kwin/plugins/scenes/qpainter/scene_qpainter.h
David Edmundson 40b0296d5c [libkwineffects] Introduce API to easily show a QtQuick scene in an effect
Summary:
EffectQuickView/Scene is a convenient class to render a QtQuick
scenegraph into an effect.

Current methods (such as present windows) involve creating an underlying
platform window which is expensive, causes a headache to filter out
again in the rest of the code, and only works as an overlay.

The new class exposes things more natively to an effect where we don't
mess with real windows, we can perform the painting anywhere in the view
and we don't have issues with hiding/closing.

QtQuick has both software and hardware accelerated modes, and kwin also
has 3 render backends. Every combination is supported.

* When used in OpenGL mode for both, we render into an FBO export the
texture ID then it's up to the effect to render that into a scene.

* When using software QtQuick rendering we blit into an image, upload
that into a KWinGLTexture which serves as an abstraction layer and
render that into the scene.

* When using GL for QtQuick and XRender/QPainter in kwin everything is
rendered into the internal FBO, blit and exported as an image.

* When using software rendering for both an image gets passed directly.

Mouse and keyboard events can be forwarded, only if the effect
intercepts them.

The class is meant to be generic enough that we can remove all the
QtQuick code from Aurorae.

The intention is also to replace EffectFrameImpl using this backend and
we can kill all of the EffectFrame code throughout the scenes.

The close button in present windows will also be ported to this,
simplifiying that code base.

Classes that handle the rendering and handling QML are intentionally
split so that in the future we can have a declarative effects API create
overlays from within the same context. Similar to how one can
instantiate windows from a typical QML scene.

Notes:
I don't like how I pass the kwin GL context from the backends into the
effect, but I need something that works with the library separation. It
also currently has wayland problem if I create a QOpenGLContext before
the QPA is set up with a scene - but I don't have anything better?

I know for the EffectFrame we need an API to push things through the
effects stack to handle blur/invert etc. Will deal with that when we
port the EffectFrame.

Test Plan: Used in an effect

Reviewers: #kwin, zzag

Reviewed By: #kwin, zzag

Subscribers: zzag, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D24215
2019-09-27 16:11:05 +01:00

203 lines
5.5 KiB
C++

/********************************************************************
KWin - the KDE window manager
This file is part of the KDE project.
Copyright (C) 2013 Martin Gräßlin <mgraesslin@kde.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*********************************************************************/
#ifndef KWIN_SCENE_QPAINTER_H
#define KWIN_SCENE_QPAINTER_H
#include "scene.h"
#include <platformsupport/scenes/qpainter/backend.h>
#include "shadow.h"
#include "decorations/decorationrenderer.h"
namespace KWin {
class KWIN_EXPORT SceneQPainter : public Scene
{
Q_OBJECT
public:
~SceneQPainter() override;
bool usesOverlayWindow() const override;
OverlayWindow* overlayWindow() const override;
qint64 paint(QRegion damage, ToplevelList windows) override;
void paintGenericScreen(int mask, ScreenPaintData data) override;
CompositingType compositingType() const override;
bool initFailed() const override;
EffectFrame *createEffectFrame(EffectFrameImpl *frame) override;
Shadow *createShadow(Toplevel *toplevel) override;
Decoration::Renderer *createDecorationRenderer(Decoration::DecoratedClientImpl *impl) override;
void screenGeometryChanged(const QSize &size) override;
bool animationsSupported() const override {
return false;
}
QPainter *scenePainter() const override;
QImage *qpainterRenderBuffer() const override;
QPainterBackend *backend() const {
return m_backend.data();
}
static SceneQPainter *createScene(QObject *parent);
protected:
void paintBackground(QRegion region) override;
Scene::Window *createWindow(Toplevel *toplevel) override;
void paintCursor() override;
void paintEffectQuickView(EffectQuickView *w) override;
private:
explicit SceneQPainter(QPainterBackend *backend, QObject *parent = nullptr);
QScopedPointer<QPainterBackend> m_backend;
QScopedPointer<QPainter> m_painter;
class Window;
};
class SceneQPainter::Window : public Scene::Window
{
public:
Window(SceneQPainter *scene, Toplevel *c);
~Window() override;
void performPaint(int mask, QRegion region, WindowPaintData data) override;
protected:
WindowPixmap *createWindowPixmap() override;
private:
void renderShadow(QPainter *painter);
void renderWindowDecorations(QPainter *painter);
SceneQPainter *m_scene;
};
class QPainterWindowPixmap : public WindowPixmap
{
public:
explicit QPainterWindowPixmap(Scene::Window *window);
~QPainterWindowPixmap() override;
void create() override;
bool isValid() const override;
void updateBuffer() override;
const QImage &image();
protected:
WindowPixmap *createChild(const QPointer<KWayland::Server::SubSurfaceInterface> &subSurface) override;
private:
explicit QPainterWindowPixmap(const QPointer<KWayland::Server::SubSurfaceInterface> &subSurface, WindowPixmap *parent);
QImage m_image;
};
class QPainterEffectFrame : public Scene::EffectFrame
{
public:
QPainterEffectFrame(EffectFrameImpl *frame, SceneQPainter *scene);
~QPainterEffectFrame() override;
void crossFadeIcon() override {}
void crossFadeText() override {}
void free() override {}
void freeIconFrame() override {}
void freeTextFrame() override {}
void freeSelection() override {}
void render(QRegion region, double opacity, double frameOpacity) override;
private:
SceneQPainter *m_scene;
};
class SceneQPainterShadow : public Shadow
{
public:
SceneQPainterShadow(Toplevel* toplevel);
~SceneQPainterShadow() override;
QImage &shadowTexture() {
return m_texture;
}
protected:
void buildQuads() override;
bool prepareBackend() override;
private:
QImage m_texture;
};
class SceneQPainterDecorationRenderer : public Decoration::Renderer
{
Q_OBJECT
public:
enum class DecorationPart : int {
Left,
Top,
Right,
Bottom,
Count
};
explicit SceneQPainterDecorationRenderer(Decoration::DecoratedClientImpl *client);
~SceneQPainterDecorationRenderer() override;
void render() override;
void reparent(Deleted *deleted) override;
QImage image(DecorationPart part) const;
private:
void resizeImages();
QImage m_images[int(DecorationPart::Count)];
};
class KWIN_EXPORT QPainterFactory : public SceneFactory
{
Q_OBJECT
Q_INTERFACES(KWin::SceneFactory)
Q_PLUGIN_METADATA(IID "org.kde.kwin.Scene" FILE "qpainter.json")
public:
explicit QPainterFactory(QObject *parent = nullptr);
~QPainterFactory() override;
Scene *create(QObject *parent = nullptr) const override;
};
inline
bool SceneQPainter::usesOverlayWindow() const
{
return m_backend->usesOverlayWindow();
}
inline
OverlayWindow* SceneQPainter::overlayWindow() const
{
return m_backend->overlayWindow();
}
inline
QPainter* SceneQPainter::scenePainter() const
{
return m_painter.data();
}
inline
const QImage &QPainterWindowPixmap::image()
{
return m_image;
}
} // KWin
#endif // KWIN_SCENEQPAINTER_H