kwin/plugins/platforms/drm/drm_output.h
Vlad Zahorodnii b8a70e62d5 Introduce RenderLoop
At the moment, our frame scheduling infrastructure is still heavily
based on Xinerama-style rendering. Specifically, we assume that painting
is driven by a single timer, etc.

This change introduces a new type - RenderLoop. Its main purpose is to
drive compositing on a specific output, or in case of X11, on the
overlay window.

With RenderLoop, compositing is synchronized to vblank events. It
exposes the last and the next estimated presentation timestamp. The
expected presentation timestamp can be used by effects to ensure that
animations are synchronized with the upcoming vblank event.

On Wayland, every outputs has its own render loop. On X11, per screen
rendering is not possible, therefore the platform exposes the render
loop for the overlay window. Ideally, the Scene has to expose the
RenderLoop, but as the first step towards better compositing scheduling
it's good as is for the time being.

The RenderLoop tries to minimize the latency by delaying compositing as
close as possible to the next vblank event. One tricky thing about it is
that if compositing is too close to the next vblank event, animations
may become a little bit choppy. However, increasing the latency reduces
the choppiness.

Given that, there is no any "silver bullet" solution for the choppiness
issue, a new option has been added in the Compositing KCM to specify the
amount of latency. By default, it's "Medium," but if a user is not
satisfied with the upstream default, they can tweak it.
2021-01-06 16:59:29 +00:00

189 lines
4.9 KiB
C++

/*
KWin - the KDE window manager
This file is part of the KDE project.
SPDX-FileCopyrightText: 2015 Martin Gräßlin <mgraesslin@kde.org>
SPDX-License-Identifier: GPL-2.0-or-later
*/
#ifndef KWIN_DRM_OUTPUT_H
#define KWIN_DRM_OUTPUT_H
#include "abstract_wayland_output.h"
#include "drm_pointer.h"
#include "drm_object.h"
#include "drm_object_plane.h"
#include "edid.h"
#include <QObject>
#include <QPoint>
#include <QSize>
#include <QVector>
#include <xf86drmMode.h>
namespace KWin
{
class DrmBackend;
class DrmBuffer;
class DrmDumbBuffer;
class DrmPlane;
class DrmConnector;
class DrmCrtc;
class Cursor;
class DrmGpu;
class KWIN_EXPORT DrmOutput : public AbstractWaylandOutput
{
Q_OBJECT
public:
///deletes the output, calling this whilst a page flip is pending will result in an error
~DrmOutput() override;
RenderLoop *renderLoop() const override;
///queues deleting the output after a page flip has completed.
void teardown();
void releaseGbm();
bool showCursor(DrmDumbBuffer *buffer);
bool showCursor();
bool hideCursor();
bool updateCursor();
void moveCursor();
bool init(drmModeConnector *connector);
bool present(DrmBuffer *buffer);
void pageFlipped();
// These values are defined by the kernel
enum class DpmsMode {
On = DRM_MODE_DPMS_ON,
Standby = DRM_MODE_DPMS_STANDBY,
Suspend = DRM_MODE_DPMS_SUSPEND,
Off = DRM_MODE_DPMS_OFF
};
Q_ENUM(DpmsMode);
bool isDpmsEnabled() const {
// We care for current as well as pending mode in order to allow first present in AMS.
return m_dpmsModePending == DpmsMode::On;
}
DpmsMode dpmsMode() const {
return m_dpmsMode;
}
DpmsMode dpmsModePending() const {
return m_dpmsModePending;
}
const DrmCrtc *crtc() const {
return m_crtc;
}
const DrmConnector *connector() const {
return m_conn;
}
const DrmPlane *primaryPlane() const {
return m_primaryPlane;
}
bool initCursor(const QSize &cursorSize);
/**
* Drm planes might be capable of realizing the current output transform without usage
* of compositing. This is a getter to query the current state of that
*
* @return true if the hardware realizes the transform without further assistance
*/
bool hardwareTransforms() const;
DrmGpu *gpu() {
return m_gpu;
}
private:
friend class DrmGpu;
friend class DrmBackend;
friend class DrmCrtc; // TODO: For use of setModeLegacy. Remove later when we allow multiple connectors per crtc
// and save the connector ids in the DrmCrtc instance.
DrmOutput(DrmBackend *backend, DrmGpu* gpu);
bool presentAtomically(DrmBuffer *buffer);
enum class AtomicCommitMode {
Test,
Real
};
bool doAtomicCommit(AtomicCommitMode mode);
bool presentLegacy(DrmBuffer *buffer);
bool setModeLegacy(DrmBuffer *buffer);
void initEdid(drmModeConnector *connector);
void initDpms(drmModeConnector *connector);
void initOutputDevice(drmModeConnector *connector);
bool isCurrentMode(const drmModeModeInfo *mode) const;
void initUuid();
bool initPrimaryPlane();
bool initCursorPlane();
void atomicEnable();
void atomicDisable();
void updateEnablement(bool enable) override;
bool dpmsAtomicOff();
bool dpmsLegacyApply();
void dpmsFinishOn();
void dpmsFinishOff();
bool atomicReqModesetPopulate(drmModeAtomicReq *req, bool enable);
void updateDpms(KWaylandServer::OutputInterface::DpmsMode mode) override;
void updateMode(int modeIndex) override;
void updateMode(uint32_t width, uint32_t height, uint32_t refreshRate);
void setWaylandMode();
void updateTransform(Transform transform) override;
int gammaRampSize() const override;
bool setGammaRamp(const GammaRamp &gamma) override;
DrmBackend *m_backend;
DrmGpu *m_gpu;
DrmConnector *m_conn = nullptr;
DrmCrtc *m_crtc = nullptr;
bool m_lastGbm = false;
drmModeModeInfo m_mode;
Edid m_edid;
DrmScopedPointer<drmModePropertyRes> m_dpms;
DpmsMode m_dpmsMode = DpmsMode::On;
DpmsMode m_dpmsModePending = DpmsMode::On;
QByteArray m_uuid;
RenderLoop *m_renderLoop;
uint32_t m_blobId = 0;
DrmPlane *m_primaryPlane = nullptr;
DrmPlane *m_cursorPlane = nullptr;
QVector<DrmPlane*> m_nextPlanesFlipList;
bool m_pageFlipPending = false;
bool m_atomicOffPending = false;
bool m_modesetRequested = true;
struct {
Transform transform;
drmModeModeInfo mode;
DrmPlane::Transformations planeTransformations;
QPoint globalPos;
bool valid = false;
} m_lastWorkingState;
QScopedPointer<DrmDumbBuffer> m_cursor[2];
int m_cursorIndex = 0;
bool m_hasNewCursor = false;
bool m_deleted = false;
};
}
Q_DECLARE_METATYPE(KWin::DrmOutput*)
QDebug& operator<<(QDebug& stream, const KWin::DrmOutput *);
#endif