wayland: add support for configure bounds

In wayland-protocols 1.25, xdg-shell got a version bump which added the
configure_bounds event. The compositor can send this to clients to
indicate that they should not resize past a certain size. For mpv, we'll
choose to only listen to this on reconfig events (i.e. when the window
first appears and if the video resolution changes later in the
playlist). However, this behavior is still exposed as a user option
(default on) because it will neccesarily conflict with a user setting a
specific geometry size and/or window scale. Presumably, if someone is
setting a really large size that goes beyond the bounds of their
monitor, they actually want it like that. The wayland-protocols version
is newer-ish, but we can get around having to poke the build system by
just using a define that exists in the generated xdg-shell header.

DOCS/interface-changes.rst

@@ -45,6 +45,7 @@ Interface changes
     - add `--x11-present` for controlling whether to use xorg's present extension
     - add `engine` option to the `rubberband` audio filter to support the new
       engine introduced in rubberband 3.0.0. Defaults to `finer` (new engine).
+    - add `--wayland-configure-bounds` option
  --- mpv 0.34.0 ---
     - deprecate selecting by card number with `--drm-connector`, add
       `--drm-device` which can be used instead

DOCS/man/options.rst

@@ -5570,6 +5570,14 @@ them.
 ``--wayland-app-id=<string>``
     Set the client app id for Wayland-based video output methods (default: ``mpv``).
 
+``--wayland-configure-bounds=<yes|no>``
+    Controls whether or not mpv opts into the configure bounds event if sent by the
+    compositor (default: yes). This restricts the initial size of the mpv window to
+    a certain maximum size intended by the compositor. In most cases, this simply
+    just prevents the mpv window from being larger than the size of the monitor when
+    it first renders. This option will take precedence over any ``autofit`` or
+    ``geometry`` type settings if the configure bounds are used.
+
 ``--wayland-disable-vsync=<yes|no>``
     Disable mpv's internal vsync for Wayland-based video output (default: no).
     This is mainly useful for benchmarking wayland VOs when combined with

video/out/wayland_common.c

@@ -112,6 +112,7 @@ static const struct mp_keymap keymap[] = {
 #define OPT_BASE_STRUCT struct wayland_opts
 const struct m_sub_options wayland_conf = {
     .opts = (const struct m_option[]) {
+        {"wayland-configure-bounds", OPT_FLAG(configure_bounds)},
         {"wayland-disable-vsync", OPT_FLAG(disable_vsync)},
         {"wayland-edge-pixels-pointer", OPT_INT(edge_pixels_pointer),
             M_RANGE(0, INT_MAX)},
@@ -121,6 +122,7 @@ const struct m_sub_options wayland_conf = {
     },
     .size = sizeof(struct wayland_opts),
     .defaults = &(struct wayland_opts) {
+        .configure_bounds = true,
         .disable_vsync = false,
         .edge_pixels_pointer = 10,
         .edge_pixels_touch = 32,
@@ -918,9 +920,22 @@ static void handle_toplevel_close(void *data, struct xdg_toplevel *xdg_toplevel)
     mp_input_put_key(wl->vo->input_ctx, MP_KEY_CLOSE_WIN);
 }
 
+#ifdef XDG_TOPLEVEL_CONFIGURE_BOUNDS_SINCE_VERSION
+static void handle_configure_bounds(void *data, struct xdg_toplevel *xdg_toplevel,
+                                    int32_t width, int32_t height)
+{
+    struct vo_wayland_state *wl = data;
+    wl->bounded_width = width;
+    wl->bounded_height = height;
+}
+#endif
+
 static const struct xdg_toplevel_listener xdg_toplevel_listener = {
     handle_toplevel_config,
     handle_toplevel_close,
+#ifdef XDG_TOPLEVEL_CONFIGURE_BOUNDS_SINCE_VERSION
+    handle_configure_bounds,
+#endif
 };
 
 static void configure_decorations(void *data,
@@ -1117,7 +1132,7 @@ static void registry_handle_add(void *data, struct wl_registry *reg, uint32_t id
     }
 
     if (!strcmp(interface, xdg_wm_base_interface.name) && found++) {
-        ver = MPMIN(ver, 2); /* We can use either 1 or 2 */
+        ver = MPMIN(ver, 4); /* Cap at 4 in case new events are added later. */
         wl->wm_base = wl_registry_bind(reg, id, &xdg_wm_base_interface, ver);
         xdg_wm_base_add_listener(wl->wm_base, &xdg_wm_base_listener, wl);
     }
@@ -1477,6 +1492,14 @@ static void set_surface_scaling(struct vo_wayland_state *wl)
     wl_surface_set_buffer_scale(wl->surface, wl->scaling);
 }
 
+static void set_window_bounds(struct vo_wayland_state *wl)
+{
+    if (wl->bounded_width && wl->bounded_width < wl->window_size.x1)
+        wl->window_size.x1 = wl->bounded_width;
+    if (wl->bounded_height && wl->bounded_height < wl->window_size.y1)
+        wl->window_size.y1 = wl->bounded_height;
+}
+
 static int spawn_cursor(struct vo_wayland_state *wl)
 {
     /* Reuse if size is identical */
@@ -1773,6 +1796,8 @@ int vo_wayland_init(struct vo *vo)
         .display = wl_display_connect(NULL),
         .vo = vo,
         .log = mp_log_new(wl, vo->log, "wayland"),
+        .bounded_width = 0,
+        .bounded_height = 0,
         .refresh_interval = 0,
         .scaling = 1,
         .wakeup_pipe = {-1, -1},
@@ -1885,9 +1910,11 @@ int vo_wayland_reconfig(struct vo *vo)
     }
 
     set_geometry(wl);
-
     wl->window_size = wl->vdparams;
 
+    if (wl->opts->configure_bounds)
+        set_window_bounds(wl);
+
     if ((!wl->vo_opts->fullscreen && !wl->vo_opts->window_maximized) ||
         mp_rect_w(wl->geometry) == 0 || mp_rect_h(wl->geometry) == 0)
     {

video/out/wayland_common.h

@@ -23,6 +23,7 @@
 #include "vo.h"
 
 struct wayland_opts {
+    int configure_bounds;
     int disable_vsync;
     int edge_pixels_pointer;
     int edge_pixels_touch;
@@ -50,6 +51,8 @@ struct vo_wayland_state {
     struct mp_rect window_size;
     struct wl_list output_list;
     struct vo_wayland_output *current_output;
+    int bounded_height;
+    int bounded_width;
     int gcd;
     int reduced_height;
     int reduced_width;