/*
Copyright (C) 1999-2006 Id Software, Inc. and contributors.
For a list of contributors, see the accompanying CONTRIBUTORS file.

This file is part of GtkRadiant.

GtkRadiant is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

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

You should have received a copy of the GNU General Public License
along with GtkRadiant; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/
// qrad.c

#include "qrad.h"



/*

NOTES
-----

every surface must be divided into at least two patches each axis

*/

patch_t		*face_patches[MAX_MAP_FACES];
entity_t	*face_entity[MAX_MAP_FACES];
patch_t		patches[MAX_PATCHES];
unsigned	num_patches;

vec3_t		radiosity[MAX_PATCHES];		// light leaving a patch
vec3_t		illumination[MAX_PATCHES];	// light arriving at a patch

vec3_t		face_offset[MAX_MAP_FACES];		// for rotating bmodels
dplane_t	backplanes[MAX_MAP_PLANES];

char		inbase[32], outbase[32];

int			fakeplanes;					// created planes for origin offset 

int		numbounce = 8;
qboolean	extrasamples;

float	subdiv = 64;
qboolean	dumppatches;

void BuildLightmaps (void);
int TestLine (vec3_t start, vec3_t stop);

int		junk;

float	ambient = 0;
float	maxlight = 196;

float	lightscale = 1.0;

qboolean	glview;

qboolean	nopvs;

char		source[1024];

float	direct_scale =	0.4;
float	entity_scale =	1.0;

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

MISC

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


/*
=============
MakeBackplanes
=============
*/
void MakeBackplanes (void)
{
	int		i;

	for (i=0 ; i<numplanes ; i++)
	{
		backplanes[i].dist = -dplanes[i].dist;
		VectorSubtract (vec3_origin, dplanes[i].normal, backplanes[i].normal);
	}
}

int		leafparents[MAX_MAP_LEAFS];
int		nodeparents[MAX_MAP_NODES];

/*
=============
MakeParents
=============
*/
void MakeParents (int nodenum, int parent)
{
	int		i, j;
	dnode_t	*node;

	nodeparents[nodenum] = parent;
	node = &dnodes[nodenum];

	for (i=0 ; i<2 ; i++)
	{
		j = node->children[i];
		if (j < 0)
			leafparents[-j - 1] = nodenum;
		else
			MakeParents (j, nodenum);
	}
}


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

TRANSFER SCALES

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

int	PointInLeafnum (vec3_t point)
{
	int		nodenum;
	vec_t	dist;
	dnode_t	*node;
	dplane_t	*plane;

	nodenum = 0;
	while (nodenum >= 0)
	{
		node = &dnodes[nodenum];
		plane = &dplanes[node->planenum];
		dist = DotProduct (point, plane->normal) - plane->dist;
		if (dist > 0)
			nodenum = node->children[0];
		else
			nodenum = node->children[1];
	}

	return -nodenum - 1;
}


dleaf_t		*Rad_PointInLeaf (vec3_t point)
{
	int		num;

	num = PointInLeafnum (point);
	return &dleafs[num];
}


qboolean PvsForOrigin (vec3_t org, byte *pvs)
{
	dleaf_t	*leaf;

	if (!visdatasize)
	{
		memset (pvs, 255, (numleafs+7)/8 );
		return true;
	}

	leaf = Rad_PointInLeaf (org);
	if (leaf->cluster == -1)
		return false;		// in solid leaf

	DecompressVis (dvisdata + dvis->bitofs[leaf->cluster][DVIS_PVS], pvs);
	return true;
}


/*
=============
MakeTransfers

=============
*/
int	total_transfer;

void MakeTransfers (int i)
{
	int			j;
	vec3_t		delta;
	vec_t		dist, scale;
	float		trans;
	int			itrans;
	patch_t		*patch, *patch2;
	float		total;
	dplane_t	plane;
	vec3_t		origin;
	float		transfers[MAX_PATCHES], *all_transfers;
	int			s;
	int			itotal;
	byte		pvs[(MAX_MAP_LEAFS+7)/8];
	int			cluster;

	patch = patches + i;
	total = 0;

	VectorCopy (patch->origin, origin);
	plane = *patch->plane;

	if (!PvsForOrigin (patch->origin, pvs))
		return;

	// find out which patch2s will collect light
	// from patch

	all_transfers = transfers;
	patch->numtransfers = 0;
	for (j=0, patch2 = patches ; j<num_patches ; j++, patch2++)
	{
		transfers[j] = 0;

		if (j == i)
			continue;

		// check pvs bit
		if (!nopvs)
		{
			cluster = patch2->cluster;
			if (cluster == -1)
				continue;
			if ( ! ( pvs[cluster>>3] & (1<<(cluster&7)) ) )
				continue;		// not in pvs
		}

		// calculate vector
		VectorSubtract (patch2->origin, origin, delta);
		dist = VectorNormalize (delta, delta);
		if (!dist)
			continue;	// should never happen

		// reletive angles
		scale = DotProduct (delta, plane.normal);
		scale *= -DotProduct (delta, patch2->plane->normal);
		if (scale <= 0)
			continue;

		// check exact tramsfer
		if (TestLine_r (0, patch->origin, patch2->origin) )
			continue;

		trans = scale * patch2->area / (dist*dist);

		if (trans < 0)
			trans = 0;		// rounding errors...

		transfers[j] = trans;
		if (trans > 0)
		{
			total += trans;
			patch->numtransfers++;
		}
	}

	// copy the transfers out and normalize
	// total should be somewhere near PI if everything went right
	// because partial occlusion isn't accounted for, and nearby
	// patches have underestimated form factors, it will usually
	// be higher than PI
	if (patch->numtransfers)
	{
		transfer_t	*t;
		
		if (patch->numtransfers < 0 || patch->numtransfers > MAX_PATCHES)
			Error ("Weird numtransfers");
		s = patch->numtransfers * sizeof(transfer_t);
		patch->transfers = malloc (s);
		if (!patch->transfers)
			Error ("Memory allocation failure");

		//
		// normalize all transfers so all of the light
		// is transfered to the surroundings
		//
		t = patch->transfers;
		itotal = 0;
		for (j=0 ; j<num_patches ; j++)
		{
			if (transfers[j] <= 0)
				continue;
			itrans = transfers[j]*0x10000 / total;
			itotal += itrans;
			t->transfer = itrans;
			t->patch = j;
			t++;
		}
	}

	// don't bother locking around this.  not that important.
	total_transfer += patch->numtransfers;
}


/*
=============
FreeTransfers
=============
*/
void FreeTransfers (void)
{
	int		i;

	for (i=0 ; i<num_patches ; i++)
	{
		free (patches[i].transfers);
		patches[i].transfers = NULL;
	}
}


//===================================================================

/*
=============
WriteWorld
=============
*/
void WriteWorld (char *name)
{
	int		i, j;
	FILE		*out;
	patch_t		*patch;
	winding_t	*w;

	out = fopen (name, "w");
	if (!out)
		Error ("Couldn't open %s", name);

	for (j=0, patch=patches ; j<num_patches ; j++, patch++)
	{
		w = patch->winding;
		fprintf (out, "%i\n", w->numpoints);
		for (i=0 ; i<w->numpoints ; i++)
		{
			fprintf (out, "%5.2f %5.2f %5.2f %5.3f %5.3f %5.3f\n",
				w->p[i][0],
				w->p[i][1],
				w->p[i][2],
				patch->totallight[0],
				patch->totallight[1],
				patch->totallight[2]);
		}
		fprintf (out, "\n");
	}

	fclose (out);
}

/*
=============
WriteGlView
=============
*/
void WriteGlView (void)
{
	char	name[1024];
	FILE	*f;
	int		i, j;
	patch_t	*p;
	winding_t	*w;

	strcpy (name, source);
	StripExtension (name);
	strcat (name, ".glr");

	f = fopen (name, "w");
	if (!f)
		Error ("Couldn't open %s", f);

	for (j=0 ; j<num_patches ; j++)
	{
		p = &patches[j];
		w = p->winding;
		fprintf (f, "%i\n", w->numpoints);
		for (i=0 ; i<w->numpoints ; i++)
		{
			fprintf (f, "%5.2f %5.2f %5.2f %5.3f %5.3f %5.3f\n",
				w->p[i][0],
				w->p[i][1],
				w->p[i][2],
				p->totallight[0]/128,
				p->totallight[1]/128,
				p->totallight[2]/128);
		}
		fprintf (f, "\n");
	}

	fclose (f);
}


//==============================================================

/*
=============
CollectLight
=============
*/
float CollectLight (void)
{
	int		i, j;
	patch_t	*patch;
	vec_t	total;

	total = 0;

	for (i=0, patch=patches ; i<num_patches ; i++, patch++)
	{
		// skys never collect light, it is just dropped
		if (patch->sky)
		{
			VectorClear (radiosity[i]);
			VectorClear (illumination[i]);
			continue;
		}

		for (j=0 ; j<3 ; j++)
		{
			patch->totallight[j] += illumination[i][j] / patch->area;
			radiosity[i][j] = illumination[i][j] * patch->reflectivity[j];
		}

		total += radiosity[i][0] + radiosity[i][1] + radiosity[i][2];
		VectorClear (illumination[i]);
	}

	return total;
}


/*
=============
ShootLight

Send light out to other patches
  Run multi-threaded
=============
*/
void ShootLight (int patchnum)
{
	int			k, l;
	transfer_t	*trans;
	int			num;
	patch_t		*patch;
	vec3_t		send;

	// this is the amount of light we are distributing
	// prescale it so that multiplying by the 16 bit
	// transfer values gives a proper output value
	for (k=0 ; k<3 ; k++)
		send[k] = radiosity[patchnum][k] / 0x10000;
	patch = &patches[patchnum];

	trans = patch->transfers;
	num = patch->numtransfers;

	for (k=0 ; k<num ; k++, trans++)
	{
		for (l=0 ; l<3 ; l++)
			illumination[trans->patch][l] += send[l]*trans->transfer;
	}
}

/*
=============
BounceLight
=============
*/
void BounceLight (void)
{
	int		i, j;
	float	added;
	char	name[64];
	patch_t	*p;

	for (i=0 ; i<num_patches ; i++)
	{
		p = &patches[i];
		for (j=0 ; j<3 ; j++)
		{
//			p->totallight[j] = p->samplelight[j];
			radiosity[i][j] = p->samplelight[j] * p->reflectivity[j] * p->area;
		}
	}

	for (i=0 ; i<numbounce ; i++)
	{
		RunThreadsOnIndividual (num_patches, false, ShootLight);
		added = CollectLight ();

		Sys_FPrintf( SYS_VRB, "bounce:%i added:%f\n", i, added);
		if ( dumppatches && (i==0 || i == numbounce-1) )
		{
			sprintf (name, "bounce%i.txt", i);
			WriteWorld (name);
		}
	}
}



//==============================================================

void CheckPatches (void)
{
	int		i;
	patch_t	*patch;

	for (i=0 ; i<num_patches ; i++)
	{
		patch = &patches[i];
		if (patch->totallight[0] < 0 || patch->totallight[1] < 0 || patch->totallight[2] < 0)
			Error ("negative patch totallight\n");
	}
}

/*
=============
RadWorld
=============
*/
void RadWorld (void)
{
	if (numnodes == 0 || numfaces == 0)
		Error ("Empty map");
	MakeBackplanes ();
	MakeParents (0, -1);
	MakeTnodes (&dmodels[0]);

	// turn each face into a single patch
	MakePatches ();

	// subdivide patches to a maximum dimension
	SubdividePatches ();

	// create directlights out of patches and lights
	CreateDirectLights ();

	// build initial facelights
	RunThreadsOnIndividual (numfaces, true, BuildFacelights);

	if (numbounce > 0)
	{
		// build transfer lists
		RunThreadsOnIndividual (num_patches, true, MakeTransfers);
		Sys_FPrintf( SYS_VRB, "transfer lists: %5.1f megs\n"
		, (float)total_transfer * sizeof(transfer_t) / (1024*1024));

		// spread light around
		BounceLight ();
		
		FreeTransfers ();

		CheckPatches ();
	}

	if (glview)
		WriteGlView ();

	// blend bounced light into direct light and save
	PairEdges ();
	LinkPlaneFaces ();

	lightdatasize = 0;
	RunThreadsOnIndividual (numfaces, true, FinalLightFace);
}


/*
========
main

light modelfile
========
*/
int RAD_Main ()
{
	double		start, end;
	char		name[1024];
	int		total_rad_time;

	Sys_Printf ("\n----- RAD ----\n\n");

	if (maxlight > 255)
		maxlight = 255;

	start = I_FloatTime ();

	if ( !strcmp( game, "heretic2" ) )
		CalcTextureReflectivity = &CalcTextureReflectivity_Heretic2;
	else
		CalcTextureReflectivity = &CalcTextureReflectivity_Quake2;
		
	SetQdirFromPath (mapname);	
	strcpy (source, ExpandArg(mapname));
	StripExtension (source);
	DefaultExtension (source, ".bsp");

//	ReadLightFile ();

	sprintf (name, "%s%s", inbase, source);
	Sys_Printf ("reading %s\n", name);
	LoadBSPFile (name);
	ParseEntities ();
	(*CalcTextureReflectivity) ();

	if (!visdatasize)
	{
		Sys_Printf ("No vis information, direct lighting only.\n");
		numbounce = 0;
		ambient = 0.1;
	}

	RadWorld ();

	sprintf (name, "%s%s", outbase, source);
	Sys_Printf ("writing %s\n", name);
	WriteBSPFile (name);

	end = I_FloatTime ();
	total_rad_time = (int) (end-start);
	Sys_Printf("\nRAD Time: ");
	if ( total_rad_time > 59 )
		Sys_Printf("%d Minutes ", total_rad_time/60 );
	Sys_Printf( "%d Seconds\n", total_rad_time%60 );
	
	
	return 0;
}