image.c

   1 /*
   2  * image.c - image object
   3  *
   4  * Copyright © 2008 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 "structs.h"
  23
  24 extern awesome_t globalconf;
  25
  26 DO_LUA_NEW(extern, image_t, image, "image", image_ref)
  27 DO_LUA_GC(image_t, image, "image", image_unref)
  28 DO_LUA_EQ(image_t, image, "image")
  29
  30 static const char *
  31 image_imlib_load_strerror(Imlib_Load_Error e)
  32 {
  33     switch(e)
  34     {
  35       case IMLIB_LOAD_ERROR_FILE_DOES_NOT_EXIST:
  36         return "no such file or directory";
  37       case IMLIB_LOAD_ERROR_FILE_IS_DIRECTORY:
  38         return "file is a directory";
  39       case IMLIB_LOAD_ERROR_PERMISSION_DENIED_TO_READ:
  40         return "read permission denied";
  41       case IMLIB_LOAD_ERROR_NO_LOADER_FOR_FILE_FORMAT:
  42         return "no loader for file format";
  43       case IMLIB_LOAD_ERROR_PATH_TOO_LONG:
  44         return "path too long";
  45       case IMLIB_LOAD_ERROR_PATH_COMPONENT_NON_EXISTANT:
  46         return "path component non existant";
  47       case IMLIB_LOAD_ERROR_PATH_COMPONENT_NOT_DIRECTORY:
  48         return "path compoment not a directory";
  49       case IMLIB_LOAD_ERROR_PATH_POINTS_OUTSIDE_ADDRESS_SPACE:
  50         return "path points oustide address space";
  51       case IMLIB_LOAD_ERROR_TOO_MANY_SYMBOLIC_LINKS:
  52         return "too many symbolic links";
  53       case IMLIB_LOAD_ERROR_OUT_OF_MEMORY:
  54         return "out of memory";
  55       case IMLIB_LOAD_ERROR_OUT_OF_FILE_DESCRIPTORS:
  56         return "out of file descriptors";
  57       case IMLIB_LOAD_ERROR_PERMISSION_DENIED_TO_WRITE:
  58         return "write permission denied";
  59       case IMLIB_LOAD_ERROR_OUT_OF_DISK_SPACE:
  60         return "out of disk space";
  61       case IMLIB_LOAD_ERROR_UNKNOWN:
  62         return "unknown error, that's really bad";
  63       case IMLIB_LOAD_ERROR_NONE:
  64         return "no error, oops";
  65     }
  66
  67     return "unknown error";
  68 }
  69
  70 /** Recompute the ARGB32 data from an image.
  71  * \param image The image.
  72  * \return Data.
  73  */
  74 static void
  75 image_compute(image_t *image)
  76 {
  77     int size, i;
  78     uint32_t *data;
  79     double alpha;
  80     uint8_t *dataimg;
  81
  82     imlib_context_set_image(image->image);
  83
  84     data = imlib_image_get_data_for_reading_only();
  85
  86     image->width = imlib_image_get_width();
  87     image->height = imlib_image_get_height();
  88
  89     size = image->width * image->height;
  90
  91     p_delete(&image->data);
  92     image->data = dataimg = p_new(uint8_t, size * 4);
  93
  94     for(i = 0; i < size; i++, dataimg += 4)
  95     {
  96         dataimg[3] = (data[i] >> 24) & 0xff;           /* A */
  97         /* cairo wants pre-multiplied alpha */
  98         alpha = dataimg[3] / 255.0;
  99         dataimg[2] = ((data[i] >> 16) & 0xff) * alpha; /* R */
 100         dataimg[1] = ((data[i] >>  8) & 0xff) * alpha; /* G */
 101         dataimg[0] = (data[i]         & 0xff) * alpha; /* B */
 102     }
 103 }
 104
 105 /** Create a new image from ARGB32 data.
 106  * \param width The image width.
 107  * \param height The image height.
 108  * \param data The image data.
 109  * \return A brand new image.
 110  */
 111 image_t *
 112 image_new_from_argb32(int width, int height, uint32_t *data)
 113 {
 114     Imlib_Image imimage;
 115     image_t *image = NULL;
 116
 117     if((imimage = imlib_create_image_using_data(width, height, data)))
 118     {
 119         image = p_new(image_t, 1);
 120         image->image = imimage;
 121         image_compute(image);
 122     }
 123
 124     return image;
 125 }
 126
 127 /** Load an image from filename.
 128  * \param filename The image file to load.
 129  * \return A new image.
 130  */
 131 image_t *
 132 image_new_from_file(const char *filename)
 133 {
 134     Imlib_Image imimage;
 135     Imlib_Load_Error e = IMLIB_LOAD_ERROR_NONE;
 136     image_t *image;
 137
 138     if(!filename)
 139         return NULL;
 140
 141     if(!(imimage = imlib_load_image_with_error_return(filename, &e)))
 142     {
 143         warn("cannot load image %s: %s", filename, image_imlib_load_strerror(e));
 144         return NULL;
 145     }
 146
 147     image = p_new(image_t, 1);
 148     image->image = imimage;
 149
 150     image_compute(image);
 151
 152     return image;
 153 }
 154
 155 /** Create a new image object.
 156  * \param L The Lua stack.
 157  * \return The number of elements pushed on stack.
 158  * \luastack
 159  * \lparam The image path, or nil to create an empty image.
 160  * \lparam The image width if nil was set as first arg.
 161  * \lparam The image height if nil was set as first arg.
 162  * \lreturn An image object.
 163  */
 164 static int
 165 luaA_image_new(lua_State *L)
 166 {
 167     const char *filename;
 168
 169     if((filename = lua_tostring(L, 2)))
 170     {
 171         image_t *image;
 172         if((image = image_new_from_file(filename)))
 173             return luaA_image_userdata_new(L, image);
 174     }
 175     else if(lua_isnil(L, 2))
 176     {
 177         int width = luaL_checknumber(L, 3);
 178         int height = luaL_checknumber(L, 4);
 179
 180         if(width <= 0 || height <= 0)
 181             luaL_error(L, "request image has invalid size");
 182
 183         Imlib_Image imimage = imlib_create_image(width, height);
 184         image_t *image = p_new(image_t, 1);
 185         image->image = imimage;
 186         image_compute(image);
 187         return luaA_image_userdata_new(L, image);
 188     }
 189
 190     return 0;
 191 }
 192
 193 /** Create a new image object from ARGB32 data.
 194  * \param L The Lua stack.
 195  * \return The number of elements pushed on stack.
 196  * \luastack
 197  * \lparam The image width.
 198  * \lparam The image height.
 199  * \lparam The image data as a string in ARGB32 format.
 200  * \lreturn An image object.
 201  */
 202 static int
 203 luaA_image_argb32_new(lua_State *L)
 204 {
 205     size_t len;
 206     image_t *image;
 207     unsigned int width = luaL_checknumber(L, 1);
 208     unsigned int height = luaL_checknumber(L, 2);
 209     const char *data = luaL_checklstring(L, 3, &len);
 210
 211     if(width * height * 4 != len)
 212         luaL_error(L, "string size does not match image size");
 213
 214     if((image = image_new_from_argb32(width, height, (uint32_t *) data)))
 215         return luaA_image_userdata_new(L, image);
 216
 217     return 0;
 218 }
 219
 220 /** Rotate an image with specified angle radians and return a new image.
 221  * \param L The Lua VM state.
 222  * \return The number of elements pushed on stack.
 223  * \luastack
 224  * \lvalue An image.
 225  * \lparam The angle in radians.
 226  * \lreturn A rotated image.
 227  */
 228 static int
 229 luaA_image_rotate(lua_State *L)
 230 {
 231     image_t **image = luaA_checkudata(L, 1, "image"), *new;
 232     double angle = luaL_checknumber(L, 2);
 233
 234     new = p_new(image_t, 1);
 235
 236     imlib_context_set_image((*image)->image);
 237     new->image = imlib_create_rotated_image(angle);
 238
 239     image_compute(new);
 240
 241     return luaA_image_userdata_new(L, new);
 242 }
 243
 244 /** Crop an image to the given rectangle.
 245  * \return The number of elements pushed on stack.
 246  * \luastack
 247  * \lvalue An image.
 248  * \lparam The top left x coordinate of the rectangle.
 249  * \lparam The top left y coordinate of the rectangle.
 250  * \lparam The width of the rectangle.
 251  * \lparam The height of the rectangle.
 252  * \lreturn A cropped image.
 253  */
 254 static int
 255 luaA_image_crop(lua_State *L)
 256 {
 257     image_t **image = luaA_checkudata(L, 1, "image"), *new;
 258     int x = luaL_checkint(L, 2);
 259     int y = luaL_checkint(L, 3);
 260     int w = luaL_checkint(L, 4);
 261     int h = luaL_checkint(L, 5);
 262
 263     new = p_new(image_t, 1);
 264
 265     imlib_context_set_image((*image)->image);
 266     new->image = imlib_create_cropped_image(x, y, w, h);
 267
 268     image_compute(new);
 269
 270     return luaA_image_userdata_new(L, new);
 271 }
 272
 273 /** Crop the image to the given rectangle and scales it.
 274  * \param L The Lua VM state.
 275  * \return The number of elements pushed on stack.
 276  * \luastack
 277  * \lvalue An image.
 278  * \lparam The top left x coordinate of the source rectangle.
 279  * \lparam The top left y coordinate of the source rectangle.
 280  * \lparam The width of the source rectangle.
 281  * \lparam The height of the source rectangle.
 282  * \lparam The width of the destination rectangle.
 283  * \lparam The height of the destination rectangle.
 284  * \lreturn A cropped image.
 285  */
 286 static int
 287 luaA_image_crop_and_scale(lua_State *L)
 288 {
 289     image_t **image = luaA_checkudata(L, 1, "image"), *new;
 290     int source_x = luaL_checkint(L, 2);
 291     int source_y = luaL_checkint(L, 3);
 292     int w = luaL_checkint(L, 4);
 293     int h = luaL_checkint(L, 5);
 294     int dest_w = luaL_checkint(L, 6);
 295     int dest_h = luaL_checkint(L, 7);
 296
 297     new = p_new(image_t, 1);
 298
 299     imlib_context_set_image((*image)->image);
 300     new->image = imlib_create_cropped_scaled_image(source_x,
 301                                                    source_y,
 302                                                    w, h,
 303                                                    dest_w, dest_h);
 304
 305     image_compute(new);
 306
 307     return luaA_image_userdata_new(L, new);
 308 }
 309
 310 /** Image object.
 311  * \param L The Lua VM state.
 312  * \return The number of elements pushed on stack.
 313  * \luastack
 314  * \lvalue An image
 315  * \lfield width The image width.
 316  * \lfield height The image height.
 317  */
 318 static int
 319 luaA_image_index(lua_State *L)
 320 {
 321     if(luaA_usemetatable(L, 1, 2))
 322         return 1;
 323
 324     image_t **image = luaA_checkudata(L, 1, "image");
 325     size_t len;
 326     const char *attr = luaL_checklstring(L, 2, &len);
 327
 328     switch(a_tokenize(attr, len))
 329     {
 330       case A_TK_WIDTH:
 331         imlib_context_set_image((*image)->image);
 332         lua_pushnumber(L, imlib_image_get_width());
 333         break;
 334       case A_TK_HEIGHT:
 335         imlib_context_set_image((*image)->image);
 336         lua_pushnumber(L, imlib_image_get_height());
 337         break;
 338       default:
 339         return 0;
 340     }
 341
 342     return 1;
 343 }
 344
 345 const struct luaL_reg awesome_image_methods[] =
 346 {
 347     { "__call", luaA_image_new },
 348     { "argb32", luaA_image_argb32_new },
 349     { NULL, NULL }
 350 };
 351 const struct luaL_reg awesome_image_meta[] =
 352 {
 353     { "__index", luaA_image_index },
 354     { "rotate", luaA_image_rotate },
 355     { "crop", luaA_image_crop },
 356     { "crop_and_scale", luaA_image_crop_and_scale },
 357     { "__gc", luaA_image_gc },
 358     { "__eq", luaA_image_eq },
 359     { "__tostring", luaA_image_tostring },
 360     { NULL, NULL }
 361 };
 362
 363 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80