gstwayland: Support wp_single_pixel_buffer_v1

This protocol does what it says on the box, avoiding the need for a 1x1
wl_shm buffer.

A wayland-projects wrap has been added for users who do not have v1.26
available.

This commit was partly authored by Robert Mader.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2662>

subprojects/gst-plugins-bad/gst-libs/gst/wayland/gstwldisplay.c

@@ -26,6 +26,7 @@
 
 #include "fullscreen-shell-unstable-v1-client-protocol.h"
 #include "linux-dmabuf-unstable-v1-client-protocol.h"
+#include "single-pixel-buffer-v1-client-protocol.h"
 #include "viewporter-client-protocol.h"
 #include "xdg-shell-client-protocol.h"
 
@@ -48,6 +49,7 @@ typedef struct _GstWlDisplayPrivate
   struct wl_subcompositor *subcompositor;
   struct xdg_wm_base *xdg_wm_base;
   struct zwp_fullscreen_shell_v1 *fullscreen_shell;
+  struct wp_single_pixel_buffer_manager_v1 *single_pixel_buffer;
   struct wl_shm *shm;
   struct wp_viewporter *viewporter;
   struct zwp_linux_dmabuf_v1 *dmabuf;
@@ -146,6 +148,9 @@ gst_wl_display_finalize (GObject * gobject)
   if (priv->fullscreen_shell)
     zwp_fullscreen_shell_v1_release (priv->fullscreen_shell);
 
+  if (priv->single_pixel_buffer)
+    wp_single_pixel_buffer_manager_v1_destroy (priv->single_pixel_buffer);
+
   if (priv->compositor)
     wl_compositor_destroy (priv->compositor);
 
@@ -323,6 +328,10 @@ registry_handle_global (void *data, struct wl_registry *registry,
     priv->dmabuf =
         wl_registry_bind (registry, id, &zwp_linux_dmabuf_v1_interface, 3);
     zwp_linux_dmabuf_v1_add_listener (priv->dmabuf, &dmabuf_listener, self);
+  } else if (g_strcmp0 (interface, "wp_single_pixel_buffer_manager_v1") == 0) {
+    priv->single_pixel_buffer =
+        wl_registry_bind (registry, id,
+        &wp_single_pixel_buffer_manager_v1_interface, 1);
   }
 }
 
@@ -610,6 +619,14 @@ gst_wl_display_get_dmabuf_formats (GstWlDisplay * self)
   return priv->dmabuf_formats;
 }
 
+struct wp_single_pixel_buffer_manager_v1 *
+gst_wl_display_get_single_pixel_buffer_manager_v1 (GstWlDisplay * self)
+{
+  GstWlDisplayPrivate *priv = gst_wl_display_get_instance_private (self);
+
+  return priv->single_pixel_buffer;
+}
+
 gboolean
 gst_wl_display_has_own_display (GstWlDisplay * self)
 {

subprojects/gst-plugins-bad/gst-libs/gst/wayland/gstwldisplay.h

@@ -99,6 +99,9 @@ GArray *gst_wl_display_get_dmabuf_modifiers (GstWlDisplay * self);
 GST_WL_API
 struct zwp_linux_dmabuf_v1 *gst_wl_display_get_dmabuf_v1 (GstWlDisplay * self);
 
+GST_WL_API
+struct wp_single_pixel_buffer_manager_v1 * gst_wl_display_get_single_pixel_buffer_manager_v1 (GstWlDisplay * self);
+
 GST_WL_API
 gboolean gst_wl_display_has_own_display (GstWlDisplay * self);
 

subprojects/gst-plugins-bad/gst-libs/gst/wayland/gstwlwindow.c

@@ -27,6 +27,7 @@
 #include "gstwlwindow.h"
 
 #include "fullscreen-shell-unstable-v1-client-protocol.h"
+#include "single-pixel-buffer-v1-client-protocol.h"
 #include "viewporter-client-protocol.h"
 #include "xdg-shell-client-protocol.h"
 
@@ -553,13 +554,11 @@ static void
 gst_wl_window_update_borders (GstWlWindow * self)
 {
   GstWlWindowPrivate *priv = gst_wl_window_get_instance_private (self);
-  GstVideoFormat format;
-  GstVideoInfo info;
   gint width, height;
   GstBuffer *buf;
   struct wl_buffer *wlbuf;
+  struct wp_single_pixel_buffer_manager_v1 *single_pixel;
   GstWlBuffer *gwlbuf;
-  GstAllocator *alloc;
 
   if (gst_wl_display_get_viewporter (priv->display)) {
     wp_viewport_set_destination (priv->area_viewport,
@@ -579,19 +578,34 @@ gst_wl_window_update_borders (GstWlWindow * self)
     height = priv->render_rectangle.h;
   }
 
+  /* draw the area_subsurface */
+  single_pixel =
+      gst_wl_display_get_single_pixel_buffer_manager_v1 (priv->display);
+  if (width == 1 && height == 1 && single_pixel) {
+    buf = gst_buffer_new_allocate (NULL, 1, NULL);
+    wlbuf =
+        wp_single_pixel_buffer_manager_v1_create_u32_rgba_buffer (single_pixel,
+        0, 0, 0, 0xffffffffU);
+  } else {
+    GstVideoFormat format;
+    GstVideoInfo info;
+    GstAllocator *alloc;
+
     /* we want WL_SHM_FORMAT_XRGB8888 */
     format = GST_VIDEO_FORMAT_BGRx;
-
-  /* draw the area_subsurface */
     gst_video_info_set_format (&info, format, width, height);
-
     alloc = gst_shm_allocator_get ();
 
     buf = gst_buffer_new_allocate (alloc, info.size, NULL);
     gst_buffer_memset (buf, 0, 0, info.size);
+
     wlbuf =
         gst_wl_shm_memory_construct_wl_buffer (gst_buffer_peek_memory (buf, 0),
         priv->display, &info);
+
+    g_object_unref (alloc);
+  }
+
   gwlbuf = gst_buffer_add_wl_buffer (buf, wlbuf, priv->display);
   gst_wl_buffer_attach (gwlbuf, priv->area_surface_wrapper);
   wl_surface_damage_buffer (priv->area_surface_wrapper, 0, 0, G_MAXINT32,
@@ -600,7 +614,6 @@ gst_wl_window_update_borders (GstWlWindow * self)
   /* at this point, the GstWlBuffer keeps the buffer
    * alive and will free it on wl_buffer::release */
   gst_buffer_unref (buf);
-  g_object_unref (alloc);
 }
 
 static void

subprojects/gst-plugins-bad/gst-libs/gst/wayland/meson.build

@@ -1,6 +1,7 @@
 wl_req = '>= 1.15'
 wl_client_dep = dependency('wayland-client', version: wl_req, required: get_option('wayland'))
 libdrm_dep = dependency('libdrm', version: '>= 2.4.98', required: get_option('wayland'))
+wl_proto_req = '>= 1.26'
 wl_protocol_dep = dependency('wayland-protocols', version: wl_req, required: get_option('wayland'))
 wl_scanner = find_program('wayland-scanner', required: get_option('wayland'))
 # Also used in ext/wayland
@@ -38,7 +39,8 @@ if use_wayland
     ['viewporter', 'stable', ],
     ['linux-dmabuf', 'unstable', 'v1', ],
     ['fullscreen-shell', 'unstable', 'v1', ],
-    ['xdg-shell', 'stable', ]
+    ['xdg-shell', 'stable', ],
+    ['single-pixel-buffer', 'staging', 'v1' ],
   ]
   protocols_files = []
 

subprojects/wayland-protocols.wrap

@@ -0,0 +1,10 @@
+[wrap-file]
+directory = wayland-protocols-1.32
+source_url = https://gitlab.freedesktop.org/wayland/wayland-protocols/-/releases/1.32/downloads/wayland-protocols-1.32.tar.xz
+source_filename = wayland-protocols-1.32.tar.xz
+source_hash = 7459799d340c8296b695ef857c07ddef24c5a09b09ab6a74f7b92640d2b1ba11
+source_fallback_url = https://github.com/mesonbuild/wrapdb/releases/download/wayland-protocols_1.32-1/wayland-protocols-1.32.tar.xz
+wrapdb_version = 1.32-1
+
+[provide]
+wayland-protocols = wayland_protocols