backends/drm: introduce DrmDisplayDevice

DrmDisplayDevice is a new parent class for both normal and lease outputs,
which makes it possible to simplify a few things

src/backends/drm/CMakeLists.txt

@@ -13,6 +13,7 @@ set(DRM_SOURCES
     drm_gpu.cpp
     dumb_swapchain.cpp
     shadowbuffer.cpp
+    drm_display_device.cpp
     drm_pipeline.cpp
     drm_pipeline_legacy.cpp
     drm_abstract_output.cpp

src/backends/drm/drm_abstract_output.cpp

@@ -15,16 +15,11 @@ namespace KWin
 
 DrmAbstractOutput::DrmAbstractOutput(DrmGpu *gpu)
     : AbstractWaylandOutput(gpu->platform())
+    , DrmDisplayDevice(gpu)
     , m_renderLoop(new RenderLoop(this))
-    , m_gpu(gpu)
 {
 }
 
-DrmGpu *DrmAbstractOutput::gpu() const
-{
-    return m_gpu;
-}
-
 RenderLoop *DrmAbstractOutput::renderLoop() const
 {
     return m_renderLoop;

src/backends/drm/drm_abstract_output.h

@@ -9,41 +9,25 @@
 #pragma once
 
 #include "abstract_wayland_output.h"
+#include "drm_display_device.h"
 
 namespace KWin
 {
 
 class DrmBackend;
-class DrmGpu;
-class DrmBuffer;
-class GbmBuffer;
 
-class DrmAbstractOutput : public AbstractWaylandOutput
+class DrmAbstractOutput : public AbstractWaylandOutput, public DrmDisplayDevice
 {
     Q_OBJECT
 public:
-    virtual bool present(const QSharedPointer<DrmBuffer> &buffer, QRegion damagedRegion) = 0;
+    DrmAbstractOutput(DrmGpu *gpu);
 
-    virtual bool needsSoftwareTransformation() const = 0;
-    virtual QSize bufferSize() const = 0;
-    virtual QSize sourceSize() const = 0;
-    virtual bool isFormatSupported(uint32_t drmFormat) const = 0;
-    virtual QVector<uint64_t> supportedModifiers(uint32_t drmFormat) const = 0;
-    /**
-     * returns the maximum bits per color channel that make sense to be used for this output
-     */
-    virtual int maxBpc() const = 0;
-
-    DrmGpu *gpu() const;
     RenderLoop *renderLoop() const override;
 
 protected:
-    friend class DrmBackend;
     friend class DrmGpu;
-    DrmAbstractOutput(DrmGpu *gpu);
 
     RenderLoop *m_renderLoop;
-    DrmGpu *m_gpu;
 };
 
 }

src/backends/drm/drm_display_device.cpp

@@ -0,0 +1,24 @@
+/*
+    KWin - the KDE window manager
+    This file is part of the KDE project.
+
+    SPDX-FileCopyrightText: 2022 Xaver Hugl <xaver.hugl@gmail.com>
+
+    SPDX-License-Identifier: GPL-2.0-or-later
+*/
+#include "drm_display_device.h"
+
+namespace KWin
+{
+
+DrmDisplayDevice::DrmDisplayDevice(DrmGpu *gpu)
+    : m_gpu(gpu)
+{
+}
+
+DrmGpu *DrmDisplayDevice::gpu() const
+{
+    return m_gpu;
+}
+
+}

src/backends/drm/drm_display_device.h

@@ -0,0 +1,41 @@
+/*
+    KWin - the KDE window manager
+    This file is part of the KDE project.
+
+    SPDX-FileCopyrightText: 2022 Xaver Hugl <xaver.hugl@gmail.com>
+
+    SPDX-License-Identifier: GPL-2.0-or-later
+*/
+#pragma once
+
+#include <QRegion>
+
+#include "drm_object_plane.h"
+
+namespace KWin
+{
+
+class DrmBuffer;
+class DrmGpu;
+
+class DrmDisplayDevice
+{
+public:
+    DrmDisplayDevice(DrmGpu *gpu);
+    virtual ~DrmDisplayDevice() = default;
+
+    DrmGpu *gpu() const;
+
+    virtual bool present(const QSharedPointer<DrmBuffer> &buffer, QRegion damagedRegion) = 0;
+    virtual DrmPlane::Transformations softwareTransforms() const = 0;
+    virtual QSize bufferSize() const = 0;
+    virtual QSize sourceSize() const = 0;
+    virtual bool isFormatSupported(uint32_t drmFormat) const = 0;
+    virtual QVector<uint64_t> supportedModifiers(uint32_t drmFormat) const = 0;
+    virtual int maxBpc() const = 0;
+
+protected:
+    DrmGpu *const m_gpu;
+};
+
+}

src/backends/drm/drm_lease_output.cpp

@@ -29,6 +29,7 @@ DrmLeaseOutput::DrmLeaseOutput(DrmPipeline *pipeline, KWaylandServer::DrmLeaseDe
         pipeline->connector()->modelName(),
         QStringLiteral("%1 %2").arg(pipeline->connector()->edid()->manufacturerString(), pipeline->connector()->modelName())
     )
+    , DrmDisplayDevice(pipeline->gpu())
     , m_pipeline(pipeline)
 {
     qCDebug(KWIN_DRM) << "offering connector" << m_pipeline->connector()->id() << "for lease";
@@ -75,4 +76,45 @@ DrmPipeline *DrmLeaseOutput::pipeline() const
     return m_pipeline;
 }
 
+bool DrmLeaseOutput::present(const QSharedPointer<DrmBuffer> &buffer, QRegion damagedRegion)
+{
+    Q_UNUSED(buffer)
+    Q_UNUSED(damagedRegion)
+    return false;
+}
+
+DrmPlane::Transformations DrmLeaseOutput::softwareTransforms() const
+{
+    return DrmPlane::Transformation::Rotate0;
+}
+
+QSize DrmLeaseOutput::bufferSize() const
+{
+    return m_pipeline->bufferSize();
+}
+
+QSize DrmLeaseOutput::sourceSize() const
+{
+    return m_pipeline->sourceSize();
+}
+
+bool DrmLeaseOutput::isFormatSupported(uint32_t drmFormat) const
+{
+    return m_pipeline->isFormatSupported(drmFormat);
+}
+
+QVector<uint64_t> DrmLeaseOutput::supportedModifiers(uint32_t drmFormat) const
+{
+    return m_pipeline->supportedModifiers(drmFormat);
+}
+
+int DrmLeaseOutput::maxBpc() const
+{
+    if (const auto prop = m_pipeline->connector()->getProp(DrmConnector::PropertyIndex::MaxBpc)) {
+        return prop->maxValue();
+    } else {
+        return 8;
+    }
+}
+
 }

src/backends/drm/drm_lease_output.h

@@ -13,6 +13,8 @@
 #include <QVector>
 #include <KWaylandServer/drmleasedevice_v1_interface.h>
 
+#include "drm_display_device.h"
+
 namespace KWin
 {
 
@@ -24,7 +26,7 @@ class DrmPipeline;
  * that is not used directly by the compositor but is instead leased out to
  * applications (usually VR compositors) that drive the output themselves
  */
-class DrmLeaseOutput : public KWaylandServer::DrmLeaseConnectorV1Interface
+class DrmLeaseOutput : public KWaylandServer::DrmLeaseConnectorV1Interface, public DrmDisplayDevice
 {
     Q_OBJECT
 public:
@@ -38,6 +40,14 @@ public:
     KWaylandServer::DrmLeaseV1Interface *lease() const;
     DrmPipeline *pipeline() const;
 
+    bool present(const QSharedPointer<DrmBuffer> &buffer, QRegion damagedRegion) override;
+    DrmPlane::Transformations softwareTransforms() const override;
+    QSize bufferSize() const override;
+    QSize sourceSize() const override;
+    bool isFormatSupported(uint32_t drmFormat) const override;
+    QVector<uint64_t> supportedModifiers(uint32_t drmFormat) const override;
+    int maxBpc() const override;
+
 private:
     DrmPipeline *m_pipeline;
     KWaylandServer::DrmLeaseV1Interface *m_lease = nullptr;

src/backends/drm/drm_output.cpp

@@ -318,11 +318,6 @@ void DrmOutput::updateModes()
     }
 }
 
-bool DrmOutput::needsSoftwareTransformation() const
-{
-    return m_pipeline->pending.bufferTransformation != m_pipeline->pending.sourceTransformation;
-}
-
 bool DrmOutput::present(const QSharedPointer<DrmBuffer> &buffer, QRegion damagedRegion)
 {
     if (!buffer || buffer->bufferId() == 0) {
@@ -472,4 +467,14 @@ bool DrmOutput::usesSoftwareCursor() const
     return !m_setCursorSuccessful || !m_moveCursorSuccessful;
 }
 
+DrmPlane::Transformations DrmOutput::softwareTransforms() const
+{
+    if (m_pipeline->pending.bufferTransformation == m_pipeline->pending.sourceTransformation) {
+        return DrmPlane::Transformation::Rotate0;
+    } else {
+        // TODO handle sourceTransformation != Rotate0
+        return m_pipeline->pending.sourceTransformation;
+    }
+}
+
 }

src/backends/drm/drm_output.h

@@ -52,7 +52,7 @@ public:
     QSize sourceSize() const override;
     bool isFormatSupported(uint32_t drmFormat) const override;
     QVector<uint64_t> supportedModifiers(uint32_t drmFormat) const override;
-    bool needsSoftwareTransformation() const override;
+    DrmPlane::Transformations softwareTransforms() const override;
     int maxBpc() const override;
 
     bool queueChanges(const WaylandOutputConfig &config);

src/backends/drm/drm_virtual_output.cpp

@@ -109,14 +109,14 @@ bool DrmVirtualOutput::setGammaRamp(const GammaRamp &gamma)
     return true;
 }
 
-bool DrmVirtualOutput::needsSoftwareTransformation() const
-{
-    return false;
-}
-
 int DrmVirtualOutput::maxBpc() const
 {
     return 8;
 }
 
+DrmPlane::Transformations DrmVirtualOutput::softwareTransforms() const
+{
+    return DrmPlane::Transformation::Rotate0;
+}
+
 }

src/backends/drm/drm_virtual_output.h

@@ -38,7 +38,7 @@ public:
 
     int gammaRampSize() const override;
     bool setGammaRamp(const GammaRamp &gamma) override;
-    bool needsSoftwareTransformation() const override;
+    DrmPlane::Transformations softwareTransforms() const override;
 
 private:
     void vblank(std::chrono::nanoseconds timestamp);

src/backends/drm/egl_gbm_layer.cpp

@@ -85,7 +85,7 @@ std::optional<QRegion> EglGbmLayer::startRendering()
         if (doesShadowBufferFit(m_oldShadowBuffer.data())) {
             m_shadowBuffer = m_oldShadowBuffer;
         } else {
-            if (m_output->needsSoftwareTransformation()) {
+            if (m_output->softwareTransforms() != DrmPlane::Transformations(DrmPlane::Transformation::Rotate0)) {
                 const auto format = m_renderGpu->eglBackend()->gbmFormatForDrmFormat(m_gbmSurface->format());
                 m_shadowBuffer = QSharedPointer<ShadowBuffer>::create(m_output->sourceSize(), format);
                 if (!m_shadowBuffer->isComplete()) {
@@ -200,7 +200,7 @@ bool EglGbmLayer::doesGbmSurfaceFit(GbmSurface *surf) const
 
 bool EglGbmLayer::doesShadowBufferFit(ShadowBuffer *buffer) const
 {
-    if (m_output->needsSoftwareTransformation()) {
+    if (m_output->softwareTransforms() != DrmPlane::Transformations(DrmPlane::Transformation::Rotate0)) {
         return buffer && buffer->texture()->size() == m_output->sourceSize() && buffer->drmFormat() == m_gbmSurface->format();
     } else {
         return buffer == nullptr;