/*
	gl_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 <string.h>
#include <stdio.h>

#include "bothdefs.h"   // needed by: common.h, net.h, client.h

#include "bspfile.h"    // needed by: glquake.h
#include "vid.h"
#include "sys.h"
#include "mathlib.h"    // needed by: protocol.h, render.h, client.h,
                        //  modelgen.h, glmodel.h
#include "wad.h"
#include "draw.h"
#include "cvar.h"
#include "net.h"        // needed by: client.h
#include "protocol.h"   // needed by: client.h
#include "cmd.h"
#include "sbar.h"
#include "render.h"     // needed by: client.h, model.h, glquake.h
#include "client.h"     // need cls in this file
#include "model.h"      // needed by: glquake.h
#include "console.h"
#include "glquake.h"

extern  byte            *host_basepal;
extern      double          host_frametime;
extern int	onground;
extern	byte	gammatable[256];

extern cvar_t  *gl_cshiftpercent;

byte ramps[3][256];
float	v_blend[4];

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

/*
	V_CalcBlend

	LordHavoc made this a real, (messy,) true alpha blend.  Cleaned it up
	 a bit, but otherwise this is his code.  --KB
*/
void
V_CalcBlend (void)
{
	float		r, g, b, a, a2, a3;
	int		j;

	r = 0;
	g = 0;
	b = 0;
	a = 0;

	for (j=0 ; j<NUM_CSHIFTS ; j++)
	{
		if (!gl_cshiftpercent->value)
			continue;

		a2 = ((cl.cshifts[j].percent * gl_cshiftpercent->value) / 100.0) / 255.0;

		if (!a2)
			continue;

		a2 = min(a2, 1.0);
		r += (cl.cshifts[j].destcolor[0]-r) * a2;
		g += (cl.cshifts[j].destcolor[1]-g) * a2;
		b += (cl.cshifts[j].destcolor[2]-b) * a2;
		
		a3 = (1.0 - a) * (1.0 - a2);
		a = 1.0 - a3;
	}

	// LordHavoc: saturate color
	if (a)
	{
		a2 = 1.0 / a;
		r *= a2;
		g *= a2;
		b *= a2;
		if (a > 1) // clamp alpha blend too
			a = 1;
	}

	v_blend[0] = min(r, 255.0)/255.0;
	v_blend[1] = min(g, 255.0)/255.0;
	v_blend[2] = min(b, 255.0)/255.0;
	v_blend[3] = bound (0.0, a, 1.0);
}

/*
=============
V_UpdatePalette
=============
*/

void V_UpdatePalette (void)
{
	int		i, j;
	qboolean	new;
	byte	*basepal, *newpal;
	byte	pal[768];
	float	r,g,b,a;
	int		ir, ig, ib;
	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;

	V_CalcBlend ();

//Con_Printf("b: %4.2f %4.2f %4.2f %4.6f\n", v_blend[0],	v_blend[1],	v_blend[2],	v_blend[3]);

	a = v_blend[3];
	r = 255*v_blend[0]*a;
	g = 255*v_blend[1]*a;
	b = 255*v_blend[2]*a;

	a = 1-a;
	for (i=0 ; i<256 ; i++)
	{
		ir = min(i*a + r, 255);
		ig = min(i*a + g, 255);
		ib = min(i*a + b, 255);

		ramps[0][i] = gammatable[ir];
		ramps[1][i] = gammatable[ig];
		ramps[2][i] = gammatable[ib];
	}

	basepal = host_basepal;
	newpal = pal;
	
	for (i=0; i<256; i++) {
		ir = basepal[0];
		ig = basepal[1];
		ib = basepal[2];
		basepal += 3;
		
		newpal[0] = ramps[0][ir];
		newpal[1] = ramps[1][ig];
		newpal[2] = ramps[2][ib];
		newpal += 3;
	}

	VID_ShiftPalette (pal);	
}

/*
	BuildGammaTable

	In software mode, this function gets the palette ready for changing...in
	in GL, it does very little as you can see.
*/

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

	for (i = 0; i < 256; i++)
		gammatable[i] = i;
	return;
}