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 <gdk-pixbuf/gdk-pixbuf.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 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 cairo_surface_t *
 109 draw_surface_from_data(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     return surface;
 137 }
 138
 139 /** Create a surface object from this pixbuf
 140  * \param buf The pixbuf
 141  * \return Number of items pushed on the lua stack.
 142  */
 143 static cairo_surface_t *
 144 draw_surface_from_pixbuf(GdkPixbuf *buf)
 145 {
 146     int width = gdk_pixbuf_get_width(buf);
 147     int height = gdk_pixbuf_get_height(buf);
 148     int pix_stride = gdk_pixbuf_get_rowstride(buf);
 149     guchar *pixels = gdk_pixbuf_get_pixels(buf);
 150     int channels = gdk_pixbuf_get_n_channels(buf);
 151     cairo_surface_t *surface;
 152     int cairo_stride;
 153     unsigned char *cairo_pixels;
 154
 155     cairo_format_t format = CAIRO_FORMAT_ARGB32;
 156     if (channels == 3)
 157         format = CAIRO_FORMAT_RGB24;
 158
 159     surface = cairo_image_surface_create(format, width, height);
 160     cairo_surface_flush(surface);
 161     cairo_stride = cairo_image_surface_get_stride(surface);
 162     cairo_pixels = cairo_image_surface_get_data(surface);
 163
 164     for (int y = 0; y < height; y++)
 165     {
 166         guchar *row = pixels;
 167         uint32_t *cairo = (uint32_t *) cairo_pixels;
 168         for (int x = 0; x < width; x++) {
 169             if (channels == 3)
 170             {
 171                 uint8_t r = *row++;
 172                 uint8_t g = *row++;
 173                 uint8_t b = *row++;
 174                 *cairo++ = (r << 16) | (g << 8) | b;
 175             } else {
 176                 uint8_t r = *row++;
 177                 uint8_t g = *row++;
 178                 uint8_t b = *row++;
 179                 uint8_t a = *row++;
 180                 double alpha = a / 255.0;
 181                 r = r * alpha;
 182                 g = g * alpha;
 183                 b = b * alpha;
 184                 *cairo++ = (a << 24) | (r << 16) | (g << 8) | b;
 185             }
 186         }
 187         pixels += pix_stride;
 188         cairo_pixels += cairo_stride;
 189     }
 190
 191     cairo_surface_mark_dirty(surface);
 192     return surface;
 193 }
 194
 195 /** Duplicate the specified image surface.
 196  * \param surface The surface to copy
 197  * \return A pointer to a new cairo image surface.
 198  */
 199 cairo_surface_t *
 200 draw_dup_image_surface(cairo_surface_t *surface)
 201 {
 202     cairo_surface_t *res = cairo_image_surface_create(
 203             cairo_image_surface_get_format(surface),
 204             cairo_image_surface_get_width(surface),
 205             cairo_image_surface_get_height(surface));
 206
 207     cairo_t *cr = cairo_create(res);
 208     cairo_set_source_surface(cr, surface, 0, 0);
 209     cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
 210     cairo_paint(cr);
 211     cairo_destroy(cr);
 212
 213     return res;
 214 }
 215
 216 /** Load the specified path into a cairo surface
 217  * \param L Lua state
 218  * \param path file to load
 219  * \return A cairo image surface or NULL on error.
 220  */
 221 cairo_surface_t *
 222 draw_load_image(lua_State *L, const char *path)
 223 {
 224     GError *error = NULL;
 225     cairo_surface_t *ret;
 226     GdkPixbuf *buf = gdk_pixbuf_new_from_file(path, &error);
 227
 228     if (!buf) {
 229         luaL_where(L, 1);
 230         lua_pushstring(L, error->message);
 231         lua_concat(L, 2);
 232         g_error_free(error);
 233         lua_error(L);
 234         return NULL;
 235     }
 236
 237     ret = draw_surface_from_pixbuf(buf);
 238     g_object_unref(buf);
 239     return ret;
 240 }
 241
 242 xcb_visualtype_t *draw_find_visual(const xcb_screen_t *s, xcb_visualid_t visual)
 243 {
 244     xcb_depth_iterator_t depth_iter = xcb_screen_allowed_depths_iterator(s);
 245
 246     if(depth_iter.data)
 247         for(; depth_iter.rem; xcb_depth_next (&depth_iter))
 248             for(xcb_visualtype_iterator_t visual_iter = xcb_depth_visuals_iterator(depth_iter.data);
 249                 visual_iter.rem; xcb_visualtype_next (&visual_iter))
 250                 if(visual == visual_iter.data->visual_id)
 251                     return visual_iter.data;
 252
 253     return NULL;
 254 }
 255
 256 xcb_visualtype_t *draw_default_visual(const xcb_screen_t *s)
 257 {
 258     return draw_find_visual(s, s->root_visual);
 259 }
 260
 261 xcb_visualtype_t *draw_argb_visual(const xcb_screen_t *s)
 262 {
 263     xcb_depth_iterator_t depth_iter = xcb_screen_allowed_depths_iterator(s);
 264
 265     if(depth_iter.data)
 266         for(; depth_iter.rem; xcb_depth_next (&depth_iter))
 267             if(depth_iter.data->depth == 32)
 268                 for(xcb_visualtype_iterator_t visual_iter = xcb_depth_visuals_iterator(depth_iter.data);
 269                     visual_iter.rem; xcb_visualtype_next (&visual_iter))
 270                     return visual_iter.data;
 271
 272     return NULL;
 273 }
 274
 275 uint8_t draw_visual_depth(const xcb_screen_t *s, xcb_visualid_t vis)
 276 {
 277     xcb_depth_iterator_t depth_iter = xcb_screen_allowed_depths_iterator(s);
 278
 279     if(depth_iter.data)
 280         for(; depth_iter.rem; xcb_depth_next (&depth_iter))
 281             for(xcb_visualtype_iterator_t visual_iter = xcb_depth_visuals_iterator(depth_iter.data);
 282                 visual_iter.rem; xcb_visualtype_next (&visual_iter))
 283                 if(vis == visual_iter.data->visual_id)
 284                     return depth_iter.data->depth;
 285
 286     fatal("Could not find a visual's depth");
 287 }
 288
 289 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80