kwin/plugins/platforms/drm/drm_gpu.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

152 lines
3.1 KiB
C++

/*
KWin - the KDE window manager
This file is part of the KDE project.
SPDX-FileCopyrightText: 2020 Xaver Hugl <xaver.hugl@gmail.com>
SPDX-License-Identifier: GPL-2.0-or-later
*/
#ifndef DRM_GPU_H
#define DRM_GPU_H
#include <qobject.h>
#include <QVector>
#include <epoxy/egl.h>
#include "drm_buffer.h"
struct gbm_device;
namespace KWin
{
class DrmOutput;
class DrmPlane;
class DrmCrtc;
class DrmConnector;
class DrmBackend;
class AbstractEglBackend;
class DrmGpu : public QObject
{
Q_OBJECT
public:
DrmGpu(DrmBackend *backend, QByteArray devNode, int fd, int drmId);
~DrmGpu();
// getters
QVector<DrmOutput*> outputs() const {
return m_outputs;
}
int fd() const {
return m_fd;
}
int drmId() const {
return m_drmId;
}
bool atomicModeSetting() const {
return m_atomicModeSetting;
}
bool useEglStreams() const {
return m_useEglStreams;
}
bool deleteBufferAfterPageFlip() const {
return m_deleteBufferAfterPageFlip;
}
QByteArray devNode() const {
return m_devNode;
}
gbm_device *gbmDevice() const {
return m_gbmDevice;
}
EGLDisplay eglDisplay() const {
return m_eglDisplay;
}
QVector<DrmPlane*> planes() const {
return m_planes;
}
AbstractEglBackend *eglBackend() {
return m_eglBackend;
}
void setGbmDevice(gbm_device *d) {
m_gbmDevice = d;
}
void setEglDisplay(EGLDisplay display) {
m_eglDisplay = display;
}
void setDeleteBufferAfterPageFlip(bool deleteBuffer) {
m_deleteBufferAfterPageFlip = deleteBuffer;
}
DrmDumbBuffer *createBuffer(const QSize &size) const {
return new DrmDumbBuffer(m_fd, size);
}
void setEglBackend(AbstractEglBackend *eglBackend) {
m_eglBackend = eglBackend;
}
/**
* Returns the clock from which presentation timestamps are sourced. The returned value
* can be either CLOCK_MONOTONIC or CLOCK_REALTIME.
*/
clockid_t presentationClock() const;
Q_SIGNALS:
void outputAdded(DrmOutput *output);
void outputRemoved(DrmOutput *output);
void outputEnabled(DrmOutput *output);
void outputDisabled(DrmOutput *output);
protected:
friend class DrmBackend;
void tryAMS();
bool updateOutputs();
private:
DrmOutput *findOutput(quint32 connector);
DrmBackend* const m_backend;
AbstractEglBackend *m_eglBackend;
const QByteArray m_devNode;
QSize m_cursorSize;
const int m_fd;
const int m_drmId;
bool m_atomicModeSetting;
bool m_useEglStreams;
bool m_deleteBufferAfterPageFlip;
gbm_device* m_gbmDevice;
EGLDisplay m_eglDisplay = EGL_NO_DISPLAY;
clockid_t m_presentationClock;
// all available planes: primarys, cursors and overlays
QVector<DrmPlane*> m_planes;
QVector<DrmPlane*> m_overlayPlanes;
// crtcs
QVector<DrmCrtc*> m_crtcs;
// connectors
QVector<DrmConnector*> m_connectors;
// active output pipelines (planes + crtc + encoder + connector)
QVector<DrmOutput*> m_outputs;
};
}
#endif // DRM_GPU_H