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 "config.h"
  23 #include "draw.h"
  24
  25 #include <langinfo.h>
  26 #include <iconv.h>
  27 #include <errno.h>
  28 #include <ctype.h>
  29 #include <math.h>
  30
  31 #include <gdk-pixbuf/gdk-pixbuf.h>
  32 #include <cairo-xcb.h>
  33 #include <lauxlib.h>
  34
  35 /** Convert text from any charset to UTF-8 using iconv.
  36  * \param iso The ISO string to convert.
  37  * \param len The string size.
  38  * \param dest The destination pointer. Memory will be allocated, up to you to
  39  * free, like any char *.
  40  * \param dlen The destination length, can be NULL.
  41  * \return True if conversion was done.
  42  */
  43 bool
  44 draw_iso2utf8(const char *iso, size_t len, char **dest, ssize_t *dlen)
  45 {
  46     static iconv_t iso2utf8 = (iconv_t) -1;
  47     static int8_t dont_need_convert = -1;
  48
  49     if(dont_need_convert == -1)
  50         dont_need_convert = A_STREQ(nl_langinfo(CODESET), "UTF-8");
  51
  52     if(!len || dont_need_convert)
  53         return false;
  54
  55     if(iso2utf8 == (iconv_t) -1)
  56     {
  57         iso2utf8 = iconv_open("UTF-8", nl_langinfo(CODESET));
  58         if(iso2utf8 == (iconv_t) -1)
  59         {
  60             if(errno == EINVAL)
  61                 warn("unable to convert text from %s to UTF-8, not available",
  62                      nl_langinfo(CODESET));
  63             else
  64                 warn("unable to convert text: %s", strerror(errno));
  65
  66             return false;
  67         }
  68     }
  69
  70     size_t orig_utf8len, utf8len;
  71     char *utf8;
  72
  73     orig_utf8len = utf8len = 2 * len + 1;
  74     utf8 = *dest = p_new(char, utf8len);
  75
  76     if(iconv(iso2utf8, (char **) &iso, &len, &utf8, &utf8len) == (size_t) -1)
  77     {
  78         warn("text conversion failed: %s", strerror(errno));
  79         p_delete(dest);
  80         return false;
  81     }
  82
  83     if(dlen)
  84         *dlen = orig_utf8len - utf8len;
  85
  86     return true;
  87 }
  88
  89 static cairo_user_data_key_t data_key;
  90
  91 static inline void
  92 free_data(void *data)
  93 {
  94     p_delete(&data);
  95 }
  96
  97 /** Create a surface object from this image data.
  98  * \param L The lua stack.
  99  * \param width The width of the image.
 100  * \param height The height of the image
 101  * \param data The image's data in ARGB format, will be copied by this function.
 102  * \return Number of items pushed on the lua stack.
 103  */
 104 cairo_surface_t *
 105 draw_surface_from_data(int width, int height, uint32_t *data)
 106 {
 107     unsigned long int len = width * height;
 108     unsigned long int i;
 109     uint32_t *buffer = p_new(uint32_t, len);
 110     cairo_surface_t *surface;
 111
 112     /* Cairo wants premultiplied alpha, meh :( */
 113     for(i = 0; i < len; i++)
 114     {
 115         uint8_t a = (data[i] >> 24) & 0xff;
 116         double alpha = a / 255.0;
 117         uint8_t r = ((data[i] >> 16) & 0xff) * alpha;
 118         uint8_t g = ((data[i] >>  8) & 0xff) * alpha;
 119         uint8_t b = ((data[i] >>  0) & 0xff) * alpha;
 120         buffer[i] = (a << 24) | (r << 16) | (g << 8) | b;
 121     }
 122
 123     surface =
 124         cairo_image_surface_create_for_data((unsigned char *) buffer,
 125                                             CAIRO_FORMAT_ARGB32,
 126                                             width,
 127                                             height,
 128                                             width*4);
 129     /* This makes sure that buffer will be freed */
 130     cairo_surface_set_user_data(surface, &data_key, buffer, &free_data);
 131
 132     return surface;
 133 }
 134
 135 /** Create a surface object from this pixbuf
 136  * \param buf The pixbuf
 137  * \return Number of items pushed on the lua stack.
 138  */
 139 static cairo_surface_t *
 140 draw_surface_from_pixbuf(GdkPixbuf *buf)
 141 {
 142     int width = gdk_pixbuf_get_width(buf);
 143     int height = gdk_pixbuf_get_height(buf);
 144     int pix_stride = gdk_pixbuf_get_rowstride(buf);
 145     guchar *pixels = gdk_pixbuf_get_pixels(buf);
 146     int channels = gdk_pixbuf_get_n_channels(buf);
 147     cairo_surface_t *surface;
 148     int cairo_stride;
 149     unsigned char *cairo_pixels;
 150
 151     cairo_format_t format = CAIRO_FORMAT_ARGB32;
 152     if (channels == 3)
 153         format = CAIRO_FORMAT_RGB24;
 154
 155     surface = cairo_image_surface_create(format, width, height);
 156     cairo_surface_flush(surface);
 157     cairo_stride = cairo_image_surface_get_stride(surface);
 158     cairo_pixels = cairo_image_surface_get_data(surface);
 159
 160     for (int y = 0; y < height; y++)
 161     {
 162         guchar *row = pixels;
 163         uint32_t *cairo = (uint32_t *) cairo_pixels;
 164         for (int x = 0; x < width; x++) {
 165             if (channels == 3)
 166             {
 167                 uint8_t r = *row++;
 168                 uint8_t g = *row++;
 169                 uint8_t b = *row++;
 170                 *cairo++ = (r << 16) | (g << 8) | b;
 171             } else {
 172                 uint8_t r = *row++;
 173                 uint8_t g = *row++;
 174                 uint8_t b = *row++;
 175                 uint8_t a = *row++;
 176                 double alpha = a / 255.0;
 177                 r = r * alpha;
 178                 g = g * alpha;
 179                 b = b * alpha;
 180                 *cairo++ = (a << 24) | (r << 16) | (g << 8) | b;
 181             }
 182         }
 183         pixels += pix_stride;
 184         cairo_pixels += cairo_stride;
 185     }
 186
 187     cairo_surface_mark_dirty(surface);
 188     return surface;
 189 }
 190
 191 /** Duplicate the specified image surface.
 192  * \param surface The surface to copy
 193  * \return A pointer to a new cairo image surface.
 194  */
 195 cairo_surface_t *
 196 draw_dup_image_surface(cairo_surface_t *surface)
 197 {
 198     cairo_surface_t *res = cairo_image_surface_create(
 199             cairo_image_surface_get_format(surface),
 200             cairo_image_surface_get_width(surface),
 201             cairo_image_surface_get_height(surface));
 202
 203     cairo_t *cr = cairo_create(res);
 204     cairo_set_source_surface(cr, surface, 0, 0);
 205     cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
 206     cairo_paint(cr);
 207     cairo_destroy(cr);
 208
 209     return res;
 210 }
 211
 212 /** Load the specified path into a cairo surface
 213  * \param L Lua state
 214  * \param path file to load
 215  * \return A cairo image surface or NULL on error.
 216  */
 217 cairo_surface_t *
 218 draw_load_image(lua_State *L, const char *path)
 219 {
 220     GError *error = NULL;
 221     cairo_surface_t *ret;
 222     GdkPixbuf *buf = gdk_pixbuf_new_from_file(path, &error);
 223
 224     if (!buf) {
 225         luaL_where(L, 1);
 226         lua_pushstring(L, error->message);
 227         lua_concat(L, 2);
 228         g_error_free(error);
 229         lua_error(L);
 230         return NULL;
 231     }
 232
 233     ret = draw_surface_from_pixbuf(buf);
 234     g_object_unref(buf);
 235     return ret;
 236 }
 237
 238 xcb_visualtype_t *draw_find_visual(const xcb_screen_t *s, xcb_visualid_t visual)
 239 {
 240     xcb_depth_iterator_t depth_iter = xcb_screen_allowed_depths_iterator(s);
 241
 242     if(depth_iter.data)
 243         for(; depth_iter.rem; xcb_depth_next (&depth_iter))
 244             for(xcb_visualtype_iterator_t visual_iter = xcb_depth_visuals_iterator(depth_iter.data);
 245                 visual_iter.rem; xcb_visualtype_next (&visual_iter))
 246                 if(visual == visual_iter.data->visual_id)
 247                     return visual_iter.data;
 248
 249     return NULL;
 250 }
 251
 252 xcb_visualtype_t *draw_default_visual(const xcb_screen_t *s)
 253 {
 254     return draw_find_visual(s, s->root_visual);
 255 }
 256
 257 xcb_visualtype_t *draw_argb_visual(const xcb_screen_t *s)
 258 {
 259     xcb_depth_iterator_t depth_iter = xcb_screen_allowed_depths_iterator(s);
 260
 261     if(depth_iter.data)
 262         for(; depth_iter.rem; xcb_depth_next (&depth_iter))
 263             if(depth_iter.data->depth == 32)
 264                 for(xcb_visualtype_iterator_t visual_iter = xcb_depth_visuals_iterator(depth_iter.data);
 265                     visual_iter.rem; xcb_visualtype_next (&visual_iter))
 266                     return visual_iter.data;
 267
 268     return NULL;
 269 }
 270
 271 uint8_t draw_visual_depth(const xcb_screen_t *s, xcb_visualid_t vis)
 272 {
 273     xcb_depth_iterator_t depth_iter = xcb_screen_allowed_depths_iterator(s);
 274
 275     if(depth_iter.data)
 276         for(; depth_iter.rem; xcb_depth_next (&depth_iter))
 277             for(xcb_visualtype_iterator_t visual_iter = xcb_depth_visuals_iterator(depth_iter.data);
 278                 visual_iter.rem; xcb_visualtype_next (&visual_iter))
 279                 if(vis == visual_iter.data->visual_id)
 280                     return depth_iter.data->depth;
 281
 282     fatal("Could not find a visual's depth");
 283 }
 284
 285 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80