RGB.CPP (12611B)
1 // 2 // Copyright 2020 Electronic Arts Inc. 3 // 4 // TiberianDawn.DLL and RedAlert.dll and corresponding source code is free 5 // software: you can redistribute it and/or modify it under the terms of 6 // the GNU General Public License as published by the Free Software Foundation, 7 // either version 3 of the License, or (at your option) any later version. 8 9 // TiberianDawn.DLL and RedAlert.dll and corresponding source code is distributed 10 // in the hope that it will be useful, but with permitted additional restrictions 11 // under Section 7 of the GPL. See the GNU General Public License in LICENSE.TXT 12 // distributed with this program. You should have received a copy of the 13 // GNU General Public License along with permitted additional restrictions 14 // with this program. If not, see https://github.com/electronicarts/CnC_Remastered_Collection 15 16 /* $Header: /CounterStrike/RGB.CPP 1 3/03/97 10:25a Joe_bostic $ */ 17 /*********************************************************************************************** 18 *** 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 *** 19 *********************************************************************************************** 20 * * 21 * Project Name : Command & Conquer * 22 * * 23 * File Name : RGB.CPP * 24 * * 25 * Programmer : Joe L. Bostic * 26 * * 27 * Start Date : 12/02/95 * 28 * * 29 * Last Update : February 20, 1996 [JLB] * 30 * * 31 *---------------------------------------------------------------------------------------------* 32 * Functions: * 33 * RGBClass::Adjust -- Adjust one RGB value toward another. * 34 * RGBClass::Difference -- Determines the "distance" between two colors. * 35 * RGBClass::Set -- Set the color index to the RGB object specified. * 36 * RGBClass::operator HSVClass -- Conversion operator for RGB to HSV object. * 37 * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ 38 39 #include "watcom.h" 40 #include "rgb.h" 41 #include "hsv.h" 42 #include "palettec.h" 43 44 RGBClass const BlackColor(0, 0, 0); 45 46 47 /*********************************************************************************************** 48 * RGBClass::Adjust -- Adjust one RGB value toward another. * 49 * * 50 * This routine is used to modify an RGB value to proportionately match another RGB value * 51 * according to the ratio parameter specified. Typical use of this routine is in palette * 52 * fading from one palette to another or to black. * 53 * * 54 * INPUT: ratio -- The ration of transformation. This value is in the form of 0 to 255, * 55 * with 0 being no change, and 255 being 100% transformed into the * 56 * destination color. * 57 * * 58 * rgb -- Reference to the destination RGB color to transform this color into. * 59 * * 60 * OUTPUT: none * 61 * * 62 * WARNINGS: none * 63 * * 64 * HISTORY: * 65 * 12/02/1995 JLB : Created. * 66 *=============================================================================================*/ 67 void RGBClass::Adjust(int ratio, RGBClass const & rgb) 68 { 69 /* 70 ** Ratio conversion is limited to 0 through 100%. This is 71 ** the range of 0 to 255. 72 */ 73 ratio &= 0x00FF; 74 75 /* 76 ** Adjust the color guns by the ratio specified toward the 77 ** destination color. 78 */ 79 int value = (int)rgb.Red - (int)Red; 80 Red = (int)Red + (value * ratio) / 256; 81 82 value = (int)rgb.Green - (int)Green; 83 Green = (int)Green + (value * ratio) / 256; 84 85 value = (int)rgb.Blue - (int)Blue; 86 Blue = (int)Blue + (value * ratio) / 256; 87 } 88 89 90 /*********************************************************************************************** 91 * RGBClass::Difference -- Determines the "distance" between two colors. * 92 * * 93 * This routine is used to calculate a relative distance between two colors. The value is * 94 * relative only to itself and thus is useful only for determining the magnitude of * 95 * color difference rather than the nature of the color difference. Palette remapping * 96 * code uses this routine to find closest matches for colors. * 97 * * 98 * INPUT: rgb -- Reference to the color to be compared to this color. * 99 * * 100 * OUTPUT: Returns the difference between the two colors. The value returned is zero if the * 101 * colors exactly match. The greater the positive value the greater the difference * 102 * between the colors. * 103 * * 104 * WARNINGS: none * 105 * * 106 * HISTORY: * 107 * 12/02/1995 JLB : Created. * 108 *=============================================================================================*/ 109 int RGBClass::Difference(RGBClass const & rgb) const 110 { 111 int r = (int)Red - (int)rgb.Red; 112 if (r < 0) r = -r; 113 114 int g = (int)Green - (int)rgb.Green; 115 if (g < 0) g = -g; 116 117 int b = (int)Blue - (int)rgb.Blue; 118 if (b < 0) b = -b; 119 120 return(r*r + g*g + b*b); 121 } 122 123 124 /*********************************************************************************************** 125 * RGBClass::operator HSVClass -- Conversion operator for RGB to HSV object. * 126 * * 127 * This conversion operator will convert an RGBClass object into an HSVClass object. * 128 * * 129 * INPUT: none * 130 * * 131 * OUTPUT: Returns with a reference (implicit) to the HSVClass object that most closely * 132 * represents the RGBClass object. * 133 * * 134 * WARNINGS: none * 135 * * 136 * HISTORY: * 137 * 02/20/1996 JLB : Created. * 138 *=============================================================================================*/ 139 RGBClass::operator HSVClass (void) const 140 { 141 int hue; 142 int saturation; 143 int value; 144 145 /* 146 ** Fetch working component values for the color guns. 147 */ 148 int red = Red_Component(); 149 int green = Green_Component(); 150 int blue = Blue_Component(); 151 152 /* 153 ** The hue defaults to none. Only if there is a saturation value will the 154 ** hue be calculated. 155 */ 156 hue = 0; 157 158 /* 159 ** Set the value (brightness) to match the brightest color gun. 160 */ 161 value = (red > green) ? red : green; 162 if (blue > value) value = blue; 163 164 /* 165 ** Determine the amount of true white present in the color. This is the 166 ** minimum color gun value. The white component is used to determine 167 ** color saturation. 168 */ 169 int white = (red < green) ? red : green; 170 if (blue < white) white = blue; 171 172 /* 173 ** Determine the saturation (intensity) of the color by comparing the 174 ** ratio of true white as a component of the overall color. The more 175 ** white component, the less saturation. 176 */ 177 saturation = 0; 178 if (value) { 179 saturation = ((value - white) * 255) / value; 180 } 181 182 /* 183 ** If there is any saturation at all, then the hue must be calculated. The 184 ** hue is based on a six sided color wheel. 185 */ 186 if (saturation != 0) { 187 unsigned int tmp = value - white; 188 unsigned int r1 = ((value - red) * 255) / tmp; 189 unsigned int g1 = ((value - green) * 255) / tmp; 190 unsigned int b1 = ((value - blue) * 255) / tmp; 191 192 // Find effect of second most predominant color. 193 // In which section of the hexagon of colors does the color lie? 194 if (value == red) { 195 if (white == green) { 196 tmp = 5 * 256 + b1; 197 } else { 198 tmp = 1 * 256 - g1; 199 } 200 } else { 201 if (value == green) { 202 if (white == blue) { 203 tmp = 1 * 256 + r1; 204 } else { 205 tmp = 3 * 256 - b1; 206 } 207 } else { 208 if (white == red) { 209 tmp = 3 * 256 + g1; 210 } else { 211 tmp = 5 * 256 - r1; 212 } 213 } 214 } 215 216 // Divide by six and round. 217 hue = tmp / 6; 218 } 219 220 return(HSVClass(hue, saturation, value)); 221 } 222 223 224 /*********************************************************************************************** 225 * RGBClass::Set -- Set the color index to the RGB object specified. * 226 * * 227 * This routine will set the specified color index with this RGBClass object. Use this * 228 * routine to set one color. * 229 * * 230 * INPUT: color -- The color index to set with this RGBClass object. * 231 * * 232 * OUTPUT: none * 233 * * 234 * WARNINGS: none * 235 * * 236 * HISTORY: * 237 * 02/20/1996 JLB : Created. * 238 *=============================================================================================*/ 239 void RGBClass::Set(int color) const 240 { 241 Raw_Color_Prep(color); 242 Raw_Set(); 243 244 ((RGBClass &)PaletteClass::CurrentPalette[color]) = *this; 245 } 246