draw.c

   1 /*
   2  * draw.c - draw functions
   3  *
   4  * Copyright © 2007-2009 Julien Danjou <julien@danjou.info>
   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 along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  */
  21
  22 #include <cairo-xcb.h>
  23
  24 #include "config.h"
  25
  26 #include <langinfo.h>
  27 #include <iconv.h>
  28 #include <errno.h>
  29 #include <ctype.h>
  30 #include <math.h>
  31
  32 #include "globalconf.h"
  33 #include "screen.h"
  34
  35 #include "common/xutil.h"
  36
  37 /** Convert text from any charset to UTF-8 using iconv.
  38  * \param iso The ISO string to convert.
  39  * \param len The string size.
  40  * \param dest The destination pointer. Memory will be allocated, up to you to
  41  * free, like any char *.
  42  * \param dlen The destination length, can be NULL.
  43  * \return True if conversion was done.
  44  */
  45 bool
  46 draw_iso2utf8(const char *iso, size_t len, char **dest, ssize_t *dlen)
  47 {
  48     static iconv_t iso2utf8 = (iconv_t) -1;
  49     static int8_t dont_need_convert = -1;
  50
  51     if(dont_need_convert == -1)
  52         dont_need_convert = !a_strcmp(nl_langinfo(CODESET), "UTF-8");
  53
  54     if(!len || dont_need_convert)
  55         return false;
  56
  57     if(iso2utf8 == (iconv_t) -1)
  58     {
  59         iso2utf8 = iconv_open("UTF-8", nl_langinfo(CODESET));
  60         if(iso2utf8 == (iconv_t) -1)
  61         {
  62             if(errno == EINVAL)
  63                 warn("unable to convert text from %s to UTF-8, not available",
  64                      nl_langinfo(CODESET));
  65             else
  66                 warn("unable to convert text: %s", strerror(errno));
  67
  68             return false;
  69         }
  70     }
  71
  72     size_t orig_utf8len, utf8len;
  73     char *utf8;
  74
  75     orig_utf8len = utf8len = 2 * len + 1;
  76     utf8 = *dest = p_new(char, utf8len);
  77
  78     if(iconv(iso2utf8, (char **) &iso, &len, &utf8, &utf8len) == (size_t) -1)
  79     {
  80         warn("text conversion failed: %s", strerror(errno));
  81         p_delete(dest);
  82         return false;
  83     }
  84
  85     if(dlen)
  86         *dlen = orig_utf8len - utf8len;
  87
  88     return true;
  89 }
  90
  91 static cairo_user_data_key_t data_key;
  92
  93 static inline void
  94 free_data(void *data)
  95 {
  96     p_delete(&data);
  97 }
  98
  99 /** Create a surface object on the lua stack from this image data.
 100  * \param L The lua stack.
 101  * \param width The width of the image.
 102  * \param height The height of the image
 103  * \param data The image's data in ARGB format, will be copied by this function.
 104  * \return Number of items pushed on the lua stack.
 105  */
 106 int
 107 luaA_surface_from_data(lua_State *L, int width, int height, uint32_t *data)
 108 {
 109     unsigned long int len = width * height;
 110     unsigned long int i;
 111     uint32_t *buffer = p_new(uint32_t, len);
 112     cairo_surface_t *surface;
 113
 114     /* Cairo wants premultiplied alpha, meh :( */
 115     for(i = 0; i < len; i++)
 116     {
 117         uint8_t a = (data[i] >> 24) & 0xff;
 118         double alpha = a / 255.0;
 119         uint8_t r = ((data[i] >> 16) & 0xff) * alpha;
 120         uint8_t g = ((data[i] >>  8) & 0xff) * alpha;
 121         uint8_t b = ((data[i] >>  0) & 0xff) * alpha;
 122         buffer[i] = (a << 24) | (r << 16) | (g << 8) | b;
 123     }
 124
 125     surface =
 126         cairo_image_surface_create_for_data((unsigned char *) buffer,
 127                                             CAIRO_FORMAT_ARGB32,
 128                                             width,
 129                                             height,
 130                                             width*4);
 131     /* This makes sure that buffer will be freed */
 132     cairo_surface_set_user_data(surface, &data_key, buffer, &free_data);
 133
 134     /* This will increase the reference count of the surface */
 135     int ret = oocairo_surface_push(globalconf.L, surface);
 136     /* So we have to drop our own reference */
 137     cairo_surface_destroy(surface);
 138
 139     return ret;
 140 }
 141
 142 /** Duplicate the specified image surface.
 143  * \param surface The surface to copy
 144  * \return A pointer to a new cairo image surface.
 145  */
 146 cairo_surface_t *
 147 draw_dup_image_surface(cairo_surface_t *surface)
 148 {
 149     cairo_surface_t *res = cairo_image_surface_create(
 150             cairo_image_surface_get_format(surface),
 151             cairo_image_surface_get_width(surface),
 152             cairo_image_surface_get_height(surface));
 153
 154     cairo_t *cr = cairo_create(res);
 155     cairo_set_source_surface(cr, surface, 0, 0);
 156     cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
 157     cairo_paint(cr);
 158     cairo_destroy(cr);
 159
 160     return res;
 161 }
 162
 163 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80