src/color.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
   2 /*
   3  * color.cpp: Colors
   4  *
   5  * Contact:
   6  *   Moonlight List (moonlight-list@lists.ximian.com)
   7  *
   8  * Copyright 2007 Novell, Inc. (http://www.novell.com)
   9  *
  10  * See the LICENSE file included with the distribution for details.
  11  *
  12  */
  13
  14 #include <config.h>
  15
  16 #include <string.h>
  17 #include <stdlib.h>
  18 #include <math.h>
  19
  20 #include "color.h"
  21 #include "utils.h"
  22
  23 // match System.Windows.Media.Colors properties
  24 typedef struct {
  25         const char *name;
  26         const unsigned int color;
  27 } named_colors_t;
  28
  29 named_colors_t named_colors [] = {
  30         // NOTE: samples shows that XAML supports more than the colors defined in System.Windows.Media.Colors
  31         // in fact tests shows that all System.Drawing.Color seems to be available
  32         { "transparent",                0x00FFFFFF },
  33         { "aliceblue",                  0xFFF0F8FF },
  34         { "antiquewhite",               0xFFFAEBD7 },
  35         { "aqua",                       0xFF00FFFF },
  36         { "aquamarine",                 0xFF7FFFD4 },
  37         { "azure",                      0xFFF0FFFF },
  38         { "beige",                      0xFFF5F5DC },
  39         { "bisque",                     0xFFFFE4C4 },
  40         { "black",                      0xFF000000 },
  41         { "blanchedalmond",             0xFFFFEBCD },
  42         { "blue",                       0xFF0000FF },
  43         { "blueviolet",                 0xFF8A2BE2 },
  44         { "brown",                      0xFFA52A2A },
  45         { "burlywood",                  0xFFDEB887 },
  46         { "cadetblue",                  0xFF5F9EA0 },
  47         { "chartreuse",                 0xFF7FFF00 },
  48         { "chocolate",                  0xFFD2691E },
  49         { "coral",                      0xFFFF7F50 },
  50         { "cornflowerblue",             0xFF6495ED },
  51         { "cornsilk",                   0xFFFFF8DC },
  52         { "crimson",                    0xFFDC143C },
  53         { "cyan",                       0xFF00FFFF },
  54         { "darkblue",                   0xFF00008B },
  55         { "darkcyan",                   0xFF008B8B },
  56         { "darkgoldenrod",              0xFFB8860B },
  57         { "darkgray",                   0xFFA9A9A9 },
  58         { "darkgreen",                  0xFF006400 },
  59         { "darkkhaki",                  0xFFBDB76B },
  60         { "darkmagenta",                0xFF8B008B },
  61         { "darkolivegreen",             0xFF556B2F },
  62         { "darkorange",                 0xFFFF8C00 },
  63         { "darkorchid",                 0xFF9932CC },
  64         { "darkred",                    0xFF8B0000 },
  65         { "darksalmon",                 0xFFE9967A },
  66         { "darkseagreen",               0xFF8FBC8B },
  67         { "darkslateblue",              0xFF483D8B },
  68         { "darkslategray",              0xFF2F4F4F },
  69         { "darkturquoise",              0xFF00CED1 },
  70         { "darkviolet",                 0xFF9400D3 },
  71         { "deeppink",                   0xFFFF1493 },
  72         { "deepskyblue",                0xFF00BFFF },
  73         { "dimgray",                    0xFF696969 },
  74         { "dodgerblue",                 0xFF1E90FF },
  75         { "firebrick",                  0xFFB22222 },
  76         { "floralwhite",                0xFFFFFAF0 },
  77         { "forestgreen",                0xFF228B22 },
  78         { "fuchsia",                    0xFFFF00FF },
  79         { "gainsboro",                  0xFFDCDCDC },
  80         { "ghostwhite",                 0xFFF8F8FF },
  81         { "gold",                       0xFFFFD700 },
  82         { "goldenrod",                  0xFFDAA520 },
  83         { "gray",                       0xFF808080 },
  84         { "green",                      0xFF008000 },
  85         { "greenyellow",                0xFFADFF2F },
  86         { "honeydew",                   0xFFF0FFF0 },
  87         { "hotpink",                    0xFFFF69B4 },
  88         { "indianred",                  0xFFCD5C5C },
  89         { "indigo",                     0xFF4B0082 },
  90         { "ivory",                      0xFFFFFFF0 },
  91         { "khaki",                      0xFFF0E68C },
  92         { "lavender",                   0xFFE6E6FA },
  93         { "lavenderblush",              0xFFFFF0F5 },
  94         { "lawngreen",                  0xFF7CFC00 },
  95         { "lemonchiffon",               0xFFFFFACD },
  96         { "lightblue",                  0xFFADD8E6 },
  97         { "lightcoral",                 0xFFF08080 },
  98         { "lightcyan",                  0xFFE0FFFF },
  99         { "lightgoldenrodyellow",       0xFFFAFAD2 },
 100         { "lightgreen",                 0xFF90EE90 },
 101         { "lightgray",                  0xFFD3D3D3 },
 102         { "lightpink",                  0xFFFFB6C1 },
 103         { "lightsalmon",                0xFFFFA07A },
 104         { "lightseagreen",              0xFF20B2AA },
 105         { "lightskyblue",               0xFF87CEFA },
 106         { "lightslategray",             0xFF778899 },
 107         { "lightsteelblue",             0xFFB0C4DE },
 108         { "lightyellow",                0xFFFFFFE0 },
 109         { "lime",                       0xFF00FF00 },
 110         { "limegreen",                  0xFF32CD32 },
 111         { "linen",                      0xFFFAF0E6 },
 112         { "magenta",                    0xFFFF00FF },
 113         { "maroon",                     0xFF800000 },
 114         { "mediumaquamarine",           0xFF66CDAA },
 115         { "mediumblue",                 0xFF0000CD },
 116         { "mediumorchid",               0xFFBA55D3 },
 117         { "mediumpurple",               0xFF9370DB },
 118         { "mediumseagreen",             0xFF3CB371 },
 119         { "mediumslateblue",            0xFF7B68EE },
 120         { "mediumspringgreen",          0xFF00FA9A },
 121         { "mediumturquoise",            0xFF48D1CC },
 122         { "mediumvioletred",            0xFFC71585 },
 123         { "midnightblue",               0xFF191970 },
 124         { "mintcream",                  0xFFF5FFFA },
 125         { "mistyrose",                  0xFFFFE4E1 },
 126         { "moccasin",                   0xFFFFE4B5 },
 127         { "navajowhite",                0xFFFFDEAD },
 128         { "navy",                       0xFF000080 },
 129         { "oldlace",                    0xFFFDF5E6 },
 130         { "olive",                      0xFF808000 },
 131         { "olivedrab",                  0xFF6B8E23 },
 132         { "orange",                     0xFFFFA500 },
 133         { "orangered",                  0xFFFF4500 },
 134         { "orchid",                     0xFFDA70D6 },
 135         { "palegoldenrod",              0xFFEEE8AA },
 136         { "palegreen",                  0xFF98FB98 },
 137         { "paleturquoise",              0xFFAFEEEE },
 138         { "palevioletred",              0xFFDB7093 },
 139         { "papayawhip",                 0xFFFFEFD5 },
 140         { "peachpuff",                  0xFFFFDAB9 },
 141         { "peru",                       0xFFCD853F },
 142         { "pink",                       0xFFFFC0CB },
 143         { "plum",                       0xFFDDA0DD },
 144         { "powderblue",                 0xFFB0E0E6 },
 145         { "purple",                     0xFF800080 },
 146         { "red",                        0xFFFF0000 },
 147         { "rosybrown",                  0xFFBC8F8F },
 148         { "royalblue",                  0xFF4169E1 },
 149         { "saddlebrown",                0xFF8B4513 },
 150         { "salmon",                     0xFFFA8072 },
 151         { "sandybrown",                 0xFFF4A460 },
 152         { "seagreen",                   0xFF2E8B57 },
 153         { "seashell",                   0xFFFFF5EE },
 154         { "sienna",                     0xFFA0522D },
 155         { "silver",                     0xFFC0C0C0 },
 156         { "skyblue",                    0xFF87CEEB },
 157         { "slateblue",                  0xFF6A5ACD },
 158         { "slategray",                  0xFF708090 },
 159         { "snow",                       0xFFFFFAFA },
 160         { "springgreen",                0xFF00FF7F },
 161         { "steelblue",                  0xFF4682B4 },
 162         { "tan",                        0xFFD2B48C },
 163         { "teal",                       0xFF008080 },
 164         { "thistle",                    0xFFD8BFD8 },
 165         { "tomato",                     0xFFFF6347 },
 166         { "turquoise",                  0xFF40E0D0 },
 167         { "violet",                     0xFFEE82EE },
 168         { "wheat",                      0xFFF5DEB3 },
 169         { "white",                      0xFFFFFFFF },
 170         { "whitesmoke",                 0xFFF5F5F5 },
 171         { "yellow",                     0xFFFFFF00 },
 172         { "yellowgreen",                0xFF9ACD32 },
 173         { NULL, 0 }
 174 };
 175
 176 /**
 177  * see: http://msdn2.microsoft.com/en-us/library/system.windows.media.solidcolorbrush.aspx
 178  *
 179  * If no color is found, NULL is returned.
 180  */
 181 Color *
 182 color_from_str (const char *name)
 183 {
 184         size_t len;
 185
 186         if (!name)
 187                 return new Color (0x00FFFFFF);
 188
 189         if ((len = strlen (name)) == 0)
 190                 return new Color (0x00000000);
 191
 192         if (name [0] == '#') {
 193                 char a [3] = "FF";
 194                 char r [3] = "FF";
 195                 char g [3] = "FF";
 196                 char b [3] = "FF";
 197
 198                 // Relaxed parsing with some it's-the-web-and-it's-broken
 199                 // "error tolerance"
 200                 int real_len = len - 1;
 201                 if (real_len >= 8) {
 202                         // aarrggbb
 203                         a [0] = name [1]; a [1] = name [2];
 204                         r [0] = name [3]; r [1] = name [4];
 205                         g [0] = name [5]; g [1] = name [6];
 206                         b [0] = name [7]; b [1] = name [8];
 207                 } else if (real_len >= 6) {
 208                         // rrggbb
 209                         r [0] = name [1]; r [1] = name [2];
 210                         g [0] = name [3]; g [1] = name [4];
 211                         b [0] = name [5]; b [1] = name [6];
 212                 } else if (real_len >= 4) {
 213                         // argb
 214                         a [1] = a [0] = name [1];
 215                         r [1] = r [0] = name [2];
 216                         g [1] = g [0] = name [3];
 217                         b [1] = b [0] = name [4];
 218                 } else if (real_len == 3) {
 219                         // rgb
 220                         r [1] = r [0] = name [1];
 221                         g [1] = g [0] = name [2];
 222                         b [1] = b [0] = name [3];
 223                 }
 224
 225                 return new Color (strtol (r, NULL, 16) / 255.0F, strtol (g, NULL, 16) / 255.0F,
 226                                   strtol (b, NULL, 16) / 255.0F, strtol (a, NULL, 16) / 255.0F);
 227         }
 228
 229         if (name [0] == 's' && name [1] == 'c' && name [2] == '#') {
 230                 char *iter = (char *) name + 3;
 231                 double a = 1.0, r = 1.0, g = 1.0, b = 1.0;
 232                 GArray *channels = double_garray_from_str (iter, 0);
 233
 234                 if (channels != NULL) {
 235                         int i = 0;
 236                         if (channels->len >= 4) {
 237                                 a = g_array_index (channels, double, 0);
 238                                 i++;
 239                         }
 240
 241                         if (channels->len >= 3) {
 242                                 r = g_array_index (channels, double, 0 + i);
 243                                 g = g_array_index (channels, double, 1 + i);
 244                                 b = g_array_index (channels, double, 2 + i);
 245                         }
 246
 247                         g_array_free (channels, TRUE);
 248                 }
 249
 250                 /* Clamp values. scRGB theoretically supports negative numbers
 251                  * ('darker than black') as a refference to another source but here
 252                  * it doesn't make too much sense. */
 253                 r = MIN (1.0, r); r = MAX (0.0, r);
 254                 g = MIN (1.0, g); g = MAX (0.0, g);
 255                 b = MIN (1.0, b); b = MAX (0.0, b);
 256                 a = MIN (1.0, a); a = MAX (0.0, a);
 257
 258                 /* NOTE: This is not a fully accurate scRGB -> sRGB conversion.
 259                  * The real stuff has slightly different/more complex band shaping.
 260                  * But I'd call it "good enough" for now. */
 261                 r = powf (r, 0.4545);
 262                 g = powf (g, 0.46);
 263                 b = powf (b, 0.4545);
 264
 265                 return new Color (r, g, b, a);
 266         }
 267
 268         if (name[0] >= '0' && name[0] <= '9') {
 269                 guint32 color = strtoul (name, NULL, 10);
 270
 271                 return new Color (color);
 272         }
 273
 274         for (int i = 0; named_colors [i].name; i++) {
 275                 if (!g_ascii_strcasecmp (named_colors [i].name, name))
 276                         return new Color (named_colors [i].color);
 277         }
 278
 279         return NULL;
 280 }
 281
 282
 283 const char *
 284 color_to_string (Color *color)
 285 {
 286         static char hex[16] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
 287         static char buf[10];
 288         guint8 v;
 289
 290         buf[0] = '#';
 291
 292         v = (guint8) (color->r * 256);
 293         buf[1] = hex[(v >> 4) & 0x0f];
 294         buf[2] = hex[v & 0x0f];
 295
 296         v = (guint8) (color->g * 256);
 297         buf[3] = hex[(v >> 4) & 0x0f];
 298         buf[4] = hex[v & 0x0f];
 299
 300         v = (guint8) (color->b * 256);
 301         buf[5] = hex[(v >> 4) & 0x0f];
 302         buf[6] = hex[v & 0x0f];
 303
 304         v = (guint8) (color->a * 256);
 305         if (v > 0) {
 306                 buf[7] = hex[(v >> 4) & 0x0f];
 307                 buf[8] = hex[v & 0x0f];
 308         } else {
 309                 buf[7] = '\0';
 310                 buf[8] = '\0';
 311         }
 312
 313         buf[9] = '\0';
 314
 315         return buf;
 316 }