libgeda/src/s_color.c

   1 /* gEDA - GPL Electronic Design Automation
   2  * libgeda - gEDA's library
   3  * Copyright (C) 1998-2010 Ales Hvezda
   4  * Copyright (C) 1998-2010 gEDA Contributors (see ChangeLog for details)
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111 USA
  19  */
  20 #include <config.h>
  21
  22 #include <stdio.h>
  23 #include <math.h>
  24 #ifdef HAVE_STRING_H
  25 #include <string.h>
  26 #endif
  27
  28 #include "libgeda_priv.h"
  29
  30 #ifdef HAVE_LIBDMALLOC
  31 #include <dmalloc.h>
  32 #endif
  33
  34 COLOR print_colors[MAX_COLORS];
  35
  36 #define NOCOLOR {0xff, 0xff, 0xff, 0xff, FALSE}
  37 #define WHITE   {0xff, 0xff, 0xff, 0xff, TRUE}
  38 #define GRAY    {0x88, 0x88, 0x88, 0xff, TRUE}
  39 #define BLACK   {0x00, 0x00, 0x00, 0xff, TRUE}
  40 #define ENDMAP  {0x00, 0x00, 0x00, 0x00, FALSE}
  41
  42 static COLOR default_colors[] = {
  43   WHITE,           /*  0: background         */
  44   BLACK,           /*  1: pin                */
  45   BLACK,           /*  2: net-endpoint       */
  46   BLACK,           /*  3: graphic            */
  47   BLACK,           /*  4: net                */
  48   BLACK,           /*  5: attribute          */
  49   BLACK,           /*  6: logic-bubble       */
  50   BLACK,           /*  7: dots-grid          */
  51   BLACK,           /*  8: detached-attribute */
  52   BLACK,           /*  9: text               */
  53   BLACK,           /* 10: bus                */
  54   GRAY,            /* 11: select             */
  55   GRAY,            /* 12: bounding-box       */
  56   GRAY,            /* 13: zoom-box           */
  57   GRAY,            /* 14: stroke             */
  58   BLACK,           /* 15: lock               */
  59   NOCOLOR,         /* 16: output-background  */
  60   NOCOLOR,         /* 17: freestyle1         */
  61   NOCOLOR,         /* 18: freestyle2         */
  62   NOCOLOR,         /* 19: freestyle3         */
  63   NOCOLOR,         /* 20: freestyle4         */
  64   BLACK,           /* 21: junction           */
  65   GRAY,            /* 22: mesh-grid-major    */
  66   NOCOLOR,         /* 23: mesh-grid-minor    */
  67   ENDMAP
  68 };
  69
  70 /*! \brief Initialises the color subsystem
  71  *  \par Function Description
  72  *  At the moment, just initialises the print color map.
  73  */
  74 void
  75 s_color_init(void)
  76 {
  77   s_color_map_defaults (print_colors);
  78 }
  79
  80 /*! \brief Initialise a color map to B&W
  81  *  \par Function Description
  82  *  Initialises a color map to a simple default: black features on a
  83  *  white background, with "special" colors as gray.
  84  *
  85  *  \warning \a map must be have length of at least #MAX_COLORS.
  86  *
  87  *  \param map Color map to initialise.
  88  */
  89 void
  90 s_color_map_defaults (COLOR *map)
  91 {
  92   int i;
  93   gboolean reached_end = FALSE;
  94   COLOR c;
  95   for (i = 0; i < MAX_COLORS; i++) {
  96     if (reached_end) {
  97       map[i].enabled = FALSE;
  98       continue;
  99     }
 100     c = default_colors[i];
 101     if (c.a == 0) { /* Check for end of default map */
 102       reached_end = TRUE;
 103       i--;
 104       continue;
 105     }
 106     map[i] = c;
 107   }
 108 }
 109
 110 /* \brief Decode a hexadecimal RGB or RGBA color code.
 111  * \par Function Description
 112  * Accepts a hexadecimal color code \a rgba of either the form #RRGGBB
 113  * or #RRGGBBAA, and parses it to extract the numerical color values,
 114  * placing them in the the #guchar pointers passed as arguments. If
 115  * the six-digit form is used, the alpha channel is set to full
 116  * opacity. If an error occurs during parsing, the return values are
 117  * set to solid white.
 118  *
 119  * Note that this function implements similar functionality to
 120  * gdk_color_parse(). However, for consistency, <em>only</em> this
 121  * function should be used to parse color strings from gEDA
 122  * configuration files, as gdk_color_parse() does not support the
 123  * alpha channel.
 124  *
 125  * \todo Use GError mechanism to give more specific error messages.
 126  *
 127  * \param [in]  rgba Colour code to parse.
 128  * \param [out] r    Location to store red value.
 129  * \param [out] g    Location to store green value.
 130  * \param [out] b    Location to store blue value.
 131  *
 132  *  \returns #TRUE on success, #FALSE on failure.
 133  */
 134 gboolean
 135 s_color_rgba_decode (const gchar *rgba,
 136                      guint8 *r, guint8 *g, guint8 *b, guint8 *a)
 137 {
 138   gint len, i, ri, gi, bi, ai;
 139   gchar c;
 140
 141   /* Default to solid white */
 142   *r = 0xff; *g = 0xff; *b = 0xff; *a = 0xff;
 143
 144   /* Check that the string is a valid length and starts with a '#' */
 145   len = strlen (rgba);
 146   if ((len != 9 && len != 7) || rgba[0] != '#')
 147     return FALSE;
 148
 149   /* Check we only have [0-9a-fA-F] */
 150   for (i = 1; i < len; i++) {
 151     c = rgba[i];
 152     if ((c < '0' || c > '9')
 153         && (c < 'a' || c > 'f')
 154         && (c < 'A' || c > 'F'))
 155       return FALSE;
 156   }
 157
 158   /* Use sscanf to extract values */
 159   c = sscanf (rgba + 1, "%2x%2x%2x", &ri, &gi, &bi);
 160   if (c != 3)
 161     return FALSE;
 162   *r = (guint8) ri; *g = (guint8) gi; *b = (guint8) bi;
 163
 164   if (len == 9) {
 165     c = sscanf (rgba + 7, "%2x", &ai);
 166     if (c != 1)
 167       return FALSE;
 168     *a = (guint8) ai;
 169   }
 170
 171   return TRUE;
 172 }
 173
 174 /* \brief Encode a hexadecimal RGB or RGBA color code.
 175  * \par Function Description
 176  * Encodes four colour components into either the form #RRGGBB or
 177  * #RRGGBBAA. The shorter form is used when the alpha component is
 178  * 0xff.
 179  *
 180  * \param [in] r Red component.
 181  * \param [in] g Green component.
 182  * \param [in] b Blue component.
 183  * \returns A newly allocated string containing the encoded string.
 184  */
 185 gchar *
 186 s_color_rgba_encode (guint8 r, guint8 g, guint8 b, guint8 a)
 187 {
 188   if (a < 0xff)
 189     return g_strdup_printf("#%02x%02x%02x%02x",
 190                            (gint) r, (gint) g, (gint) b, (gint) a);
 191   else
 192     return g_strdup_printf("#%02x%02x%02x",
 193                            (gint) r, (gint) g, (gint) b);
 194 }
 195
 196 /*! \todo Finish function documentation!!!
 197  *  \brief
 198  *  \par Function Description
 199  *
 200  */
 201 gchar *s_color_ps_string(gint color)
 202 {
 203   COLOR c;
 204
 205   if (color >= MAX_COLORS) {
 206     g_warning (_("Color index out of range"));
 207     return NULL;
 208   }
 209
 210   c = print_colors[color];
 211
 212   if ((c.a == 0) || !c.enabled) {
 213     return NULL;
 214   } else {
 215     return g_strdup_printf ("%.3f %.3f %.3f",
 216                             (gdouble) c.r/255.0,
 217                             (gdouble) c.g/255.0,
 218                             (gdouble) c.b/255.0);
 219   }
 220 }
 221
 222 SCM
 223 s_color_map_to_scm (const COLOR *map)
 224 {
 225   SCM result = SCM_EOL;
 226   int i;
 227   for (i = MAX_COLORS - 1; i >= 0; i--) {
 228     SCM color_val = SCM_BOOL_F;
 229     if (map[i].enabled) {
 230       COLOR c = map[i];
 231       gchar *rgba = s_color_rgba_encode (c.r, c.g, c.b, c.a);
 232       color_val = scm_from_locale_string (rgba);
 233       g_free (rgba);
 234     }
 235     result = scm_cons (scm_list_2 (scm_from_int (i), color_val), result);
 236   }
 237   return result;
 238 }
 239
 240 /*!
 241  * \warning This function should ONLY be called from Scheme procedures.
 242  */
 243 void
 244 s_color_map_from_scm (COLOR *map, SCM lst, const char *scheme_proc_name)
 245 {
 246   SCM curr = lst;
 247   SCM wrong_type_arg_sym = scm_from_locale_symbol ("wrong-type-arg");
 248   SCM proc_name = scm_from_locale_string (scheme_proc_name);
 249   while (curr != SCM_EOL) {
 250     int i;
 251     char *rgba;
 252     SCM s;
 253     COLOR c;
 254     gboolean result;
 255     SCM entry = scm_car (curr);
 256
 257     /* Check map entry has correct type */
 258     if (!scm_is_true (scm_list_p (entry))
 259         || (scm_to_int (scm_length (entry)) != 2)) {
 260       scm_error_scm (wrong_type_arg_sym, proc_name,
 261                      scm_from_locale_string (_("Color map entry must be a two-element list")),
 262                      SCM_EOL, scm_list_1 (entry));
 263     }
 264
 265     /* Check color index has correct type, and extract it */
 266     s = scm_car (entry);
 267     if (!scm_is_integer (s)) {
 268       scm_error_scm (wrong_type_arg_sym, proc_name,
 269                      scm_from_locale_string (_("Index in color map entry must be an integer")),
 270                      SCM_EOL, scm_list_1 (s));
 271     }
 272     i = scm_to_int (s);
 273
 274     /* Check color index is within bounds. If it's out of bounds, it's
 275      * legal, but warn & ignore it.
 276      *
 277      * FIXME one day we will have dynamically-expanding colorspace.
 278      * One day. */
 279     if ((i < 0) || (i >= MAX_COLORS)) {
 280       g_critical ("Color map index out of bounds: %i\n", i);
 281       goto color_map_next;
 282     }
 283
 284     /* If color value is #F, disable color */
 285     s = scm_cadr (entry);
 286     if (scm_is_false (s)) {
 287       map[i].enabled = FALSE;
 288       goto color_map_next;
 289     }
 290
 291     /* Otherwise, we require a string */
 292     s = scm_cadr (entry);
 293     if (!scm_is_string (s)) {
 294       scm_error_scm (wrong_type_arg_sym, proc_name,
 295                      scm_from_locale_string (_("Value in color map entry must be #f or a string")),
 296                      SCM_EOL, scm_list_1 (s));
 297     }
 298     rgba = scm_to_locale_string (s);
 299
 300     result = s_color_rgba_decode (rgba, &c.r, &c.g, &c.b, &c.a);
 301
 302     /* FIXME should we generate a Guile error if there's a problem here? */
 303     if (!result) {
 304       g_critical ("Invalid color map value: %s\n", rgba);
 305     } else {
 306       map[i] = c;
 307       map[i].enabled = TRUE;
 308     }
 309
 310   color_map_next:
 311     /* Go to next element in map */
 312     curr = scm_cdr (curr);
 313   }
 314   scm_remember_upto_here_2 (wrong_type_arg_sym, proc_name);
 315 }