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         c->base.current_alpha = 255;
 185         glUniform1f(shader->texwidth_uniform, 1);
 186
 187         n = texture_border(output);
 188
 189         glBindTexture(GL_TEXTURE_2D, c->border.texture);
 190
 191         v = c->base.vertices.data;
 192         glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof *v, &v[0]);
 193         glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof *v, &v[2]);
 194         glEnableVertexAttribArray(0);
 195         glEnableVertexAttribArray(1);
 196
 197         glDrawElements(GL_TRIANGLES, n * 6,
 198                        GL_UNSIGNED_INT, c->base.indices.data);
 199
 200         glDisableVertexAttribArray(1);
 201         glDisableVertexAttribArray(0);
 202
 203         c->base.vertices.size = 0;
 204         c->base.indices.size = 0;
 205 }
 206
 207 static void
 208 create_border(struct wayland_compositor *c)
 209 {
 210         uint32_t *pixels, stride;
 211
 212         pixels = weston_load_image(DATADIR "/weston/border.png",
 213                                    &c->border.width,
 214                                    &c->border.height, &stride);
 215         if (!pixels) {
 216                 fprintf(stderr, "could'nt load border image\n");
 217                 return;
 218         }
 219
 220         glGenTextures(1, &c->border.texture);
 221         glBindTexture(GL_TEXTURE_2D, c->border.texture);
 222         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 223         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 224         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 225         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 226
 227         glTexImage2D(GL_TEXTURE_2D, 0, GL_BGRA_EXT,
 228                      c->border.width,
 229                      c->border.height,
 230                      0, GL_BGRA_EXT, GL_UNSIGNED_BYTE, pixels);
 231
 232         c->border.top = 25;
 233         c->border.bottom = 50;
 234         c->border.left = 25;
 235         c->border.right = 25;
 236 }
 237
 238 static int
 239 wayland_input_create(struct wayland_compositor *c)
 240 {
 241         struct weston_input_device *input;
 242
 243         input = malloc(sizeof *input);
 244         if (input == NULL)
 245                 return -1;
 246
 247         memset(input, 0, sizeof *input);
 248         weston_input_device_init(input, &c->base);
 249
 250         c->base.input_device = &input->input_device;
 251
 252         return 0;
 253 }
 254
 255 static int
 256 wayland_compositor_init_egl(struct wayland_compositor *c)
 257 {
 258         EGLint major, minor;
 259         EGLint n;
 260         const char *extensions;
 261         EGLint config_attribs[] = {
 262                 EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
 263                 EGL_RED_SIZE, 1,
 264                 EGL_GREEN_SIZE, 1,
 265                 EGL_BLUE_SIZE, 1,
 266                 EGL_ALPHA_SIZE, 1,
 267                 EGL_DEPTH_SIZE, 1,
 268                 EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
 269                 EGL_NONE
 270         };
 271         static const EGLint context_attribs[] = {
 272                 EGL_CONTEXT_CLIENT_VERSION, 2,
 273                 EGL_NONE
 274         };
 275
 276         c->base.display = eglGetDisplay(c->parent.display);
 277         if (c->base.display == NULL) {
 278                 fprintf(stderr, "failed to create display\n");
 279                 return -1;
 280         }
 281
 282         if (!eglInitialize(c->base.display, &major, &minor)) {
 283                 fprintf(stderr, "failed to initialize display\n");
 284                 return -1;
 285         }
 286
 287         extensions = eglQueryString(c->base.display, EGL_EXTENSIONS);
 288         if (!strstr(extensions, "EGL_KHR_surfaceless_gles2")) {
 289                 fprintf(stderr, "EGL_KHR_surfaceless_gles2 not available\n");
 290                 return -1;
 291         }
 292
 293         if (!eglBindAPI(EGL_OPENGL_ES_API)) {
 294                 fprintf(stderr, "failed to bind EGL_OPENGL_ES_API\n");
 295                 return -1;
 296         }
 297         if (!eglChooseConfig(c->base.display, config_attribs,
 298                              &c->base.config, 1, &n) || n == 0) {
 299                 fprintf(stderr, "failed to choose config: %d\n", n);
 300                 return -1;
 301         }
 302
 303         c->base.context = eglCreateContext(c->base.display, c->base.config,
 304                                            EGL_NO_CONTEXT, context_attribs);
 305         if (c->base.context == NULL) {
 306                 fprintf(stderr, "failed to create context\n");
 307                 return -1;
 308         }
 309
 310         if (!eglMakeCurrent(c->base.display, EGL_NO_SURFACE,
 311                             EGL_NO_SURFACE, c->base.context)) {
 312                 fprintf(stderr, "failed to make context current\n");
 313                 return -1;
 314         }
 315
 316         return 0;
 317 }
 318
 319 static void
 320 frame_done(void *data, struct wl_callback *callback, uint32_t time)
 321 {
 322         struct weston_output *output = data;
 323
 324         wl_callback_destroy(callback);
 325         weston_output_finish_frame(output, time);
 326 }
 327
 328 static const struct wl_callback_listener frame_listener = {
 329         frame_done
 330 };
 331
 332 static void
 333 wayland_output_repaint(struct weston_output *output_base)
 334 {
 335         struct wayland_output *output = (struct wayland_output *) output_base;
 336         struct wayland_compositor *compositor =
 337                 (struct wayland_compositor *) output->base.compositor;
 338         struct wl_callback *callback;
 339         struct weston_surface *surface;
 340
 341         if (!eglMakeCurrent(compositor->base.display, output->egl_surface,
 342                             output->egl_surface, compositor->base.context)) {
 343                 fprintf(stderr, "failed to make current\n");
 344                 return;
 345         }
 346
 347         wl_list_for_each_reverse(surface, &compositor->base.surface_list, link)
 348                 weston_surface_draw(surface, &output->base);
 349
 350         draw_border(output);
 351
 352         eglSwapBuffers(compositor->base.display, output->egl_surface);
 353         callback = wl_surface_frame(output->parent.surface);
 354         wl_callback_add_listener(callback, &frame_listener, output);
 355
 356         return;
 357 }
 358
 359 static int
 360 wayland_output_set_cursor(struct weston_output *output_base,
 361                           struct weston_input_device *input)
 362 {
 363         return -1;
 364 }
 365
 366 static void
 367 wayland_output_destroy(struct weston_output *output_base)
 368 {
 369         struct wayland_output *output = (struct wayland_output *) output_base;
 370         struct weston_compositor *ec = output->base.compositor;
 371
 372         eglDestroySurface(ec->display, output->egl_surface);
 373         wl_egl_window_destroy(output->parent.egl_window);
 374         free(output);
 375
 376         return;
 377 }
 378
 379 static int
 380 wayland_compositor_create_output(struct wayland_compositor *c,
 381                                  int width, int height)
 382 {
 383         struct wayland_output *output;
 384
 385         output = malloc(sizeof *output);
 386         if (output == NULL)
 387                 return -1;
 388         memset(output, 0, sizeof *output);
 389
 390         output->mode.flags =
 391                 WL_OUTPUT_MODE_CURRENT | WL_OUTPUT_MODE_PREFERRED;
 392         output->mode.width = width;
 393         output->mode.height = height;
 394         output->mode.refresh = 60;
 395         wl_list_init(&output->base.mode_list);
 396         wl_list_insert(&output->base.mode_list, &output->mode.link);
 397
 398         output->base.current = &output->mode;
 399         weston_output_init(&output->base, &c->base, 0, 0, width, height,
 400                          WL_OUTPUT_FLIPPED);
 401
 402         output->base.border.top = c->border.top;
 403         output->base.border.bottom = c->border.bottom;
 404         output->base.border.left = c->border.left;
 405         output->base.border.right = c->border.right;
 406
 407         weston_output_move(&output->base, 0, 0);
 408
 409         output->parent.surface =
 410                 wl_compositor_create_surface(c->parent.compositor);
 411         wl_surface_set_user_data(output->parent.surface, output);
 412
 413         output->parent.egl_window =
 414                 wl_egl_window_create(output->parent.surface,
 415                                      width + c->border.left + c->border.right,
 416                                      height + c->border.top + c->border.bottom);
 417         if (!output->parent.egl_window) {
 418                 fprintf(stderr, "failure to create wl_egl_window\n");
 419                 goto cleanup_output;
 420         }
 421
 422         output->egl_surface =
 423                 eglCreateWindowSurface(c->base.display, c->base.config,
 424                                        output->parent.egl_window, NULL);
 425         if (!output->egl_surface) {
 426                 fprintf(stderr, "failed to create window surface\n");
 427                 goto cleanup_window;
 428         }
 429
 430         if (!eglMakeCurrent(c->base.display, output->egl_surface,
 431                             output->egl_surface, c->base.context)) {
 432                 fprintf(stderr, "failed to make surface current\n");
 433                 goto cleanup_surface;
 434                 return -1;
 435         }
 436
 437         output->parent.shell_surface =
 438                 wl_shell_get_shell_surface(c->parent.shell,
 439                                            output->parent.surface);
 440         /* FIXME: add shell_surface listener for resizing */
 441         wl_shell_surface_set_toplevel(output->parent.shell_surface);
 442
 443         output->base.repaint = wayland_output_repaint;
 444         output->base.set_hardware_cursor = wayland_output_set_cursor;
 445         output->base.destroy = wayland_output_destroy;
 446
 447         wl_list_insert(c->base.output_list.prev, &output->base.link);
 448
 449         return 0;
 450
 451 cleanup_surface:
 452         eglDestroySurface(c->base.display, output->egl_surface);
 453 cleanup_window:
 454         wl_egl_window_destroy(output->parent.egl_window);
 455 cleanup_output:
 456         /* FIXME: cleanup weston_output */
 457         free(output);
 458
 459         return -1;
 460 }
 461
 462 /* Events received from the wayland-server this compositor is client of: */
 463
 464 /* parent output interface */
 465 static void
 466 display_handle_geometry(void *data,
 467                         struct wl_output *wl_output,
 468                         int x,
 469                         int y,
 470                         int physical_width,
 471                         int physical_height,
 472                         int subpixel,
 473                         const char *make,
 474                         const char *model)
 475 {
 476         struct wayland_compositor *c = data;
 477
 478         c->parent.screen_allocation.x = x;
 479         c->parent.screen_allocation.y = y;
 480 }
 481
 482 static void
 483 display_handle_mode(void *data,
 484                     struct wl_output *wl_output,
 485                     uint32_t flags,
 486                     int width,
 487                     int height,
 488                     int refresh)
 489 {
 490         struct wayland_compositor *c = data;
 491
 492         c->parent.screen_allocation.width = width;
 493         c->parent.screen_allocation.height = height;
 494 }
 495
 496 static const struct wl_output_listener output_listener = {
 497         display_handle_geometry,
 498         display_handle_mode
 499 };
 500
 501 /* parent input interface */
 502 static void
 503 input_handle_motion(void *data, struct wl_input_device *input_device,
 504                      uint32_t time,
 505                      int32_t x, int32_t y, int32_t sx, int32_t sy)
 506 {
 507         struct wayland_input *input = data;
 508         struct wayland_compositor *c = input->compositor;
 509
 510         notify_motion(c->base.input_device, time,
 511                       sx - c->border.left, sy - c->border.top);
 512 }
 513
 514 static void
 515 input_handle_button(void *data,
 516                      struct wl_input_device *input_device,
 517                      uint32_t time, uint32_t button, uint32_t state)
 518 {
 519         struct wayland_input *input = data;
 520         struct wayland_compositor *c = input->compositor;
 521
 522         notify_button(c->base.input_device, time, button, state);
 523 }
 524
 525 static void
 526 input_handle_key(void *data, struct wl_input_device *input_device,
 527                   uint32_t time, uint32_t key, uint32_t state)
 528 {
 529         struct wayland_input *input = data;
 530         struct wayland_compositor *c = input->compositor;
 531
 532         notify_key(c->base.input_device, time, key, state);
 533 }
 534
 535 static void
 536 input_handle_pointer_focus(void *data,
 537                             struct wl_input_device *input_device,
 538                             uint32_t time, struct wl_surface *surface,
 539                             int32_t x, int32_t y, int32_t sx, int32_t sy)
 540 {
 541         struct wayland_input *input = data;
 542         struct wayland_output *output;
 543         struct wayland_compositor *c = input->compositor;
 544
 545         if (surface) {
 546                 output = wl_surface_get_user_data(surface);
 547                 notify_pointer_focus(c->base.input_device,
 548                                      time, &output->base, sx, sy);
 549
 550                 wl_input_device_attach(input->input_device, time, NULL, 0, 0);
 551         } else {
 552                 notify_pointer_focus(c->base.input_device, time, NULL, 0, 0);
 553         }
 554 }
 555
 556 static void
 557 input_handle_keyboard_focus(void *data,
 558                              struct wl_input_device *input_device,
 559                              uint32_t time,
 560                              struct wl_surface *surface,
 561                              struct wl_array *keys)
 562 {
 563         struct wayland_input *input = data;
 564         struct wayland_compositor *c = input->compositor;
 565         struct wayland_output *output;
 566
 567         if (surface) {
 568                 output = wl_surface_get_user_data(surface);
 569                 notify_keyboard_focus(c->base.input_device,
 570                                       time, &output->base, keys);
 571         } else {
 572                 notify_keyboard_focus(c->base.input_device, time, NULL, NULL);
 573         }
 574 }
 575
 576 static const struct wl_input_device_listener input_device_listener = {
 577         input_handle_motion,
 578         input_handle_button,
 579         input_handle_key,
 580         input_handle_pointer_focus,
 581         input_handle_keyboard_focus,
 582 };
 583
 584 static void
 585 display_add_input(struct wayland_compositor *c, uint32_t id)
 586 {
 587         struct wayland_input *input;
 588
 589         input = malloc(sizeof *input);
 590         if (input == NULL)
 591                 return;
 592
 593         memset(input, 0, sizeof *input);
 594
 595         input->compositor = c;
 596         input->input_device = wl_display_bind(c->parent.display,
 597                                               id, &wl_input_device_interface);
 598         wl_list_insert(c->input_list.prev, &input->link);
 599
 600         wl_input_device_add_listener(input->input_device,
 601                                      &input_device_listener, input);
 602         wl_input_device_set_user_data(input->input_device, input);
 603 }
 604
 605 static void
 606 display_handle_global(struct wl_display *display, uint32_t id,
 607                       const char *interface, uint32_t version, void *data)
 608 {
 609         struct wayland_compositor *c = data;
 610
 611         if (strcmp(interface, "wl_compositor") == 0) {
 612                 c->parent.compositor =
 613                         wl_display_bind(display, id, &wl_compositor_interface);
 614         } else if (strcmp(interface, "wl_output") == 0) {
 615                 c->parent.output =
 616                         wl_display_bind(display, id, &wl_output_interface);
 617                 wl_output_add_listener(c->parent.output, &output_listener, c);
 618         } else if (strcmp(interface, "wl_input_device") == 0) {
 619                 display_add_input(c, id);
 620         } else if (strcmp(interface, "wl_shell") == 0) {
 621                 c->parent.shell =
 622                         wl_display_bind(display, id, &wl_shell_interface);
 623         }
 624 }
 625
 626 static int
 627 update_event_mask(uint32_t mask, void *data)
 628 {
 629         struct wayland_compositor *c = data;
 630
 631         c->parent.event_mask = mask;
 632         if (c->parent.wl_source)
 633                 wl_event_source_fd_update(c->parent.wl_source, mask);
 634
 635         return 0;
 636 }
 637
 638 static int
 639 wayland_compositor_handle_event(int fd, uint32_t mask, void *data)
 640 {
 641         struct wayland_compositor *c = data;
 642
 643         if (mask & WL_EVENT_READABLE)
 644                 wl_display_iterate(c->parent.display, WL_DISPLAY_READABLE);
 645         if (mask & WL_EVENT_WRITABLE)
 646                 wl_display_iterate(c->parent.display, WL_DISPLAY_WRITABLE);
 647
 648         return 1;
 649 }
 650
 651 static void
 652 wayland_destroy(struct weston_compositor *ec)
 653 {
 654         weston_compositor_shutdown(ec);
 655
 656         free(ec);
 657 }
 658
 659 static struct weston_compositor *
 660 wayland_compositor_create(struct wl_display *display,
 661                           int width, int height, const char *display_name)
 662 {
 663         struct wayland_compositor *c;
 664         struct wl_event_loop *loop;
 665         int fd;
 666
 667         c = malloc(sizeof *c);
 668         if (c == NULL)
 669                 return NULL;
 670
 671         memset(c, 0, sizeof *c);
 672
 673         c->parent.display = wl_display_connect(display_name);
 674
 675         if (c->parent.display == NULL) {
 676                 fprintf(stderr, "failed to create display: %m\n");
 677                 return NULL;
 678         }
 679
 680         wl_list_init(&c->input_list);
 681         wl_display_add_global_listener(c->parent.display,
 682                                 display_handle_global, c);
 683
 684         wl_display_iterate(c->parent.display, WL_DISPLAY_READABLE);
 685
 686         c->base.wl_display = display;
 687         if (wayland_compositor_init_egl(c) < 0)
 688                 return NULL;
 689
 690         c->base.destroy = wayland_destroy;
 691
 692         /* Can't init base class until we have a current egl context */
 693         if (weston_compositor_init(&c->base, display) < 0)
 694                 return NULL;
 695
 696         create_border(c);
 697         if (wayland_compositor_create_output(c, width, height) < 0)
 698                 return NULL;
 699
 700         if (wayland_input_create(c) < 0)
 701                 return NULL;
 702
 703         loop = wl_display_get_event_loop(c->base.wl_display);
 704
 705         fd = wl_display_get_fd(c->parent.display, update_event_mask, c);
 706         c->parent.wl_source =
 707                 wl_event_loop_add_fd(loop, fd, c->parent.event_mask,
 708                                      wayland_compositor_handle_event, c);
 709         if (c->parent.wl_source == NULL)
 710                 return NULL;
 711
 712         return &c->base;
 713 }
 714
 715 struct weston_compositor *
 716 backend_init(struct wl_display *display, char *options);
 717
 718 WL_EXPORT struct weston_compositor *
 719 backend_init(struct wl_display *display, char *options)
 720 {
 721         int width = 1024, height = 640, i;
 722         char *p, *value, *display_name = NULL;
 723
 724         static char * const tokens[] = { "width", "height", "display", NULL };
 725
 726         p = options;
 727         while (i = getsubopt(&p, tokens, &value), i != -1) {
 728                 switch (i) {
 729                 case 0:
 730                         width = strtol(value, NULL, 0);
 731                         break;
 732                 case 1:
 733                         height = strtol(value, NULL, 0);
 734                         break;
 735                 case 2:
 736                         display_name = strdup(value);
 737                         break;
 738                 }
 739         }
 740
 741         return wayland_compositor_create(display, width, height, display_name);
 742 }