feat(capture/linux): add KWin direct screencast capture method (#5009)

Co-authored-by: Ramalama2 <6314556+Ramalama2@users.noreply.github.com>

cmake/compile_definitions/linux.cmake

@@ -76,8 +76,8 @@ if(CUDA_FOUND)
     add_compile_definitions(SUNSHINE_BUILD_CUDA)
 endif()
 
-# libdrm is required for both DRM (KMS) and Wayland
-if(${SUNSHINE_ENABLE_DRM} OR ${SUNSHINE_ENABLE_WAYLAND})
+# libdrm is required for DRM (KMS), KWin ScreenCast and Wayland
+if(${SUNSHINE_ENABLE_DRM} OR ${SUNSHINE_ENABLE_KWIN} OR ${SUNSHINE_ENABLE_WAYLAND})
     find_package(LIBDRM REQUIRED)
 else()
     set(LIBDRM_FOUND OFF)
@@ -243,7 +243,7 @@ if(GIO_FOUND)
 endif()
 
 # Pipewire
-if(${SUNSHINE_ENABLE_PORTAL})
+if(${SUNSHINE_ENABLE_KWIN} OR ${SUNSHINE_ENABLE_PORTAL})
     pkg_check_modules(PIPEWIRE libpipewire-0.3 REQUIRED)
 else()
     set(PIPEWIRE_FOUND OFF)
@@ -264,13 +264,27 @@ if(PIPEWIRE_FOUND AND GIO_FOUND AND ${SUNSHINE_ENABLE_PORTAL})
             "${CMAKE_SOURCE_DIR}/src/platform/linux/portalgrab.cpp")
 endif()
 
+# KWin ScreenCast (direct Wayland protocol, bypasses portal)
+set(KWIN_FOUND OFF)
+if(PIPEWIRE_FOUND AND WAYLAND_FOUND AND ${SUNSHINE_ENABLE_KWIN})
+    set(KWIN_FOUND ON)
+    add_compile_definitions(SUNSHINE_BUILD_KWIN)
+    GEN_WAYLAND("${CMAKE_SOURCE_DIR}/third-party/plasma-wayland-protocols/src/protocols" "" kde-output-order-v1)
+    GEN_WAYLAND("${CMAKE_SOURCE_DIR}/third-party/plasma-wayland-protocols/src/protocols" "" zkde-screencast-unstable-v1)
+    list(APPEND PLATFORM_TARGET_FILES
+            "${CMAKE_SOURCE_DIR}/src/platform/linux/kwingrab.cpp")
+elseif(${SUNSHINE_ENABLE_KWIN} AND NOT WAYLAND_FOUND)
+    message(FATAL_ERROR "SUNSHINE_ENABLE_KWIN requires SUNSHINE_ENABLE_WAYLAND — KWin capture disabled")
+endif()
+
 if(NOT ${CUDA_FOUND}
-        AND NOT ${WAYLAND_FOUND}
-        AND NOT ${X11_FOUND}
-        AND NOT ${PORTAL_FOUND}
         AND NOT (${LIBDRM_FOUND} AND ${LIBCAP_FOUND})
-        AND NOT ${LIBVA_FOUND})
-    message(FATAL_ERROR "Couldn't find either cuda, libva, pipewire, wayland, x11, or (libdrm and libcap)")
+        AND NOT ${LIBVA_FOUND}
+        AND NOT ${KWIN_FOUND}
+        AND NOT ${PORTAL_FOUND}
+        AND NOT ${WAYLAND_FOUND}
+        AND NOT ${X11_FOUND})
+    message(FATAL_ERROR "Couldn't find either cuda, (libdrm and libcap), libva, kwin, pipewire, portal, wayland or x11")
 endif()
 
 # tray icon

cmake/packaging/linux.cmake

@@ -173,6 +173,10 @@ install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_FQDN}.desktop"
 if(NOT ${SUNSHINE_BUILD_APPIMAGE} AND NOT ${SUNSHINE_BUILD_FLATPAK})
     install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_FQDN}.terminal.desktop"
             DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/applications")
+    if(${SUNSHINE_ENABLE_KWIN})
+        install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_FQDN}.kwin.desktop"
+                DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/applications")
+    endif()
 endif()
 
 # metadata file

cmake/prep/options.cmake

@@ -64,6 +64,8 @@ elseif(UNIX)  # Linux
             "Enable building wayland specific code." ON)
     option(SUNSHINE_ENABLE_X11
             "Enable X11 grab if available." ON)
+    option(SUNSHINE_ENABLE_KWIN
+            "Enable KWin ScreenCast grab if available" ON)
     option(SUNSHINE_ENABLE_PORTAL
             "Enable XDG portal grab if available" ON)
 endif()

cmake/prep/special_package_configuration.cmake

@@ -26,6 +26,11 @@ elseif(UNIX)
     # configure service
     configure_file(packaging/linux/app-${PROJECT_FQDN}.service.in app-${PROJECT_FQDN}.service @ONLY)
 
+    # configure kwin desktop permission file
+    if (${SUNSHINE_ENABLE_KWIN})
+        configure_file(packaging/linux/${PROJECT_FQDN}.kwin.desktop.in ${PROJECT_FQDN}.kwin.desktop @ONLY)
+    endif()
+
     # configure the arch linux pkgbuild
     if(${SUNSHINE_CONFIGURE_PKGBUILD})
         configure_file(packaging/linux/Arch/PKGBUILD PKGBUILD @ONLY)

cmake/targets/common.cmake

@@ -31,15 +31,7 @@ endif()
 
 target_link_libraries(sunshine ${SUNSHINE_EXTERNAL_LIBRARIES} ${EXTRA_LIBS})
 target_compile_definitions(sunshine PUBLIC ${SUNSHINE_DEFINITIONS})
-if(APPLE AND NOT SUNSHINE_BUILD_HOMEBREW)
-    # codesign on Mac won't sign an .app that uses a symlink
-    set_target_properties(sunshine PROPERTIES CXX_STANDARD 23)
-else()
-    # symlink sunshine -> sunshine-PROJECT_VERSION
-    set_target_properties(sunshine PROPERTIES CXX_STANDARD 23
-            VERSION ${PROJECT_VERSION}
-            SOVERSION ${PROJECT_VERSION_MAJOR})
-endif()
+set_target_properties(sunshine PROPERTIES CXX_STANDARD 23)
 
 # CLion complains about unknown flags after running cmake, and cannot add symbols to the index for cuda files
 if(CUDA_INHERIT_COMPILE_OPTIONS)