Make Wayland::EGL optional again

This is needed to make KWin build-able on non-Linux, but is actually
only a workaround. The dependency should also be available on non-Linux.

This disables the EGL integration in the Wayland backend (QPainter still
available) and the EGL fallback in the qpa plugin (preferred context
sharing still available, but requires a working OpenGL Scene).

REVIEW: 126202

CMakeLists.txt

@@ -135,11 +135,16 @@ set_package_properties(epoxy PROPERTIES DESCRIPTION "libepoxy"
                        PURPOSE "OpenGL dispatch library"
                       )
 
-find_package(Wayland 1.2 REQUIRED COMPONENTS Egl Cursor)
+find_package(Wayland 1.2 REQUIRED COMPONENTS Cursor OPTIONAL_COMPONENTS Egl)
 set_package_properties(Wayland PROPERTIES
                        TYPE REQUIRED
                        PURPOSE "Required for building KWin with Wayland support"
                       )
+add_feature_info("Wayland::EGL" Wayland_Egl_FOUND "Enable building of Wayland backend and QPA with EGL support.")
+set(HAVE_WAYLAND_EGL FALSE)
+if(Wayland_Egl_FOUND)
+    set(HAVE_WAYLAND_EGL TRUE)
+endif()
 
 find_package(XKB 0.4.1)
 set_package_properties(XKB PROPERTIES

backends/wayland/CMakeLists.txt

@@ -2,11 +2,18 @@ set(WAYLAND_BACKEND_SOURCES
     logging.cpp
     scene_qpainter_wayland_backend.cpp
     wayland_backend.cpp
-    egl_wayland_backend.cpp
 )
 
+if(HAVE_WAYLAND_EGL)
+    set(WAYLAND_BACKEND_SOURCES egl_wayland_backend.cpp ${WAYLAND_BACKEND_SOURCES})
+endif()
+
 add_library(KWinWaylandWaylandBackend MODULE ${WAYLAND_BACKEND_SOURCES})
-target_link_libraries(KWinWaylandWaylandBackend kwin KF5::WaylandClient Wayland::Egl)
+target_link_libraries(KWinWaylandWaylandBackend kwin KF5::WaylandClient)
+
+if(HAVE_WAYLAND_EGL)
+    target_link_libraries(KWinWaylandWaylandBackend Wayland::Egl)
+endif()
 
 install(
     TARGETS

backends/wayland/wayland_backend.cpp

@@ -19,6 +19,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************/
 // own
 #include "wayland_backend.h"
+#include <config-kwin.h>
 // KWin
 #include "cursor.h"
 #include "logging.h"
@@ -27,7 +28,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "screens.h"
 #include "wayland_server.h"
 #include "wayland_cursor_theme.h"
+#if HAVE_WAYLAND_EGL
 #include "egl_wayland_backend.h"
+#endif
 #include <KWayland/Client/buffer.h>
 #include <KWayland/Client/compositor.h>
 #include <KWayland/Client/connection_thread.h>
@@ -449,7 +452,11 @@ Screens *WaylandBackend::createScreens(QObject *parent)
 
 OpenGLBackend *WaylandBackend::createOpenGLBackend()
 {
+#if HAVE_WAYLAND_EGL
     return new EglWaylandBackend(this);
+#else
+    return nullptr;
+#endif
 }
 
 QPainterBackend *WaylandBackend::createQPainterBackend()

config-kwin.h.cmake

@@ -13,6 +13,7 @@
 #cmakedefine01 HAVE_DRM
 #cmakedefine01 HAVE_GBM
 #cmakedefine01 HAVE_LIBHYBRIS
+#cmakedefine01 HAVE_WAYLAND_EGL
 
 /* Define to 1 if you have the <unistd.h> header file. */
 #cmakedefine HAVE_UNISTD_H 1

plugins/qpa/CMakeLists.txt

@@ -18,12 +18,15 @@ add_library(KWinQpaPlugin MODULE ${QPA_SOURCES})
 target_link_libraries(KWinQpaPlugin
     kwin
     KF5::WaylandClient
-    Wayland::Egl
     Qt5PlatformSupport::Qt5PlatformSupport
     ${FONTCONFIG_LIBRARIES}
     ${FREETYPE_LIBRARIES}
 )
 
+if(HAVE_WAYLAND_EGL)
+    target_link_libraries(KWinQpaPlugin Wayland::Egl)
+endif()
+
 install(
     TARGETS
         KWinQpaPlugin

plugins/qpa/window.cpp

@@ -54,9 +54,11 @@ Window::~Window()
     if (m_eglSurface != EGL_NO_SURFACE) {
         eglDestroySurface(m_integration->eglDisplay(), m_eglSurface);
     }
+#if HAVE_WAYLAND_EGL
     if (m_eglWaylandWindow) {
         wl_egl_window_destroy(m_eglWaylandWindow);
     }
+#endif
     delete m_shellSurface;
     delete m_surface;
 }
@@ -95,9 +97,11 @@ void Window::setGeometry(const QRect &rect)
             m_resized = true;
         }
     }
+#if HAVE_WAYLAND_EGL
     if (m_eglWaylandWindow) {
         wl_egl_window_resize(m_eglWaylandWindow, geometry().width(), geometry().height(), 0, 0);
     }
+#endif
 }
 
 void Window::unmap()
@@ -116,12 +120,14 @@ void Window::unmap()
 
 void Window::createEglSurface(EGLDisplay dpy, EGLConfig config)
 {
+#if HAVE_WAYLAND_EGL
     const QSize size = window()->size();
     m_eglWaylandWindow = wl_egl_window_create(*m_surface, size.width(), size.height());
     if (!m_eglWaylandWindow) {
         return;
     }
     m_eglSurface = eglCreateWindowSurface(dpy, config, m_eglWaylandWindow, nullptr);
+#endif
 }
 
 void Window::bindContentFBO()

plugins/qpa/window.h

@@ -24,7 +24,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <fixx11h.h>
 #include <qpa/qplatformwindow.h>
 // wayland
+#include <config-kwin.h>
+#if HAVE_WAYLAND_EGL
 #include <wayland-egl.h>
+#endif
 
 class QOpenGLFramebufferObject;
 

workspace.cpp

@@ -1387,6 +1387,12 @@ QString Workspace::supportInformation() const
     support.append(yes);
 #else
     support.append(no);
+#endif
+    support.append(QStringLiteral("HAVE_WAYLAND_EGL: "));
+#if HAVE_WAYLAND_EGL
+    support.append(yes);
+#else
+    support.append(no);
 #endif
     support.append(QStringLiteral("\n"));