/*
	sw_view.c

	player eye positioning

	Copyright (C) 1996-1997  Id Software, Inc.

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

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

	See the GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to:

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

	$Id$
*/

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

#include "host.h"
#include "r_local.h"

extern byte gammatable[256];

void        V_CalcPowerupCshift (void);
qboolean    V_CheckGamma (void);

/*
=============
V_UpdatePalette
=============
*/
void
V_UpdatePalette (void)
{
	int         i, j;
	qboolean    new;
	byte       *basepal, *newpal;
	byte        pal[768];
	int         r, g, b;
	qboolean    force;

	V_CalcPowerupCshift ();

	new = false;

	for (i = 0; i < NUM_CSHIFTS; i++) {
		if (cl.cshifts[i].percent != cl.prev_cshifts[i].percent) {
			new = true;
			cl.prev_cshifts[i].percent = cl.cshifts[i].percent;
		}
		for (j = 0; j < 3; j++) {
			if (cl.cshifts[i].destcolor[j] != cl.prev_cshifts[i].destcolor[j]) {
				new = true;
				cl.prev_cshifts[i].destcolor[j] = cl.cshifts[i].destcolor[j];
			}
		}
	}

	// drop the damage value
	cl.cshifts[CSHIFT_DAMAGE].percent -= host_frametime * 150;
	if (cl.cshifts[CSHIFT_DAMAGE].percent <= 0)
		cl.cshifts[CSHIFT_DAMAGE].percent = 0;

	// drop the bonus value
	cl.cshifts[CSHIFT_BONUS].percent -= host_frametime * 100;
	if (cl.cshifts[CSHIFT_BONUS].percent <= 0)
		cl.cshifts[CSHIFT_BONUS].percent = 0;

	force = V_CheckGamma ();
	if (!new && !force)
		return;

	basepal = host_basepal;
	newpal = pal;

	for (i = 0; i < 256; i++) {
		r = basepal[0];
		g = basepal[1];
		b = basepal[2];
		basepal += 3;

		for (j = 0; j < NUM_CSHIFTS; j++) {
			r +=
				(cl.cshifts[j].percent * (cl.cshifts[j].destcolor[0] - r)) >> 8;
			g +=
				(cl.cshifts[j].percent * (cl.cshifts[j].destcolor[1] - g)) >> 8;
			b +=
				(cl.cshifts[j].percent * (cl.cshifts[j].destcolor[2] - b)) >> 8;
		}

		newpal[0] = gammatable[r];
		newpal[1] = gammatable[g];
		newpal[2] = gammatable[b];
		newpal += 3;
	}
	VID_ShiftPalette (pal);
}

void
BuildGammaTable (float b, float c)
{
	int         i, inf;

	if ((b == 1.0) && (c == 1.0)) {
		for (i = 0; i < 256; i++)
			gammatable[i] = i;
		return;
	}

	for (i = 0; i < 256; i++) {			// weighted average toward the
										// median, 127
		inf = (i * b);					// gamma is brightness now, and
										// positive
		inf = bound (0, inf, 255);
		gammatable[i] = inf + (int) ((127 - inf) * (1 - c));
	}
}