kwin/plugins/platforms/drm/egl_multi_backend.h
Vlad Zahorodnii 0ceff5fd24 Swap buffers after finishing a compositing cycle
The compositing timing algorithm assumes that glXSwapBuffers() and
eglSwapBuffers() block. While this was true long time ago with NVIDIA
drivers, nowadays, it's not the case. The NVIDIA driver queues
several buffers in advance and if the application runs out of them,
it will block. With Mesa driver, swapping buffer was never blocking.

This change makes the render backends swap buffers right after ending
a compositing cycle. This may potentially block, but it shouldn't be
an issue with modern drivers. In case it gets proven, we can move
glXSwapBuffers() and eglSwapBuffers() in a separate thread.

Note that this change breaks the compositing timing algorithm, but
it's already sort of broken with Mesa drivers.
2021-01-06 16:59:29 +00:00

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1.2 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 EGLMULTIBACKEND_H
#define EGLMULTIBACKEND_H
#include "abstract_egl_drm_backend.h"
namespace KWin
{
class EglMultiBackend : public OpenGLBackend
{
public:
EglMultiBackend(AbstractEglDrmBackend *backend0);
~EglMultiBackend();
void init() override;
QRegion beginFrame(int screenId) override;
void endFrame(int screenId, const QRegion &damage, const QRegion &damagedRegion) override;
bool makeCurrent() override;
void doneCurrent() override;
SceneOpenGLTexturePrivate *createBackendTexture(SceneOpenGLTexture *texture) override;
QSharedPointer<GLTexture> textureForOutput(AbstractOutput *requestedOutput) const override;
bool usesOverlayWindow() const override;
void screenGeometryChanged(const QSize &size) override;
void addBackend(AbstractEglDrmBackend *backend);
private:
QVector<AbstractEglDrmBackend*> m_backends;
AbstractEglDrmBackend *findBackend(int screenId, int& internalScreenId);
};
}
#endif // EGLMULTIBACKEND_H