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) 1998-2020 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 COLOR print_colors[MAX_COLORS];
  31
  32 #define NOCOLOR {0xff, 0xff, 0xff, 0xff, FALSE}
  33 #define WHITE   {0xff, 0xff, 0xff, 0xff, TRUE}
  34 #define GRAY    {0x88, 0x88, 0x88, 0xff, TRUE}
  35 #define BLACK   {0x00, 0x00, 0x00, 0xff, TRUE}
  36 #define ENDMAP  {0x00, 0x00, 0x00, 0x00, FALSE}
  37
  38 static COLOR default_colors[] = {
  39   WHITE,           /*  0: background         */
  40   BLACK,           /*  1: pin                */
  41   BLACK,           /*  2: net-endpoint       */
  42   BLACK,           /*  3: graphic            */
  43   BLACK,           /*  4: net                */
  44   BLACK,           /*  5: attribute          */
  45   BLACK,           /*  6: logic-bubble       */
  46   BLACK,           /*  7: dots-grid          */
  47   BLACK,           /*  8: detached-attribute */
  48   BLACK,           /*  9: text               */
  49   BLACK,           /* 10: bus                */
  50   GRAY,            /* 11: select             */
  51   GRAY,            /* 12: bounding-box       */
  52   GRAY,            /* 13: zoom-box           */
  53   GRAY,            /* 14: stroke             */
  54   BLACK,           /* 15: lock               */
  55   NOCOLOR,         /* 16: output-background  */
  56   NOCOLOR,         /* 17: freestyle1         */
  57   NOCOLOR,         /* 18: freestyle2         */
  58   NOCOLOR,         /* 19: freestyle3         */
  59   NOCOLOR,         /* 20: freestyle4         */
  60   BLACK,           /* 21: junction           */
  61   GRAY,            /* 22: mesh-grid-major    */
  62   NOCOLOR,         /* 23: mesh-grid-minor    */
  63   BLACK,           /* 24: origin             */
  64   BLACK,           /* 25: place-origin       */
  65   ENDMAP
  66 };
  67
  68 /*! \brief Initialises the color subsystem
  69  *  \par Function Description
  70  *  At the moment, just initialises the print color map.
  71  */
  72 void
  73 s_color_init(void)
  74 {
  75   s_color_map_defaults (print_colors);
  76 }
  77
  78 /*! \brief Initialise a color map to B&W
  79  *  \par Function Description
  80  *  Initialises a color map to a simple default: black features on a
  81  *  white background, with "special" colors as gray.
  82  *
  83  *  \warning \a map must be have length of at least #MAX_COLORS.
  84  *
  85  *  \param map Color map to initialise.
  86  */
  87 void
  88 s_color_map_defaults (COLOR *map)
  89 {
  90   int i;
  91   gboolean reached_end = FALSE;
  92   COLOR c;
  93   for (i = 0; i < MAX_COLORS; i++) {
  94     if (reached_end) {
  95       map[i].enabled = FALSE;
  96       continue;
  97     }
  98     c = default_colors[i];
  99     if (c.a == 0) { /* Check for end of default map */
 100       reached_end = TRUE;
 101       i--;
 102       continue;
 103     }
 104     map[i] = c;
 105   }
 106 }
 107
 108 /* \brief Decode a hexadecimal RGB or RGBA color code.
 109  * \par Function Description
 110  * Accepts a hexadecimal color code \a rgba of either the form #RRGGBB
 111  * or #RRGGBBAA, and parses it to extract the numerical color values,
 112  * placing them in the the #guchar pointers passed as arguments. If
 113  * the six-digit form is used, the alpha channel is set to full
 114  * opacity. If an error occurs during parsing, the return values are
 115  * set to solid white.
 116  *
 117  * Note that this function implements similar functionality to
 118  * gdk_color_parse(). However, for consistency, <em>only</em> this
 119  * function should be used to parse color strings from gEDA
 120  * configuration files, as gdk_color_parse() does not support the
 121  * alpha channel.
 122  *
 123  * \todo Use GError mechanism to give more specific error messages.
 124  *
 125  * \param [in]  rgba Colour code to parse.
 126  * \param [out] r    Location to store red value.
 127  * \param [out] g    Location to store green value.
 128  * \param [out] b    Location to store blue value.
 129  *
 130  *  \returns #TRUE on success, #FALSE on failure.
 131  */
 132 gboolean
 133 s_color_rgba_decode (const gchar *rgba,
 134                      guint8 *r, guint8 *g, guint8 *b, guint8 *a)
 135 {
 136   gint len, i, ri, gi, bi, ai;
 137   gchar c;
 138
 139   /* Default to solid white */
 140   *r = 0xff; *g = 0xff; *b = 0xff; *a = 0xff;
 141
 142   /* Check that the string is a valid length and starts with a '#' */
 143   len = strlen (rgba);
 144   if ((len != 9 && len != 7) || rgba[0] != '#')
 145     return FALSE;
 146
 147   /* Check we only have [0-9a-fA-F] */
 148   for (i = 1; i < len; i++) {
 149     c = rgba[i];
 150     if ((c < '0' || c > '9')
 151         && (c < 'a' || c > 'f')
 152         && (c < 'A' || c > 'F'))
 153       return FALSE;
 154   }
 155
 156   /* Use sscanf to extract values */
 157   c = sscanf (rgba + 1, "%2x%2x%2x", &ri, &gi, &bi);
 158   if (c != 3)
 159     return FALSE;
 160   *r = (guint8) ri; *g = (guint8) gi; *b = (guint8) bi;
 161
 162   if (len == 9) {
 163     c = sscanf (rgba + 7, "%2x", &ai);
 164     if (c != 1)
 165       return FALSE;
 166     *a = (guint8) ai;
 167   }
 168
 169   return TRUE;
 170 }
 171
 172 /* \brief Encode a hexadecimal RGB or RGBA color code.
 173  * \par Function Description
 174  * Encodes four colour components into either the form #RRGGBB or
 175  * #RRGGBBAA. The shorter form is used when the alpha component is
 176  * 0xff.
 177  *
 178  * \param [in] r Red component.
 179  * \param [in] g Green component.
 180  * \param [in] b Blue component.
 181  * \returns A newly allocated string containing the encoded string.
 182  */
 183 gchar *
 184 s_color_rgba_encode (guint8 r, guint8 g, guint8 b, guint8 a)
 185 {
 186   if (a < 0xff)
 187     return g_strdup_printf("#%02x%02x%02x%02x",
 188                            (gint) r, (gint) g, (gint) b, (gint) a);
 189   else
 190     return g_strdup_printf("#%02x%02x%02x",
 191                            (gint) r, (gint) g, (gint) b);
 192 }
 193
 194 SCM
 195 s_color_map_to_scm (const COLOR *map)
 196 {
 197   SCM result = SCM_EOL;
 198   int i;
 199   for (i = MAX_COLORS - 1; i >= 0; i--) {
 200     SCM color_val = SCM_BOOL_F;
 201     if (map[i].enabled) {
 202       COLOR c = map[i];
 203       gchar *rgba = s_color_rgba_encode (c.r, c.g, c.b, c.a);
 204       color_val = scm_from_utf8_string (rgba);
 205       g_free (rgba);
 206     }
 207     result = scm_cons (scm_list_2 (scm_from_int (i), color_val), result);
 208   }
 209   return result;
 210 }
 211
 212 /*!
 213  * \warning This function should ONLY be called from Scheme procedures.
 214  */
 215 void
 216 s_color_map_from_scm (COLOR *map, SCM lst, const char *scheme_proc_name)
 217 {
 218   SCM curr = lst;
 219   SCM wrong_type_arg_sym = scm_from_utf8_symbol ("wrong-type-arg");
 220   SCM proc_name = scm_from_utf8_string (scheme_proc_name);
 221   while (!scm_is_null (curr)) {
 222     int i;
 223     char *rgba;
 224     SCM s;
 225     COLOR c = {0x00, 0x00, 0x00, FALSE};
 226     gboolean result;
 227     SCM entry = scm_car (curr);
 228
 229     /* Check map entry has correct type */
 230     if (!scm_is_true (scm_list_p (entry))
 231         || (scm_to_int (scm_length (entry)) != 2)) {
 232       scm_error_scm (wrong_type_arg_sym, proc_name,
 233                      scm_from_utf8_string (_("Color map entry must be a two-element list")),
 234                      SCM_EOL, scm_list_1 (entry));
 235     }
 236
 237     /* Check color index has correct type, and extract it */
 238     s = scm_car (entry);
 239     if (!scm_is_integer (s)) {
 240       scm_error_scm (wrong_type_arg_sym, proc_name,
 241                      scm_from_utf8_string (_("Index in color map entry must be an integer")),
 242                      SCM_EOL, scm_list_1 (s));
 243     }
 244     i = scm_to_int (s);
 245
 246     /* Check color index is within bounds. If it's out of bounds, it's
 247      * legal, but warn & ignore it.
 248      *
 249      * FIXME one day we will have dynamically-expanding colorspace.
 250      * One day. */
 251     if ((i < 0) || (i >= MAX_COLORS)) {
 252       g_critical ("Color map index out of bounds: %i\n", i);
 253       goto color_map_next;
 254     }
 255
 256     /* If color value is #F, disable color */
 257     s = scm_cadr (entry);
 258     if (scm_is_false (s)) {
 259       map[i].enabled = FALSE;
 260       goto color_map_next;
 261     }
 262
 263     /* Otherwise, we require a string */
 264     s = scm_cadr (entry);
 265     if (!scm_is_string (s)) {
 266       scm_error_scm (wrong_type_arg_sym, proc_name,
 267                      scm_from_utf8_string (_("Value in color map entry must be #f or a string")),
 268                      SCM_EOL, scm_list_1 (s));
 269     }
 270     rgba = scm_to_utf8_string (s);
 271
 272     result = s_color_rgba_decode (rgba, &c.r, &c.g, &c.b, &c.a);
 273
 274     /* FIXME should we generate a Guile error if there's a problem here? */
 275     if (!result) {
 276       g_critical ("Invalid color map value: %s\n", rgba);
 277     } else {
 278       map[i] = c;
 279       map[i].enabled = TRUE;
 280     }
 281
 282   color_map_next:
 283     /* Go to next element in map */
 284     curr = scm_cdr (curr);
 285   }
 286   scm_remember_upto_here_2 (wrong_type_arg_sym, proc_name);
 287 }