Improvements for direct scanout

Instead of cancelling direct scanout if the client buffer is not
fitting, adjust the atomic planes. Also ignore all toplevels from
other screens.

src/plugins/platforms/drm/drm_output.cpp

@@ -955,14 +955,23 @@ bool DrmOutput::atomicReqModesetPopulate(drmModeAtomicReq *req, bool enable)
 {
     if (enable) {
         const QSize mSize = modeSize();
-        const QSize sourceSize = hardwareTransforms() ? pixelSize() : mSize;
+        const QSize bufferSize = m_primaryPlane->next() ? m_primaryPlane->next()->size() : pixelSize();
+        const QSize sourceSize = hardwareTransforms() ? bufferSize : mSize;
+        QRect targetRect = QRect(QPoint(0, 0), mSize);
+        if (mSize != sourceSize) {
+            targetRect.setSize(sourceSize.scaled(mSize, Qt::AspectRatioMode::KeepAspectRatio));
+            targetRect.setX((mSize.width() - targetRect.width()) / 2);
+            targetRect.setY((mSize.height() - targetRect.height()) / 2);
+        }
 
         m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::SrcX), 0);
         m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::SrcY), 0);
         m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::SrcW), sourceSize.width() << 16);
         m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::SrcH), sourceSize.height() << 16);
-        m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcW), mSize.width());
-        m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcH), mSize.height());
+        m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcX), targetRect.x());
+        m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcY), targetRect.y());
+        m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcW), targetRect.width());
+        m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcH), targetRect.height());
         m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcId), m_crtc->id());
     } else {
         if (m_gpu->deleteBufferAfterPageFlip()) {
@@ -976,6 +985,8 @@ bool DrmOutput::atomicReqModesetPopulate(drmModeAtomicReq *req, bool enable)
         m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::SrcY), 0);
         m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::SrcW), 0);
         m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::SrcH), 0);
+        m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcX), 0);
+        m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcY), 0);
         m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcW), 0);
         m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcH), 0);
         m_primaryPlane->setValue(int(DrmPlane::PropertyIndex::CrtcId), 0);

src/plugins/platforms/drm/egl_gbm_backend.cpp

@@ -698,7 +698,8 @@ bool EglGbmBackend::scanout(int screenId, KWaylandServer::SurfaceInterface *surf
     }
     auto buffer = surface->buffer();
     Output output = m_outputs[screenId];
-    if (buffer->linuxDmabufBuffer()->size() != output.output->modeSize()) {
+    if (buffer->linuxDmabufBuffer()->size() != output.output->modeSize()
+        && output.output->isBeingRecorded()) {
         return false;
     }
     EglDmabufBuffer *dmabuf = static_cast<EglDmabufBuffer*>(buffer->linuxDmabufBuffer());
@@ -739,7 +740,7 @@ bool EglGbmBackend::scanout(int screenId, KWaylandServer::SurfaceInterface *surf
     }
     // damage tracking for screen casting
     QRegion damage;
-    if (output.surfaceInterface == surface) {
+    if (output.surfaceInterface == surface && buffer->size() == output.output->modeSize()) {
         QRegion trackedDamage = surface->trackedDamage();
         surface->resetTrackedDamage();
         for (const auto &rect : trackedDamage) {

src/plugins/scenes/opengl/scene_opengl.cpp

@@ -638,24 +638,23 @@ void SceneOpenGL::paint(int screenId, const QRegion &damage, const QList<Topleve
             if (!implEffects->blocksDirectScanout()) {
                 for (int i = stacking_order.count() - 1; i >= 0; i--) {
                     Window *window = stacking_order[i];
-                    AbstractClient *c = dynamic_cast<AbstractClient*>(window->window());
-                    if (!c) {
-                        break;
-                    }
-                    if (c->isOnScreen(screenId)) {
-                        if (window->isOpaque() && c->isFullScreen()) {
-                            auto pixmap = window->windowPixmap<WindowPixmap>();
-                            if (!pixmap) {
-                                break;
-                            }
-                            pixmap->update();
-                            pixmap = pixmap->topMostSurface();
-                            // the subsurface has to be able to cover the whole window
-                            if (pixmap->position() != QPoint(0, 0)) {
-                                break;
-                            }
-                            directScanout = m_backend->scanout(screenId, pixmap->surface());
+                    Toplevel *toplevel = window->window();
+                    if (toplevel->isOnScreen(screenId)) {
+                        AbstractClient *c = dynamic_cast<AbstractClient*>(toplevel);
+                        if (!c || !c->isFullScreen() || !window->isOpaque()) {
+                            break;
+                        }
+                        auto pixmap = window->windowPixmap<WindowPixmap>();
+                        if (!pixmap) {
+                            break;
+                        }
+                        pixmap->update();
+                        pixmap = pixmap->topMostSurface();
+                        // the subsurface has to be able to cover the whole window
+                        if (pixmap->position() != QPoint(0, 0)) {
+                            break;
                         }
+                        directScanout = m_backend->scanout(screenId, pixmap->surface());
                         break;
                     }
                 }