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 <Imlib2.h>
  33
  34 #include "globalconf.h"
  35 #include "screen.h"
  36
  37 #include "common/xutil.h"
  38
  39 /** Convert text from any charset to UTF-8 using iconv.
  40  * \param iso The ISO string to convert.
  41  * \param len The string size.
  42  * \param dest The destination pointer. Memory will be allocated, up to you to
  43  * free, like any char *.
  44  * \param dlen The destination length, can be NULL.
  45  * \return True if conversion was done.
  46  */
  47 bool
  48 draw_iso2utf8(const char *iso, size_t len, char **dest, ssize_t *dlen)
  49 {
  50     static iconv_t iso2utf8 = (iconv_t) -1;
  51     static int8_t dont_need_convert = -1;
  52
  53     if(dont_need_convert == -1)
  54         dont_need_convert = A_STREQ(nl_langinfo(CODESET), "UTF-8");
  55
  56     if(!len || dont_need_convert)
  57         return false;
  58
  59     if(iso2utf8 == (iconv_t) -1)
  60     {
  61         iso2utf8 = iconv_open("UTF-8", nl_langinfo(CODESET));
  62         if(iso2utf8 == (iconv_t) -1)
  63         {
  64             if(errno == EINVAL)
  65                 warn("unable to convert text from %s to UTF-8, not available",
  66                      nl_langinfo(CODESET));
  67             else
  68                 warn("unable to convert text: %s", strerror(errno));
  69
  70             return false;
  71         }
  72     }
  73
  74     size_t orig_utf8len, utf8len;
  75     char *utf8;
  76
  77     orig_utf8len = utf8len = 2 * len + 1;
  78     utf8 = *dest = p_new(char, utf8len);
  79
  80     if(iconv(iso2utf8, (char **) &iso, &len, &utf8, &utf8len) == (size_t) -1)
  81     {
  82         warn("text conversion failed: %s", strerror(errno));
  83         p_delete(dest);
  84         return false;
  85     }
  86
  87     if(dlen)
  88         *dlen = orig_utf8len - utf8len;
  89
  90     return true;
  91 }
  92
  93 static cairo_user_data_key_t data_key;
  94
  95 static inline void
  96 free_data(void *data)
  97 {
  98     p_delete(&data);
  99 }
 100
 101 /** Create a surface object on the lua stack from this image data.
 102  * \param L The lua stack.
 103  * \param width The width of the image.
 104  * \param height The height of the image
 105  * \param data The image's data in ARGB format, will be copied by this function.
 106  * \return Number of items pushed on the lua stack.
 107  */
 108 int
 109 luaA_surface_from_data(lua_State *L, int width, int height, uint32_t *data)
 110 {
 111     unsigned long int len = width * height;
 112     unsigned long int i;
 113     uint32_t *buffer = p_new(uint32_t, len);
 114     cairo_surface_t *surface;
 115
 116     /* Cairo wants premultiplied alpha, meh :( */
 117     for(i = 0; i < len; i++)
 118     {
 119         uint8_t a = (data[i] >> 24) & 0xff;
 120         double alpha = a / 255.0;
 121         uint8_t r = ((data[i] >> 16) & 0xff) * alpha;
 122         uint8_t g = ((data[i] >>  8) & 0xff) * alpha;
 123         uint8_t b = ((data[i] >>  0) & 0xff) * alpha;
 124         buffer[i] = (a << 24) | (r << 16) | (g << 8) | b;
 125     }
 126
 127     surface =
 128         cairo_image_surface_create_for_data((unsigned char *) buffer,
 129                                             CAIRO_FORMAT_ARGB32,
 130                                             width,
 131                                             height,
 132                                             width*4);
 133     /* This makes sure that buffer will be freed */
 134     cairo_surface_set_user_data(surface, &data_key, buffer, &free_data);
 135
 136     /* This will increase the reference count of the surface */
 137     int ret = oocairo_surface_push(globalconf.L, surface);
 138     /* So we have to drop our own reference */
 139     cairo_surface_destroy(surface);
 140
 141     return ret;
 142 }
 143
 144 /** Duplicate the specified image surface.
 145  * \param surface The surface to copy
 146  * \return A pointer to a new cairo image surface.
 147  */
 148 cairo_surface_t *
 149 draw_dup_image_surface(cairo_surface_t *surface)
 150 {
 151     cairo_surface_t *res = cairo_image_surface_create(
 152             cairo_image_surface_get_format(surface),
 153             cairo_image_surface_get_width(surface),
 154             cairo_image_surface_get_height(surface));
 155
 156     cairo_t *cr = cairo_create(res);
 157     cairo_set_source_surface(cr, surface, 0, 0);
 158     cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
 159     cairo_paint(cr);
 160     cairo_destroy(cr);
 161
 162     return res;
 163 }
 164
 165 static const char *
 166 image_imlib_load_strerror(Imlib_Load_Error e)
 167 {
 168     switch(e)
 169     {
 170       case IMLIB_LOAD_ERROR_FILE_DOES_NOT_EXIST:
 171         return "no such file or directory";
 172       case IMLIB_LOAD_ERROR_FILE_IS_DIRECTORY:
 173         return "file is a directory";
 174       case IMLIB_LOAD_ERROR_PERMISSION_DENIED_TO_READ:
 175         return "read permission denied";
 176       case IMLIB_LOAD_ERROR_NO_LOADER_FOR_FILE_FORMAT:
 177         return "no loader for file format";
 178       case IMLIB_LOAD_ERROR_PATH_TOO_LONG:
 179         return "path too long";
 180       case IMLIB_LOAD_ERROR_PATH_COMPONENT_NON_EXISTANT:
 181         return "path component non existent";
 182       case IMLIB_LOAD_ERROR_PATH_COMPONENT_NOT_DIRECTORY:
 183         return "path component not a directory";
 184       case IMLIB_LOAD_ERROR_PATH_POINTS_OUTSIDE_ADDRESS_SPACE:
 185         return "path points outside address space";
 186       case IMLIB_LOAD_ERROR_TOO_MANY_SYMBOLIC_LINKS:
 187         return "too many symbolic links";
 188       case IMLIB_LOAD_ERROR_OUT_OF_MEMORY:
 189         return "out of memory";
 190       case IMLIB_LOAD_ERROR_OUT_OF_FILE_DESCRIPTORS:
 191         return "out of file descriptors";
 192       case IMLIB_LOAD_ERROR_PERMISSION_DENIED_TO_WRITE:
 193         return "write permission denied";
 194       case IMLIB_LOAD_ERROR_OUT_OF_DISK_SPACE:
 195         return "out of disk space";
 196       case IMLIB_LOAD_ERROR_UNKNOWN:
 197         return "unknown error, that's really bad";
 198       case IMLIB_LOAD_ERROR_NONE:
 199         return "no error, oops";
 200     }
 201
 202     return "unknown error";
 203 }
 204
 205 /** Load the specified path into a cairo surface
 206  * \param L Lua state
 207  * \param path file to load
 208  * \return A cairo image surface or NULL on error.
 209  */
 210 int
 211 draw_load_image(lua_State *L, const char *path)
 212 {
 213     Imlib_Image imimage;
 214     Imlib_Load_Error e = IMLIB_LOAD_ERROR_NONE;
 215     int ret;
 216
 217     imimage = imlib_load_image_with_error_return(path, &e);
 218     if (!imimage) {
 219         luaL_error(L, "Cannot load image '%s': %s", path, image_imlib_load_strerror(e));
 220         return 0;
 221     }
 222
 223     imlib_context_set_image(imimage);
 224     ret = luaA_surface_from_data(L, imlib_image_get_width(),
 225             imlib_image_get_height(), imlib_image_get_data_for_reading_only());
 226     imlib_free_image_and_decache();
 227     return ret;
 228 }
 229
 230 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80