/*
** Command & Conquer Renegade(tm)
** Copyright 2025 Electronic Arts 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 3 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, see <http://www.gnu.org/licenses/>.
*/
/***********************************************************************************************
*** C O N F I D E N T I A L --- W E S T W O O D S T U D I O S ***
***********************************************************************************************
* *
* Project Name : Command & Conquer *
* *
* $Archive:: /Commando/Library/HSV.CPP $*
* *
* $Author:: Greg_h $*
* *
* $Modtime:: 7/22/97 11:37a $*
* *
* $Revision:: 1 $*
* *
*---------------------------------------------------------------------------------------------*
* Functions: *
* HSVClass::Adjust -- Adjust an HSV color toward specified color. *
* HSVClass::Difference -- Finds the difference between two HSV color objects. *
* HSVClass::operator RGBClass -- Conversion operator for RGBClass object. *
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
#include "always.h"
#include "hsv.h"
#include "rgb.h"
HSVClass const HSVClass::BlackColor(0, 0, 0);
/***********************************************************************************************
* HSVClass::Adjust -- Adjust an HSV color toward specified color. *
* *
* This routine will adjust the HSV color object toward the color of the specified HSV *
* object. Typical users of this would be palette morphing or fading routines. *
* *
* INPUT: ratio -- The ratio to move the HSV object toward the color specified. A value *
* of zero means no movement at all. A value of 255 means move completely *
* toward the specified color (changed completely). *
* *
* hsv -- A reference to the color that the current HSV object is to change *
* toward. *
* *
* OUTPUT: none *
* *
* WARNINGS: none *
* *
* HISTORY: *
* 02/20/1996 JLB : Created. *
*=============================================================================================*/
void HSVClass::Adjust(int ratio, HSVClass const & hsv)
{
/*
** Ratio conversion is limited to 0 through 100%. This is
** the range of 0 to 255.
*/
ratio &= 0x00FF;
/*
** Adjust the color guns by the ratio specified toward the
** destination color.
*/
int value = hsv.Get_Value() - Get_Value();
Value = (unsigned char)(Get_Value() + (value * ratio) / 256);
int saturation = hsv.Get_Saturation() - Get_Saturation();
Saturation = (unsigned char)(Get_Saturation() + (saturation * ratio) / 256);
int hue = hsv.Get_Hue() - Get_Hue();
Hue = (unsigned char)(Get_Hue() + (hue * ratio) / 256);
}
/***********************************************************************************************
* HSVClass::Difference -- Finds the difference between two HSV color objects. *
* *
* This routine will determine a color difference between two HSV objects. The difference *
* has no particular meaning other that larger numbers meaning greater difference. *
* *
* INPUT: hsv -- The other HSV object to compare this HSV object to. *
* *
* OUTPUT: Returns with a relative distance (in arbitrary units) between this HSV object and *
* the HSV object supplied. *
* *
* WARNINGS: none *
* *
* HISTORY: *
* 02/20/1996 JLB : Created. *
*=============================================================================================*/
int HSVClass::Difference(HSVClass const & hsv) const
{
int hue = (int)Hue - (int)hsv.Hue;
if (hue < 0) hue = -hue;
int saturation = (int)Saturation - (int)hsv.Saturation;
if (saturation < 0) saturation = -saturation;
int value = (int)Value - (int)hsv.Value;
if (value < 0) value = -value;
return(hue*hue + saturation*saturation + value*value);
}
/***********************************************************************************************
* HSVClass::operator RGBClass -- Conversion operator for RGBClass object. *
* *
* This conversion operator will convert the HSV object into an RGB object. *
* *
* INPUT: none *
* *
* OUTPUT: Returns with a reference (implied) of the RGBClass object that most closely *
* matches this HSVClass object. *
* *
* WARNINGS: none *
* *
* HISTORY: *
* 02/20/1996 JLB : Created. *
*=============================================================================================*/
HSVClass::operator RGBClass (void) const
{
unsigned int i; // Integer part.
unsigned int f; // Fractional or remainder part. f/HSV_BASE gives fraction.
unsigned int tmp; // Temporary variable to help with calculations.
unsigned int values[7]; // Possible rgb values. Don't use zero.
int hue = Get_Hue();
int saturation = Get_Saturation();
int value = Get_Value();
int red, green, blue;
hue *= 6;
f = hue % 255;
// Set up possible red, green and blue values.
values[1] =
values[2] = value;
//
// The following lines of code change
// values[3] = (v * (255 - ( (s * f) / 255) )) / 255;
// values[4] = values[5] = (v * (255 - s)) / 255;
// values[6] = (v * (255 - (s * (255 - f)) / 255)) / 255;
// so that the are rounded divides.
//
tmp = (saturation * f) / 255;
values[3] = (value * (255 - tmp)) / 255;
values[4] =
values[5] = (value * (255 - saturation)) / 255;
tmp = 255 - (saturation * (255 - f)) / 255;
values[6] = (value * tmp) / 255;
// This should not be rounded.
i = hue / 255;
i += (i > 4) ? -4 : 2;
red = values[i];
i += (i > 4) ? -4 : 2;
blue = values[i];
i += (i > 4) ? -4 : 2;
green = values[i];
RGBClass rgb((unsigned char)red, (unsigned char)green, (unsigned char)blue);
return(rgb);
}