src/compositor-wayland.c

   1 /*
   2  * Copyright © 2010-2011 Benjamin Franzke
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and
   5  * its documentation for any purpose is hereby granted without fee, provided
   6  * that the above copyright notice appear in all copies and that both that
   7  * copyright notice and this permission notice appear in supporting
   8  * documentation, and that the name of the copyright holders not be used in
   9  * advertising or publicity pertaining to distribution of the software
  10  * without specific, written prior permission.  The copyright holders make
  11  * no representations about the suitability of this software for any
  12  * purpose.  It is provided "as is" without express or implied warranty.
  13  *
  14  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
  15  * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
  16  * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
  17  * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
  18  * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
  19  * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  20  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  21  */
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <stddef.h>
  28 #define _GNU_SOURCE
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <fcntl.h>
  33 #include <unistd.h>
  34
  35 #include <wayland-client.h>
  36 #include <wayland-egl.h>
  37
  38 #include <GLES2/gl2.h>
  39 #include <GLES2/gl2ext.h>
  40 #include <EGL/egl.h>
  41 #include <EGL/eglext.h>
  42
  43 #include "compositor.h"
  44
  45 struct wayland_compositor {
  46         struct weston_compositor         base;
  47
  48         struct {
  49                 struct wl_display *display;
  50                 struct wl_compositor *compositor;
  51                 struct wl_shell *shell;
  52                 struct wl_output *output;
  53
  54                 struct {
  55                         int32_t x, y, width, height;
  56                 } screen_allocation;
  57
  58                 struct wl_event_source *wl_source;
  59                 uint32_t event_mask;
  60         } parent;
  61
  62         struct {
  63                 int32_t top, bottom, left, right;
  64                 GLuint texture;
  65                 int32_t width, height;
  66         } border;
  67
  68         struct wl_list input_list;
  69 };
  70
  71 struct wayland_output {
  72         struct weston_output    base;
  73
  74         struct {
  75                 struct wl_surface       *surface;
  76                 struct wl_shell_surface *shell_surface;
  77                 struct wl_egl_window    *egl_window;
  78         } parent;
  79         EGLSurface egl_surface;
  80         struct weston_mode      mode;
  81 };
  82
  83 struct wayland_input {
  84         struct wayland_compositor *compositor;
  85         struct wl_input_device *input_device;
  86         struct wl_list link;
  87 };
  88
  89
  90 static int
  91 texture_border(struct wayland_output *output)
  92 {
  93         struct wayland_compositor *c =
  94                 (struct wayland_compositor *) output->base.compositor;
  95         GLfloat *d;
  96         unsigned int *p;
  97         int i, j, k, n;
  98         GLfloat x[4], y[4], u[4], v[4];
  99
 100         x[0] = -c->border.left;
 101         x[1] = 0;
 102         x[2] = output->base.current->width;
 103         x[3] = output->base.current->width + c->border.right;
 104
 105         y[0] = -c->border.top;
 106         y[1] = 0;
 107         y[2] = output->base.current->height;
 108         y[3] = output->base.current->height + c->border.bottom;
 109
 110         u[0] = 0.0;
 111         u[1] = (GLfloat) c->border.left / c->border.width;
 112         u[2] = (GLfloat) (c->border.width - c->border.right) / c->border.width;
 113         u[3] = 1.0;
 114
 115         v[0] = 0.0;
 116         v[1] = (GLfloat) c->border.top / c->border.height;
 117         v[2] = (GLfloat) (c->border.height - c->border.bottom) / c->border.height;
 118         v[3] = 1.0;
 119
 120         n = 8;
 121         d = wl_array_add(&c->base.vertices, n * 16 * sizeof *d);
 122         p = wl_array_add(&c->base.indices, n * 6 * sizeof *p);
 123
 124         k = 0;
 125         for (i = 0; i < 3; i++)
 126                 for (j = 0; j < 3; j++) {
 127
 128                         if (i == 1 && j == 1)
 129                                 continue;
 130
 131                         d[ 0] = x[i];
 132                         d[ 1] = y[j];
 133                         d[ 2] = u[i];
 134                         d[ 3] = v[j];
 135
 136                         d[ 4] = x[i];
 137                         d[ 5] = y[j + 1];
 138                         d[ 6] = u[i];
 139                         d[ 7] = v[j + 1];
 140
 141                         d[ 8] = x[i + 1];
 142                         d[ 9] = y[j];
 143                         d[10] = u[i + 1];
 144                         d[11] = v[j];
 145
 146                         d[12] = x[i + 1];
 147                         d[13] = y[j + 1];
 148                         d[14] = u[i + 1];
 149                         d[15] = v[j + 1];
 150
 151                         p[0] = k + 0;
 152                         p[1] = k + 1;
 153                         p[2] = k + 2;
 154                         p[3] = k + 2;
 155                         p[4] = k + 1;
 156                         p[5] = k + 3;
 157
 158                         d += 16;
 159                         p += 6;
 160                         k += 4;
 161                 }
 162
 163         return k / 4;
 164 }
 165
 166 static void
 167 draw_border(struct wayland_output *output)
 168 {
 169         struct wayland_compositor *c =
 170                 (struct wayland_compositor *) output->base.compositor;
 171         struct weston_shader *shader = &c->base.texture_shader;
 172         GLfloat *v;
 173         int n;
 174
 175         glDisable(GL_BLEND);
 176         glUseProgram(shader->program);
 177         c->base.current_shader = shader;
 178
 179         glUniformMatrix4fv(shader->proj_uniform,
 180                            1, GL_FALSE, output->base.matrix.d);
 181
 182         glUniform1i(shader->tex_uniform, 0);
 183         glUniform1f(shader->alpha_uniform, 1);
 184         glUniform1f(shader->texwidth_uniform, 1);
 185
 186         n = texture_border(output);
 187
 188         glBindTexture(GL_TEXTURE_2D, c->border.texture);
 189
 190         v = c->base.vertices.data;
 191         glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof *v, &v[0]);
 192         glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof *v, &v[2]);
 193         glEnableVertexAttribArray(0);
 194         glEnableVertexAttribArray(1);
 195
 196         glDrawElements(GL_TRIANGLES, n * 6,
 197                        GL_UNSIGNED_INT, c->base.indices.data);
 198
 199         glDisableVertexAttribArray(1);
 200         glDisableVertexAttribArray(0);
 201
 202         c->base.vertices.size = 0;
 203         c->base.indices.size = 0;
 204 }
 205
 206 static void
 207 create_border(struct wayland_compositor *c)
 208 {
 209         uint32_t *pixels, stride;
 210
 211         pixels = weston_load_image(DATADIR "/weston/border.png",
 212                                    &c->border.width,
 213                                    &c->border.height, &stride);
 214         if (!pixels) {
 215                 fprintf(stderr, "could'nt load border image\n");
 216                 return;
 217         }
 218
 219         glGenTextures(1, &c->border.texture);
 220         glBindTexture(GL_TEXTURE_2D, c->border.texture);
 221         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 222         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 223         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 224         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 225
 226         glTexImage2D(GL_TEXTURE_2D, 0, GL_BGRA_EXT,
 227                      c->border.width,
 228                      c->border.height,
 229                      0, GL_BGRA_EXT, GL_UNSIGNED_BYTE, pixels);
 230
 231         c->border.top = 25;
 232         c->border.bottom = 50;
 233         c->border.left = 25;
 234         c->border.right = 25;
 235 }
 236
 237 static int
 238 wayland_input_create(struct wayland_compositor *c)
 239 {
 240         struct weston_input_device *input;
 241
 242         input = malloc(sizeof *input);
 243         if (input == NULL)
 244                 return -1;
 245
 246         memset(input, 0, sizeof *input);
 247         weston_input_device_init(input, &c->base);
 248
 249         c->base.input_device = &input->input_device;
 250
 251         return 0;
 252 }
 253
 254 static int
 255 wayland_compositor_init_egl(struct wayland_compositor *c)
 256 {
 257         EGLint major, minor;
 258         EGLint n;
 259         const char *extensions;
 260         EGLint config_attribs[] = {
 261                 EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
 262                 EGL_RED_SIZE, 1,
 263                 EGL_GREEN_SIZE, 1,
 264                 EGL_BLUE_SIZE, 1,
 265                 EGL_ALPHA_SIZE, 1,
 266                 EGL_DEPTH_SIZE, 1,
 267                 EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
 268                 EGL_NONE
 269         };
 270         static const EGLint context_attribs[] = {
 271                 EGL_CONTEXT_CLIENT_VERSION, 2,
 272                 EGL_NONE
 273         };
 274
 275         c->base.display = eglGetDisplay(c->parent.display);
 276         if (c->base.display == NULL) {
 277                 fprintf(stderr, "failed to create display\n");
 278                 return -1;
 279         }
 280
 281         if (!eglInitialize(c->base.display, &major, &minor)) {
 282                 fprintf(stderr, "failed to initialize display\n");
 283                 return -1;
 284         }
 285
 286         extensions = eglQueryString(c->base.display, EGL_EXTENSIONS);
 287         if (!strstr(extensions, "EGL_KHR_surfaceless_gles2")) {
 288                 fprintf(stderr, "EGL_KHR_surfaceless_gles2 not available\n");
 289                 return -1;
 290         }
 291
 292         if (!eglBindAPI(EGL_OPENGL_ES_API)) {
 293                 fprintf(stderr, "failed to bind EGL_OPENGL_ES_API\n");
 294                 return -1;
 295         }
 296         if (!eglChooseConfig(c->base.display, config_attribs,
 297                              &c->base.config, 1, &n) || n == 0) {
 298                 fprintf(stderr, "failed to choose config: %d\n", n);
 299                 return -1;
 300         }
 301
 302         c->base.context = eglCreateContext(c->base.display, c->base.config,
 303                                            EGL_NO_CONTEXT, context_attribs);
 304         if (c->base.context == NULL) {
 305                 fprintf(stderr, "failed to create context\n");
 306                 return -1;
 307         }
 308
 309         if (!eglMakeCurrent(c->base.display, EGL_NO_SURFACE,
 310                             EGL_NO_SURFACE, c->base.context)) {
 311                 fprintf(stderr, "failed to make context current\n");
 312                 return -1;
 313         }
 314
 315         return 0;
 316 }
 317
 318 static void
 319 frame_done(void *data, struct wl_callback *callback, uint32_t time)
 320 {
 321         struct weston_output *output = data;
 322
 323         wl_callback_destroy(callback);
 324         weston_output_finish_frame(output, time);
 325 }
 326
 327 static const struct wl_callback_listener frame_listener = {
 328         frame_done
 329 };
 330
 331 static void
 332 wayland_output_repaint(struct weston_output *output_base)
 333 {
 334         struct wayland_output *output = (struct wayland_output *) output_base;
 335         struct wayland_compositor *compositor =
 336                 (struct wayland_compositor *) output->base.compositor;
 337         struct wl_callback *callback;
 338         struct weston_surface *surface;
 339
 340         if (!eglMakeCurrent(compositor->base.display, output->egl_surface,
 341                             output->egl_surface, compositor->base.context)) {
 342                 fprintf(stderr, "failed to make current\n");
 343                 return;
 344         }
 345
 346         wl_list_for_each_reverse(surface, &compositor->base.surface_list, link)
 347                 weston_surface_draw(surface, &output->base);
 348
 349         draw_border(output);
 350
 351         eglSwapBuffers(compositor->base.display, output->egl_surface);
 352         callback = wl_surface_frame(output->parent.surface);
 353         wl_callback_add_listener(callback, &frame_listener, output);
 354
 355         return;
 356 }
 357
 358 static int
 359 wayland_output_set_cursor(struct weston_output *output_base,
 360                           struct weston_input_device *input)
 361 {
 362         return -1;
 363 }
 364
 365 static void
 366 wayland_output_destroy(struct weston_output *output_base)
 367 {
 368         struct wayland_output *output = (struct wayland_output *) output_base;
 369         struct weston_compositor *ec = output->base.compositor;
 370
 371         eglDestroySurface(ec->display, output->egl_surface);
 372         wl_egl_window_destroy(output->parent.egl_window);
 373         free(output);
 374
 375         return;
 376 }
 377
 378 static int
 379 wayland_compositor_create_output(struct wayland_compositor *c,
 380                                  int width, int height)
 381 {
 382         struct wayland_output *output;
 383
 384         output = malloc(sizeof *output);
 385         if (output == NULL)
 386                 return -1;
 387         memset(output, 0, sizeof *output);
 388
 389         output->mode.flags =
 390                 WL_OUTPUT_MODE_CURRENT | WL_OUTPUT_MODE_PREFERRED;
 391         output->mode.width = width;
 392         output->mode.height = height;
 393         output->mode.refresh = 60;
 394         wl_list_init(&output->base.mode_list);
 395         wl_list_insert(&output->base.mode_list, &output->mode.link);
 396
 397         output->base.current = &output->mode;
 398         weston_output_init(&output->base, &c->base, 0, 0, width, height,
 399                          WL_OUTPUT_FLIPPED);
 400
 401         output->base.border.top = c->border.top;
 402         output->base.border.bottom = c->border.bottom;
 403         output->base.border.left = c->border.left;
 404         output->base.border.right = c->border.right;
 405
 406         weston_output_move(&output->base, 0, 0);
 407
 408         output->parent.surface =
 409                 wl_compositor_create_surface(c->parent.compositor);
 410         wl_surface_set_user_data(output->parent.surface, output);
 411
 412         output->parent.egl_window =
 413                 wl_egl_window_create(output->parent.surface,
 414                                      width + c->border.left + c->border.right,
 415                                      height + c->border.top + c->border.bottom);
 416         if (!output->parent.egl_window) {
 417                 fprintf(stderr, "failure to create wl_egl_window\n");
 418                 goto cleanup_output;
 419         }
 420
 421         output->egl_surface =
 422                 eglCreateWindowSurface(c->base.display, c->base.config,
 423                                        output->parent.egl_window, NULL);
 424         if (!output->egl_surface) {
 425                 fprintf(stderr, "failed to create window surface\n");
 426                 goto cleanup_window;
 427         }
 428
 429         if (!eglMakeCurrent(c->base.display, output->egl_surface,
 430                             output->egl_surface, c->base.context)) {
 431                 fprintf(stderr, "failed to make surface current\n");
 432                 goto cleanup_surface;
 433                 return -1;
 434         }
 435
 436         output->parent.shell_surface =
 437                 wl_shell_get_shell_surface(c->parent.shell,
 438                                            output->parent.surface);
 439         /* FIXME: add shell_surface listener for resizing */
 440         wl_shell_surface_set_toplevel(output->parent.shell_surface);
 441
 442         output->base.repaint = wayland_output_repaint;
 443         output->base.set_hardware_cursor = wayland_output_set_cursor;
 444         output->base.destroy = wayland_output_destroy;
 445
 446         wl_list_insert(c->base.output_list.prev, &output->base.link);
 447
 448         return 0;
 449
 450 cleanup_surface:
 451         eglDestroySurface(c->base.display, output->egl_surface);
 452 cleanup_window:
 453         wl_egl_window_destroy(output->parent.egl_window);
 454 cleanup_output:
 455         /* FIXME: cleanup weston_output */
 456         free(output);
 457
 458         return -1;
 459 }
 460
 461 /* Events received from the wayland-server this compositor is client of: */
 462
 463 /* parent output interface */
 464 static void
 465 display_handle_geometry(void *data,
 466                         struct wl_output *wl_output,
 467                         int x,
 468                         int y,
 469                         int physical_width,
 470                         int physical_height,
 471                         int subpixel,
 472                         const char *make,
 473                         const char *model)
 474 {
 475         struct wayland_compositor *c = data;
 476
 477         c->parent.screen_allocation.x = x;
 478         c->parent.screen_allocation.y = y;
 479 }
 480
 481 static void
 482 display_handle_mode(void *data,
 483                     struct wl_output *wl_output,
 484                     uint32_t flags,
 485                     int width,
 486                     int height,
 487                     int refresh)
 488 {
 489         struct wayland_compositor *c = data;
 490
 491         c->parent.screen_allocation.width = width;
 492         c->parent.screen_allocation.height = height;
 493 }
 494
 495 static const struct wl_output_listener output_listener = {
 496         display_handle_geometry,
 497         display_handle_mode
 498 };
 499
 500 /* parent input interface */
 501 static void
 502 input_handle_motion(void *data, struct wl_input_device *input_device,
 503                     uint32_t time, int32_t sx, int32_t sy)
 504 {
 505         struct wayland_input *input = data;
 506         struct wayland_compositor *c = input->compositor;
 507
 508         notify_motion(c->base.input_device, time,
 509                       sx - c->border.left, sy - c->border.top);
 510 }
 511
 512 static void
 513 input_handle_button(void *data,
 514                      struct wl_input_device *input_device,
 515                      uint32_t time, uint32_t button, uint32_t state)
 516 {
 517         struct wayland_input *input = data;
 518         struct wayland_compositor *c = input->compositor;
 519
 520         notify_button(c->base.input_device, time, button, state);
 521 }
 522
 523 static void
 524 input_handle_key(void *data, struct wl_input_device *input_device,
 525                   uint32_t time, uint32_t key, uint32_t state)
 526 {
 527         struct wayland_input *input = data;
 528         struct wayland_compositor *c = input->compositor;
 529
 530         notify_key(c->base.input_device, time, key, state);
 531 }
 532
 533 static void
 534 input_handle_pointer_focus(void *data,
 535                            struct wl_input_device *input_device,
 536                            uint32_t time, struct wl_surface *surface,
 537                            int32_t sx, int32_t sy)
 538 {
 539         struct wayland_input *input = data;
 540         struct wayland_output *output;
 541         struct wayland_compositor *c = input->compositor;
 542
 543         if (surface) {
 544                 output = wl_surface_get_user_data(surface);
 545                 notify_pointer_focus(c->base.input_device,
 546                                      time, &output->base, sx, sy);
 547
 548                 wl_input_device_attach(input->input_device, time, NULL, 0, 0);
 549         } else {
 550                 notify_pointer_focus(c->base.input_device, time, NULL, 0, 0);
 551         }
 552 }
 553
 554 static void
 555 input_handle_keyboard_focus(void *data,
 556                              struct wl_input_device *input_device,
 557                              uint32_t time,
 558                              struct wl_surface *surface,
 559                              struct wl_array *keys)
 560 {
 561         struct wayland_input *input = data;
 562         struct wayland_compositor *c = input->compositor;
 563         struct wayland_output *output;
 564
 565         if (surface) {
 566                 output = wl_surface_get_user_data(surface);
 567                 notify_keyboard_focus(c->base.input_device,
 568                                       time, &output->base, keys);
 569         } else {
 570                 notify_keyboard_focus(c->base.input_device, time, NULL, NULL);
 571         }
 572 }
 573
 574 static const struct wl_input_device_listener input_device_listener = {
 575         input_handle_motion,
 576         input_handle_button,
 577         input_handle_key,
 578         input_handle_pointer_focus,
 579         input_handle_keyboard_focus,
 580 };
 581
 582 static void
 583 display_add_input(struct wayland_compositor *c, uint32_t id)
 584 {
 585         struct wayland_input *input;
 586
 587         input = malloc(sizeof *input);
 588         if (input == NULL)
 589                 return;
 590
 591         memset(input, 0, sizeof *input);
 592
 593         input->compositor = c;
 594         input->input_device = wl_display_bind(c->parent.display,
 595                                               id, &wl_input_device_interface);
 596         wl_list_insert(c->input_list.prev, &input->link);
 597
 598         wl_input_device_add_listener(input->input_device,
 599                                      &input_device_listener, input);
 600         wl_input_device_set_user_data(input->input_device, input);
 601 }
 602
 603 static void
 604 display_handle_global(struct wl_display *display, uint32_t id,
 605                       const char *interface, uint32_t version, void *data)
 606 {
 607         struct wayland_compositor *c = data;
 608
 609         if (strcmp(interface, "wl_compositor") == 0) {
 610                 c->parent.compositor =
 611                         wl_display_bind(display, id, &wl_compositor_interface);
 612         } else if (strcmp(interface, "wl_output") == 0) {
 613                 c->parent.output =
 614                         wl_display_bind(display, id, &wl_output_interface);
 615                 wl_output_add_listener(c->parent.output, &output_listener, c);
 616         } else if (strcmp(interface, "wl_input_device") == 0) {
 617                 display_add_input(c, id);
 618         } else if (strcmp(interface, "wl_shell") == 0) {
 619                 c->parent.shell =
 620                         wl_display_bind(display, id, &wl_shell_interface);
 621         }
 622 }
 623
 624 static int
 625 update_event_mask(uint32_t mask, void *data)
 626 {
 627         struct wayland_compositor *c = data;
 628
 629         c->parent.event_mask = mask;
 630         if (c->parent.wl_source)
 631                 wl_event_source_fd_update(c->parent.wl_source, mask);
 632
 633         return 0;
 634 }
 635
 636 static int
 637 wayland_compositor_handle_event(int fd, uint32_t mask, void *data)
 638 {
 639         struct wayland_compositor *c = data;
 640
 641         if (mask & WL_EVENT_READABLE)
 642                 wl_display_iterate(c->parent.display, WL_DISPLAY_READABLE);
 643         if (mask & WL_EVENT_WRITABLE)
 644                 wl_display_iterate(c->parent.display, WL_DISPLAY_WRITABLE);
 645
 646         return 1;
 647 }
 648
 649 static void
 650 wayland_destroy(struct weston_compositor *ec)
 651 {
 652         weston_compositor_shutdown(ec);
 653
 654         free(ec);
 655 }
 656
 657 static struct weston_compositor *
 658 wayland_compositor_create(struct wl_display *display,
 659                           int width, int height, const char *display_name)
 660 {
 661         struct wayland_compositor *c;
 662         struct wl_event_loop *loop;
 663         int fd;
 664
 665         c = malloc(sizeof *c);
 666         if (c == NULL)
 667                 return NULL;
 668
 669         memset(c, 0, sizeof *c);
 670
 671         c->parent.display = wl_display_connect(display_name);
 672
 673         if (c->parent.display == NULL) {
 674                 fprintf(stderr, "failed to create display: %m\n");
 675                 return NULL;
 676         }
 677
 678         wl_list_init(&c->input_list);
 679         wl_display_add_global_listener(c->parent.display,
 680                                 display_handle_global, c);
 681
 682         wl_display_iterate(c->parent.display, WL_DISPLAY_READABLE);
 683
 684         c->base.wl_display = display;
 685         if (wayland_compositor_init_egl(c) < 0)
 686                 return NULL;
 687
 688         c->base.destroy = wayland_destroy;
 689
 690         /* Can't init base class until we have a current egl context */
 691         if (weston_compositor_init(&c->base, display) < 0)
 692                 return NULL;
 693
 694         create_border(c);
 695         if (wayland_compositor_create_output(c, width, height) < 0)
 696                 return NULL;
 697
 698         if (wayland_input_create(c) < 0)
 699                 return NULL;
 700
 701         loop = wl_display_get_event_loop(c->base.wl_display);
 702
 703         fd = wl_display_get_fd(c->parent.display, update_event_mask, c);
 704         c->parent.wl_source =
 705                 wl_event_loop_add_fd(loop, fd, c->parent.event_mask,
 706                                      wayland_compositor_handle_event, c);
 707         if (c->parent.wl_source == NULL)
 708                 return NULL;
 709
 710         return &c->base;
 711 }
 712
 713 struct weston_compositor *
 714 backend_init(struct wl_display *display, char *options);
 715
 716 WL_EXPORT struct weston_compositor *
 717 backend_init(struct wl_display *display, char *options)
 718 {
 719         int width = 1024, height = 640, i;
 720         char *p, *value, *display_name = NULL;
 721
 722         static char * const tokens[] = { "width", "height", "display", NULL };
 723
 724         p = options;
 725         while (i = getsubopt(&p, tokens, &value), i != -1) {
 726                 switch (i) {
 727                 case 0:
 728                         width = strtol(value, NULL, 0);
 729                         break;
 730                 case 1:
 731                         height = strtol(value, NULL, 0);
 732                         break;
 733                 case 2:
 734                         display_name = strdup(value);
 735                         break;
 736                 }
 737         }
 738
 739         return wayland_compositor_create(display, width, height, display_name);
 740 }