platformsupport: remove initBufferConfigs

Instead, rely on EGL_KHR_no_config_context everywhere except the standalone x11 backend

src/backends/drm/drm_egl_backend.cpp

@@ -107,10 +107,10 @@ void EglGbmBackend::init()
 
 bool EglGbmBackend::initRenderingContext()
 {
-    return createContext(initBufferConfigs()) && makeCurrent();
+    return initBufferConfigs() && createContext(EGL_NO_CONFIG_KHR) && makeCurrent();
 }
 
-EGLConfig EglGbmBackend::initBufferConfigs()
+bool EglGbmBackend::initBufferConfigs()
 {
     const EGLint config_attribs[] = {
         EGL_SURFACE_TYPE,
@@ -136,7 +136,7 @@ EGLConfig EglGbmBackend::initBufferConfigs()
                          sizeof(configs) / sizeof(EGLConfig),
                          &count)) {
         qCCritical(KWIN_DRM) << "eglChooseConfig failed:" << getEglErrorString();
-        return EGL_NO_CONFIG_KHR;
+        return false;
     }
 
     // Loop through all configs, choosing the first one that has suitable format.
@@ -159,7 +159,7 @@ EGLConfig EglGbmBackend::initBufferConfigs()
         m_formats[gbmFormat] = format;
     }
     if (!m_formats.isEmpty()) {
-        return EGL_NO_CONFIG_KHR;
+        return true;
     }
 
     qCCritical(KWIN_DRM, "Choosing EGL config did not return a supported config. There were %u configs", count);
@@ -174,7 +174,7 @@ EGLConfig EglGbmBackend::initBufferConfigs()
         gbm_format_get_name(gbmFormat, &name);
         qCCritical(KWIN_DRM, "EGL config %d has format %s with %d,%d,%d,%d bits for r,g,b,a", i, name.name, redSize, greenSize, blueSize, alphaSize);
     }
-    return EGL_NO_CONFIG_KHR;
+    return false;
 }
 
 std::unique_ptr<SurfaceTexture> EglGbmBackend::createSurfaceTextureInternal(SurfacePixmapInternal *pixmap)

src/backends/drm/drm_egl_backend.h

@@ -82,7 +82,7 @@ public:
 
 private:
     bool initializeEgl();
-    EGLConfig initBufferConfigs() override;
+    bool initBufferConfigs();
     bool initRenderingContext();
 
     DrmBackend *m_backend;

src/backends/virtual/virtual_egl_backend.cpp

@@ -137,11 +137,7 @@ void VirtualEglBackend::init()
 
 bool VirtualEglBackend::initRenderingContext()
 {
-    if (!createContext(initBufferConfigs())) {
-        return false;
-    }
-
-    return makeCurrent();
+    return createContext(EGL_NO_CONFIG_KHR) && makeCurrent();
 }
 
 void VirtualEglBackend::addOutput(Output *output)

src/backends/wayland/wayland_egl_backend.cpp

@@ -382,7 +382,7 @@ void WaylandEglBackend::init()
 
 bool WaylandEglBackend::initRenderingContext()
 {
-    if (!createContext(initBufferConfigs())) {
+    if (!createContext(EGL_NO_CONFIG_KHR)) {
         return false;
     }
 

src/backends/x11/standalone/x11_standalone_egl_backend.cpp

@@ -199,7 +199,7 @@ bool EglBackend::initRenderingContext()
 
     setEglDisplay(display);
 
-    if (!createContext(initBufferConfigs())) {
+    if (!createContext(chooseBufferConfig())) {
         qCCritical(KWIN_CORE) << "Create OpenGL context failed";
         return false;
     }
@@ -256,7 +256,7 @@ EGLSurface EglBackend::createSurface(xcb_window_t window)
     return surface;
 }
 
-EGLConfig EglBackend::initBufferConfigs()
+EGLConfig EglBackend::chooseBufferConfig()
 {
     const EGLint config_attribs[] = {
         EGL_SURFACE_TYPE,

src/backends/x11/standalone/x11_standalone_egl_backend.h

@@ -53,7 +53,7 @@ public:
     OutputLayer *primaryLayer(Output *output) override;
 
 protected:
-    EGLConfig initBufferConfigs() override;
+    EGLConfig chooseBufferConfig();
     bool initRenderingContext();
 
 private:

src/backends/x11/windowed/x11_windowed_egl_backend.cpp

@@ -305,7 +305,7 @@ bool X11WindowedEglBackend::initializeEgl()
 
 bool X11WindowedEglBackend::initRenderingContext()
 {
-    if (!createContext(initBufferConfigs())) {
+    if (!createContext(EGL_NO_CONFIG_KHR)) {
         return false;
     }
 

src/platformsupport/scenes/opengl/abstract_egl_backend.cpp

@@ -356,39 +356,6 @@ QHash<uint32_t, QVector<uint64_t>> AbstractEglBackend::supportedFormats() const
     return m_supportedFormats;
 }
 
-EGLConfig AbstractEglBackend::initBufferConfigs()
-{
-    const EGLint config_attribs[] = {
-        EGL_SURFACE_TYPE,
-        EGL_WINDOW_BIT,
-        EGL_RED_SIZE,
-        1,
-        EGL_GREEN_SIZE,
-        1,
-        EGL_BLUE_SIZE,
-        1,
-        EGL_ALPHA_SIZE,
-        0,
-        EGL_RENDERABLE_TYPE,
-        isOpenGLES() ? EGL_OPENGL_ES2_BIT : EGL_OPENGL_BIT,
-        EGL_CONFIG_CAVEAT,
-        EGL_NONE,
-        EGL_NONE,
-    };
-
-    EGLint count;
-    EGLConfig configs[1024];
-    if (eglChooseConfig(eglDisplay(), config_attribs, configs, 1, &count) == EGL_FALSE) {
-        qCCritical(KWIN_OPENGL) << "choose config failed";
-        return EGL_NO_CONFIG_KHR;
-    }
-    if (count != 1) {
-        qCCritical(KWIN_OPENGL) << "choose config did not return a config" << count;
-        return EGL_NO_CONFIG_KHR;
-    }
-    return configs[0];
-}
-
 ::EGLDisplay AbstractEglBackend::eglDisplay() const
 {
     return m_display->handle();

src/platformsupport/scenes/opengl/abstract_egl_backend.h

@@ -77,7 +77,6 @@ protected:
     bool hasClientExtension(const QByteArray &ext) const;
     bool isOpenGLES() const;
     bool createContext(EGLConfig config);
-    virtual EGLConfig initBufferConfigs();
 
 private:
     bool ensureGlobalShareContext(EGLConfig config);