tools/source/generic/color.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <sal/config.h>
  21
  22 #include <algorithm>
  23 #include <iomanip>
  24 #include <sstream>
  25 #include <stdlib.h>
  26
  27 #include <tools/color.hxx>
  28 #include <tools/helpers.hxx>
  29 #include <tools/long.hxx>
  30 #include <o3tl/string_view.hxx>
  31 #include <basegfx/color/bcolortools.hxx>
  32
  33 void Color::IncreaseLuminance(sal_uInt8 cLumInc)
  34 {
  35     R = sal_uInt8(std::clamp(R + cLumInc, 0, 255));
  36     G = sal_uInt8(std::clamp(G + cLumInc, 0, 255));
  37     B = sal_uInt8(std::clamp(B + cLumInc, 0, 255));
  38 }
  39
  40 void Color::DecreaseLuminance(sal_uInt8 cLumDec)
  41 {
  42     R = sal_uInt8(std::clamp(R - cLumDec, 0, 255));
  43     G = sal_uInt8(std::clamp(G - cLumDec, 0, 255));
  44     B = sal_uInt8(std::clamp(B - cLumDec, 0, 255));
  45 }
  46
  47 void Color::DecreaseContrast(sal_uInt8 nContDec)
  48 {
  49     if (nContDec)
  50     {
  51         const double fM = (128.0 - 0.4985 * nContDec) / 128.0;
  52         const double fOff = 128.0 - fM * 128.0;
  53
  54         R = sal_uInt8(std::clamp(FRound(R * fM + fOff), tools::Long(0), tools::Long(255)));
  55         G = sal_uInt8(std::clamp(FRound(G * fM + fOff), tools::Long(0), tools::Long(255)));
  56         B = sal_uInt8(std::clamp(FRound(B * fM + fOff), tools::Long(0), tools::Long(255)));
  57     }
  58 }
  59
  60 // color space conversion
  61
  62 void Color::RGBtoHSB( sal_uInt16& nHue, sal_uInt16& nSat, sal_uInt16& nBri ) const
  63 {
  64     sal_uInt8 c[3];
  65     sal_uInt8 cMax, cMin;
  66
  67     c[0] = R;
  68     c[1] = G;
  69     c[2] = B;
  70
  71     cMax = c[0];
  72     if( c[1] > cMax )
  73         cMax = c[1];
  74     if( c[2] > cMax )
  75         cMax = c[2];
  76
  77     // Brightness = max(R, G, B);
  78     nBri = cMax * 100 / 255;
  79
  80     cMin = c[0];
  81     if( c[1] < cMin )
  82         cMin = c[1];
  83     if( c[2] < cMin )
  84         cMin = c[2];
  85
  86     sal_uInt8 cDelta = cMax - cMin;
  87
  88     // Saturation = max - min / max
  89     if( nBri > 0 )
  90         nSat = cDelta * 100 / cMax;
  91     else
  92         nSat = 0;
  93
  94     if( nSat == 0 )
  95         nHue = 0; // Default = undefined
  96     else
  97     {
  98         double dHue = 0.0;
  99
 100         if( c[0] == cMax )
 101         {
 102             dHue = static_cast<double>( c[1] - c[2] ) / static_cast<double>(cDelta);
 103         }
 104         else if( c[1] == cMax )
 105         {
 106             dHue = 2.0 + static_cast<double>( c[2] - c[0] ) / static_cast<double>(cDelta);
 107         }
 108         else if ( c[2] == cMax )
 109         {
 110             dHue = 4.0 + static_cast<double>( c[0] - c[1] ) / static_cast<double>(cDelta);
 111         }
 112         dHue *= 60.0;
 113
 114         if( dHue < 0.0 )
 115             dHue += 360.0;
 116
 117         nHue = static_cast<sal_uInt16>(dHue);
 118     }
 119 }
 120
 121 Color Color::HSBtoRGB( sal_uInt16 nHue, sal_uInt16 nSat, sal_uInt16 nBri )
 122 {
 123     sal_uInt8 cR=0,cG=0,cB=0;
 124     sal_uInt8 nB = static_cast<sal_uInt8>( nBri * 255 / 100 );
 125
 126     if( nSat == 0 )
 127     {
 128         cR = nB;
 129         cG = nB;
 130         cB = nB;
 131     }
 132     else
 133     {
 134         double dH = nHue;
 135         double f;
 136         sal_uInt16 n;
 137         if( dH == 360.0 )
 138             dH = 0.0;
 139
 140         dH /= 60.0;
 141         n = static_cast<sal_uInt16>(dH);
 142         f = dH - n;
 143
 144         sal_uInt8 a = static_cast<sal_uInt8>( nB * ( 100 - nSat ) / 100 );
 145         sal_uInt8 b = static_cast<sal_uInt8>( nB * ( 100 - ( static_cast<double>(nSat) * f ) ) / 100 );
 146         sal_uInt8 c = static_cast<sal_uInt8>( nB * ( 100 - ( static_cast<double>(nSat) * ( 1.0 - f ) ) ) / 100 );
 147
 148         switch( n )
 149         {
 150             case 0: cR = nB;    cG = c;     cB = a;     break;
 151             case 1: cR = b;     cG = nB;    cB = a;     break;
 152             case 2: cR = a;     cG = nB;    cB = c;     break;
 153             case 3: cR = a;     cG = b;     cB = nB;    break;
 154             case 4: cR = c;     cG = a;     cB = nB;    break;
 155             case 5: cR = nB;    cG = a;     cB = b;     break;
 156         }
 157     }
 158
 159     return Color( cR, cG, cB );
 160 }
 161
 162 Color Color::STRtoRGB(std::u16string_view colorname)
 163 {
 164     Color col;
 165     if(colorname.empty()) return col;
 166
 167     switch(colorname.size()){
 168         case 7:
 169             col.mValue = o3tl::toUInt32(colorname.substr(1,6), 16);
 170             break;
 171         case 6:
 172             col.mValue = o3tl::toUInt32(colorname, 16);
 173             break;
 174         case 4:
 175         {
 176             sal_Unicode data[6] = { colorname[1], colorname[1], colorname[2],
 177                                      colorname[2], colorname[3], colorname[3] };
 178             col.mValue = o3tl::toUInt32(std::u16string_view(data,6), 16);
 179             break;
 180         }
 181         case 3:
 182         {
 183             sal_Unicode data[6] = { colorname[0], colorname[0], colorname[1],
 184                                      colorname[1], colorname[2], colorname[2] };
 185             col.mValue = o3tl::toUInt32(std::u16string_view(data,6), 16);
 186             break;
 187         }
 188         default:
 189             break;
 190     }
 191     return col;
 192 }
 193
 194 OUString Color::AsRGBHexString() const
 195 {
 196     std::stringstream ss;
 197     ss << std::hex << std::setfill ('0') << std::setw(6) << sal_uInt32(GetRGBColor());
 198     return OUString::createFromAscii(ss.str());
 199 }
 200
 201 OUString Color::AsRGBHEXString() const
 202 {
 203     std::stringstream ss;
 204     ss << std::hex << std::uppercase << std::setfill ('0') << std::setw(6) << sal_uInt32(GetRGBColor());
 205     return OUString::createFromAscii(ss.str());
 206 }
 207
 208 void Color::ApplyTintOrShade(sal_Int16 n100thPercent)
 209 {
 210     if (n100thPercent == 0)
 211         return;
 212
 213     basegfx::BColor aBColor = basegfx::utils::rgb2hsl(getBColor());
 214     double fFactor = 1.0 - (std::abs(double(n100thPercent)) / 10000.0);
 215     double fResult;
 216
 217     if (n100thPercent > 0) // tint
 218     {
 219         fResult = aBColor.getBlue() * fFactor + (1.0 - fFactor);
 220     }
 221     else // shade
 222     {
 223         fResult = aBColor.getBlue() * fFactor;
 224     }
 225
 226     aBColor.setBlue(fResult);
 227     aBColor = basegfx::utils::hsl2rgb(aBColor);
 228
 229     R = sal_uInt8(std::lround(aBColor.getRed()   * 255.0));
 230     G = sal_uInt8(std::lround(aBColor.getGreen() * 255.0));
 231     B = sal_uInt8(std::lround(aBColor.getBlue()  * 255.0));
 232 }
 233
 234 void Color::ApplyLumModOff(sal_Int16 nMod, sal_Int16 nOff)
 235 {
 236     if (nMod == 10000 && nOff == 0)
 237     {
 238         return;
 239     }
 240     // Switch to HSL, where applying these transforms is easier.
 241     basegfx::BColor aBColor = basegfx::utils::rgb2hsl(getBColor());
 242
 243     // 50% is half luminance, 200% is double luminance. Unit is 100th percent.
 244     aBColor.setBlue(std::clamp(aBColor.getBlue() * nMod / 10000, 0.0, 1.0));
 245     // If color changes to black or white, it will stay gray if luminance changes again.
 246     if ((aBColor.getBlue() == 0.0) || (aBColor.getBlue() == 1.0))
 247     {
 248         aBColor.setGreen(0.0);
 249     }
 250
 251     // Luminance offset means hue and saturation is left unchanged. Unit is 100th percent.
 252     aBColor.setBlue(std::clamp(aBColor.getBlue() + static_cast<double>(nOff) / 10000, 0.0, 1.0));
 253     // If color changes to black or white, it will stay gray if luminance changes again.
 254     if ((aBColor.getBlue() == 0.0) || (aBColor.getBlue() == 1.0))
 255     {
 256         aBColor.setGreen(0.0);
 257     }
 258
 259     // Switch back to RGB.
 260     aBColor = basegfx::utils::hsl2rgb(aBColor);
 261     R = sal_uInt8(std::lround(aBColor.getRed()   * 255.0));
 262     G = sal_uInt8(std::lround(aBColor.getGreen() * 255.0));
 263     B = sal_uInt8(std::lround(aBColor.getBlue()  * 255.0));
 264 }
 265
 266 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */