wayland: add vulkan wayland platform support

Add a `vulkan platform` implementation for wayland, effectively enabling
the usage of the vulkan libplacebo display on Wayland environments.

modules/video_output/wayland/Makefile.am

@@ -73,6 +73,14 @@ libegl_wl_plugin_la_CPPFLAGS = $(AM_CPPFLAGS) -DUSE_PLATFORM_WAYLAND=1
 libegl_wl_plugin_la_CFLAGS = $(AM_CFLAGS) $(EGL_CFLAGS) $(WAYLAND_EGL_CFLAGS)
 libegl_wl_plugin_la_LIBADD = $(EGL_LIBS) $(WAYLAND_EGL_LIBS)
 
+libvk_wl_plugin_la_SOURCES = \
+	video_output/vulkan/platform.h \
+	video_output/wayland/vulkan.c
+libvk_wl_plugin_la_CFLAGS = $(AM_CFLAGS) \
+	$(WAYLAND_CFLAGS) $(VULKAN_COMMONCFLAGS) \
+	-DVK_USE_PLATFORM_WAYLAND_KHR
+libvk_wl_plugin_la_LIBADD = $(VULKAN_COMMONLIBS) $(WAYLAND_LIBS)
+
 if HAVE_WAYLAND
 BUILT_SOURCES += $(nodist_libwl_shm_plugin_la_SOURCES)
 vout_LTLIBRARIES += libwl_shm_plugin.la
@@ -82,4 +90,7 @@ vout_LTLIBRARIES += libxdg_shell_plugin.la
 if HAVE_EGL
 vout_LTLIBRARIES += libegl_wl_plugin.la
 endif
+if HAVE_VULKAN
+vout_LTLIBRARIES += libvk_wl_plugin.la
+endif
 endif

modules/video_output/wayland/vulkan.c

@@ -0,0 +1,76 @@
+/**
+ * @file vulkan.c
+ * @brief Vulkan platform-specific code for Wayland
+ */
+/*****************************************************************************
+ * Copyright © 2020 VideoLabs
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <vlc_common.h>
+#include <vlc_plugin.h>
+
+#include "../vulkan/instance.h"
+
+static void ClosePlatform(vlc_vk_t *vk)
+    { (void)vk; }
+
+static int CreateSurface(vlc_vk_t *vk, VkInstance vkinst, VkSurfaceKHR *surface_out)
+{
+    VkWaylandSurfaceCreateInfoKHR surface_info = {
+        .sType = VK_STRUCTURE_TYPE_WAYLAND_SURFACE_CREATE_INFO_KHR,
+        .display = vk->window->display.wl,
+        .surface = vk->window->handle.wl,
+    };
+
+    VkResult res = vkCreateWaylandSurfaceKHR(vkinst, &surface_info, NULL, surface_out);
+    if (res != VK_SUCCESS) {
+        msg_Err(vk, "Failed creating Wayland surface");
+        return VLC_EGENERIC;
+    }
+
+    return VLC_SUCCESS;
+}
+
+static const struct vlc_vk_operations platform_ops =
+{
+    .close = ClosePlatform,
+    .create_surface = CreateSurface,
+};
+
+static int InitPlatform(vlc_vk_t *vk)
+{
+    if (vk->window->type != VOUT_WINDOW_TYPE_WAYLAND)
+        return VLC_EGENERIC;
+
+    vk->platform_ext = VK_KHR_WAYLAND_SURFACE_EXTENSION_NAME;
+    vk->ops = &platform_ops;
+    return VLC_SUCCESS;
+}
+
+vlc_module_begin()
+    set_shortname("Vulkan Wayland")
+    set_description(N_("Wayland platform support for Vulkan"))
+    set_category(CAT_VIDEO)
+    set_subcategory(SUBCAT_VIDEO_VOUT)
+    set_capability("vulkan platform", 50)
+    set_callback(InitPlatform)
+    add_shortcut("vk_wl")
+vlc_module_end()