Remove Platform::repaint()

It doesn't belong in Platform.

src/backends/x11/windowed/x11_windowed_backend.cpp

@@ -572,7 +572,11 @@ void X11WindowedBackend::handleButtonPress(xcb_button_press_event_t *event)
 
 void X11WindowedBackend::handleExpose(xcb_expose_event_t *event)
 {
-    repaint(QRect(event->x, event->y, event->width, event->height));
+    X11WindowedOutput *output = findOutput(event->window);
+    if (output) {
+        output->addExposedArea(QRect(event->x, event->y, event->width, event->height));
+        output->renderLoop()->scheduleRepaint();
+    }
 }
 
 void X11WindowedBackend::updateSize(xcb_configure_notify_event_t *event)

src/backends/x11/windowed/x11_windowed_egl_backend.cpp

@@ -19,7 +19,7 @@
 namespace KWin
 {
 
-X11WindowedEglOutput::X11WindowedEglOutput(X11WindowedEglBackend *backend, Output *output, EGLSurface surface)
+X11WindowedEglOutput::X11WindowedEglOutput(X11WindowedEglBackend *backend, X11WindowedOutput *output, EGLSurface surface)
     : m_eglSurface(surface)
     , m_output(output)
     , m_backend(backend)
@@ -43,9 +43,13 @@ std::optional<OutputLayerBeginFrameInfo> X11WindowedEglOutput::beginFrame()
     eglMakeCurrent(m_backend->eglDisplay(), m_eglSurface, m_eglSurface, m_backend->context());
     ensureFbo();
     GLFramebuffer::pushFramebuffer(m_fbo.get());
+
+    QRegion repaint = m_output->exposedArea() + m_output->rect();
+    m_output->clearExposedArea();
+
     return OutputLayerBeginFrameInfo{
         .renderTarget = RenderTarget(m_fbo.get()),
-        .repaint = m_output->rect(),
+        .repaint = repaint,
     };
 }
 
@@ -97,7 +101,7 @@ bool X11WindowedEglBackend::createSurfaces()
         if (s == EGL_NO_SURFACE) {
             return false;
         }
-        m_outputs[output] = std::make_shared<X11WindowedEglOutput>(this, output, s);
+        m_outputs[output] = std::make_shared<X11WindowedEglOutput>(this, static_cast<X11WindowedOutput *>(output), s);
     }
     if (m_outputs.isEmpty()) {
         return false;

src/backends/x11/windowed/x11_windowed_egl_backend.h

@@ -18,12 +18,13 @@ namespace KWin
 {
 
 class X11WindowedBackend;
+class X11WindowedOutput;
 class X11WindowedEglBackend;
 
 class X11WindowedEglOutput : public OutputLayer
 {
 public:
-    X11WindowedEglOutput(X11WindowedEglBackend *backend, Output *output, EGLSurface surface);
+    X11WindowedEglOutput(X11WindowedEglBackend *backend, X11WindowedOutput *output, EGLSurface surface);
     ~X11WindowedEglOutput();
 
     std::optional<OutputLayerBeginFrameInfo> beginFrame() override;
@@ -38,7 +39,7 @@ private:
     std::unique_ptr<GLFramebuffer> m_fbo;
     QRegion m_lastDamage;
 
-    Output *const m_output;
+    X11WindowedOutput *const m_output;
     X11WindowedEglBackend *const m_backend;
 };
 

src/backends/x11/windowed/x11_windowed_output.cpp

@@ -49,6 +49,21 @@ X11WindowedOutput::~X11WindowedOutput()
     xcb_flush(m_backend->connection());
 }
 
+QRegion X11WindowedOutput::exposedArea() const
+{
+    return m_exposedArea;
+}
+
+void X11WindowedOutput::addExposedArea(const QRect &rect)
+{
+    m_exposedArea += rect;
+}
+
+void X11WindowedOutput::clearExposedArea()
+{
+    m_exposedArea = QRegion();
+}
+
 RenderLoop *X11WindowedOutput::renderLoop() const
 {
     return m_renderLoop.get();

src/backends/x11/windowed/x11_windowed_output.h

@@ -69,6 +69,10 @@ public:
     bool usesSoftwareCursor() const override;
     void updateEnablement(bool enabled) override;
 
+    QRegion exposedArea() const;
+    void addExposedArea(const QRect &rect);
+    void clearExposedArea();
+
 private:
     void initXInputForWindow();
     void vblank(std::chrono::nanoseconds timestamp);
@@ -78,6 +82,7 @@ private:
     std::unique_ptr<RenderLoop> m_renderLoop;
     std::unique_ptr<SoftwareVsyncMonitor> m_vsyncMonitor;
     QPoint m_hostPosition;
+    QRegion m_exposedArea;
 
     X11WindowedBackend *m_backend;
 };

src/backends/x11/windowed/x11_windowed_qpainter_backend.cpp

@@ -14,7 +14,7 @@
 namespace KWin
 {
 
-X11WindowedQPainterOutput::X11WindowedQPainterOutput(Output *output, xcb_window_t window)
+X11WindowedQPainterOutput::X11WindowedQPainterOutput(X11WindowedOutput *output, xcb_window_t window)
     : window(window)
     , m_output(output)
 {
@@ -33,9 +33,13 @@ void X11WindowedQPainterOutput::ensureBuffer()
 std::optional<OutputLayerBeginFrameInfo> X11WindowedQPainterOutput::beginFrame()
 {
     ensureBuffer();
+
+    QRegion repaint = m_output->exposedArea() + m_output->rect();
+    m_output->clearExposedArea();
+
     return OutputLayerBeginFrameInfo{
         .renderTarget = RenderTarget(&buffer),
-        .repaint = m_output->rect(),
+        .repaint = repaint,
     };
 }
 
@@ -69,7 +73,8 @@ X11WindowedQPainterBackend::~X11WindowedQPainterBackend()
 
 void X11WindowedQPainterBackend::addOutput(Output *output)
 {
-    m_outputs[output] = std::make_unique<X11WindowedQPainterOutput>(output, m_backend->windowForScreen(output));
+    X11WindowedOutput *x11Output = static_cast<X11WindowedOutput *>(output);
+    m_outputs[output] = std::make_unique<X11WindowedQPainterOutput>(x11Output, m_backend->windowForScreen(x11Output));
 }
 
 void X11WindowedQPainterBackend::removeOutput(Output *output)

src/backends/x11/windowed/x11_windowed_qpainter_backend.h

@@ -23,11 +23,12 @@ namespace KWin
 {
 
 class X11WindowedBackend;
+class X11WindowedOutput;
 
 class X11WindowedQPainterOutput : public OutputLayer
 {
 public:
-    X11WindowedQPainterOutput(Output *output, xcb_window_t window);
+    X11WindowedQPainterOutput(X11WindowedOutput *output, xcb_window_t window);
 
     void ensureBuffer();
 
@@ -36,7 +37,7 @@ public:
 
     xcb_window_t window;
     QImage buffer;
-    Output *const m_output;
+    X11WindowedOutput *const m_output;
 };
 
 class X11WindowedQPainterBackend : public QPainterBackend

src/platform.cpp

@@ -164,13 +164,6 @@ Output *Platform::findOutput(const QString &name) const
     return nullptr;
 }
 
-void Platform::repaint(const QRect &rect)
-{
-    if (Compositor::compositing()) {
-        Compositor::self()->scene()->addRepaint(rect);
-    }
-}
-
 void Platform::setReady(bool ready)
 {
     if (m_ready == ready) {

src/platform.h

@@ -372,7 +372,6 @@ Q_SIGNALS:
 
 protected:
     explicit Platform(QObject *parent = nullptr);
-    void repaint(const QRect &rect);
     void setReady(bool ready);
     QSize initialWindowSize() const
     {