/**
 * @file glfile.c
 * @brief
 */

/*
Copyright (C) 1997-2001 Id Software, Inc.

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

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/


#include "qbsp.h"

static int c_glfaces = 0;

/**
 * @brief
 */
static int PortalVisibleSides (portal_t *p)
{
	int fcon, bcon;

	if (!p->onnode)
		return 0;		/* outside */

	fcon = p->nodes[0]->contents;
	bcon = p->nodes[1]->contents;

	/* same contents never create a face */
	if (fcon == bcon)
		return 0;

	/* FIXME: is this correct now? */
	if (!fcon)
		return 1;
	if (!bcon)
		return 2;
	return 0;
}

/**
 * @brief
 */
static void OutputWinding (winding_t *w, FILE *glview)
{
	static int level = 128;
	vec_t light;
	int i;

	fprintf (glview, "%i\n", w->numpoints);
	level += 28;
	light = (level & 255) / 255.0;
	for (i = 0; i < w->numpoints; i++) {
		fprintf (glview, "%6.3f %6.3f %6.3f %6.3f %6.3f %6.3f\n",
			w->p[i][0],
			w->p[i][1],
			w->p[i][2],
			light,
			light,
			light);
	}
	fprintf (glview, "\n");
}

/**
 * @brief
 */
static void OutputPortal (portal_t *p, FILE *glview)
{
	winding_t *w;
	int sides;

	sides = PortalVisibleSides (p);
	if (!sides)
		return;

	c_glfaces++;

	w = p->winding;

	if (sides == 2)		/* back side */
		w = ReverseWinding (w);

	OutputWinding (w, glview);

	if (sides == 2)
		FreeWinding(w);
}

/**
 * @brief
 */
static void WriteGLView_r (node_t *node, FILE *glview)
{
	portal_t *p, *nextp;

	if (node->planenum != PLANENUM_LEAF) {
		WriteGLView_r (node->children[0], glview);
		WriteGLView_r (node->children[1], glview);
		return;
	}

	/* write all the portals */
	for (p = node->portals; p; p = nextp) {
		if (p->nodes[0] == node) {
			OutputPortal (p, glview);
			nextp = p->next[0];
		} else
			nextp = p->next[1];
	}
}

/**
 * @brief
 * @note Currently unused
 */
extern void WriteGLView (tree_t *tree, char *source)
{
	char name[1024];
	FILE *glview;

	c_glfaces = 0;
	sprintf (name, "%s%s.gl",outbase, source);
	Sys_Printf ("Writing %s\n", name);

	glview = fopen (name, "w");
	if (!glview)
		Error ("Couldn't open %s", name);
	WriteGLView_r (tree->headnode, glview);
	fclose (glview);

	Sys_Printf ("%5i c_glfaces\n", c_glfaces);
}