/*
	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 "quakedef.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, j;
	int 	inf = 0;
	
	if ((b == 1.0) && (c == 1.0)) {
		for (i = 0; i < 256; i++)
			gammatable[i] = i;
		return;
	}
	
	for (i=0 ; i<256 ; i++) {
		if (!(i == 128)) {
			if (i < 128) {
				j = i + (int) ((128 - i) * (1 - c));
			} else {
				j = i + (int) ((i - 128) * (1 - c));
			}
		} else {
			j = i;
		}
		inf = (j * b);	// gamma is brightness now, and positive
		inf = bound(0, inf, 255);
		gammatable[i] = inf;
	}
}