xserver-multidpi/hw/xwayland/xwayland-screen.c

/*
 * Copyright © 2011-2014 Intel Corporation
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without
 * fee, provided that the above copyright notice appear in all copies
 * and that both that copyright notice and this permission notice
 * appear in supporting documentation, and that the name of the
 * copyright holders not be used in advertising or publicity
 * pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied
 * warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
 * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

#include <xwayland-config.h>

#include <stdio.h>
#include <unistd.h>
#include <errno.h>

#ifdef XWL_HAS_GLAMOR
#include <glamor.h>
#endif

#include <X11/Xatom.h>
#include <micmap.h>
#include <misyncshm.h>
#include <os.h>
#include <fb.h>
#include <dixstruct.h>
#include <propertyst.h>
#include <inputstr.h>
#include <xserver_poll.h>

#include "xwayland-cursor.h"
#include "xwayland-screen.h"
#include "xwayland-window.h"
#include "xwayland-input.h"
#include "xwayland-output.h"
#include "xwayland-pixmap.h"
#include "xwayland-present.h"
#include "xwayland-shm.h"
#include "xwayland-window-buffers.h"

#ifdef MITSHM
#include "shmint.h"
#endif

#include "xdg-output-unstable-v1-client-protocol.h"
#include "viewporter-client-protocol.h"
#include "xdg-shell-client-protocol.h"

static DevPrivateKeyRec xwl_screen_private_key;
static DevPrivateKeyRec xwl_client_private_key;

#define DEFAULT_DPI 96

_X_NORETURN
static void _X_ATTRIBUTE_PRINTF(1, 2)
xwl_give_up(const char *f, ...)
{
    va_list args;

    va_start(args, f);
    VErrorFSigSafe(f, args);
    va_end(args);

    CloseWellKnownConnections();
    OsCleanup(TRUE);
    fflush(stderr);
    exit(1);
}

struct xwl_client *
xwl_client_get(ClientPtr client)
{
    return dixLookupPrivate(&client->devPrivates, &xwl_client_private_key);
}

struct xwl_screen *
xwl_screen_get(ScreenPtr screen)
{
    return dixLookupPrivate(&screen->devPrivates, &xwl_screen_private_key);
}

Bool
xwl_screen_has_viewport_support(struct xwl_screen *xwl_screen)
{
    return wl_compositor_get_version(xwl_screen->compositor) >=
                            WL_SURFACE_DAMAGE_BUFFER_SINCE_VERSION &&
           xwl_screen->viewporter != NULL;
}

Bool
xwl_screen_has_resolution_change_emulation(struct xwl_screen *xwl_screen)
{
    /* Resolution change emulation is only supported in rootless mode and
     * it requires viewport support.
     */
    return xwl_screen->rootless && xwl_screen_has_viewport_support(xwl_screen);
}

int
xwl_scale_to(struct xwl_screen *xwl_screen, int value)
{
    return value / (double)xwl_screen->global_output_scale + 0.5;
}

/* Return the output @ 0x0, falling back to the first output in the list */
struct xwl_output *
xwl_screen_get_first_output(struct xwl_screen *xwl_screen)
{
    struct xwl_output *xwl_output;

    xorg_list_for_each_entry(xwl_output, &xwl_screen->output_list, link) {
        if (xwl_output->x == 0 && xwl_output->y == 0)
            return xwl_output;
    }

    if (xorg_list_is_empty(&xwl_screen->output_list))
        return NULL;

    return xorg_list_first_entry(&xwl_screen->output_list, struct xwl_output, link);
}

static void
xwl_screen_set_global_scale_from_property(struct xwl_screen *screen,
                                          PropertyPtr prop)
{
    CARD32 *propdata;

    if (prop->type != XA_CARDINAL || prop->format != 32 || prop->size != 1) {
        // TODO: handle warnings more cleanly.
        LogMessageVerb(X_WARNING, 0, "Bad value for property %s.\n",
                        NameForAtom(prop->propertyName));
        return;
    }

    propdata = prop->data;
    xwl_screen_set_global_scale(screen, propdata[0]);
}

static void
xwl_screen_update_property(struct xwl_screen *screen,
                           PropertyStateRec *propstate)
{
    switch (propstate->state) {
    case PropertyNewValue:
        xwl_screen_set_global_scale_from_property(screen, propstate->prop);
        break;
    case PropertyDelete:
        xwl_screen_set_global_scale(screen, 1);
        break;
    }
}

static void
xwl_property_callback(CallbackListPtr *pcbl, void *closure,
                      void *calldata)
{
    ScreenPtr screen = closure;
    PropertyStateRec *rec = calldata;
    struct xwl_screen *xwl_screen;

    if (rec->win->drawable.pScreen != screen)
        return;

    xwl_screen = xwl_screen_get(screen);

    if (rec->prop->propertyName == xwl_screen->allow_commits_prop) {
        struct xwl_window *xwl_window;

        xwl_window = xwl_window_get(rec->win);
        if (!xwl_window)
            return;

        xwl_window_update_property(xwl_window, rec);
    }
    else if (rec->prop->propertyName == xwl_screen->global_output_scale_prop) {
        xwl_screen_update_property(xwl_screen, rec);
    }
}

Bool
xwl_close_screen(ScreenPtr screen)
{
    struct xwl_screen *xwl_screen = xwl_screen_get(screen);
    struct xwl_output *xwl_output, *next_xwl_output;
    struct xwl_seat *xwl_seat, *next_xwl_seat;

    DeleteCallback(&PropertyStateCallback, xwl_property_callback, screen);

    xorg_list_for_each_entry_safe(xwl_output, next_xwl_output,
                                  &xwl_screen->output_list, link)
        xwl_output_destroy(xwl_output);

    xorg_list_for_each_entry_safe(xwl_seat, next_xwl_seat,
                                  &xwl_screen->seat_list, link)
        xwl_seat_destroy(xwl_seat);

    xwl_screen_release_tablet_manager(xwl_screen);

    RemoveNotifyFd(xwl_screen->wayland_fd);

    wl_display_disconnect(xwl_screen->display);

    screen->CloseScreen = xwl_screen->CloseScreen;
    free(xwl_screen);

    return screen->CloseScreen(screen);
}

static struct xwl_seat *
xwl_screen_get_default_seat(struct xwl_screen *xwl_screen)
{
    if (xorg_list_is_empty(&xwl_screen->seat_list))
        return NULL;

    return container_of(xwl_screen->seat_list.prev,
                        struct xwl_seat,
                        link);
}

static void
xwl_cursor_warped_to(DeviceIntPtr device,
                     ScreenPtr screen,
                     ClientPtr client,
                     WindowPtr window,
                     SpritePtr sprite,
                     int x, int y)
{
    struct xwl_screen *xwl_screen = xwl_screen_get(screen);
    struct xwl_seat *xwl_seat = device->public.devicePrivate;
    struct xwl_window *xwl_window;
    WindowPtr focus;

    if (!xwl_seat)
        xwl_seat = xwl_screen_get_default_seat(xwl_screen);

    if (!window)
        window = XYToWindow(sprite, x, y);

    xwl_window = xwl_window_from_window(window);
    if (!xwl_window && xwl_seat->focus_window) {
        focus = xwl_seat->focus_window->window;

        /* Warps on non wl_surface backed Windows are only allowed
         * as long as the pointer stays within the focus window.
         */
        if (x >= focus->drawable.x &&
            y >= focus->drawable.y &&
            x < focus->drawable.x + focus->drawable.width &&
            y < focus->drawable.y + focus->drawable.height) {
            if (!window) {
                DebugF("Warp relative to pointer, assuming pointer focus\n");
                xwl_window = xwl_seat->focus_window;
            } else if (window == screen->root) {
                DebugF("Warp on root window, assuming pointer focus\n");
                xwl_window = xwl_seat->focus_window;
            }
        }
    }
    if (!xwl_window)
        return;

    xwl_seat_emulate_pointer_warp(xwl_seat, xwl_window, sprite, x, y);
}

static struct xwl_window *
find_matching_input_output_window(struct xwl_screen *xwl_screen,
                                  WindowPtr window)
{
    struct xwl_window *xwl_window;

    xorg_list_for_each_entry(xwl_window, &xwl_screen->window_list, link_window) {
        /* When confining happens on InputOnly windows, work out the InputOutput
         * window that would be covered by its geometry.
         */
        if (window->drawable.x < xwl_window->window->drawable.x ||
            window->drawable.x + window->drawable.width >
            xwl_window->window->drawable.x + xwl_window->window->drawable.width ||
            window->drawable.y < xwl_window->window->drawable.y ||
            window->drawable.y + window->drawable.height >
            xwl_window->window->drawable.y + xwl_window->window->drawable.height)
            continue;

        if (xwl_window->window->drawable.class == InputOnly)
            continue;

        return xwl_window;
    }

    return NULL;
}

static void
xwl_cursor_confined_to(DeviceIntPtr device,
                       ScreenPtr screen,
                       WindowPtr window)
{
    struct xwl_screen *xwl_screen = xwl_screen_get(screen);
    struct xwl_seat *xwl_seat = device->public.devicePrivate;
    struct xwl_window *xwl_window;

    if (!xwl_seat)
        xwl_seat = xwl_screen_get_default_seat(xwl_screen);

    /* xwl_seat hasn't been setup yet, don't do anything just yet */
    if (!xwl_seat)
        return;

    if (window == screen->root) {
        xwl_seat_unconfine_pointer(xwl_seat);
        return;
    }

    xwl_window = xwl_window_from_window(window);
    if (!xwl_window && window->drawable.class == InputOnly) {
        DebugF("Confine on InputOnly window, finding matching toplevel\n");
        xwl_window = find_matching_input_output_window(xwl_screen, window);
    }
    if (!xwl_window)
        return;

    xwl_seat_confine_pointer(xwl_seat, xwl_window);
}

void
xwl_screen_check_resolution_change_emulation(struct xwl_screen *xwl_screen)
{
    struct xwl_window *xwl_window;

    xorg_list_for_each_entry(xwl_window, &xwl_screen->window_list, link_window)
        xwl_window_check_resolution_change_emulation(xwl_window);
}

static void
xwl_screen_post_damage(struct xwl_screen *xwl_screen)
{
    struct xwl_window *xwl_window, *next_xwl_window;
    struct xorg_list commit_window_list;

    xorg_list_init(&commit_window_list);

    xorg_list_for_each_entry_safe(xwl_window, next_xwl_window,
                                  &xwl_screen->damage_window_list, link_damage) {
        /* If we're waiting on a frame callback from the server,
         * don't attach a new buffer. */
        if (xwl_window->frame_callback)
            continue;

        if (!xwl_window->allow_commits)
            continue;

#ifdef XWL_HAS_GLAMOR
        if (xwl_screen->glamor && !xwl_glamor_allow_commits(xwl_window))
            continue;
#endif

        xwl_window_post_damage(xwl_window);
        xorg_list_del(&xwl_window->link_damage);
        xorg_list_append(&xwl_window->link_damage, &commit_window_list);
    }

    if (xorg_list_is_empty(&commit_window_list))
        return;

#ifdef XWL_HAS_GLAMOR
    if (xwl_glamor_needs_buffer_flush(xwl_screen))
        glamor_block_handler(xwl_screen->screen);
#endif

    xorg_list_for_each_entry_safe(xwl_window, next_xwl_window,
                                  &commit_window_list, link_damage) {
        wl_surface_commit(xwl_window->surface);
        xorg_list_del(&xwl_window->link_damage);
    }
}

static void
xdg_wm_base_ping(void *data, struct xdg_wm_base *xdg_wm_base,
                 uint32_t serial)
{
    xdg_wm_base_pong(xdg_wm_base, serial);
}

static const struct xdg_wm_base_listener xdg_wm_base_listener = {
    xdg_wm_base_ping,
};

static void
registry_global(void *data, struct wl_registry *registry, uint32_t id,
                const char *interface, uint32_t version)
{
    struct xwl_screen *xwl_screen = data;

    if (strcmp(interface, "wl_compositor") == 0) {
        uint32_t request_version = 1;

        if (version >= WL_SURFACE_DAMAGE_BUFFER_SINCE_VERSION)
            request_version = WL_SURFACE_DAMAGE_BUFFER_SINCE_VERSION;

        xwl_screen->compositor =
            wl_registry_bind(registry, id, &wl_compositor_interface, request_version);
    }
    else if (strcmp(interface, "wl_shm") == 0) {
        xwl_screen->shm = wl_registry_bind(registry, id, &wl_shm_interface, 1);
    }
    else if (strcmp(interface, "xdg_wm_base") == 0) {
        xwl_screen->xdg_wm_base =
            wl_registry_bind(registry, id, &xdg_wm_base_interface, 1);
        xdg_wm_base_add_listener(xwl_screen->xdg_wm_base,
                                 &xdg_wm_base_listener,
                                 NULL);
    }
    else if (strcmp(interface, "wl_output") == 0 && version >= 2) {
        if (xwl_output_create(xwl_screen, id))
            xwl_screen->expecting_event++;
    }
    else if (strcmp(interface, "zxdg_output_manager_v1") == 0) {
        /* We support xdg-output from version 1 to version 3 */
        version = min(version, 3);
        xwl_screen->xdg_output_manager =
            wl_registry_bind(registry, id, &zxdg_output_manager_v1_interface, version);
        xwl_screen_init_xdg_output(xwl_screen);
    }
    else if (strcmp(interface, "wp_viewporter") == 0) {
        xwl_screen->viewporter = wl_registry_bind(registry, id, &wp_viewporter_interface, 1);
    }
#ifdef XWL_HAS_GLAMOR
    else if (xwl_screen->glamor) {
        xwl_glamor_init_wl_registry(xwl_screen, registry, id, interface,
                                    version);
    }
#endif
}

static void
global_remove(void *data, struct wl_registry *registry, uint32_t name)
{
    struct xwl_screen *xwl_screen = data;
    struct xwl_output *xwl_output, *tmp_xwl_output;

    xorg_list_for_each_entry_safe(xwl_output, tmp_xwl_output,
                                  &xwl_screen->output_list, link) {
        if (xwl_output->server_output_id == name) {
            xwl_output_remove(xwl_output);
            break;
        }
    }
}

static const struct wl_registry_listener registry_listener = {
    registry_global,
    global_remove
};

static void
xwl_read_events (struct xwl_screen *xwl_screen)
{
    int ret;

    if (xwl_screen->wait_flush)
        return;

    ret = wl_display_read_events(xwl_screen->display);
    if (ret == -1)
        xwl_give_up("failed to read Wayland events: %s\n", strerror(errno));

    xwl_screen->prepare_read = 0;

    ret = wl_display_dispatch_pending(xwl_screen->display);
    if (ret == -1)
        xwl_give_up("failed to dispatch Wayland events: %s\n", strerror(errno));
}

static int
xwl_display_pollout (struct xwl_screen *xwl_screen, int timeout)
{
    struct pollfd poll_fd;

    poll_fd.fd = wl_display_get_fd(xwl_screen->display);
    poll_fd.events = POLLOUT;

    return xserver_poll(&poll_fd, 1, timeout);
}

static void
xwl_dispatch_events (struct xwl_screen *xwl_screen)
{
    int ret = 0;
    int ready;

    if (xwl_screen->wait_flush)
        goto pollout;

    while (xwl_screen->prepare_read == 0 &&
           wl_display_prepare_read(xwl_screen->display) == -1) {
        ret = wl_display_dispatch_pending(xwl_screen->display);
        if (ret == -1)
            xwl_give_up("failed to dispatch Wayland events: %s\n",
                       strerror(errno));
    }

    xwl_screen->prepare_read = 1;

pollout:
    ready = xwl_display_pollout(xwl_screen, 5);
    if (ready == -1 && errno != EINTR)
        xwl_give_up("error polling on XWayland fd: %s\n", strerror(errno));

    if (ready > 0)
        ret = wl_display_flush(xwl_screen->display);

    if (ret == -1 && errno != EAGAIN)
        xwl_give_up("failed to write to XWayland fd: %s\n", strerror(errno));

    xwl_screen->wait_flush = (ready == 0 || ready == -1 || ret == -1);
}

static void
socket_handler(int fd, int ready, void *data)
{
    struct xwl_screen *xwl_screen = data;

    xwl_read_events (xwl_screen);
}

static void
wakeup_handler(void *data, int err)
{
}

static void
block_handler(void *data, void *timeout)
{
    struct xwl_screen *xwl_screen = data;

    xwl_screen_post_damage(xwl_screen);
    xwl_dispatch_events (xwl_screen);
}

void
xwl_sync_events (struct xwl_screen *xwl_screen)
{
    xwl_dispatch_events (xwl_screen);
    xwl_read_events (xwl_screen);
}

void xwl_surface_damage(struct xwl_screen *xwl_screen,
                        struct wl_surface *surface,
                        int32_t x, int32_t y, int32_t width, int32_t height)
{
    if (wl_surface_get_version(surface) >= WL_SURFACE_DAMAGE_BUFFER_SINCE_VERSION)
        wl_surface_damage_buffer(surface, x, y, width, height);
    else {
        x = xwl_scale_to(xwl_screen, x);
        y = xwl_scale_to(xwl_screen, y);
        width = xwl_scale_to(xwl_screen, width);
        height = xwl_scale_to(xwl_screen, height);

        wl_surface_damage(surface, x, y, width, height);
    }
}

void
xwl_screen_roundtrip(struct xwl_screen *xwl_screen)
{
    int ret;

    ret = wl_display_roundtrip(xwl_screen->display);
    while (ret >= 0 && xwl_screen->expecting_event)
        ret = wl_display_roundtrip(xwl_screen->display);

    if (ret < 0)
        xwl_give_up("could not connect to wayland server\n");
}

void
xwl_screen_set_global_scale(struct xwl_screen *xwl_screen, int32_t scale)
{
    struct xwl_output *it;
    struct xwl_window *xwl_window;

    xwl_screen->global_output_scale = scale;

    /* change randr resolutions and positions */
    xorg_list_for_each_entry(it, &xwl_screen->output_list, link) {
        xwl_output_apply_changes(it);
    }

    if (!xwl_screen->rootless && xwl_screen->screen->root) {
        /* Clear all the buffers, so that they'll be remade with the new sizes
         * (this doesn't occur automatically because as far as Xorg is
         *  concerned, the window's size is the same) */
        xorg_list_for_each_entry(xwl_window, &xwl_screen->window_list, link_window) {
            xwl_window_buffers_recycle(xwl_window);
        }
    }
}

Bool
xwl_screen_init(ScreenPtr pScreen, int argc, char **argv)
{
    static const char allow_commits[] = "_XWAYLAND_ALLOW_COMMITS";
    static const char global_output_scale[] = "_XWAYLAND_GLOBAL_OUTPUT_SCALE";
    struct xwl_screen *xwl_screen;
    Pixel red_mask, blue_mask, green_mask;
    int ret, bpc, green_bpc, i;
#ifdef XWL_HAS_GLAMOR
    Bool use_eglstreams = FALSE;
#endif

    xwl_screen = calloc(1, sizeof *xwl_screen);
    if (xwl_screen == NULL)
        return FALSE;

    if (!dixRegisterPrivateKey(&xwl_screen_private_key, PRIVATE_SCREEN, 0))
        return FALSE;
    if (!xwl_pixmap_init())
        return FALSE;
    if (!xwl_window_init())
        return FALSE;
    /* There are no easy to use new / delete client hooks, we could use a
     * ClientStateCallback, but it is easier to let the dix code manage the
     * memory for us. This will zero fill the initial xwl_client data.
     */
    if (!dixRegisterPrivateKey(&xwl_client_private_key, PRIVATE_CLIENT,
                               sizeof(struct xwl_client)))
        return FALSE;

    dixSetPrivate(&pScreen->devPrivates, &xwl_screen_private_key, xwl_screen);
    xwl_screen->screen = pScreen;

#ifdef XWL_HAS_GLAMOR
    xwl_screen->glamor = 1;
#endif
    xwl_screen->global_output_scale = 1;

    for (i = 1; i < argc; i++) {
        if (strcmp(argv[i], "-rootless") == 0) {
            xwl_screen->rootless = 1;

            /* Disable the XSS extension on Xwayland rootless.
             *
             * Xwayland is just a Wayland client, no X11 screensaver
             * should be expected to work reliably on Xwayland rootless.
             */
#ifdef SCREENSAVER
            noScreenSaverExtension = TRUE;
#endif
            ScreenSaverTime = 0;
            ScreenSaverInterval = 0;
            defaultScreenSaverTime = 0;
            defaultScreenSaverInterval = 0;
        }
        else if (strcmp(argv[i], "-shm") == 0) {
            xwl_screen->glamor = 0;
        }
        else if (strcmp(argv[i], "-eglstream") == 0) {
#ifdef XWL_HAS_EGLSTREAM
            use_eglstreams = TRUE;
#else
            ErrorF("xwayland glamor: this build does not have EGLStream support\n");
#endif
        }
    }

#ifdef XWL_HAS_GLAMOR
    if (xwl_screen->glamor)
        xwl_glamor_init_backends(xwl_screen, use_eglstreams);
#endif

    /* In rootless mode, we don't have any screen storage, and the only
     * rendering should be to redirected mode. */
    if (xwl_screen->rootless)
        xwl_screen->root_clip_mode = ROOT_CLIP_INPUT_ONLY;
    else
        xwl_screen->root_clip_mode = ROOT_CLIP_FULL;

    xorg_list_init(&xwl_screen->output_list);
    xorg_list_init(&xwl_screen->seat_list);
    xorg_list_init(&xwl_screen->damage_window_list);
    xorg_list_init(&xwl_screen->window_list);
    xwl_screen->depth = 24;

    if (!monitorResolution)
        monitorResolution = DEFAULT_DPI;

    xwl_screen->display = wl_display_connect(NULL);
    if (xwl_screen->display == NULL) {
        ErrorF("could not connect to wayland server\n");
        return FALSE;
    }

    if (!xwl_screen_init_output(xwl_screen))
        return FALSE;

    xwl_screen->expecting_event = 0;
    xwl_screen->registry = wl_display_get_registry(xwl_screen->display);
    wl_registry_add_listener(xwl_screen->registry,
                             &registry_listener, xwl_screen);
    xwl_screen_roundtrip(xwl_screen);

    if (!xwl_screen->rootless && !xwl_screen->xdg_wm_base) {
        ErrorF("missing XDG-WM-Base protocol\n");
        return FALSE;
    }

    bpc = xwl_screen->depth / 3;
    green_bpc = xwl_screen->depth - 2 * bpc;
    blue_mask = (1 << bpc) - 1;
    green_mask = ((1 << green_bpc) - 1) << bpc;
    red_mask = blue_mask << (green_bpc + bpc);

    miSetVisualTypesAndMasks(xwl_screen->depth,
                             ((1 << TrueColor) | (1 << DirectColor)),
                             green_bpc, TrueColor,
                             red_mask, green_mask, blue_mask);

    miSetPixmapDepths();

    ret = fbScreenInit(pScreen, NULL,
                       xwl_screen->width, xwl_screen->height,
                       monitorResolution, monitorResolution, 0,
                       BitsPerPixel(xwl_screen->depth));
    if (!ret)
        return FALSE;

    fbPictureInit(pScreen, 0, 0);

#ifdef MITSHM
    ShmRegisterFbFuncs(pScreen);
#endif

#ifdef HAVE_XSHMFENCE
    if (!miSyncShmScreenInit(pScreen))
        return FALSE;
#endif

    xwl_screen->wayland_fd = wl_display_get_fd(xwl_screen->display);
    SetNotifyFd(xwl_screen->wayland_fd, socket_handler, X_NOTIFY_READ, xwl_screen);
    RegisterBlockAndWakeupHandlers(block_handler, wakeup_handler, xwl_screen);

    pScreen->blackPixel = 0;
    pScreen->whitePixel = 1;

    ret = fbCreateDefColormap(pScreen);

    if (!xwl_screen_init_cursor(xwl_screen))
        return FALSE;

#ifdef XWL_HAS_GLAMOR
    if (xwl_screen->glamor) {
        xwl_glamor_select_backend(xwl_screen, use_eglstreams);

        if (xwl_screen->egl_backend == NULL || !xwl_glamor_init(xwl_screen)) {
           ErrorF("Failed to initialize glamor, falling back to sw\n");
           xwl_screen->glamor = 0;
        }
    }

    if (xwl_screen->glamor && xwl_screen->rootless)
        xwl_screen->present = xwl_present_init(pScreen);
#endif

    if (!xwl_screen->glamor) {
        xwl_screen->CreateScreenResources = pScreen->CreateScreenResources;
        pScreen->CreateScreenResources = xwl_shm_create_screen_resources;
        pScreen->CreatePixmap = xwl_shm_create_pixmap;
        pScreen->DestroyPixmap = xwl_shm_destroy_pixmap;
    }

    xwl_screen->RealizeWindow = pScreen->RealizeWindow;
    pScreen->RealizeWindow = xwl_realize_window;

    xwl_screen->UnrealizeWindow = pScreen->UnrealizeWindow;
    pScreen->UnrealizeWindow = xwl_unrealize_window;

    xwl_screen->DestroyWindow = pScreen->DestroyWindow;
    pScreen->DestroyWindow = xwl_destroy_window;

    xwl_screen->CloseScreen = pScreen->CloseScreen;
    pScreen->CloseScreen = xwl_close_screen;

    xwl_screen->ChangeWindowAttributes = pScreen->ChangeWindowAttributes;
    pScreen->ChangeWindowAttributes = xwl_change_window_attributes;

    xwl_screen->ResizeWindow = pScreen->ResizeWindow;
    pScreen->ResizeWindow = xwl_resize_window;

    xwl_screen->MoveWindow = pScreen->MoveWindow;
    pScreen->MoveWindow = xwl_move_window;

    if (xwl_screen->rootless) {
        xwl_screen->SetWindowPixmap = pScreen->SetWindowPixmap;
        pScreen->SetWindowPixmap = xwl_window_set_window_pixmap;
    }

    pScreen->CursorWarpedTo = xwl_cursor_warped_to;
    pScreen->CursorConfinedTo = xwl_cursor_confined_to;

    xwl_screen->allow_commits_prop = MakeAtom(allow_commits,
                                              strlen(allow_commits),
                                              TRUE);
    if (xwl_screen->allow_commits_prop == BAD_RESOURCE)
        return FALSE;

    xwl_screen->global_output_scale_prop = MakeAtom(global_output_scale,
                                                    strlen(global_output_scale),
                                                    TRUE);
    if (xwl_screen->global_output_scale_prop == BAD_RESOURCE)
        return FALSE;

    AddCallback(&PropertyStateCallback, xwl_property_callback, pScreen);

    xwl_screen_roundtrip(xwl_screen);

    return ret;
}