx;
	vec2_t relightmin;
#endif
} heightmap_t;


static void ted_dorelight(heightmap_t *hm);
static qboolean Terr_Collect(heightmap_t *hm);


#ifndef SERVERONLY
static texid_t Terr_LoadTexture(char *name)
{
	extern texid_t missing_texture;
	texid_t id;
	if (*name)
	{
		id = R_LoadHiResTexture(name, NULL, 0);
		if (!TEXVALID(id))
		{
			id = missing_texture;
			Con_Printf("Unable to load texture %s\n", name);
		}
	}
	else
		id = missing_texture;
	return id;
}
#endif

static void Terr_LoadSectionTextures(hmsection_t *s)
{
#ifndef SERVERONLY
	extern texid_t missing_texture;
	//CL_CheckOrEnqueDownloadFile(s->texname[0], NULL, 0);
	//CL_CheckOrEnqueDownloadFile(s->texname[1], NULL, 0);
	//CL_CheckOrEnqueDownloadFile(s->texname[2], NULL, 0);
	//CL_CheckOrEnqueDownloadFile(s->texname[3], NULL, 0);
	if (s->hmmod->tiled)
	{
		s->textures.base			= Terr_LoadTexture(va("maps/%s/atlas.tga", s->hmmod->path));
		s->textures.fullbright		= Terr_LoadTexture(va("maps/%s/atlas_luma.tga", s->hmmod->path));
		s->textures.bump			= Terr_LoadTexture(va("maps/%s/atlas_norm.tga", s->hmmod->path));
		s->textures.specular		= Terr_LoadTexture(va("maps/%s/atlas_spec.tga", s->hmmod->path));
		s->textures.upperoverlay	= missing_texture;
		s->textures.loweroverlay	= missing_texture;
	}
	else
	{
		s->textures.base			= Terr_LoadTexture(s->texname[0]);
		s->textures.upperoverlay	= Terr_LoadTexture(s->texname[1]);
		s->textures.loweroverlay	= Terr_LoadTexture(s->texname[2]);
		s->textures.fullbright		= Terr_LoadTexture(s->texname[3]);
		s->textures.bump			= *s->texname[0]?R_LoadHiResTexture(va("%s_norm", s->texname[0]), NULL, 0):r_nulltex;
		s->textures.specular		= *s->texname[0]?R_LoadHiResTexture(va("%s_spec", s->texname[0]), NULL, 0):r_nulltex;
	}
#endif
}

#ifndef SERVERONLY
static void Terr_InitLightmap(hmsection_t *s)
{
	heightmap_t *hm = s->hmmod;
	struct lmsect_s *lms;

	if (!hm->unusedlmsects)
	{
		int lm;
		int i;
		lm = Surf_NewLightmaps(1, SECTTEXSIZE*LMCHUNKS, SECTTEXSIZE*LMCHUNKS, false);
		for (i = 0; i < LMCHUNKS*LMCHUNKS; i++)
		{
			lms = BZ_Malloc(sizeof(*lms));
			lms->lm = lm;
			lms->x = (i & (LMCHUNKS-1))*SECTTEXSIZE;
			lms->y = (i / LMCHUNKS)*SECTTEXSIZE;
			lms->next = hm->unusedlmsects;
			hm->unusedlmsects = lms;
		}
	}

	lms = hm->unusedlmsects;
	hm->unusedlmsects = lms->next;
	
	s->lightmap = lms->lm;
	s->lmx = lms->x;
	s->lmy = lms->y;

	Z_Free(lms);
}
#endif

static char *Terr_DiskSectionName(heightmap_t *hm, int sx, int sy)
{
	sx -= CHUNKBIAS;
	sy -= CHUNKBIAS;
	//wrap cleanly
	sx &= CHUNKLIMIT-1;
	sy &= CHUNKLIMIT-1;
	return va("maps/%s/sect_%03x_%03x.hms", hm->path, sx, sy);
}
static char *Terr_TempDiskSectionName(heightmap_t *hm, int sx, int sy)
{
	sx -= CHUNKBIAS;
	sy -= CHUNKBIAS;
	//wrap cleanly
	sx &= CHUNKLIMIT-1;
	sy &= CHUNKLIMIT-1;
	return va("temp/%s/sect_%03x_%03x.hms", hm->path, sx, sy);
}

static int dehex_e(int i, qboolean *error)
{
	if      (i >= '0' && i <= '9')
		return (i-'0');
	else if (i >= 'A' && i <= 'F')
		return (i-'A'+10);
	else if (i >= 'a' && i <= 'f')
		return (i-'a'+10);
	else
		*error = true;
	return 0;
}
static qboolean Terr_IsSectionFName(heightmap_t *hm, char *fname, int *sx, int *sy)
{
	int l;
	qboolean error = false;
	*sx = 0xdeafbeef;	//something clearly invalid
	*sy = 0xdeafbeef;

	//not this model...
	if (!hm)
		return false;

	//expect the first 5 chars to be maps/ or temp/
	fname += 5;

	l = strlen(hm->path);
	if (strncmp(fname, hm->path, l) || fname[l] != '/')
		return false;
	fname += l+1;

	//fname now has a fixed length.
	if (strlen(fname) != 16)
		return false;
	if (strncmp(fname, "sect_", 5) || fname[8] != '_' || (strcmp(fname+12, ".hms") && strcmp(fname+12, ".tmp")))
		return false;

	*sx = 0;
	*sx += dehex_e(fname[5], &error)<<8;
	*sx += dehex_e(fname[6], &error)<<4;
	*sx += dehex_e(fname[7], &error)<<0;

	*sy = 0;
	*sy += dehex_e(fname[9], &error)<<8;
	*sy += dehex_e(fname[10], &error)<<4;
	*sy += dehex_e(fname[11], &error)<<0;

	*sx += CHUNKBIAS;
	*sy += CHUNKBIAS;

	if ((unsigned)*sx >= CHUNKLIMIT)
		*sx -= CHUNKLIMIT;
	if ((unsigned)*sy >= CHUNKLIMIT)
		*sy -= CHUNKLIMIT;

	//make sure its a valid section index.
	if ((unsigned)*sx >= CHUNKLIMIT)
		return false;
	if ((unsigned)*sy >= CHUNKLIMIT)
		return false;
	return true;
}
static hmsection_t *Terr_ReadSection(heightmap_t *hm, hmsection_t *s, int sx, int sy, dsection_t *ds, unsigned int dslen)
{
	int i, j;
#ifndef SERVERONLY
	dsmesh_t *dm;
	unsigned char *lm;
	float *colours;
#endif
	void *ptr;

	if (ds)
	{
		if (ds->magic != SECTION_MAGIC)
			return NULL;
		if (ds->ver != SECTION_VER)
		{
			//generate a new one if the version doesn't match
			ds = NULL;
		}
	}

	if (!s)
	{
		s = Z_Malloc(sizeof(*s));
		if (!s)
		{
			FS_FreeFile(ds);
			return NULL;
		}

		InsertLinkBefore(&s->recycle, &hm->recycle);
		s->sx = sx;
		s->sy = sy;
		hm->activesections++;
		
#ifndef SERVERONLY
		s->lightmap = -1;
#endif
	}

	s->hmmod = hm;

#ifndef SERVERONLY
	s->flags |= TSF_DIRTY;

	if (s->lightmap < 0 && qrenderer != QR_NONE)
		Terr_InitLightmap(s);
#endif

	if (ds)
	{
		s->flags = ds->flags | TSF_DIRTY;

		/*load the heights*/
		for (i = 0; i < SECTHEIGHTSIZE*SECTHEIGHTSIZE; i++)
		{
			s->heights[i] = LittleFloat(ds->heights[i]);
		}
		s->minh = ds->minh;
		s->maxh = ds->maxh;
		s->waterheight = ds->waterheight;
		s->holes = ds->holes;

		ptr = ds+1;

#ifndef SERVERONLY
		/*deal with textures*/
		Q_strncpyz(s->texname[0], ds->texname[0], sizeof(s->texname[0]));
		Q_strncpyz(s->texname[1], ds->texname[1], sizeof(s->texname[1]));
		Q_strncpyz(s->texname[2], ds->texname[2], sizeof(s->texname[2]));
		Q_strncpyz(s->texname[3], ds->texname[3], sizeof(s->texname[3]));

		if (*s->texname[0])
			CL_CheckOrEnqueDownloadFile(s->texname[0], NULL, 0);
		if (*s->texname[1])
			CL_CheckOrEnqueDownloadFile(s->texname[1], NULL, 0);
		if (*s->texname[2])
			CL_CheckOrEnqueDownloadFile(s->texname[2], NULL, 0);
		if (*s->texname[3])
			CL_CheckOrEnqueDownloadFile(s->texname[3], NULL, 0);

		/*load in the mixture/lighting*/
		if (s->lightmap >= 0)
		{
			lm = lightmap[s->lightmap]->lightmaps;
			lm += (s->lmy * HMLMSTRIDE + s->lmx) * lightmap_bytes;
			for (i = 0; i < SECTTEXSIZE; i++)
			{
				memcpy(lm, ds->texmap + i, sizeof(ds->texmap[0]));
				lm += (HMLMSTRIDE)*lightmap_bytes;
			}
			lightmap[s->lightmap]->modified = true;
			lightmap[s->lightmap]->rectchange.l = 0;
			lightmap[s->lightmap]->rectchange.t = 0;
			lightmap[s->lightmap]->rectchange.w = HMLMSTRIDE;
			lightmap[s->lightmap]->rectchange.h = HMLMSTRIDE;
		}

		s->mesh.colors4f_array = s->colours;
		if (ds->flags & TSF_HASCOLOURS)
		{
			for (i = 0, colours = (float*)ptr; i < SECTHEIGHTSIZE*SECTHEIGHTSIZE; i++, colours+=4)
			{
				s->colours[i][0] = LittleFloat(colours[0]);
				s->colours[i][1] = LittleFloat(colours[1]);
				s->colours[i][2] = LittleFloat(colours[2]);
				s->colours[i][3] = LittleFloat(colours[3]);
			}
			ptr = colours;
		}
		else
		{
			for (i = 0; i < SECTHEIGHTSIZE*SECTHEIGHTSIZE; i++)
			{
				s->colours[i][0] = 1;
				s->colours[i][1] = 1;
				s->colours[i][2] = 1;
				s->colours[i][3] = 1;
			}
		}

		/*load any static ents*/
		s->numents = ds->ents_num;
		s->maxents = s->numents;
		if (s->maxents)
			s->ents = Z_Malloc(sizeof(*s->ents) * s->maxents);
		else
			s->ents = NULL;
		if (!s->ents)
			s->numents = s->maxents = 0;
		for (i = 0, dm = (dsmesh_t*)ptr; i < s->numents; i++, dm = (dsmesh_t*)((qbyte*)dm + dm->size))
		{
			s->ents[i].model = Mod_ForName((char*)(dm + 1), false);
			if (!s->ents[i].model || s->ents[i].model->type == mod_dummy)
			{
				s->numents--;
				i--;
				continue;
			}
			s->ents[i].scale = dm->scale;
			VectorCopy(dm->axisorg[0], s->ents[i].axis[0]);
			VectorCopy(dm->axisorg[1], s->ents[i].axis[1]);
			VectorCopy(dm->axisorg[2], s->ents[i].axis[2]);
			VectorCopy(dm->axisorg[3], s->ents[i].origin);
			s->ents[i].origin[0] += (sx-CHUNKBIAS)*hm->sectionsize;
			s->ents[i].origin[1] += (sy-CHUNKBIAS)*hm->sectionsize;
			s->ents[i].shaderRGBAf[0] = 1;
			s->ents[i].shaderRGBAf[1] = 1;
			s->ents[i].shaderRGBAf[2] = 1;
			s->ents[i].shaderRGBAf[3] = 1;
		}
#endif
	}
	else
	{
//		s->flags |= TSF_RELIGHT;

#ifndef SERVERONLY
		if (s->lightmap >= 0)
		{
			lm = lightmap[s->lightmap]->lightmaps;
			lm += (s->lmy * HMLMSTRIDE + s->lmx) * lightmap_bytes;
			for (i = 0; i < SECTTEXSIZE; i++)
			{
				for (j = 0; j < SECTTEXSIZE; j++)
				{
					lm[j*4+0] = 0;
					lm[j*4+0] = 0;
					lm[j*4+0] = 0;
					lm[j*4+3] = 255;
				}
				lm += (HMLMSTRIDE)*lightmap_bytes;
			}
			lightmap[s->lightmap]->modified = true;
			lightmap[s->lightmap]->rectchange.l = 0;
			lightmap[s->lightmap]->rectchange.t = 0;
			lightmap[s->lightmap]->rectchange.w = HMLMSTRIDE;
			lightmap[s->lightmap]->rectchange.h = HMLMSTRIDE;
		}
		for (i = 0; i < SECTHEIGHTSIZE*SECTHEIGHTSIZE; i++)
		{
			s->colours[i][0] = 1;
			s->colours[i][1] = 1;
			s->colours[i][2] = 1;
			s->colours[i][3] = 1;
		}
#endif

#if 0//def DEBUG
		void *f;
		if (lightmap_bytes == 4 && lightmap_bgra && FS_LoadFile(va("maps/%s/splatt.png", hm->path), &f) >= 0)
		{
			//temp
			int vx, vy;
			int x, y;
			extern qbyte *Read32BitImageFile(qbyte *buf, int len, int *width, int *height, qboolean *hasalpha, char *fname);
			int sw, sh;
			qboolean hasalpha;
			unsigned char *splatter = Read32BitImageFile(f, com_filesize, &sw, &sh, &hasalpha, "splattermap");
			if (splatter)
			{
				lm = lightmap[s->lightmap]->lightmaps;
				lm += (s->lmy * HMLMSTRIDE + s->lmx) * lightmap_bytes;

				for (vx = 0; vx < SECTTEXSIZE; vx++)
				{
					x = sw * (((float)sy) + ((float)vx / (SECTTEXSIZE-1))) / hm->numsegsx;
					if (x > sw-1)
						x = sw-1;
					for (vy = 0; vy < SECTTEXSIZE; vy++)
					{
						y = sh * (((float)sx) + ((float)vy / (SECTTEXSIZE-1))) / hm->numsegsy;
						if (y > sh-1)
							y = sh-1;

						lm[2] = splatter[(y + x*sh)*4+0];
						lm[1] = splatter[(y + x*sh)*4+1];
						lm[0] = splatter[(y + x*sh)*4+2];
						lm[3] = splatter[(y + x*sh)*4+3];
						lm += 4;
					}
					lm += (HMLMSTRIDE - SECTTEXSIZE)*lightmap_bytes;
				}
				BZ_Free(splatter);

				lightmap[s->lightmap]->modified = true;
				lightmap[s->lightmap]->rectchange.l = 0;
				lightmap[s->lightmap]->rectchange.t = 0;
				lightmap[s->lightmap]->rectchange.w = HMLMSTRIDE;
				lightmap[s->lightmap]->rectchange.h = HMLMSTRIDE;
			}
			FS_FreeFile(f);
		}

		if (lightmap_bytes == 4 && lightmap_bgra && FS_LoadFile(va("maps/%s/heightmap.png", hm->path), &f) >= 0)
		{
			//temp
			int vx, vy;
			int x, y;
			extern qbyte *Read32BitImageFile(qbyte *buf, int len, int *width, int *height, qboolean *hasalpha, char *fname);
			int sw, sh;
			float *h;
			qboolean hasalpha;
			unsigned char *hmimage = Read32BitImageFile(f, com_filesize, &sw, &sh, &hasalpha, "heightmap");
			if (hmimage)
			{
				h = s->heights;

				for (vx = 0; vx < SECTHEIGHTSIZE; vx++)
				{
					x = sw * (((float)sy) + ((float)vx / (SECTHEIGHTSIZE-1))) / hm->numsegsx;
					if (x > sw-1)
						x = sw-1;
					for (vy = 0; vy < SECTHEIGHTSIZE; vy++)
					{
						y = sh * (((float)sx) + ((float)vy / (SECTHEIGHTSIZE-1))) / hm->numsegsy;
						if (y > sh-1)
							y = sh-1;

						*h = 0;
						*h += hmimage[(y + x*sh)*4+0];
						*h += hmimage[(y + x*sh)*4+1]<<8;
						*h += hmimage[(y + x*sh)*4+2]<<16;
						*h *= 4.0f/(1<<16);
						h++;
					}
				}
				BZ_Free(hmimage);
			}
			FS_FreeFile(f);
		}
#endif
	}

	Terr_LoadSectionTextures(s);

	return s;
}

#ifndef SERVERONLY
qboolean Terr_DownloadedSection(char *fname)
{
	int len;
	void *fileptr;
	int x, y;
	heightmap_t *hm;

	if (!cl.worldmodel)
		return false;

	hm = cl.worldmodel->terrain;

	if (Terr_IsSectionFName(hm, fname, &x, &y))
	{
		len = FS_LoadFile(fname, &fileptr);
		if (len < 0)
			fileptr = NULL;

		{
			int cx = x / MAXSECTIONS;
			int cy = y / MAXSECTIONS;
			int sx = x & (MAXSECTIONS-1);
			int sy = y & (MAXSECTIONS-1);
			hmcluster_t *cluster = hm->cluster[cx + cy*MAXSECTIONS];
			if (!cluster)
			{
				cluster = Z_Malloc(sizeof(*cluster));
				if (cluster)
					hm->cluster[cx + cy*MAXSECTIONS] = cluster;
			}
			if (cluster)
				cluster->section[sx + sy*MAXSECTIONS] = Terr_ReadSection(hm, cluster->section[sx + sy*MAXSECTIONS], x, y, fileptr, len);
		}
		if (fileptr)
			FS_FreeFile(fileptr);
		return true;
	}

	return false;
}
#endif

static hmsection_t *Terr_LoadSection(heightmap_t *hm, hmsection_t *s, int sx, int sy, qboolean force)
{
	hmsection_t *sect;
	void *diskimage;
	int len;
#ifndef SERVERONLY
	//when using networked terrain, the client will never load a section from disk, but only loading it from the server
	if (mod_terrain_networked.ival && !sv.state)
	{
		//try to download it now...
		if (!cl.downloadlist)
			CL_CheckOrEnqueDownloadFile(Terr_DiskSectionName(hm, sx, sy), Terr_TempDiskSectionName(hm, sx, sy), DLLF_OVERWRITE|DLLF_TEMPORARY);
		return NULL;
	}
#endif

	diskimage = NULL;
	len = FS_LoadFile(Terr_DiskSectionName(hm, sx, sy), (void**)&diskimage);

	/*queue the file for download if we don't have it yet*/
	if (len < 0)
	{
		if (!force)
		{
#ifndef SERVERONLY
			if (!cl.downloadlist)
				CL_CheckOrEnqueDownloadFile(Terr_DiskSectionName(hm, sx, sy), NULL, 0);
#endif
			return NULL;
		}
	}
	sect = Terr_ReadSection(hm, s, sx, sy, diskimage, len);

	if (diskimage)
		FS_FreeFile(diskimage);
	return sect;
}

//doesn't clear edited/dirty flags or anything
static qboolean Terr_SaveSection(heightmap_t *hm, hmsection_t *s, int sx, int sy, char *fname)
{
#ifndef SERVERONLY
	dsection_t ds;
	dsmesh_t dm;
	unsigned char *lm;
	vfsfile_t *f;
	int nothing = 0;
	int i;
	vec4_t dcolours[SECTHEIGHTSIZE*SECTHEIGHTSIZE];
	//if its invalid or doesn't contain all the data...
	if (!s || s->lightmap < 0)
		return true;

	memset(&ds, 0, sizeof(ds));
	memset(&dm, 0, sizeof(dm));

	ds.magic = SECTION_MAGIC;
	ds.ver = SECTION_VER;
	//mask off the flags which are only valid in memory
	ds.flags = s->flags & ~(TSF_INTERNAL);

	//kill the haswater flag if its entirely above any possible water anyway.
	if (s->waterheight < s->minh)
		ds.flags &= ~TSF_HASWATER;
	ds.flags &= ~TSF_HASCOLOURS;	//recalculated

	Q_strncpyz(ds.texname[0], s->texname[0], sizeof(ds.texname[0]));
	Q_strncpyz(ds.texname[1], s->texname[1], sizeof(ds.texname[1]));
	Q_strncpyz(ds.texname[2], s->texname[2], sizeof(ds.texname[2]));
	Q_strncpyz(ds.texname[3], s->texname[3], sizeof(ds.texname[3]));

	lm = lightmap[s->lightmap]->lightmaps;
	lm += (s->lmy * HMLMSTRIDE + s->lmx) * lightmap_bytes;
	for (i = 0; i < SECTTEXSIZE; i++)
	{
		memcpy(ds.texmap + i, lm, sizeof(ds.texmap[0]));
		lm += (HMLMSTRIDE)*lightmap_bytes;
	}

	for (i = 0; i < SECTHEIGHTSIZE*SECTHEIGHTSIZE; i++)
	{
		ds.heights[i] = LittleFloat(s->heights[i]);

		if (s->colours[i][0] != 1 || s->colours[i][1] != 1 || s->colours[i][2] != 1 || s->colours[i][3] != 1)
		{
			ds.flags |= TSF_HASCOLOURS;
			dcolours[i][0] = LittleFloat(s->colours[i][0]);
			dcolours[i][1] = LittleFloat(s->colours[i][1]);
			dcolours[i][2] = LittleFloat(s->colours[i][2]);
			dcolours[i][3] = LittleFloat(s->colours[i][3]);
		}
		else
		{
			dcolours[i][0] = dcolours[i][1] = dcolours[i][2] = dcolours[i][3] = LittleFloat(1);
		}
	}
	ds.waterheight = s->waterheight;
	ds.holes = s->holes;
	ds.minh = s->minh;
	ds.maxh = s->maxh;
	ds.ents_num = s->numents;

	FS_CreatePath(fname, FS_GAMEONLY);

	f = FS_OpenVFS(fname, "wb", FS_GAMEONLY);
	if (!f)
	{
		Con_Printf("Failed to open %s\n", fname);
		return false;
	}
	VFS_WRITE(f, &ds, sizeof(ds));
	if (ds.flags & TSF_HASCOLOURS)
		VFS_WRITE(f, dcolours, sizeof(dcolours));
	for (i = 0; i < s->numents; i++)
	{
		int pad;
		dm.scale = s->ents[i].scale;
		VectorCopy(s->ents[i].axis[0], dm.axisorg[0]);
		VectorCopy(s->ents[i].axis[1], dm.axisorg[1]);
		VectorCopy(s->ents[i].axis[2], dm.axisorg[2]);
		VectorCopy(s->ents[i].origin, dm.axisorg[3]);
		dm.axisorg[3][0] += (CHUNKBIAS-sx)*hm->sectionsize;
		dm.axisorg[3][1] += (CHUNKBIAS-sy)*hm->sectionsize;
		dm.size = sizeof(dm) + strlen(s->ents[i].model->name) + 1;
		if (dm.size & 3)
			pad = 4 - (dm.size&3);
		else
			pad = 0;
		dm.size += pad;
		VFS_WRITE(f, &dm, sizeof(dm));
		VFS_WRITE(f, s->ents[i].model->name, strlen(s->ents[i].model->name)+1);
		if (pad)
			VFS_WRITE(f, &nothing, pad);
	}
	VFS_CLOSE(f);
#endif
	return true;
}

/*convienience function*/
#define TGS_NOLOAD		0
#define TGS_LOAD		1
#define TGS_FORCELOAD	2
static hmsection_t *Terr_GetSection(heightmap_t *hm, int x, int y, unsigned int flags)
{
	hmcluster_t *cluster;
	hmsection_t *section;
	int cx = x / MAXSECTIONS;
	int cy = y / MAXSECTIONS;
	int sx = x & (MAXSECTIONS-1);
	int sy = y & (MAXSECTIONS-1);
	cluster = hm->cluster[cx + cy*MAXSECTIONS];
	if (!cluster)
	{
		if (flags & (TGS_LOAD|TGS_FORCELOAD))
		{
			cluster = Z_Malloc(sizeof(*cluster));
			if (!cluster)
				return NULL;
			hm->cluster[cx + cy*MAXSECTIONS] = cluster;
		}
		else
			return NULL;
	}
	section = cluster->section[sx + sy*MAXSECTIONS];
	if (!section)
	{
		if (flags & (TGS_LOAD|TGS_FORCELOAD))
		{
//			while (hm->activesections > TERRAINACTIVESECTIONS)
//				Terr_Collect(hm);
			section = cluster->section[sx + sy*MAXSECTIONS] = Terr_LoadSection(hm, section, x, y, !!(flags & TGS_FORCELOAD));
		}
	}
#ifndef SERVERONLY
	//when using networked terrain, the client will never load a section from disk, but only loading it from the server
	if (section && (section->flags & TSF_NOTIFY) && mod_terrain_networked.ival && !sv.state)
	{
		//try to download it now...
		if (!cl.downloadlist)
		{
			CL_CheckOrEnqueDownloadFile(Terr_DiskSectionName(hm, x, y), Terr_TempDiskSectionName(hm, x, y), DLLF_OVERWRITE|DLLF_TEMPORARY);

			section->flags &= ~TSF_NOTIFY;
		}
	}
#endif

	return section;
}

/*save all currently loaded sections*/
int Heightmap_Save(heightmap_t *hm)
{
	hmsection_t *s;
	int x, y;
	int sectionssaved = 0;
	for (x = hm->firstsegx; x < hm->maxsegx; x++)
	{
		for (y = hm->firstsegy; y < hm->maxsegy; y++)
		{
			s = Terr_GetSection(hm, x, y, TGS_NOLOAD);
			if (!s)
				continue;
			if (s->flags & TSF_EDITED)
			{
				if (Terr_SaveSection(hm, s, x, y, Terr_DiskSectionName(hm, x, y)))
				{
					s->flags &= ~TSF_EDITED;
					sectionssaved++;
				}
			}
		}
	}

	return sectionssaved;
}

#ifndef CLIENTONLY
//on servers, we can get requests to download current map sections. if so, give them it.
qboolean Terrain_LocateSection(char *name, flocation_t *loc)
{
	heightmap_t *hm;
	hmsection_t *s;
	int x, y;
	int nlen = strlen(name);

	//reject if its not in maps
	if (strncmp(name, "maps/", 5))
		return false;

	if (!sv.world.worldmodel)
		return false;
	hm = sv.world.worldmodel->terrain;
	if (!Terr_IsSectionFName(hm, name, &x, &y))
		return false;

	//verify that its valid
	if (strcmp(name, Terr_DiskSectionName(hm, x, y)))
		return false;

	s = Terr_GetSection(hm, x, y, TGS_NOLOAD);
	if (!s || !(s->flags & TSF_EDITED))
		return false;	//its not been edited, might as well just use the regular file

	name = Terr_TempDiskSectionName(hm, x, y);
	if (!Terr_SaveSection(hm, s, x, y, name))
		return false;

	return FS_FLocateFile(name, FSLFRT_IFFOUND, loc);
}
#endif

void Terr_DestroySection(heightmap_t *hm, hmsection_t *s, qboolean lightmapreusable)
{
	RemoveLink(&s->recycle);
#ifndef SERVERONLY
	if (lightmapreusable && s->lightmap >= 0)
	{
		struct lmsect_s *lms;

		lms = BZ_Malloc(sizeof(*lms));
		lms->lm = s->lightmap;
		lms->x = s->lmx;
		lms->y = s->lmy;
		lms->next = hm->unusedlmsects;
		hm->unusedlmsects = lms;
	}

	if (hm->relight == s)
		hm->relight = NULL;

#ifdef GLQUAKE
	if (qrenderer == QR_OPENGL && qglDeleteBuffersARB)
	{
		qglDeleteBuffersARB(1, &s->vbo.coord.gl.vbo);
		qglDeleteBuffersARB(1, &s->vbo.indicies.gl.vbo);
	}
#endif

	Z_Free(s->ents);
	Z_Free(s->mesh.xyz_array);
	Z_Free(s->mesh.indexes);
#endif

	Z_Free(s);

	hm->activesections--;
}

static void Terr_DoEditNotify(heightmap_t *hm)
{
	int i;
	char *cmd;
	hmsection_t *s;
	link_t *ln = &hm->recycle;

	if (!sv.state)
		return;

	for (i = 0; i < sv.allocated_client_slots; i++)
	{
		if (svs.clients[i].state > cs_zombie && svs.clients[i].netchan.remote_address.type != NA_LOOPBACK)
		{
			if (svs.clients[i].backbuf.cursize)
				return;
		}
	}

	for (ln = &hm->recycle; ln->next != &hm->recycle; ln = &s->recycle)
	{
		s = (hmsection_t*)ln->next;
		if (s->flags & TSF_NOTIFY)
		{
			s->flags &= ~TSF_NOTIFY;
			cmd = va("mod_terrain_reload %s %i %i\n", hm->path, s->sx - CHUNKBIAS, s->sy - CHUNKBIAS);
			for (i = 0; i < sv.allocated_client_slots; i++)
			{
				if (svs.clients[i].state > cs_zombie && svs.clients[i].netchan.remote_address.type != NA_LOOPBACK)
				{
					SV_StuffcmdToClient(&svs.clients[i], cmd);
				}
			}
			return;
		}
	}
}

//garbage collect the oldest section, to make space for another
static qboolean Terr_Collect(heightmap_t *hm)
{
	hmcluster_t *c;
	hmsection_t *s;
	int cx, cy;
	int sx, sy;

	link_t *ln = &hm->recycle;
	for (ln = &hm->recycle; ln->next != &hm->recycle; )
	{
		s = (hmsection_t*)ln->next;
		if (s->flags & TSF_EDITED)
			ln = &s->recycle;
		else
		{
			cx = s->sx/MAXSECTIONS;
			cy = s->sy/MAXSECTIONS;
			c = hm->cluster[cx + cy*MAXSECTIONS];
			sx = s->sx & (MAXSECTIONS-1);
			sy = s->sy & (MAXSECTIONS-1);
			if (c->section[sx+sy*MAXSECTIONS] != s)
				Sys_Error("invalid section collection");
			c->section[sx+sy*MAXSECTIONS] = NULL;

			Terr_DestroySection(hm, s, true);
			return true;
		}
	}
	return false;
}

/*purge all sections
lightmaps only are purged whenever the client rudely kills lightmaps
we'll reload those when its next seen.
(lightmaps will already have been destroyed, so no poking them)
*/
void Terr_PurgeTerrainModel(model_t *mod, qboolean lightmapsonly, qboolean lightmapreusable)
{
	heightmap_t *hm = mod->terrain;
	hmcluster_t *c;
	hmsection_t *s;
	int cx, cy;
	int sx, sy;

	for (cy = 0; cy < MAXSECTIONS; cy++)
	for (cx = 0; cx < MAXSECTIONS; cx++)
	{
		c = hm->cluster[cx + cy*MAXSECTIONS];
		if (!c)
			continue;

		for (sy = 0; sy < MAXSECTIONS; sy++)
		for (sx = 0; sx < MAXSECTIONS; sx++)
		{
			s = c->section[sx + sy*MAXSECTIONS];
			if (!s)
			{
			}
			else if (lightmapsonly)
			{
#ifndef SERVERONLY
				s->lightmap = -1;
#endif
			}
			else
			{
				c->section[sx+sy*MAXSECTIONS] = NULL;

				Terr_DestroySection(hm, s, lightmapreusable);
			}
		}
		if (!lightmapsonly)
		{
			hm->cluster[cx + cy*MAXSECTIONS] = NULL;
			BZ_Free(c);
		}
	}
#ifndef SERVERONLY
	if (!lightmapreusable)
	{
		while (hm->unusedlmsects)
		{
			struct lmsect_s *lms;
			lms = hm->unusedlmsects;
			hm->unusedlmsects = lms->next;
			BZ_Free(lms);
		}
	}
#endif
}
#ifndef SERVERONLY
void Terr_DrawTerrainWater(heightmap_t *hm, float *mins, float *maxs, float waterz, float r, float g, float b, float a)
{
	scenetris_t *t;
	int flags = BEF_NOSHADOWS;
	
	if (cl_numstris && cl_stris[cl_numstris-1].shader == hm->watershader && cl_stris[cl_numstris-1].flags == flags)
	{
		t = &cl_stris[cl_numstris-1];
	}
	else
	{
		if (cl_numstris == cl_maxstris)
		{
			cl_maxstris+=8;
			cl_stris = BZ_Realloc(cl_stris, sizeof(*cl_stris)*cl_maxstris);
		}
		t = &cl_stris[cl_numstris++];
		t->shader = hm->watershader;
		t->flags = flags;
		t->firstidx = cl_numstrisidx;
		t->firstvert = cl_numstrisvert;
		t->numvert = 0;
		t->numidx = 0;
	}

	if (cl_numstrisidx+12 > cl_maxstrisidx)
	{
		cl_maxstrisidx=cl_numstrisidx+12 + 64;
		cl_strisidx = BZ_Realloc(cl_strisidx, sizeof(*cl_strisidx)*cl_maxstrisidx);
	}
	if (cl_numstrisvert+4 > cl_maxstrisvert)
	{
		cl_maxstrisvert+=64;
		cl_strisvertv = BZ_Realloc(cl_strisvertv, sizeof(*cl_strisvertv)*cl_maxstrisvert);
		cl_strisvertt = BZ_Realloc(cl_strisvertt, sizeof(*cl_strisvertt)*cl_maxstrisvert);
		cl_strisvertc = BZ_Realloc(cl_strisvertc, sizeof(*cl_strisvertc)*cl_maxstrisvert);
	}

	{
		VectorSet(cl_strisvertv[cl_numstrisvert], mins[0], mins[1], waterz);
		Vector4Set(cl_strisvertc[cl_numstrisvert], r, g, b, a);
		Vector2Set(cl_strisvertt[cl_numstrisvert], mins[0]/64, mins[1]/64);
		cl_numstrisvert++;

		VectorSet(cl_strisvertv[cl_numstrisvert], mins[0], maxs[1], waterz);
		Vector4Set(cl_strisvertc[cl_numstrisvert], r, g, b, a);
		Vector2Set(cl_strisvertt[cl_numstrisvert], mins[0]/64, maxs[1]/64);
		cl_numstrisvert++;

		VectorSet(cl_strisvertv[cl_numstrisvert], maxs[0], maxs[1], waterz);
		Vector4Set(cl_strisvertc[cl_numstrisvert], r, g, b, a);
		Vector2Set(cl_strisvertt[cl_numstrisvert], maxs[0]/64, maxs[1]/64);
		cl_numstrisvert++;

		VectorSet(cl_strisvertv[cl_numstrisvert], maxs[0], mins[1], waterz);
		Vector4Set(cl_strisvertc[cl_numstrisvert], r, g, b, a);
		Vector2Set(cl_strisvertt[cl_numstrisvert], maxs[0]/64, mins[1]/64);
		cl_numstrisvert++;
	}




	/*build the triangles*/
	cl_strisidx[cl_numstrisidx++] = t->numvert + 0;
	cl_strisidx[cl_numstrisidx++] = t->numvert + 1;
	cl_strisidx[cl_numstrisidx++] = t->numvert + 2;

	cl_strisidx[cl_numstrisidx++] = t->numvert + 0;
	cl_strisidx[cl_numstrisidx++] = t->numvert + 2;
	cl_strisidx[cl_numstrisidx++] = t->numvert + 3;

	cl_strisidx[cl_numstrisidx++] = t->numvert + 3;
	cl_strisidx[cl_numstrisidx++] = t->numvert + 2;
	cl_strisidx[cl_numstrisidx++] = t->numvert + 1;

	cl_strisidx[cl_numstrisidx++] = t->numvert + 3;
	cl_strisidx[cl_numstrisidx++] = t->numvert + 1;
	cl_strisidx[cl_numstrisidx++] = t->numvert + 0;


	t->numidx = cl_numstrisidx - t->firstidx;
	t->numvert += 4;
}

void Terr_RebuildMesh(hmsection_t *s, int x, int y)
{
	int vx, vy;
	int v;
	mesh_t *mesh = &s->mesh;
	heightmap_t *hm = s->hmmod;

	if (s->lightmap < 0)
	{
		Terr_InitLightmap(s);
	}

	s->minh = 9999999999999999.f;
	s->maxh = -9999999999999999.f;

	if (hm->tiled)
	{
		if (mesh->xyz_array)
			BZ_Free(mesh->xyz_array);
		{
			mesh->xyz_array = BZ_Malloc((sizeof(vecV_t)+sizeof(vec2_t)+sizeof(vec2_t)) * (SECTHEIGHTSIZE-1)*(SECTHEIGHTSIZE-1)*4*3);
			mesh->st_array = (void*) (mesh->xyz_array + (SECTHEIGHTSIZE-1)*(SECTHEIGHTSIZE-1)*4*3);
			mesh->lmst_array[0] = (void*) (mesh->st_array + (SECTHEIGHTSIZE-1)*(SECTHEIGHTSIZE-1)*4*3);
		}
		mesh->numvertexes = 0;

		if (mesh->indexes)
			BZ_Free(mesh->indexes);
			mesh->indexes = BZ_Malloc(sizeof(index_t) * SECTHEIGHTSIZE*SECTHEIGHTSIZE*6*3);
		mesh->numindexes = 0;
		mesh->colors4f_array = NULL;

		for (vy = 0; vy < SECTHEIGHTSIZE-1; vy++)
		{
			for (vx = 0; vx < SECTHEIGHTSIZE-1; vx++)
			{
				float st[2], inst[2];
#if SECTHEIGHTSIZE >= 4
				int holebit;

				//skip generation of the mesh above holes
				holebit = 1u<<(vx/(SECTHEIGHTSIZE>>2) + (vy/(SECTHEIGHTSIZE>>2))*4);
				if (s->holes & holebit)
					continue;
#endif

				//top face
				v = mesh->numvertexes;
				mesh->numvertexes += 4;
				mesh->xyz_array[v+0][0] = (x-CHUNKBIAS + (vx+0)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+0][1] = (y-CHUNKBIAS + (vy+0)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+0][2] = s->heights[vx + vy*SECTHEIGHTSIZE];

				mesh->xyz_array[v+1][0] = (x-CHUNKBIAS + (vx+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+1][1] = (y-CHUNKBIAS + (vy+0)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+1][2] = s->heights[vx + vy*SECTHEIGHTSIZE];

				mesh->xyz_array[v+2][0] = (x-CHUNKBIAS + (vx+0)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+2][1] = (y-CHUNKBIAS + (vy+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+2][2] = s->heights[vx + vy*SECTHEIGHTSIZE];

				mesh->xyz_array[v+3][0] = (x-CHUNKBIAS + (vx+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+3][1] = (y-CHUNKBIAS + (vy+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+3][2] = s->heights[vx + vy*SECTHEIGHTSIZE];

				if (s->maxh < mesh->xyz_array[v][2])
					s->maxh = mesh->xyz_array[v][2];
				if (s->minh > mesh->xyz_array[v][2])
					s->minh = mesh->xyz_array[v][2];

				st[0] = 1.0f/hm->tilecount[0] * vx;
				st[1] = 1.0f/hm->tilecount[1] * vy;
				inst[0] = 0.5f/(hm->tilecount[0]*hm->tilepixcount[0]);
				inst[1] = 0.5f/(hm->tilecount[1]*hm->tilepixcount[1]);
				mesh->st_array[v+0][0] = st[0]+inst[0];
				mesh->st_array[v+0][1] = st[1]+inst[1];
				mesh->st_array[v+1][0] = st[0]-inst[0]+1.0f/hm->tilecount[0];
				mesh->st_array[v+1][1] = st[1]+inst[1];
				mesh->st_array[v+2][0] = st[0]+inst[0];
				mesh->st_array[v+2][1] = st[1]-inst[1]+1.0f/hm->tilecount[1];
				mesh->st_array[v+3][0] = st[0]-inst[0]+1.0f/hm->tilecount[0];
				mesh->st_array[v+3][1] = st[1]-inst[1]+1.0f/hm->tilecount[1];

				//calc the position in the range -0.5 to 0.5
				mesh->lmst_array[0][v][0] = (((float)vx / (SECTHEIGHTSIZE-1))-0.5);
				mesh->lmst_array[0][v][1] = (((float)vy / (SECTHEIGHTSIZE-1))-0.5);
				//scale down to a half-texel
				mesh->lmst_array[0][v][0] *= (SECTTEXSIZE-1.0f)/HMLMSTRIDE;
				mesh->lmst_array[0][v][1] *= (SECTTEXSIZE-1.0f)/HMLMSTRIDE;
				//bias it
				mesh->lmst_array[0][v][0] += ((float)SECTTEXSIZE/(HMLMSTRIDE*2)) + ((float)(s->lmx) / HMLMSTRIDE);
				mesh->lmst_array[0][v][1] += ((float)SECTTEXSIZE/(HMLMSTRIDE*2)) + ((float)(s->lmy) / HMLMSTRIDE);

				mesh->indexes[mesh->numindexes++] = v+0;
				mesh->indexes[mesh->numindexes++] = v+2;
				mesh->indexes[mesh->numindexes++] = v+1;
				mesh->indexes[mesh->numindexes++] = v+1;
				mesh->indexes[mesh->numindexes++] = v+2;
				mesh->indexes[mesh->numindexes++] = v+1+2;


				//x boundary
				v = mesh->numvertexes;
				mesh->numvertexes += 4;
				mesh->xyz_array[v+0][0] = (x-CHUNKBIAS + (vx+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+0][1] = (y-CHUNKBIAS + (vy+0)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+0][2] = s->heights[vx+0 + vy*SECTHEIGHTSIZE];

				mesh->xyz_array[v+1][0] = (x-CHUNKBIAS + (vx+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+1][1] = (y-CHUNKBIAS + (vy+0)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+1][2] = s->heights[(vx+1) + vy*SECTHEIGHTSIZE];

				mesh->xyz_array[v+2][0] = (x-CHUNKBIAS + (vx+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+2][1] = (y-CHUNKBIAS + (vy+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+2][2] = s->heights[(vx+0) + vy*SECTHEIGHTSIZE];

				mesh->xyz_array[v+3][0] = (x-CHUNKBIAS + (vx+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+3][1] = (y-CHUNKBIAS + (vy+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+3][2] = s->heights[(vx+1) + vy*SECTHEIGHTSIZE];

				if (s->maxh < mesh->xyz_array[v][2])
					s->maxh = mesh->xyz_array[v][2];
				if (s->minh > mesh->xyz_array[v][2])
					s->minh = mesh->xyz_array[v][2];

				st[0] = 1.0f/hm->tilecount[0] * vx;
				st[1] = 1.0f/hm->tilecount[1] * vy;
				inst[0] = 0.5f/(hm->tilecount[0]*hm->tilepixcount[0]);
				inst[1] = 0.5f/(hm->tilecount[1]*hm->tilepixcount[1]);
				mesh->st_array[v+0][0] = st[0]+inst[0];
				mesh->st_array[v+0][1] = st[1]+inst[1];
				mesh->st_array[v+1][0] = st[0]+inst[0];
				mesh->st_array[v+1][1] = st[1]-inst[1]+1.0f/hm->tilecount[1];
				mesh->st_array[v+2][0] = st[0]-inst[0]+1.0f/hm->tilecount[0];
				mesh->st_array[v+2][1] = st[1]+inst[1];
				mesh->st_array[v+3][0] = st[0]-inst[0]+1.0f/hm->tilecount[0];
				mesh->st_array[v+3][1] = st[1]-inst[1]+1.0f/hm->tilecount[1];

				//calc the position in the range -0.5 to 0.5
				mesh->lmst_array[0][v][0] = (((float)vx / (SECTHEIGHTSIZE-1))-0.5);
				mesh->lmst_array[0][v][1] = (((float)vy / (SECTHEIGHTSIZE-1))-0.5);
				//scale down to a half-texel
				mesh->lmst_array[0][v][0] *= (SECTTEXSIZE-1.0f)/HMLMSTRIDE;
				mesh->lmst_array[0][v][1] *= (SECTTEXSIZE-1.0f)/HMLMSTRIDE;
				//bias it
				mesh->lmst_array[0][v][0] += ((float)SECTTEXSIZE/(HMLMSTRIDE*2)) + ((float)(s->lmx) / HMLMSTRIDE);
				mesh->lmst_array[0][v][1] += ((float)SECTTEXSIZE/(HMLMSTRIDE*2)) + ((float)(s->lmy) / HMLMSTRIDE);


				mesh->indexes[mesh->numindexes++] = v+0;
				mesh->indexes[mesh->numindexes++] = v+2;
				mesh->indexes[mesh->numindexes++] = v+1;
				mesh->indexes[mesh->numindexes++] = v+1;
				mesh->indexes[mesh->numindexes++] = v+2;
				mesh->indexes[mesh->numindexes++] = v+1+2;

				//y boundary
				v = mesh->numvertexes;
				mesh->numvertexes += 4;
				mesh->xyz_array[v+0][0] = (x-CHUNKBIAS + (vx+0)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+0][1] = (y-CHUNKBIAS + (vy+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+0][2] = s->heights[vx + (vy+0)*SECTHEIGHTSIZE];

				mesh->xyz_array[v+1][0] = (x-CHUNKBIAS + (vx+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+1][1] = (y-CHUNKBIAS + (vy+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+1][2] = s->heights[vx + (vy+0)*SECTHEIGHTSIZE];

				mesh->xyz_array[v+2][0] = (x-CHUNKBIAS + (vx+0)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+2][1] = (y-CHUNKBIAS + (vy+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+2][2] = s->heights[vx + (vy+1)*SECTHEIGHTSIZE];

				mesh->xyz_array[v+3][0] = (x-CHUNKBIAS + (vx+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+3][1] = (y-CHUNKBIAS + (vy+1)/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v+3][2] = s->heights[vx + (vy+1)*SECTHEIGHTSIZE];

				if (s->maxh < mesh->xyz_array[v][2])
					s->maxh = mesh->xyz_array[v][2];
				if (s->minh > mesh->xyz_array[v][2])
					s->minh = mesh->xyz_array[v][2];

				st[0] = 1.0f/hm->tilecount[0] * vx;
				st[1] = 1.0f/hm->tilecount[1] * vy;
				inst[0] = 0.5f/(hm->tilecount[0]*hm->tilepixcount[0]);
				inst[1] = 0.5f/(hm->tilecount[1]*hm->tilepixcount[1]);
				mesh->st_array[v+0][0] = st[0]+inst[0];
				mesh->st_array[v+0][1] = st[1]+inst[1];
				mesh->st_array[v+1][0] = st[0]-inst[0]+1.0f/hm->tilecount[0];
				mesh->st_array[v+1][1] = st[1]+inst[1];
				mesh->st_array[v+2][0] = st[0]+inst[0];
				mesh->st_array[v+2][1] = st[1]-inst[1]+1.0f/hm->tilecount[1];
				mesh->st_array[v+3][0] = st[0]-inst[0]+1.0f/hm->tilecount[0];
				mesh->st_array[v+3][1] = st[1]-inst[1]+1.0f/hm->tilecount[1];

				//calc the position in the range -0.5 to 0.5
				mesh->lmst_array[0][v][0] = (((float)vx / (SECTHEIGHTSIZE-1))-0.5);
				mesh->lmst_array[0][v][1] = (((float)vy / (SECTHEIGHTSIZE-1))-0.5);
				//scale down to a half-texel
				mesh->lmst_array[0][v][0] *= (SECTTEXSIZE-1.0f)/HMLMSTRIDE;
				mesh->lmst_array[0][v][1] *= (SECTTEXSIZE-1.0f)/HMLMSTRIDE;
				//bias it
				mesh->lmst_array[0][v][0] += ((float)SECTTEXSIZE/(HMLMSTRIDE*2)) + ((float)(s->lmx) / HMLMSTRIDE);
				mesh->lmst_array[0][v][1] += ((float)SECTTEXSIZE/(HMLMSTRIDE*2)) + ((float)(s->lmy) / HMLMSTRIDE);

				mesh->indexes[mesh->numindexes++] = v+0;
				mesh->indexes[mesh->numindexes++] = v+2;
				mesh->indexes[mesh->numindexes++] = v+1;
				mesh->indexes[mesh->numindexes++] = v+1;
				mesh->indexes[mesh->numindexes++] = v+2;
				mesh->indexes[mesh->numindexes++] = v+1+2;
			}
		}
	}
	else
	{
		if (!mesh->xyz_array)
		{
			mesh->xyz_array = BZ_Malloc((sizeof(vecV_t)+sizeof(vec2_t)+sizeof(vec2_t)) * (SECTHEIGHTSIZE)*(SECTHEIGHTSIZE));
			mesh->st_array = (void*) (mesh->xyz_array + (SECTHEIGHTSIZE)*(SECTHEIGHTSIZE));
			mesh->lmst_array[0] = (void*) (mesh->st_array + (SECTHEIGHTSIZE)*(SECTHEIGHTSIZE));
		}
		mesh->colors4f_array = s->colours;
		mesh->numvertexes = 0;
		/*64 quads across requires 65 verticies*/
		for (vy = 0; vy < SECTHEIGHTSIZE; vy++)
		{
			for (vx = 0; vx < SECTHEIGHTSIZE; vx++)
			{
				v = mesh->numvertexes++;
				mesh->xyz_array[v][0] = (x-CHUNKBIAS + vx/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v][1] = (y-CHUNKBIAS + vy/(SECTHEIGHTSIZE-1.0f)) * hm->sectionsize;
				mesh->xyz_array[v][2] = s->heights[vx + vy*SECTHEIGHTSIZE];

				if (s->maxh < mesh->xyz_array[v][2])
					s->maxh = mesh->xyz_array[v][2];
				if (s->minh > mesh->xyz_array[v][2])
					s->minh = mesh->xyz_array[v][2];

				mesh->st_array[v][0] = mesh->xyz_array[v][0] / 128;
				mesh->st_array[v][1] = mesh->xyz_array[v][1] / 128;

				//calc the position in the range -0.5 to 0.5
				mesh->lmst_array[0][v][0] = (((float)vx / (SECTHEIGHTSIZE-1))-0.5);
				mesh->lmst_array[0][v][1] = (((float)vy / (SECTHEIGHTSIZE-1))-0.5);
				//scale down to a half-texel
				mesh->lmst_array[0][v][0] *= (SECTTEXSIZE-1.0f)/HMLMSTRIDE;
				mesh->lmst_array[0][v][1] *= (SECTTEXSIZE-1.0f)/HMLMSTRIDE;
				//bias it
				mesh->lmst_array[0][v][0] += ((float)SECTTEXSIZE/(HMLMSTRIDE*2)) + ((float)(s->lmx) / HMLMSTRIDE);
				mesh->lmst_array[0][v][1] += ((float)SECTTEXSIZE/(HMLMSTRIDE*2)) + ((float)(s->lmy) / HMLMSTRIDE);
			}
		}

		if (!mesh->indexes)
			mesh->indexes = BZ_Malloc(sizeof(index_t) * SECTHEIGHTSIZE*SECTHEIGHTSIZE*6);

		mesh->numindexes = 0;
		for (vy = 0; vy < SECTHEIGHTSIZE-1; vy++)
		{
			for (vx = 0; vx < SECTHEIGHTSIZE-1; vx++)
			{
	#ifndef STRICTEDGES
				float d1,d2;
	#endif

	#if SECTHEIGHTSIZE >= 4
				int holebit;

				//skip generation of the mesh above holes
				holebit = 1u<<(vx/(SECTHEIGHTSIZE>>2) + (vy/(SECTHEIGHTSIZE>>2))*4);
				if (s->holes & holebit)
					continue;
	#endif
				v = vx + vy*(SECTHEIGHTSIZE);

	#ifndef STRICTEDGES
				d1 = fabs(mesh->xyz_array[v][2] - mesh->xyz_array[v+1+SECTHEIGHTSIZE][2]);
				d2 = fabs(mesh->xyz_array[v+1][2] - mesh->xyz_array[v+SECTHEIGHTSIZE][2]);
				if (d1 < d2)
				{
					mesh->indexes[mesh->numindexes++] = v+0;
					mesh->indexes[mesh->numindexes++] = v+1+SECTHEIGHTSIZE;
					mesh->indexes[mesh->numindexes++] = v+1;
					mesh->indexes[mesh->numindexes++] = v+0;
					mesh->indexes[mesh->numindexes++] = v+SECTHEIGHTSIZE;
					mesh->indexes[mesh->numindexes++] = v+1+SECTHEIGHTSIZE;
				}
				else
	#endif
				{
					mesh->indexes[mesh->numindexes++] = v+0;
					mesh->indexes[mesh->numindexes++] = v+SECTHEIGHTSIZE;
					mesh->indexes[mesh->numindexes++] = v+1;
					mesh->indexes[mesh->numindexes++] = v+1;
					mesh->indexes[mesh->numindexes++] = v+SECTHEIGHTSIZE;
					mesh->indexes[mesh->numindexes++] = v+1+SECTHEIGHTSIZE;
				}
			}
		}
	}

#ifdef GLQUAKE
	if (qrenderer == QR_OPENGL && qglGenBuffersARB)
	{
		if (s->vbo.coord.gl.vbo)
		{
			qglDeleteBuffersARB(1, &s->vbo.coord.gl.vbo);
			qglDeleteBuffersARB(1, &s->vbo.indicies.gl.vbo);
			s->vbo.coord.gl.vbo = 0;
			s->vbo.indicies.gl.vbo = 0;
		}

		if (!s->vbo.coord.gl.vbo)
		{
			qglGenBuffersARB(1, &s->vbo.coord.gl.vbo);
			GL_SelectVBO(s->vbo.coord.gl.vbo);
			qglBufferDataARB(GL_ARRAY_BUFFER_ARB, (sizeof(vecV_t)+sizeof(vec2_t)+sizeof(vec2_t)+sizeof(vec4_t)) * (mesh->numvertexes), NULL, GL_STATIC_DRAW_ARB);
		}
		else
			GL_SelectVBO(s->vbo.coord.gl.vbo);

		qglBufferSubDataARB(GL_ARRAY_BUFFER_ARB, 0, (sizeof(vecV_t)+sizeof(vec2_t)+sizeof(vec2_t)) * mesh->numvertexes, mesh->xyz_array);
		if (mesh->colors4f_array)
			qglBufferSubDataARB(GL_ARRAY_BUFFER_ARB, (sizeof(vecV_t)+sizeof(vec2_t)+sizeof(vec2_t)) * mesh->numvertexes, sizeof(vec4_t)*mesh->numvertexes,  mesh->colors4f_array);
		GL_SelectVBO(0);
		s->vbo.coord.gl.addr = 0;
		s->vbo.texcoord.gl.addr = (void*)((char*)mesh->st_array - (char*)mesh->xyz_array);
		s->vbo.texcoord.gl.vbo = s->vbo.coord.gl.vbo;
		s->vbo.lmcoord[0].gl.addr = (void*)((char*)mesh->lmst_array[0] - (char*)mesh->xyz_array);
		s->vbo.lmcoord[0].gl.vbo = s->vbo.coord.gl.vbo;
		s->vbo.colours.gl.addr = (void*)((sizeof(vecV_t)+sizeof(vec2_t)+sizeof(vec2_t)) * mesh->numvertexes);
		s->vbo.colours.gl.vbo = s->vbo.coord.gl.vbo;
//		Z_Free(mesh->xyz_array);
//		mesh->xyz_array = NULL;
//		mesh->st_array = NULL;
//		mesh->lmst_array = NULL;

		if (!s->vbo.indicies.gl.vbo)
			qglGenBuffersARB(1, &s->vbo.indicies.gl.vbo);
		s->vbo.indicies.gl.addr = 0;
		GL_SelectEBO(s->vbo.indicies.gl.vbo);
		qglBufferDataARB(GL_ELEMENT_ARRAY_BUFFER_ARB, sizeof(index_t) * mesh->numindexes, mesh->indexes, GL_STATIC_DRAW_ARB);
		GL_SelectEBO(0);
//		Z_Free(mesh->indexes);
//		mesh->indexes = NULL;
	}
#endif
#ifdef D3D11QUAKE
	if (qrenderer == QR_DIRECT3D11)
	{
		void D3D11BE_GenBatchVBOs(vbo_t **vbochain, batch_t *firstbatch, batch_t *stopbatch);
		batch_t batch = {0};
		mesh_t *meshes = &s->mesh;
		vbo_t *vbo = NULL;
		batch.maxmeshes = 1;
		batch.mesh = &meshes;

		//BE_ClearVBO(&s->vbo);
		D3D11BE_GenBatchVBOs(&vbo, &batch, NULL);
		s->vbo = *vbo;
	}
#endif
}

struct tdibctx
{
	heightmap_t *hm;
	int vx;
	int vy;
	entity_t *ent;
	batch_t **batches;
};
void Terr_DrawInBounds(struct tdibctx *ctx, int x, int y, int w, int h)
{
	vec3_t mins, maxs;
	hmsection_t *s;
	int i;
	batch_t *b;
	heightmap_t *hm = ctx->hm;

	if (w == 1 && h == 1)
	{
		mins[0] = (x+0 - CHUNKBIAS)*hm->sectionsize;
		maxs[0] = (x+w - CHUNKBIAS)*hm->sectionsize;

		mins[1] = (y+0 - CHUNKBIAS)*hm->sectionsize;
		maxs[1] = (y+h - CHUNKBIAS)*hm->sectionsize;

		mins[2] = -999999;
		maxs[2] = 999999;
		if (R_CullBox(mins, maxs))
			return;

		s = Terr_GetSection(hm, x, y, TGS_LOAD);
		if (!s)
			return;
		if (s->lightmap < 0)
			Terr_LoadSection(hm, s, x, y, false);

		if (s->flags & TSF_RELIGHT)
		{
			if (!hm->relight)
			{
				hm->relight = s;
				hm->relightidx = 0;
				hm->relightmin[0] = mins[0];
				hm->relightmin[1] = mins[1];
			}
		}

		if (s->flags & TSF_DIRTY)
		{
			s->flags &= ~TSF_DIRTY;

			Terr_RebuildMesh(s, x, y);
		}

		//chuck out any batches for models in this section
		for (i = 0; i < s->numents; i++)
		{
			if (s->ents[i].model && s->ents[i].model->type == mod_alias)
			{
				R_GAlias_GenerateBatches(&s->ents[i], ctx->batches);
			}
		}

		if (s->flags & TSF_HASWATER)
		{
			mins[2] = s->waterheight;
			maxs[2] = s->waterheight;
			if (!R_CullBox(mins, maxs))
			{
				Terr_DrawTerrainWater(hm, mins, maxs, s->waterheight, 1, 1, 1, 1);
			}
		}

		mins[2] = s->minh;
		maxs[2] = s->maxh;

//		if (!BoundsIntersect(mins, maxs, r_refdef.vieworg, r_refdef.vieworg))
			if (R_CullBox(mins, maxs))
				return;

		b = BE_GetTempBatch();
		if (!b)
			return;
		b->ent = ctx->ent;
		b->shader = hm->shader;
		b->flags = 0;
		b->mesh = &s->amesh;
		b->mesh[0] = &s->mesh;
		b->meshes = 1;
		b->buildmeshes = NULL;
		b->skin = &s->textures;
		b->texture = NULL;
		b->vbo = NULL;//&s->vbo;
		b->lightmap[0] = s->lightmap;
		b->lightmap[1] = -1;
		b->lightmap[2] = -1;
		b->lightmap[3] = -1;

		b->next = ctx->batches[b->shader->sort];
		ctx->batches[b->shader->sort] = b;
	}
	else if (w && h)
	{
		//divide and conquer, radiating outwards from the view.
		if (w > h)
		{
			i = x + w;
			w = x + w/2;
			if (ctx->vx >= w)
			{
				Terr_DrawInBounds(ctx, w, y, i-w, h);
				Terr_DrawInBounds(ctx, x, y, w-x, h);
			}
			else
			{
				Terr_DrawInBounds(ctx, x, y, w-x, h);
				Terr_DrawInBounds(ctx, w, y, i-w, h);
			}
		}
		else
		{
			i = y + h;
			h = y + h/2;
			if (ctx->vy >= h)
			{
				Terr_DrawInBounds(ctx, x, h, w, i-h);
				Terr_DrawInBounds(ctx, x, y, w, h-y);
			}
			else
			{
				Terr_DrawInBounds(ctx, x, y, w, h-y);
				Terr_DrawInBounds(ctx, x, h, w, i-h);
			}
		}
	}
}

void Terr_DrawTerrainModel (batch_t **batches, entity_t *e)
{
	model_t *m = e->model;
	heightmap_t *hm = m->terrain;
	batch_t *b;
	int bounds[4];
	struct tdibctx tdibctx;

	if (!r_refdef.recurse)
	{
		Terr_DoEditNotify(hm);
//		while (hm->activesections > 0)
//			if (!Terr_Collect(hm))
//				break;
		while (hm->activesections > TERRAINACTIVESECTIONS)
			if (!Terr_Collect(hm))
				break;
	}
	
	if (hm->relight)
		ted_dorelight(hm);

	if (e->model == cl.worldmodel)
	{
		b = BE_GetTempBatch();
		if (b)
		{
			b->lightmap[0] = -1;
			b->lightmap[1] = -1;
			b->lightmap[2] = -1;
			b->lightmap[3] = -1;
			b->ent = e;
			b->shader = hm->skyshader;
			b->flags = 0;
			b->mesh = &hm->askymesh;
			b->mesh[0] = &hm->skymesh;
			b->meshes = 1;
			b->buildmeshes = NULL;
			b->skin = &b->shader->defaulttextures;
			b->texture = NULL;
	//		vbo = b->vbo = hm->vbo[x+y*MAXSECTIONS];
			b->vbo = NULL;

			b->next = batches[b->shader->sort];
			batches[b->shader->sort] = b;
		}
	}


	if (r_refdef.gfog_rgbd[3] || gl_maxdist.value>0)
	{
		float culldist;
		extern cvar_t r_fog_exp2;

		if (r_refdef.gfog_rgbd[3])
		{
			//figure out the eyespace distance required to reach that fog value
			culldist = log(0.5/255.0f);
			if (r_fog_exp2.ival)
				culldist = sqrt(culldist / (-r_refdef.gfog_rgbd[3] * r_refdef.gfog_rgbd[3]));
			else
				culldist = culldist / (-r_refdef.gfog_rgbd[3]);
			//anything drawn beyond this point is fully obscured by fog
			culldist += 4096;
		}
		else
			culldist = 999999999999999.f;

		if (culldist > gl_maxdist.value && gl_maxdist.value>0)
			culldist = gl_maxdist.value;

		bounds[0] = bound(hm->firstsegx, (r_refdef.vieworg[0] + (CHUNKBIAS + 0)*hm->sectionsize - culldist) / hm->sectionsize,  hm->maxsegx);
		bounds[1] = bound(hm->firstsegx, (r_refdef.vieworg[0] + (CHUNKBIAS + 1)*hm->sectionsize + culldist) / hm->sectionsize,  hm->maxsegx);
		bounds[2] = bound(hm->firstsegy, (r_refdef.vieworg[1] + (CHUNKBIAS + 0)*hm->sectionsize - culldist) / hm->sectionsize,  hm->maxsegy);
		bounds[3] = bound(hm->firstsegy, (r_refdef.vieworg[1] + (CHUNKBIAS + 1)*hm->sectionsize + culldist) / hm->sectionsize,  hm->maxsegy);
	}
	else
	{
		bounds[0] = hm->firstsegx;
		bounds[1] = hm->maxsegx;
		bounds[2] = hm->firstsegy;
		bounds[3] = hm->maxsegy;
	}

	tdibctx.hm = hm;
	tdibctx.batches = batches;
	tdibctx.ent = e;
	tdibctx.vx = (r_refdef.vieworg[0] + CHUNKBIAS*hm->sectionsize) / hm->sectionsize;
	tdibctx.vy = (r_refdef.vieworg[1] + CHUNKBIAS*hm->sectionsize) / hm->sectionsize;
	Terr_DrawInBounds(&tdibctx, bounds[0], bounds[2], bounds[1]-bounds[0], bounds[3]-bounds[2]);

	/*
	for (x = bounds[0]; x < bounds[1]; x++)
	{
		mins[0] = (x+0 - CHUNKBIAS)*hm->sectionsize;
		maxs[0] = (x+1 - CHUNKBIAS)*hm->sectionsize;
		for (y = bounds[2]; y < bounds[3]; y++)
		{
			mins[1] = (y+0 - CHUNKBIAS)*hm->sectionsize;
			maxs[1] = (y+1 - CHUNKBIAS)*hm->sectionsize;

			s = Terr_GetSection(hm, x, y, TGS_LOAD);
			if (!s)
				continue;
			if (s->lightmap < 0)
				Terr_LoadSection(hm, s, x, y);

			if (s->flags & TSF_RELIGHT)
			{
				if (!hm->relight)
				{
					hm->relight = s;
					hm->relightidx = 0;
					hm->relightmin[0] = mins[0];
					hm->relightmin[1] = mins[1];
				}
			}

			mesh = &s->mesh;
			if (s->flags & TSF_DIRTY)
			{
				s->flags &= ~TSF_DIRTY;

				Terr_RebuildMesh(s, x, y);
			}

			//chuck out any batches for models in this section
			for (i = 0; i < s->numents; i++)
			{
				if (s->ents[i].model && s->ents[i].model->type == mod_alias)
				{
					R_GAlias_GenerateBatches(&s->ents[i], batches);
				}
			}

			if (s->flags & TSF_HASWATER)
			{
				mins[2] = s->waterheight;
				maxs[2] = s->waterheight;
				if (!R_CullBox(mins, maxs))
				{
					Terr_DrawTerrainWater(hm, mins, maxs, s->waterheight, 1, 1, 1, 1);
				}
			}

			mins[2] = s->minh;
			maxs[2] = s->maxh;

//			if (!BoundsIntersect(mins, maxs, r_refdef.vieworg, r_refdef.vieworg))
				if (R_CullBox(mins, maxs))
					continue;

			b = BE_GetTempBatch();
			if (!b)
				continue;
			b->ent = e;
			b->shader = hm->shader;
			b->flags = 0;
			b->mesh = &s->amesh;
			b->mesh[0] = mesh;
			b->meshes = 1;
			b->buildmeshes = NULL;
			b->skin = &s->textures;
			b->texture = NULL;
			b->vbo = NULL;//&s->vbo;
			b->lightmap[0] = s->lightmap;
			b->lightmap[1] = -1;
			b->lightmap[2] = -1;
			b->lightmap[3] = -1;

			b->next = batches[b->shader->sort];
			batches[b->shader->sort] = b;
		}
	}
	*/
}

typedef struct fragmentdecal_s fragmentdecal_t;

void Fragment_ClipPoly(fragmentdecal_t *dec, int numverts, float *inverts);
void Terrain_ClipDecal(fragmentdecal_t *dec, float *center, float radius, model_t *model)
{
	int min[2], max[2], mint[2], maxt[2];
	int x, y, tx, ty;
	vecV_t vert[6];
	hmsection_t *s;
	heightmap_t *hm = model->terrain; 
	min[0] = floor((center[0] - radius)/(hm->sectionsize)) + CHUNKBIAS;
	min[1] = floor((center[1] - radius)/(hm->sectionsize)) + CHUNKBIAS;
	max[0] = ceil((center[0] + radius)/(hm->sectionsize)) + CHUNKBIAS;
	max[1] = ceil((center[1] + radius)/(hm->sectionsize)) + CHUNKBIAS;

	min[0] = bound(hm->firstsegx, min[0], hm->maxsegx);
	min[1] = bound(hm->firstsegy, min[1], hm->maxsegy);
	max[0] = bound(hm->firstsegx, max[0], hm->maxsegx);
	max[1] = bound(hm->firstsegy, max[1], hm->maxsegy);

	for (y = min[1]; y < max[1]; y++)
	{
		for (x = min[0]; x < max[0]; x++)
		{
			s = Terr_GetSection(hm, x, y, TGS_LOAD);
			if (!s)
				continue;

			mint[0] = floor((center[0] - radius)*(SECTHEIGHTSIZE-1)/(hm->sectionsize) + (CHUNKBIAS - x)*(SECTHEIGHTSIZE-1));
			mint[1] = floor((center[1] - radius)*(SECTHEIGHTSIZE-1)/(hm->sectionsize) + (CHUNKBIAS - y)*(SECTHEIGHTSIZE-1));
			maxt[0] =  ceil((center[0] + radius)*(SECTHEIGHTSIZE-1)/(hm->sectionsize) + (CHUNKBIAS - x)*(SECTHEIGHTSIZE-1));
			maxt[1] =  ceil((center[1] + radius)*(SECTHEIGHTSIZE-1)/(hm->sectionsize) + (CHUNKBIAS - y)*(SECTHEIGHTSIZE-1));

			mint[0] = bound(0, mint[0], (SECTHEIGHTSIZE-1));
			mint[1] = bound(0, mint[1], (SECTHEIGHTSIZE-1));
			maxt[0] = bound(0, maxt[0], (SECTHEIGHTSIZE-1));
			maxt[1] = bound(0, maxt[1], (SECTHEIGHTSIZE-1));

			for (ty = mint[1]; ty < maxt[1]; ty++)
			{
				for (tx = mint[0]; tx < maxt[0]; tx++)
				{
#ifndef STRICTEDGES
					float d1, d2;
					d1 = fabs(s->heights[(tx+0) + (ty+0)*SECTHEIGHTSIZE] - s->heights[(tx+1) + (ty+1)*SECTHEIGHTSIZE]);
					d2 = fabs(s->heights[(tx+1) + (ty+0)*SECTHEIGHTSIZE] - s->heights[(tx+0) + (ty+1)*SECTHEIGHTSIZE]);
					if (d1 < d2)
					{
						vert[0][0] = (x-CHUNKBIAS)*hm->sectionsize + (tx+0)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;vert[0][1] = (y-CHUNKBIAS)*hm->sectionsize + (ty+0)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;
						vert[1][0] = (x-CHUNKBIAS)*hm->sectionsize + (tx+1)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;vert[1][1] = (y-CHUNKBIAS)*hm->sectionsize + (ty+1)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;
						vert[2][0] = (x-CHUNKBIAS)*hm->sectionsize + (tx+1)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;vert[2][1] = (y-CHUNKBIAS)*hm->sectionsize + (ty+0)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;

						vert[3][0] = (x-CHUNKBIAS)*hm->sectionsize + (tx+0)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;vert[3][1] = (y-CHUNKBIAS)*hm->sectionsize + (ty+0)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;
						vert[4][0] = (x-CHUNKBIAS)*hm->sectionsize + (tx+0)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;vert[4][1] = (y-CHUNKBIAS)*hm->sectionsize + (ty+1)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;
						vert[5][0] = (x-CHUNKBIAS)*hm->sectionsize + (tx+1)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;vert[5][1] = (y-CHUNKBIAS)*hm->sectionsize + (ty+1)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;

						vert[0][2] = s->heights[(tx+0) + (ty+0)*SECTHEIGHTSIZE];
						vert[1][2] = s->heights[(tx+1) + (ty+1)*SECTHEIGHTSIZE];
						vert[2][2] = s->heights[(tx+1) + (ty+0)*SECTHEIGHTSIZE];
						vert[3][2] = s->heights[(tx+0) + (ty+0)*SECTHEIGHTSIZE];
						vert[4][2] = s->heights[(tx+0) + (ty+1)*SECTHEIGHTSIZE];
						vert[5][2] = s->heights[(tx+1) + (ty+1)*SECTHEIGHTSIZE];
					}
					else
#endif
					{
						vert[0][0] = (x-CHUNKBIAS)*hm->sectionsize + (tx+0)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;vert[0][1] = (y-CHUNKBIAS)*hm->sectionsize + (ty+0)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;
						vert[1][0] = (x-CHUNKBIAS)*hm->sectionsize + (tx+0)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;vert[1][1] = (y-CHUNKBIAS)*hm->sectionsize + (ty+1)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;
						vert[2][0] = (x-CHUNKBIAS)*hm->sectionsize + (tx+1)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;vert[2][1] = (y-CHUNKBIAS)*hm->sectionsize + (ty+0)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;

						vert[3][0] = (x-CHUNKBIAS)*hm->sectionsize + (tx+1)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;vert[3][1] = (y-CHUNKBIAS)*hm->sectionsize + (ty+0)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;
						vert[4][0] = (x-CHUNKBIAS)*hm->sectionsize + (tx+0)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;vert[4][1] = (y-CHUNKBIAS)*hm->sectionsize + (ty+1)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;
						vert[5][0] = (x-CHUNKBIAS)*hm->sectionsize + (tx+1)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;vert[5][1] = (y-CHUNKBIAS)*hm->sectionsize + (ty+1)/(float)(SECTHEIGHTSIZE-1)*hm->sectionsize;

						vert[0][2] = s->heights[(tx+0) + (ty+0)*SECTHEIGHTSIZE];
						vert[1][2] = s->heights[(tx+0) + (ty+1)*SECTHEIGHTSIZE];
						vert[2][2] = s->heights[(tx+1) + (ty+0)*SECTHEIGHTSIZE];
						vert[3][2] = s->heights[(tx+1) + (ty+0)*SECTHEIGHTSIZE];
						vert[4][2] = s->heights[(tx+0) + (ty+1)*SECTHEIGHTSIZE];
						vert[5][2] = s->heights[(tx+1) + (ty+1)*SECTHEIGHTSIZE];
					}

					Fragment_ClipPoly(dec, 3, &vert[0][0]);
					Fragment_ClipPoly(dec, 3, &vert[3][0]);
				}
			}
		}
	}
}

#endif

unsigned int Heightmap_PointContentsHM(heightmap_t *hm, float clipmipsz, vec3_t org)
{
	float x, y;
	float z, tz;
	int sx, sy;
	unsigned int holebit;
	hmsection_t *s;
	const float wbias = CHUNKBIAS * hm->sectionsize;

	sx = (org[0]+wbias)/hm->sectionsize;
	sy = (org[1]+wbias)/hm->sectionsize;
	if (sx < hm->firstsegx || sy < hm->firstsegy)
		return hm->exteriorcontents;
	if (sx >= hm->maxsegx || sy >= hm->maxsegy)
		return hm->exteriorcontents;
	s = Terr_GetSection(hm, sx, sy, TGS_LOAD);
	if (!s)
	{
		return FTECONTENTS_SOLID;
	}

	x = (org[0]+wbias - (sx*hm->sectionsize))*(SECTHEIGHTSIZE-1)/hm->sectionsize;
	y = (org[1]+wbias - (sy*hm->sectionsize))*(SECTHEIGHTSIZE-1)/hm->sectionsize;
	z = (org[2]+clipmipsz);

	if (z < s->minh-16)
		return hm->exteriorcontents;

	sx = x; x-=sx;
	sy = y; y-=sy;

	holebit = 1u<<(sx/(SECTHEIGHTSIZE>>2) + (sy/(SECTHEIGHTSIZE>>2))*4);
	if (s->holes & (1u<<holebit))
		return FTECONTENTS_EMPTY;

	//made of two triangles:
	if (x+y>1)	//the 1, 1 triangle
	{
		float v1, v2, v3;
		v3 = 1-y;
		v2 = x+y-1;
		v1 = 1-x;
		//0, 1
		//1, 1
		//1, 0
		tz = (s->heights[(sx+0)+(sy+1)*SECTHEIGHTSIZE]*v1 +
			  s->heights[(sx+1)+(sy+1)*SECTHEIGHTSIZE]*v2 +
			  s->heights[(sx+1)+(sy+0)*SECTHEIGHTSIZE]*v3);
	}
	else
	{
		float v1, v2, v3;
		v1 = y;
		v2 = x;
		v3 = 1-y-x;

		//0, 1
		//1, 0
		//0, 0
		tz = (s->heights[(sx+0)+(sy+1)*SECTHEIGHTSIZE]*v1 +
			  s->heights[(sx+1)+(sy+0)*SECTHEIGHTSIZE]*v2 +
			  s->heights[(sx+0)+(sy+0)*SECTHEIGHTSIZE]*v3);
	}
	if (z <= tz)
		return FTECONTENTS_SOLID;	//contained within
	if (s->flags & TSF_HASWATER)
		if (z < s->waterheight)
			return FTECONTENTS_WATER;
	return FTECONTENTS_EMPTY;
}

unsigned int Heightmap_PointContents(model_t *model, vec3_t axis[3], vec3_t org)
{
	heightmap_t *hm = model->terrain;
	return Heightmap_PointContentsHM(hm, 0, org);
}
unsigned int Heightmap_NativeBoxContents(model_t *model, int hulloverride, int frame, vec3_t axis[3], vec3_t org, vec3_t mins, vec3_t maxs)
{
	heightmap_t *hm = model->terrain;
	return Heightmap_PointContentsHM(hm, mins[2], org);
}

void Heightmap_Normal(heightmap_t *hm, vec3_t org, vec3_t norm)
{
#if 0
	norm[0] = 0;
	norm[1] = 0;
	norm[2] = 1;
#else
	float x, y;
	int sx, sy;
	vec3_t d1, d2;
	const float wbias = CHUNKBIAS * hm->sectionsize;
	hmsection_t *s;

	norm[0] = 0;
	norm[1] = 0;
	norm[2] = 1;

	sx = (org[0]+wbias)/hm->sectionsize;
	sy = (org[1]+wbias)/hm->sectionsize;
	if (sx < hm->firstsegx || sy < hm->firstsegy)
		return;
	if (sx >= hm->maxsegx || sy >= hm->maxsegy)
		return;
	s = Terr_GetSection(hm, sx, sy, TGS_LOAD);
	if (!s)
		return;

	x = (org[0]+wbias - (sx*hm->sectionsize))*(SECTHEIGHTSIZE-1)/hm->sectionsize;
	y = (org[1]+wbias - (sy*hm->sectionsize))*(SECTHEIGHTSIZE-1)/hm->sectionsize;

	sx = x; x-=sx;
	sy = y; y-=sy;

	if (x+y>1)	//the 1, 1 triangle
	{
		//0, 1
		//1, 1
		//1, 0
		d1[0] = (hm->sectionsize / SECTHEIGHTSIZE);
		d1[1] = 0;
		d1[2] = (s->heights[(sx+1)+(sy+1)*SECTHEIGHTSIZE] - s->heights[(sx+0)+(sy+1)*SECTHEIGHTSIZE]);
		d2[0] = 0;
		d2[1] = (hm->sectionsize / SECTHEIGHTSIZE);
		d2[2] = (s->heights[(sx+1)+(sy+1)*SECTHEIGHTSIZE] - s->heights[(sx+1)+(sy+0)*SECTHEIGHTSIZE]);
	}
	else
	{	//the 0,0 triangle
		//0, 1
		//1, 0
		//0, 0
		d1[0] = (hm->sectionsize / SECTHEIGHTSIZE);
		d1[1] = 0;
		d1[2] = (s->heights[(sx+1)+(sy+0)*SECTHEIGHTSIZE] - s->heights[(sx+0)+(sy+0)*SECTHEIGHTSIZE]);
		d2[0] = 0;
		d2[1] = (hm->sectionsize / SECTHEIGHTSIZE);
		d2[2] = (s->heights[(sx+0)+(sy+1)*SECTHEIGHTSIZE] - s->heights[(sx+0)+(sy+0)*SECTHEIGHTSIZE]);
	}

	VectorNormalize(d1);
	VectorNormalize(d2);
	CrossProduct(d1, d2, norm);
	VectorNormalize(norm);
#endif
}

typedef struct {
	vec3_t start;
	vec3_t end;
	vec3_t impact;
	vec4_t plane;
	float frac;
	float htilesize;
	heightmap_t *hm;
	int contents;
} hmtrace_t;

static void Heightmap_Trace_Brush(hmtrace_t *tr, vec4_t *planes, int numplanes)
{
	qboolean startout;
	float *enterplane;
	double enterfrac, exitfrac, nearfrac=0;
	double enterdist=0;
	double dist, d1, d2, f;
	int i;

	startout = false;
	enterplane= NULL;
	enterfrac = -1;
	exitfrac = 10;
	for (i = 0; i < numplanes; i++)
	{
		/*calculate the distance based upon the shape of the object we're tracing for*/
		dist = planes[i][3];


		d1 = DotProduct (tr->start, planes[i]) - dist;
		d2 = DotProduct (tr->end, planes[i]) - dist;

		//if we're fully outside any plane, then we cannot possibly enter the brush, skip to the next one
		if (d1 > 0 && d2 >= d1)
			return;

		if (d1 > 0)
			startout = true;

		//if we're fully inside the plane, then whatever is happening is not relevent for this plane
		if (d1 <= 0 && d2 <= 0)
			continue;

		f = (d1) / (d1-d2);
		if (d1 > d2)
		{
			//entered the brush. favour the furthest fraction to avoid extended edges (yay for convex shapes)
			if (enterfrac < f)
			{
				enterfrac = f;
				nearfrac = (d1 - (0.03125)) / (d1-d2);
				enterplane = planes[i];
				enterdist = dist;
			}
		}
		else
		{
			//left the brush, favour the nearest plane (smallest frac)
			if (exitfrac > f)
			{
				exitfrac = f;
			}
		}
	}

	if (!startout)
	{
		tr->frac = -1;
		return;
	}
	if (enterfrac != -1 && enterfrac < exitfrac)
	{
		//impact!
		if (enterfrac < tr->frac)
		{
			if (nearfrac < 0)
				nearfrac = 0;
			tr->frac = nearfrac;//enterfrac;
			tr->plane[3] = enterdist;
			VectorCopy(enterplane, tr->plane);
		}
	}
}

//sx,sy are the tile coord
//note that tile SECTHEIGHTSIZE-1 does not exist, as the last sample overlaps the first sample of the next section
static void Heightmap_Trace_Square(hmtrace_t *tr, int tx, int ty)
{
	vec3_t d[2];
	vec3_t p[4];
	vec4_t n[5];
	int t;

#ifndef STRICTEDGES
	float d1, d2;
#endif
	int sx, sy;
	hmsection_t *s;
	unsigned int holebit;

	sx = tx/(SECTHEIGHTSIZE-1);
	sy = ty/(SECTHEIGHTSIZE-1);
	if (sx < tr->hm->firstsegx || sx >= tr->hm->maxsegx)
		s = NULL;
	else if (sy < tr->hm->firstsegy || sy >= tr->hm->maxsegy)
		s = NULL;
	else
		s = Terr_GetSection(tr->hm, sx, sy, TGS_LOAD);

	if (!s)
	{
		//you're not allowed to walk into sections that have not loaded.
		//might as well check the entire section instead of just one tile
		Vector4Set(n[0],  1, 0, 0, (tx/(SECTHEIGHTSIZE-1) + 1 - CHUNKBIAS)*tr->hm->sectionsize);
		Vector4Set(n[1], -1, 0, 0, -(tx/(SECTHEIGHTSIZE-1) + 0 - CHUNKBIAS)*tr->hm->sectionsize);
		Vector4Set(n[2], 0,  1, 0, (ty/(SECTHEIGHTSIZE-1) + 1 - CHUNKBIAS)*tr->hm->sectionsize);
		Vector4Set(n[3], 0, -1, 0, -(ty/(SECTHEIGHTSIZE-1) + 0 - CHUNKBIAS)*tr->hm->sectionsize);
		Heightmap_Trace_Brush(tr, n, 4);
		return;
	}

	sx = tx - CHUNKBIAS*(SECTHEIGHTSIZE-1);
	sy = ty - CHUNKBIAS*(SECTHEIGHTSIZE-1);

	tx = tx % (SECTHEIGHTSIZE-1);
	ty = ty % (SECTHEIGHTSIZE-1);

	holebit = 1u<<(tx/(SECTHEIGHTSIZE>>2) + (ty/(SECTHEIGHTSIZE>>2))*4);
	if (s->holes & holebit)
		return;	//no collision with holes

	if (tr->hm->tiled)
	{
		//left-most
		Vector4Set(n[0], -1, 0, 0, -tr->htilesize*(sx+0));
		//bottom-most
		Vector4Set(n[1], 0, 1, 0, tr->htilesize*(sy+1));
		//right-most
		Vector4Set(n[2], 1, 0, 0, tr->htilesize*(sx+1));
		//top-most
		Vector4Set(n[3], 0, -1, 0, -tr->htilesize*(sy+0));
		//top
		Vector4Set(n[4], 0, 0, 1, s->heights[(tx+0)+(ty+0)*SECTHEIGHTSIZE]);

		Heightmap_Trace_Brush(tr, n, 5);
		return;
	}
	
	VectorSet(p[0], tr->htilesize*(sx+0), tr->htilesize*(sy+0), s->heights[(tx+0)+(ty+0)*SECTHEIGHTSIZE]);
	VectorSet(p[1], tr->htilesize*(sx+1), tr->htilesize*(sy+0), s->heights[(tx+1)+(ty+0)*SECTHEIGHTSIZE]);
	VectorSet(p[2], tr->htilesize*(sx+0), tr->htilesize*(sy+1), s->heights[(tx+0)+(ty+1)*SECTHEIGHTSIZE]);
	VectorSet(p[3], tr->htilesize*(sx+1), tr->htilesize*(sy+1), s->heights[(tx+1)+(ty+1)*SECTHEIGHTSIZE]);


#ifndef STRICTEDGES
	d1 = fabs(p[0][2] - p[3][2]);
	d2 = fabs(p[1][2] - p[2][2]);
	if (d1 < d2)
	{
		for (t = 0; t < 2; t++)
		{
			/*generate the brush (in world space*/
			if (t == 0)
			{
				VectorSubtract(p[3], p[2], d[0]);
				VectorSubtract(p[2], p[0], d[1]);
				//left-most
				Vector4Set(n[0], -1, 0, 0, -tr->htilesize*(sx+0));
				//bottom-most
				Vector4Set(n[1], 0, 1, 0, tr->htilesize*(sy+1));
				//top-right
				VectorSet(n[2], 0.70710678118654752440084436210485, -0.70710678118654752440084436210485, 0);
				n[2][3] = DotProduct(n[2], p[0]);
				//top
				VectorNormalize(d[0]);
				VectorNormalize(d[1]);
				CrossProduct(d[0], d[1], n[3]);
				VectorNormalize(n[3]);
				n[3][3] = DotProduct(n[3], p[0]);
				//down
				VectorNegate(n[3], n[4]);
				n[4][3] = DotProduct(n[4], p[0]) - n[4][2]*TERRAINTHICKNESS;
			}
			else
			{
				VectorSubtract(p[1], p[0], d[0]);
				VectorSubtract(p[3], p[1], d[1]);

				//right-most
				Vector4Set(n[0], 1, 0, 0, tr->htilesize*(sx+1));
				//top-most
				Vector4Set(n[1], 0, -1, 0, -tr->htilesize*(sy+0));
				//bottom-left
				VectorSet(n[2], -0.70710678118654752440084436210485, 0.70710678118654752440084436210485, 0);
				n[2][3] = DotProduct(n[2], p[0]);
				//top
				VectorNormalize(d[0]);
				VectorNormalize(d[1]);
				CrossProduct(d[0], d[1], n[3]);
				VectorNormalize(n[3]);
				n[3][3] = DotProduct(n[3], p[0]);
				//down
				VectorNegate(n[3], n[4]);
				n[4][3] = DotProduct(n[4], p[0]) - n[4][2]*TERRAINTHICKNESS;
			}
			Heightmap_Trace_Brush(tr, n, 5);
		}
	}
	else
#endif
	{
		for (t = 0; t < 2; t++)
		{
			/*generate the brush (in world space*/
			if (t == 0)
			{
				VectorSubtract(p[1], p[0], d[0]);
				VectorSubtract(p[2], p[0], d[1]);
				//left-most
				Vector4Set(n[0], -1, 0, 0, -tr->htilesize*(sx+0));
				//top-most
				Vector4Set(n[1], 0, -1, 0, -tr->htilesize*(sy+0));
				//bottom-right
				VectorSet(n[2], 0.70710678118654752440084436210485, 0.70710678118654752440084436210485, 0);
				n[2][3] = DotProduct(n[2], p[1]);
				//top
				VectorNormalize(d[0]);
				VectorNormalize(d[1]);
				CrossProduct(d[0], d[1], n[3]);
				VectorNormalize(n[3]);
				n[3][3] = DotProduct(n[3], p[1]);
				//down
				VectorNegate(n[3], n[4]);
				n[4][3] = DotProduct(n[4], p[1]) - n[4][2]*TERRAINTHICKNESS;
			}
			else
			{
				VectorSubtract(p[3], p[2], d[0]);
				VectorSubtract(p[3], p[1], d[1]);

				//right-most
				Vector4Set(n[0], 1, 0, 0, tr->htilesize*(sx+1));
				//bottom-most
				Vector4Set(n[1], 0, 1, 0, tr->htilesize*(sy+1));
				//top-left
				VectorSet(n[2], -0.70710678118654752440084436210485, -0.70710678118654752440084436210485, 0);
				n[2][3] = DotProduct(n[2], p[1]);
				//top
				VectorNormalize(d[0]);
				VectorNormalize(d[1]);
				CrossProduct(d[0], d[1], n[3]);
				VectorNormalize(n[3]);
				n[3][3] = DotProduct(n[3], p[1]);
				//down
				VectorNegate(n[3], n[4]);
				n[4][3] = DotProduct(n[4], p[1]) - n[4][2]*TERRAINTHICKNESS;
			}
			Heightmap_Trace_Brush(tr, n, 5);
		}
	}
}

#define DIST_EPSILON 0
/*
Heightmap_TraceRecurse
Traces an arbitary box through a heightmap. (interface with outside)

Why is recursion good?
1: it is consistant with bsp models. :)
2: it allows us to use any size model we want
3: we don't have to work out the height of the terrain every X units, but can be more precise.

Obviously, we don't care all that much about 1
*/
qboolean Heightmap_Trace(struct model_s *model, int hulloverride, int frame, vec3_t mataxis[3], vec3_t start, vec3_t end, vec3_t mins, vec3_t maxs, unsigned int against, struct trace_s *trace)
{
	vec2_t pos, npos;
	qboolean nudge[2];
	vec2_t dir;
	vec2_t frac;
	vec2_t emins;
	vec2_t emaxs;
	int x, y;
	int axis;
	int breaklimit = 1000;
	float wbias;
	hmtrace_t hmtrace;
	hmtrace.hm = model->terrain;
	hmtrace.htilesize = hmtrace.hm->sectionsize / (SECTHEIGHTSIZE-1);
	hmtrace.frac = 1;
	hmtrace.contents = 0;

	hmtrace.plane[0] = 0;
	hmtrace.plane[1] = 0;
	hmtrace.plane[2] = 0;
	hmtrace.plane[3] = 0;

	memset(trace, 0, sizeof(*trace));
	trace->fraction = 1;

	//to tile space
	hmtrace.start[0] = (start[0]);
	hmtrace.start[1] = (start[1]);
	hmtrace.start[2] = (start[2] + mins[2]);
	hmtrace.end[0] = (end[0]);
	hmtrace.end[1] = (end[1]);
	hmtrace.end[2] = (end[2] + mins[2]);

	dir[0] = (hmtrace.end[0] - hmtrace.start[0])/hmtrace.htilesize;
	dir[1] = (hmtrace.end[1] - hmtrace.start[1])/hmtrace.htilesize;
	pos[0] = (hmtrace.start[0]+CHUNKBIAS*hmtrace.hm->sectionsize)/hmtrace.htilesize;
	pos[1] = (hmtrace.start[1]+CHUNKBIAS*hmtrace.hm->sectionsize)/hmtrace.htilesize;
	wbias = CHUNKBIAS*hmtrace.hm->sectionsize;

	emins[0] = (mins[0]-1)/hmtrace.htilesize;
	emins[1] = (mins[1]-1)/hmtrace.htilesize;
	emaxs[0] = (maxs[0]+1)/hmtrace.htilesize;
	emaxs[1] = (maxs[1]+1)/hmtrace.htilesize;

	/*fixme:
	set pos to the leading corner instead
	on boundary changes, scan across multiple blocks
	*/

	//make sure the start tile is valid
	for (y = pos[1] + emins[1]; y <= pos[1] + emaxs[1]; y++)
		for (x = pos[0] + emins[0]; x <= pos[0] + emaxs[0]; x++)
			Heightmap_Trace_Square(&hmtrace, x, y);
	for(;;)
	{
		if (breaklimit--< 0)
			break;
		for (axis = 0; axis < 2; axis++)
		{
			if (dir[axis] > 0)
			{
				nudge[axis] = false;
				npos[axis] = pos[axis] + 1-(pos[axis]-(int)pos[axis]);
				frac[axis] = (npos[axis]*hmtrace.htilesize-wbias - hmtrace.start[axis])/(hmtrace.end[axis]-hmtrace.start[axis]);
			}
			else if (dir[axis] < 0)
			{
				npos[axis] = pos[axis];
				nudge[axis] = (float)(int)pos[axis] == pos[axis];
				npos[axis] = (int)npos[axis];
				frac[axis] = (npos[axis]*hmtrace.htilesize-wbias - hmtrace.start[axis])/(hmtrace.end[axis]-hmtrace.start[axis]);
				npos[axis] -= nudge[axis];
			}
			else
				frac[axis] = 1000000000000000.0;
		}

		//which side are we going down?
		if (frac[0] < frac[1])
			axis = 0;
		else
			axis = 1;

		if (frac[axis] >= 1)
			break;

		//touch the neighbour(s)
		if (dir[axis] > 0)
		{
			pos[axis] = (int)pos[axis] + 1;
			pos[axis] = npos[axis];
			Heightmap_Trace_Square(&hmtrace, pos[0], pos[1]);
		}
		else
		{
			pos[axis] = npos[axis];
			Heightmap_Trace_Square(&hmtrace, pos[0], pos[1]);
		}
		//and make sure our position on the other axis is correct, for the next time around the loop
		if (frac[axis] > hmtrace.frac)
			break;
		pos[!axis] = ((hmtrace.end[!axis] * frac[axis]) + (hmtrace.start[!axis] * (1-frac[axis])) + CHUNKBIAS*hmtrace.hm->sectionsize)/hmtrace.htilesize;
	}

	trace->plane.dist = hmtrace.plane[3];
	trace->plane.normal[0] = hmtrace.plane[0];
	trace->plane.normal[1] = hmtrace.plane[1];
	trace->plane.normal[2] = hmtrace.plane[2];

	if (hmtrace.frac == -1)
	{
		trace->fraction = 0;
		trace->startsolid = true;
		trace->allsolid = true;
		VectorCopy(start, trace->endpos);
	}
	else
	{
		if (hmtrace.frac < 0)
			hmtrace.frac = 0;
		trace->fraction = hmtrace.frac;
		VectorInterpolate(start, hmtrace.frac, end, trace->endpos);
	}
	return trace->fraction < 1;
}

unsigned int Heightmap_FatPVS		(model_t *mod, vec3_t org, qbyte *pvsbuffer, unsigned int pvssize, qboolean add)
{
	return 0;
}

#ifndef CLIENTONLY
qboolean Heightmap_EdictInFatPVS	(model_t *mod, struct pvscache_s *edict, qbyte *pvsdata)
{
	return true;
}

void Heightmap_FindTouchedLeafs	(model_t *mod, pvscache_t *ent, float *mins, float *maxs)
{
}
#endif

void Heightmap_LightPointValues	(model_t *mod, vec3_t point, vec3_t res_diffuse, vec3_t res_ambient, vec3_t res_dir)
{
	float time = realtime;

	res_diffuse[0] = 128;
	res_diffuse[1] = 128;
	res_diffuse[2] = 128;
	res_ambient[0] = 64;
	res_ambient[1] = 64;
	res_ambient[2] = 64;
	res_dir[0] = sin(time);
	res_dir[1] = cos(time);
	res_dir[2] = sin(time);
	VectorNormalize(res_dir);
}
void Heightmap_StainNode			(mnode_t *node, float *parms)
{
}
void Heightmap_MarkLights			(dlight_t *light, int bit, mnode_t *node)
{
}

qbyte *Heightmap_LeafnumPVS	(model_t *model, int num, qbyte *buffer, unsigned int buffersize)
{
	static qbyte heightmappvs = 255;
	return &heightmappvs;
}
int	Heightmap_LeafForPoint	(model_t *model, vec3_t point)
{
	return 0;
}

#ifndef SERVERONLY
static unsigned char *ted_getlightmap(hmsection_t *s, int idx)
{
	unsigned char *lm;
	int x = idx % SECTTEXSIZE, y = idx / SECTTEXSIZE;
	if (s->lightmap < 0)
	{
		Terr_LoadSection(s->hmmod, s, x, y, true);
		if (s->lightmap < 0)
			Terr_InitLightmap(s);
	}

	s->flags |= TSF_EDITED;

	lightmap[s->lightmap]->modified = true;
	lightmap[s->lightmap]->rectchange.l = 0;
	lightmap[s->lightmap]->rectchange.t = 0;
	lightmap[s->lightmap]->rectchange.w = HMLMSTRIDE;
	lightmap[s->lightmap]->rectchange.h = HMLMSTRIDE;
	lm = lightmap[s->lightmap]->lightmaps;
	lm += ((s->lmy+y) * HMLMSTRIDE + (s->lmx+x)) * lightmap_bytes;
	return lm;
}
static void ted_dorelight(heightmap_t *hm)
{
	unsigned char *lm = ted_getlightmap(hm->relight, 0);
	int x, y;
#define EXPAND 2
	vec3_t surfnorms[(SECTTEXSIZE+EXPAND*2)*(SECTTEXSIZE+EXPAND*2)];
//	float scaletab[EXPAND*2*EXPAND*2];
	vec3_t ldir = {0.4, 0.7, 2};
	hmsection_t *s = hm->relight;
	s->flags &= ~TSF_RELIGHT;
	hm->relight = NULL;

	if (s->lightmap < 0)
		return;

	for (y = -EXPAND; y < SECTTEXSIZE+EXPAND; y++)
	for (x = -EXPAND; x < SECTTEXSIZE+EXPAND; x++)
	{
		vec3_t pos;
		pos[0] = hm->relightmin[0] + (x*hm->sectionsize/(SECTTEXSIZE-1));
		pos[1] = hm->relightmin[1] + (y*hm->sectionsize/(SECTTEXSIZE-1));
		pos[2] = 0;
		Heightmap_Normal(s->hmmod, pos, surfnorms[x+EXPAND + (y+EXPAND)*(SECTTEXSIZE+EXPAND*2)]);
	}

	VectorNormalize(ldir);

	for (y = 0; y < SECTTEXSIZE; y++, lm += (HMLMSTRIDE-SECTTEXSIZE)*4)
	for (x = 0; x < SECTTEXSIZE; x++, lm += 4)
	{
		vec3_t norm;
		float d;
		int sx,sy;
		VectorClear(norm);
		for (sy = -EXPAND; sy <= EXPAND; sy++)
		for (sx = -EXPAND; sx <= EXPAND; sx++)
		{
			d = sqrt((EXPAND*2+1)*(EXPAND*2+1) - sx*sx+sy*sy);
			VectorMA(norm, d, surfnorms[x+sx+EXPAND + (y+sy+EXPAND)*(SECTTEXSIZE+EXPAND*2)], norm);
		}

		VectorNormalize(norm);
		d = DotProduct(ldir, norm);
		if (d < 0)
			d = 0;
//		lm[0] = norm[0]*127 + 128;
//		lm[1] = norm[1]*127 + 128;
//		lm[2] = norm[2]*127 + 128;
		lm[3] = d*255;
	}

	lightmap[s->lightmap]->modified = true;
	lightmap[s->lightmap]->rectchange.l = 0;
	lightmap[s->lightmap]->rectchange.t = 0;
	lightmap[s->lightmap]->rectchange.w = HMLMSTRIDE;
	lightmap[s->lightmap]->rectchange.h = HMLMSTRIDE;
}
static void ted_sethole(void *ctx, hmsection_t *s, int idx, float wx, float wy, float w)
{
	unsigned int bit;
	unsigned int mask;
	mask = 1u<<idx;
	if (*(float*)ctx)
		bit = mask;
	else
		bit = 0;
	s->flags |= TSF_NOTIFY|TSF_DIRTY|TSF_EDITED;
	s->holes = (s->holes & ~mask) | bit;
}
static void ted_heighttally(void *ctx, hmsection_t *s, int idx, float wx, float wy, float w)
{
	/*raise the terrain*/
	((float*)ctx)[0] += s->heights[idx]*w;
	((float*)ctx)[1] += w;
}
static void ted_heightsmooth(void *ctx, hmsection_t *s, int idx, float wx, float wy, float w)
{
	s->flags |= TSF_NOTIFY|TSF_DIRTY|TSF_EDITED|TSF_RELIGHT;
	/*interpolate the terrain towards a certain value*/

	if (IS_NAN(s->heights[idx]))
		s->heights[idx] = *(float*)ctx;
	else
		s->heights[idx] = s->heights[idx]*(1-w) + w**(float*)ctx;
}
static void ted_heightraise(void *ctx, hmsection_t *s, int idx, float wx, float wy, float strength)
{
	s->flags |= TSF_NOTIFY|TSF_DIRTY|TSF_EDITED|TSF_RELIGHT;
	/*raise the terrain*/
	s->heights[idx] += strength;
}
static void ted_heightset(void *ctx, hmsection_t *s, int idx, float wx, float wy, float strength)
{
	s->flags |= TSF_NOTIFY|TSF_DIRTY|TSF_EDITED|TSF_RELIGHT;
	/*set the terrain to a specific value*/
	s->heights[idx] = *(float*)ctx;
}

static void ted_mixconcentrate(void *ctx, hmsection_t *s, int idx, float wx, float wy, float w)
{
	unsigned char *lm = ted_getlightmap(s, idx);
	s->flags |= TSF_NOTIFY|TSF_EDITED;

	/*concentrate the lightmap values to a single channel*/
	if (lm[0] > lm[1] && lm[0] > lm[2] && lm[0] > (255-(lm[0]+lm[1]+lm[2])))
	{
		lm[0] = lm[0]*(1-w) + 255*(w);
		lm[1] = lm[1]*(1-w) + 0*(w);
		lm[2] = lm[2]*(1-w) + 0*(w);
	}
	else if (lm[1] > lm[2] && lm[1] > (255-(lm[0]+lm[1]+lm[2])))
	{
		lm[0] = lm[0]*(1-w) + 0*(w);
		lm[1] = lm[1]*(1-w) + 255*(w);
		lm[2] = lm[2]*(1-w) + 0*(w);
	}
	else if (lm[2] > (255-(lm[0]+lm[1]+lm[2])))
	{
		lm[0] = lm[0]*(1-w) + 0*(w);
		lm[1] = lm[1]*(1-w) + 0*(w);
		lm[2] = lm[2]*(1-w) + 255*(w);
	}
	else
	{
		lm[0] = lm[0]*(1-w) + 0*(w);
		lm[1] = lm[1]*(1-w) + 0*(w);
		lm[2] = lm[2]*(1-w) + 0*(w);
	}
}

static void ted_mixnoise(void *ctx, hmsection_t *s, int idx, float wx, float wy, float w)
{
	unsigned char *lm = ted_getlightmap(s, idx);
	vec4_t v;
	float sc;

	s->flags |= TSF_NOTIFY|TSF_EDITED;

	/*randomize the lightmap somewhat (you'll probably want to concentrate it a bit after)*/
	v[0] = (rand()&255);
	v[1] = (rand()&255);
	v[2] = (rand()&255);
	v[3] = (rand()&255);
	sc = v[0] + v[1] + v[2] + v[3];
	Vector4Scale(v, 255/sc, v);

	lm[0] = lm[0]*(1-w) + (v[0]*(w));
	lm[1] = lm[1]*(1-w) + (v[1]*(w));
	lm[2] = lm[2]*(1-w) + (v[2]*(w));
}

static void ted_mixpaint(void *ctx, hmsection_t *s, int idx, float wx, float wy, float w)
{
	unsigned char *lm = ted_getlightmap(s, idx);
	char *texname = ctx;
	int t;
	vec3_t newval;
	if (w > 1)
		w = 1;

	s->flags |= TSF_NOTIFY|TSF_EDITED;

	for (t = 0; t < 4; t++)
	{
		if (!strncmp(s->texname[t], texname, sizeof(s->texname[t])-1))
		{
			newval[0] = (t == 0);
			newval[1] = (t == 1);
			newval[2] = (t == 2);
			lm[2] = lm[2]*(1-w) + (255*newval[0]*(w));
			lm[1] = lm[1]*(1-w) + (255*newval[1]*(w));
			lm[0] = lm[0]*(1-w) + (255*newval[2]*(w));
			return;
		}
	}

	/*special handling to make a section accept the first texture painted on it as a base texture. no more chessboard*/
	if (!*s->texname[0] && !*s->texname[1] && !*s->texname[2] && !*s->texname[3])
	{
		Q_strncpyz(s->texname[3], texname, sizeof(s->texname[3]));
		Terr_LoadSectionTextures(s);

		for (idx = 0; idx < SECTTEXSIZE*SECTTEXSIZE; idx++)
		{
			lm = ted_getlightmap(s, idx);
			lm[2] = 0;
			lm[1] = 0;
			lm[0] = 0;
		}
		return;
	}
	for (t = 0; t < 4; t++)
	{
		if (!*s->texname[t])
		{
			Q_strncpyz(s->texname[t], texname, sizeof(s->texname[t]));

			newval[0] = (t == 0);
			newval[1] = (t == 1);
			newval[2] = (t == 2);
			lm[2] = lm[2]*(1-w) + (255*newval[0]*(w));
			lm[1] = lm[1]*(1-w) + (255*newval[1]*(w));
			lm[0] = lm[0]*(1-w) + (255*newval[2]*(w));

			Terr_LoadSectionTextures(s);
			return;
		}
	}
}

/*
static void ted_mixlight(void *ctx, hmsection_t *s, int idx, float wx, float wy, float w)
{
	unsigned char *lm = ted_getlightmap(s, idx);
	vec3_t pos, pos2;
	vec3_t norm, tnorm;
	vec3_t ldir = {0.4, 0.7, 2};
	float d;
	int x,y;
	trace_t tr;
	VectorClear(norm);
	for (y = -4; y < 4; y++)
	for (x = -4; x < 4; x++)
	{
		pos[0] = wx - (CHUNKBIAS + x/64.0) * s->hmmod->sectionsize;
		pos[1] = wy - (CHUNKBIAS + y/64.0) * s->hmmod->sectionsize;
#if 0
		pos[2] = 10000;
		pos2[0] = wx - (CHUNKBIAS + x/64.0) * s->hmmod->sectionsize;
		pos2[1] = wy - (CHUNKBIAS + y/64.0) * s->hmmod->sectionsize;
		pos2[2] = -10000;
		Heightmap_Trace(cl.worldmodel, 0, 0, NULL, pos, pos2, vec3_origin, vec3_origin, FTECONTENTS_SOLID, &tr);
		VectorCopy(tr.plane.normal, tnorm);
#else
		Heightmap_Normal(s->hmmod, pos, tnorm);
#endif
		d = sqrt(32 - x*x+y*y);
		VectorMA(norm, d, tnorm, norm);
	}

	VectorNormalize(ldir);
	VectorNormalize(norm);
	d = DotProduct(ldir, norm);
	if (d < 0)
		d = 0;
	lm[3] = d*255;
}
*/
static void ted_mixset(void *ctx, hmsection_t *s, int idx, float wx, float wy, float w)
{
	unsigned char *lm = ted_getlightmap(s, idx);
	if (w > 1)
		w = 1;
	s->flags |= TSF_NOTIFY|TSF_EDITED;

	lm[2] = lm[2]*(1-w) + (255*((float*)ctx)[0]*(w));
	lm[1] = lm[1]*(1-w) + (255*((float*)ctx)[1]*(w));
	lm[0] = lm[0]*(1-w) + (255*((float*)ctx)[2]*(w));
}

static void ted_mixtally(void *ctx, hmsection_t *s, int idx, float wx, float wy, float w)
{
	unsigned char *lm = ted_getlightmap(s, idx);
	((float*)ctx)[0] += lm[0]*w;
	((float*)ctx)[1] += lm[1]*w;
	((float*)ctx)[2] += lm[2]*w;
	((float*)ctx)[3] += w;
}

static void ted_tint(void *ctx, hmsection_t *s, int idx, float wx, float wy, float w)
{
	float *col = s->colours[idx];
	float *newval = ctx;
	if (w > 1)
		w = 1;
	s->flags |= TSF_NOTIFY|TSF_DIRTY|TSF_EDITED|TSF_HASCOLOURS;	/*dirty because of the vbo*/
	col[0] = col[0]*(1-w) + (newval[0]*(w));
	col[1] = col[1]*(1-w) + (newval[1]*(w));
	col[2] = col[2]*(1-w) + (newval[2]*(w));
	col[3] = col[3]*(1-w) + (newval[3]*(w));
}

enum
{
	tid_linear,
	tid_exponential
};
//calls 'func' for each tile upon the terrain. the 'tile' can be either height or texel
static void ted_itterate(heightmap_t *hm, int distribution, float *pos, float radius, float strength, int steps, void(*func)(void *ctx, hmsection_t *s, int idx, float wx, float wy, float strength), void *ctx)
{
	int tx, ty;
	float wx, wy;
	float sc[2];
	int min[2], max[2];
	int sx,sy;
	hmsection_t *s;
	float w, xd, yd;

	min[0] = floor((pos[0] - radius)/(hm->sectionsize) - 1.5);
	min[1] = floor((pos[1] - radius)/(hm->sectionsize) - 1.5);
	max[0] = ceil((pos[0] + radius)/(hm->sectionsize) + 1.5);
	max[1] = ceil((pos[1] + radius)/(hm->sectionsize) + 1.5);

	min[0] = bound(hm->firstsegx, min[0], hm->maxsegx);
	min[1] = bound(hm->firstsegy, min[1], hm->maxsegy);
	max[0] = bound(hm->firstsegx, max[0], hm->maxsegx);
	max[1] = bound(hm->firstsegy, max[1], hm->maxsegy);

	sc[0] = hm->sectionsize/(steps-1);
	sc[1] = hm->sectionsize/(steps-1);

	for (sy = min[1]; sy < max[1]; sy++)
	{
		for (sx = min[0]; sx < max[0]; sx++)
		{
			s = Terr_GetSection(hm, sx, sy, TGS_FORCELOAD);
			if (!s)
				continue;

			for (ty = 0; ty < steps; ty++)
			{
				wy = (sy*(steps-1.0) + ty)*sc[1];
				yd = wy - pos[1];// - sc[1]/4;
//				if (yd < 0)
//					yd = 0;
				for (tx = 0; tx < steps; tx++)
				{
					/*both heights and textures have an overlapping/matching sample at the edge, there's no need for any half-pixels or anything here*/
					wx = (sx*(steps-1.0) + tx)*sc[0];
					xd = wx - pos[0];// - sc[0]/4;
//					if (xd < 0)
//						xd = 0;

					if (radius*radius >= (xd*xd+yd*yd))
					{
						if (distribution == tid_exponential)
							w = sqrt((radius*radius) - ((xd*xd)+(yd*yd)));
						else
							w = radius - sqrt(xd*xd+yd*yd);
						if (w > 0)
							func(ctx, s, tx+ty*steps, wx, wy, w*strength/(radius));
					}
				}
			}
		}
	}
}

void QCBUILTIN PF_terrain_edit(pubprogfuncs_t *prinst, struct globalvars_s *pr_globals)
{
	world_t *vmw = prinst->parms->user;
	int action = G_FLOAT(OFS_PARM0);
	vec3_t pos;// G_VECTOR(OFS_PARM1);
	float radius = G_FLOAT(OFS_PARM2);
	float quant = G_FLOAT(OFS_PARM3);
//	G_FLOAT(OFS_RETURN) = Heightmap_Edit(w->worldmodel, action, pos, radius, quant);
	model_t *mod = vmw->Get_CModel(vmw, ((wedict_t*)PROG_TO_EDICT(prinst, *vmw->g.self))->v->modelindex);
	heightmap_t *hm;
	vec4_t tally;

	G_FLOAT(OFS_RETURN) = 0;

	if (!mod || !mod->terrain)
		return;
	hm = mod->terrain;

	pos[0] = G_FLOAT(OFS_PARM1+0) + hm->sectionsize * CHUNKBIAS;
	pos[1] = G_FLOAT(OFS_PARM1+1) + hm->sectionsize * CHUNKBIAS;
	pos[2] = G_FLOAT(OFS_PARM1+2);

	switch(action)
	{
	case ter_reload:
		G_FLOAT(OFS_RETURN) = 1;
		Terr_PurgeTerrainModel(mod, false, true);
		break;
	case ter_save:
		quant = Heightmap_Save(hm);
		Con_DPrintf("ter_save: %g sections saved\n", quant);
		G_FLOAT(OFS_RETURN) = quant;
		break;
	case ter_sethole:
	/*	{
			int x, y;
			hmsection_t *s;
			x = pos[0]*4 / hm->sectionsize;
			y = pos[1]*4 / hm->sectionsize;
			x = bound(hm->firstsegx*4, x, hm->maxsegy*4-1);
			y = bound(hm->firstsegy*4, y, hm->maxsegy*4-1);
		
			s = Terr_GetSection(hm, x/4, y/4, TGS_FORCELOAD);
			if (!s)
				return;
			ted_sethole(&quant, s, (x&3) + (y&3)*4, x/4, y/4, 0);
		}
	*/	ted_itterate(hm, tid_linear, pos, radius, 1, 4, ted_sethole, &quant);
		break;
	case ter_height_set:
		ted_itterate(hm, tid_linear, pos, radius, 1, SECTHEIGHTSIZE, ted_heightset, &quant);
		break;
	case ter_height_flatten:
		tally[0] = 0;
		tally[1] = 0;
		ted_itterate(hm, tid_exponential, pos, radius, 1, SECTHEIGHTSIZE, ted_heighttally, &tally);
		tally[0] /= tally[1];
		if (IS_NAN(tally[0]))
			tally[0] = 0;
		ted_itterate(hm, tid_exponential, pos, radius, quant, SECTHEIGHTSIZE, ted_heightsmooth, &tally);
		break;
	case ter_height_smooth:
		tally[0] = 0;
		tally[1] = 0;
		ted_itterate(hm, tid_linear, pos, radius, 1, SECTHEIGHTSIZE, ted_heighttally, &tally);
		tally[0] /= tally[1];
		if (IS_NAN(tally[0]))
			tally[0] = 0;
		ted_itterate(hm, tid_linear, pos, radius, quant, SECTHEIGHTSIZE, ted_heightsmooth, &tally);
		break;
	case ter_height_spread:
		tally[0] = 0;
		tally[1] = 0;
		ted_itterate(hm, tid_exponential, pos, radius/2, 1, SECTHEIGHTSIZE, ted_heighttally, &tally);
		tally[0] /= tally[1];
		if (IS_NAN(tally[0]))
			tally[0] = 0;
		ted_itterate(hm, tid_exponential, pos, radius, 1, SECTHEIGHTSIZE, ted_heightsmooth, &tally);
		break;
	case ter_water_set:
		{
			int x, y;
			hmsection_t *s;
			x = pos[0] / hm->sectionsize;
			y = pos[1] / hm->sectionsize;
			x = bound(hm->firstsegx, x, hm->maxsegy-1);
			y = bound(hm->firstsegy, y, hm->maxsegy-1);
		
			s = Terr_GetSection(hm, x, y, TGS_LOAD);
			if (!s)
				return;
			s->flags |= TSF_HASWATER|TSF_EDITED;
			s->waterheight = quant;
		}
		break;
	case ter_lower:
		quant *= -1;
	case ter_raise:
		ted_itterate(hm, tid_exponential, pos, radius, quant, SECTHEIGHTSIZE, ted_heightraise, &quant);
		break;
	case ter_tint:
		ted_itterate(hm, tid_exponential, pos, radius, quant, SECTHEIGHTSIZE, ted_tint, G_VECTOR(OFS_PARM4));	//and parm5 too
		break;
//	case ter_mixset:
//		ted_itterate(hm, tid_exponential, pos, radius, 1, SECTTEXSIZE, ted_mixset, G_VECTOR(OFS_PARM4));
//		break;
	case ter_mix_paint:
		ted_itterate(hm, tid_exponential, pos, radius, quant/10, SECTTEXSIZE, ted_mixpaint, PR_GetStringOfs(prinst, OFS_PARM4));
		break;
	case ter_mix_concentrate:
		ted_itterate(hm, tid_exponential, pos, radius, 1, SECTTEXSIZE, ted_mixconcentrate, NULL);
		break;
	case ter_mix_noise:
		ted_itterate(hm, tid_exponential, pos, radius, 1, SECTTEXSIZE, ted_mixnoise, NULL);
		break;
	case ter_mix_blur:
		Vector4Set(tally, 0, 0, 0, 0);
		ted_itterate(hm, tid_exponential, pos, radius, 1, SECTTEXSIZE, ted_mixtally, &tally);
		VectorScale(tally, 1/(tally[3]*255), tally);
		ted_itterate(hm, tid_exponential, pos, radius, quant, SECTTEXSIZE, ted_mixset, &tally);
		break;
	case ter_tex_get:
		{
			int x, y;
			hmsection_t *s;
			x = pos[0] / hm->sectionsize;
			y = pos[1] / hm->sectionsize;
			x = bound(hm->firstsegx, x, hm->maxsegy-1);
			y = bound(hm->firstsegy, y, hm->maxsegy-1);
		
			s = Terr_GetSection(hm, x, y, TGS_LOAD);
			if (!s)
				return;
			x = bound(0, quant, 3);
			G_INT(OFS_RETURN) = PR_TempString(prinst, s->texname[x]);
		}
		break;
	case ter_tex_kill:
		{
			char *killtex = PR_GetStringOfs(prinst, OFS_PARM4);
			int x, y, t, to;
			hmsection_t *s;
			x = pos[0] / hm->sectionsize;
			y = pos[1] / hm->sectionsize;
			x = bound(hm->firstsegx, x, hm->maxsegy-1);
			y = bound(hm->firstsegy, y, hm->maxsegy-1);
		
			s = Terr_GetSection(hm, x, y, TGS_FORCELOAD);
			if (!s)
				return;
			s->flags |= TSF_EDITED;
			for (t = 0; t < 4; t++)
			{
				if (!strcmp(s->texname[t], killtex))
				{
					unsigned char *lm = ted_getlightmap(s, 0);
					s->texname[t][0] = 0;
					for (to = 0; to < 4; to++)
						if (*s->texname[to])
							break;
					if (to == 4)
						to = 0;

					if (to == 0 || to == 2)
						to = 2 - to;
					if (t == 0 || t == 2)
						t = 2 - t;

					for (y = 0; y < SECTTEXSIZE; y++)
					{
						for (x = 0; x < SECTTEXSIZE; x++, lm+=4)
						{
							if (t == 3)
							{
								//to won't be 3
								lm[to] = lm[to] + (255 - (lm[0] + lm[1] + lm[2]));
							}
							else
							{
								if (to != 3)
									lm[to] += lm[t];
								lm[t] = 0;
							}
						}
						lm += SECTTEXSIZE*4*(LMCHUNKS-1);
					}
					if (t == 0 || t == 2)
						t = 2 - t;
					Terr_LoadSectionTextures(s);
				}
			}
		}
		break;
	case ter_mesh_add:
		{
			entity_t *e;
			float *epos;
			int x, y;
			hmsection_t *s;
			epos = ((wedict_t *)G_EDICT(prinst, OFS_PARM1))->v->origin;
			x = (epos[0] / hm->sectionsize) + CHUNKBIAS;
			y = (epos[1] / hm->sectionsize) + CHUNKBIAS;
			x = bound(hm->firstsegx, x, hm->maxsegy-1);
			y = bound(hm->firstsegy, y, hm->maxsegy-1);
		
			s = Terr_GetSection(hm, x, y, TGS_FORCELOAD);
			if (!s)
				return;

			s->flags |= TSF_EDITED;

			if (s->maxents == s->numents)
			{
				s->maxents++;
				s->ents = realloc(s->ents, sizeof(*s->ents)*(s->maxents));
			}
			e = &s->ents[s->numents++];

			memset(e, 0, sizeof(*e));
			e->scale = ((wedict_t *)G_EDICT(prinst, OFS_PARM1))->xv->scale;
			e->shaderRGBAf[0] = 1;
			e->shaderRGBAf[1] = 1;
			e->shaderRGBAf[2] = 1;
			e->shaderRGBAf[3] = 1;
			VectorCopy(epos, e->origin);
			AngleVectorsFLU(((wedict_t *)G_EDICT(prinst, OFS_PARM1))->v->angles, e->axis[0], e->axis[1], e->axis[2]);
			e->model = vmw->Get_CModel(vmw, ((wedict_t *)G_EDICT(prinst, OFS_PARM1))->v->modelindex);
		}
		break;
	case ter_mesh_kill:
		{
//			int i;
//			entity_t *e;
			int x, y;
//			float r;
			hmsection_t *s;
			x = pos[0] / hm->sectionsize;
			y = pos[1] / hm->sectionsize;
			x = bound(hm->firstsegx, x, hm->maxsegy-1);
			y = bound(hm->firstsegy, y, hm->maxsegy-1);
		
			s = Terr_GetSection(hm, x, y, TGS_FORCELOAD);
			if (!s)
				return;

			s->numents = 0;
			s->flags |= TSF_EDITED;

			/*for (i = 0; i < s->numents; i++)
			{

			}*/
		}
		break;
	}
}
#else
void QCBUILTIN PF_terrain_edit(pubprogfuncs_t *prinst, struct globalvars_s *pr_globals)
{
	G_FLOAT(OFS_RETURN) = 0;
}
#endif

void Terr_ParseEntityLump(char *data, heightmap_t *heightmap)
{
	char key[128];

	heightmap->sectionsize = 1024;

	if (data)
	if ((data=COM_Parse(data)))	//read the map info.
	if (com_token[0] == '{')
	while (1)
	{
		if (!(data=COM_Parse(data)))
			break; // error
		if (com_token[0] == '}')
			break; // end of worldspawn
		if (com_token[0] == '_')
			strcpy(key, com_token + 1);	//_ vars are for comments/utility stuff that arn't visible to progs. Ignore them.
		else
			strcpy(key, com_token);
		if (!((data=COM_Parse(data))))
			break; // error		
		if (!strcmp("segmentsize", key))
			heightmap->sectionsize = atof(com_token);
		else if (!strcmp("minxsegment", key))
			heightmap->firstsegx = atoi(com_token);
		else if (!strcmp("minysegment", key))
			heightmap->firstsegy = atoi(com_token);
		else if (!strcmp("maxxsegment", key))
			heightmap->maxsegx = atoi(com_token);
		else if (!strcmp("maxysegment", key))
			heightmap->maxsegy = atoi(com_token);
		else if (!strcmp("tiles", key))
		{
			char *d;
			heightmap->tiled = true;
			d = com_token;
			d = COM_ParseOut(d, key, sizeof(key));
			heightmap->tilepixcount[0] = atoi(key);
			d = COM_ParseOut(d, key, sizeof(key));
			heightmap->tilepixcount[1] = atoi(key);
			d = COM_ParseOut(d, key, sizeof(key));
			heightmap->tilecount[0] = atoi(key);
			d = COM_ParseOut(d, key, sizeof(key));
			heightmap->tilecount[1] = atoi(key);
		}
	}

	/*bias and bound it*/
	heightmap->firstsegx += CHUNKBIAS;
	heightmap->firstsegy += CHUNKBIAS;
	heightmap->maxsegx += CHUNKBIAS;
	heightmap->maxsegy += CHUNKBIAS;
	if (heightmap->firstsegx < 0)
		heightmap->firstsegx = 0;
	if (heightmap->firstsegy < 0)
		heightmap->firstsegy = 0;
	if (heightmap->maxsegx > CHUNKLIMIT)
		heightmap->maxsegx = CHUNKLIMIT;
	if (heightmap->maxsegy > CHUNKLIMIT)
		heightmap->maxsegy = CHUNKLIMIT;
}

void Terr_FinishTerrain(heightmap_t *hm, char *shadername, char *skyname)
{
#ifndef SERVERONLY
	if (qrenderer != QR_NONE)
	{
		hm->skyshader = R_RegisterCustom(va("skybox_%s", skyname), Shader_DefaultSkybox, NULL);
		if (hm->tiled)
			hm->shader = R_RegisterShader("terraintileshader",
					"{\n"
						"{\n"
							"map $diffuse\n"	
						"}\n"
					"}\n"
				);
		else
			hm->shader = R_RegisterShader(shadername,
					"{\n"
						"{\n"
							"map $diffuse\n"
						"}\n"
						"{\n"
							"map $upperoverlay\n"
						"}\n"
						"{\n"
							"map $loweroverlay\n"
						"}\n"
						"{\n"
							"map $fullbright\n"
						"}\n"
						"{\n"
							"map $lightmap\n"
						"}\n"
						"program terrain\n"
						"if r_terraindebug\n"
						"program terraindebug\n"
						"endif\n"
					"}\n"
				);


		hm->watershader = R_RegisterCustom ("warp/terrain", Shader_DefaultBSPQ2, NULL);
		if (!TEXVALID(hm->watershader->defaulttextures.base))
			hm->watershader->defaulttextures.base = R_LoadHiResTexture("terwater", NULL, IF_NOALPHA);
		if (!TEXVALID(hm->watershader->defaulttextures.bump))
			hm->watershader->defaulttextures.bump = R_LoadBumpmapTexture("terwater_bump", NULL);
		if (!TEXVALID(hm->watershader->defaulttextures.bump))
		{
			unsigned char dat[64*64] = {0};
			int i;
			for (i = 0; i < 64*64; i++)
				dat[i] = rand()&15;
			hm->watershader->defaulttextures.bump = R_LoadTexture8BumpPal("terwater_bump", 64, 64, dat, 0);
		}
	}
#endif
}

qboolean Terr_LoadTerrainModel (model_t *mod, void *buffer)
{
	heightmap_t *hm;

	float skyrotate;
	vec3_t skyaxis;
	char shadername[MAX_QPATH];
	char skyname[MAX_QPATH];
	int sectsize = 0;

	COM_FileBase(mod->name, shadername, sizeof(shadername));
	strcpy(shadername, "terrainshader");
	strcpy(skyname, "night");

	skyrotate = 0;
	skyaxis[0] = 0;
	skyaxis[1] = 0;
	skyaxis[2] = 0;

	buffer = COM_Parse(buffer);
	if (strcmp(com_token, "terrain"))
	{
		Con_Printf(CON_ERROR "%s wasn't terrain map\n", mod->name);	//shouldn't happen
		return false;
	}

	mod->type = mod_heightmap;

	hm = Hunk_Alloc(sizeof(*hm));
	memset(hm, 0, sizeof(*hm));
	ClearLink(&hm->recycle);
	COM_FileBase(mod->name, hm->path, sizeof(hm->path));

	mod->entities = Hunk_AllocName(strlen(buffer)+1, mod->name);
	strcpy(mod->entities, buffer);

	hm->sectionsize = sectsize;
	hm->firstsegx = -1;
	hm->firstsegy = -1;
	hm->maxsegx = +1;
	hm->maxsegy = +1;
	hm->exteriorcontents = FTECONTENTS_SOLID;	//sky outside the map

	Terr_ParseEntityLump(mod->entities, hm);

	mod->mins[0] = (hm->firstsegx - CHUNKBIAS) * hm->sectionsize;
	mod->mins[1] = (hm->firstsegy - CHUNKBIAS) * hm->sectionsize;
	mod->mins[2] = -999999999999999999999999.f;
	mod->maxs[0] = (hm->maxsegy - CHUNKBIAS) * hm->sectionsize;
	mod->maxs[1] = (hm->maxsegy - CHUNKBIAS) * hm->sectionsize;
	mod->maxs[2] = 999999999999999999999999.f;

	mod->funcs.NativeTrace			= Heightmap_Trace;
	mod->funcs.PointContents		= Heightmap_PointContents;

	mod->funcs.NativeContents		= Heightmap_NativeBoxContents;

	mod->funcs.LightPointValues		= Heightmap_LightPointValues;
	mod->funcs.StainNode			= Heightmap_StainNode;
	mod->funcs.MarkLights			= Heightmap_MarkLights;

	mod->funcs.LeafnumForPoint		= Heightmap_LeafForPoint;
	mod->funcs.LeafPVS				= Heightmap_LeafnumPVS;

#ifndef CLIENTONLY
	mod->funcs.FindTouchedLeafs		= Heightmap_FindTouchedLeafs;
	mod->funcs.EdictInFatPVS		= Heightmap_EdictInFatPVS;
	mod->funcs.FatPVS				= Heightmap_FatPVS;
#endif
/*	mod->hulls[0].funcs.HullPointContents = Heightmap_PointContents;
	mod->hulls[1].funcs.HullPointContents = Heightmap_PointContents;
	mod->hulls[2].funcs.HullPointContents = Heightmap_PointContents;
	mod->hulls[3].funcs.HullPointContents = Heightmap_PointContents;
*/

	mod->terrain = hm;

	Terr_FinishTerrain(hm, shadername, skyname);

	return true;
}

void *Mod_LoadTerrainInfo(model_t *mod, char *loadname)
{
	heightmap_t *hm;
	heightmap_t potential;
	if (!mod->entities)
		return NULL;

	memset(&potential, 0, sizeof(potential));
	Terr_ParseEntityLump(mod->entities, &potential);

	if (potential.firstsegx == potential.maxsegx || potential.firstsegy == potential.maxsegy)
		return NULL;

	hm = Z_Malloc(sizeof(*hm));
	*hm = potential;
	ClearLink(&hm->recycle);
	Q_strncpyz(hm->path, loadname, sizeof(hm->path));

	hm->exteriorcontents = FTECONTENTS_EMPTY;	//bsp geometry outside the heightmap

	Terr_FinishTerrain(hm, "terrainshader", loadname);

	return hm;
}

void Mod_Terrain_Create_f(void)
{
	char *mname;
	char *mdata;
	mname = va("maps/%s.hmp", Cmd_Argv(1));
	mdata = va(
		"terrain\n"
		"{\n"
			"classname worldspawn\n"
			"_segmentsize 1024\n"
			"_minxsegment -2048\n"
			"_minysegment -2048\n"
			"_maxxsegment 2048\n"
			"_maxysegment 2048\n"
			"_segmentsize 1024\n"
//			"_tiles 64 64 8 8\n"
		"}\n"
		"{\n"
			"classname info_player_start\n"
			"origin \"0 0 1024\"\n"
		"}\n"
		, mname);
	COM_WriteFile(mname, mdata, strlen(mdata));
}
void Mod_Terrain_Reload_f(void)
{
	model_t *mod;
	heightmap_t *hm;
	if (Cmd_Argc() >= 2)
		mod = Mod_FindName(va("maps/%s.hmp", Cmd_Argv(1)));
#ifndef SERVERONLY
	else if (cls.state)
		mod = cl.worldmodel;
#endif
	else
		mod = NULL;
	if (!mod || mod->type == mod_dummy)
		return;
	hm = mod->terrain;
	if (!hm)
		return;

	if (Cmd_Argc() >= 4)
	{
		hmsection_t *s;
		int sx = atoi(Cmd_Argv(2)) + CHUNKBIAS;
		int sy = atoi(Cmd_Argv(3)) + CHUNKBIAS;
		if (hm)
		{
			s = Terr_GetSection(hm, sx, sy, TGS_NOLOAD);
			if (s)
			{
				s->flags |= TSF_NOTIFY;
			}
		}
	}
	else
		Terr_PurgeTerrainModel(mod, false, true);
}

void Terr_Init(void)
{
	Cvar_Register(&mod_terrain_networked, "Terrain");
	Cmd_AddCommand("mod_terrain_create", Mod_Terrain_Create_f);
	Cmd_AddCommand("mod_terrain_reload", Mod_Terrain_Reload_f);
}
#endif
