// Emacs style mode select   -*- C++ -*- 
//-----------------------------------------------------------------------------
//
// $Id: v_palette.cpp 5 2007-01-16 19:13:59Z denis $
//
// Copyright (C) 1998-2006 by Randy Heit (ZDoom 1.22).
// Copyright (C) 2006-2007 by The Odamex Team.
//
// 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.
//
// DESCRIPTION:
//	V_PALETTE
//
//-----------------------------------------------------------------------------


#include <string.h>
#include <math.h>

#include "v_video.h"
#include "m_alloc.h"
#include "r_main.h"		// For lighting constants
#include "w_wad.h"
#include "z_zone.h"
#include "c_dispatch.h"
#include "g_level.h"
#include "st_stuff.h"

dyncolormap_t NormalLight;

palette_t DefPal;


/****************************/
/* Palette management stuff */
/****************************/
palette_t *GetDefaultPalette (void)
{
	return &DefPal;
}


/****** Colorspace Conversion Functions ******/

// Code from http://www.cs.rit.edu/~yxv4997/t_convert.html

// r,g,b values are from 0 to 1
// h = [0,360], s = [0,1], v = [0,1]
//				if s == 0, then h = -1 (undefined)

// Green Doom guy colors:
// RGB - 0: {    .46  1 .429 } 7: {    .254 .571 .206 } 15: {    .0317 .0794 .0159 }
// HSV - 0: { 116.743 .571 1 } 7: { 112.110 .639 .571 } 15: { 105.071  .800 .0794 }

void RGBtoHSV (float r, float g, float b, float *h, float *s, float *v)
{
	float min, max, delta, foo;

	if (r == g && g == b) {
		*h = 0;
		*s = 0;
		*v = r;
		return;
	}

	foo = r < g ? r : g;
	min = (foo < b) ? foo : b;
	foo = r > g ? r : g;
	max = (foo > b) ? foo : b;

	*v = max;									// v

	delta = max - min;

	*s = delta / max;							// s

	if (r == max)
		*h = (g - b) / delta;					// between yellow & magenta
	else if (g == max)
		*h = 2 + (b - r) / delta;				// between cyan & yellow
	else
		*h = 4 + (r - g) / delta;				// between magenta & cyan

	*h *= 60;									// degrees
	if (*h < 0)
		*h += 360;
}

void HSVtoRGB (float *r, float *g, float *b, float h, float s, float v)
{
	int i;
	float f, p, q, t;

	if (s == 0) {
		// achromatic (grey)
		*r = *g = *b = v;
		return;
	}

	h /= 60;									// sector 0 to 5
	i = (int)floor (h);
	f = h - i;									// factorial part of h
	p = v * (1 - s);
	q = v * (1 - s * f);
	t = v * (1 - s * (1 - f));

	switch (i) {
		case 0:		*r = v; *g = t; *b = p; break;
		case 1:		*r = q; *g = v; *b = p; break;
		case 2:		*r = p; *g = v; *b = t; break;
		case 3:		*r = p; *g = q; *b = v; break;
		case 4:		*r = t; *g = p; *b = v; break;
		default:	*r = v; *g = p; *b = q; break;
	}
}

/****** Colored Lighting Stuffs (Sorry, 8-bit only) ******/
dyncolormap_t *GetSpecialLights (int lr, int lg, int lb, int fr, int fg, int fb)
{
	return NULL;
}

VERSION_CONTROL (v_palette_cpp, "$Id: v_palette.cpp 5 2007-01-16 19:13:59Z denis $")