Introducing QPlatformHardwareCompositor.

Can be used by applications to send hardware buffers directly to the
hardware compositor, if available. The primary usecase right now
will be from QtWayland to 2D composition of surface by bypassing
the OpenGL composition.

Change-Id: Ibdcdcc744c34869d3abbc11aad448a755f87161f
Reviewed-by: Jørgen Lind <jorgen.lind@theqtcompany.com>

5 files changed, 189 insertions, 1 deletions

diff --git a/src/gui/kernel/kernel.pri b/src/gui/kernel/kernel.pri
index e0d4464d47..6479acd3fc 100644
--- a/src/gui/kernel/kernel.pri
+++ b/src/gui/kernel/kernel.pri
@@ -68,6 +68,7 @@ HEADERS += \
         kernel/qplatformservices.h \
         kernel/qplatformsystemtrayicon.h \
         kernel/qplatformsessionmanager.h \
+        kernel/qplatformhardwarecompositor.h \
         kernel/qpixelformat.h \
         kernel/qpaintdevicewindow.h \
         kernel/qpaintdevicewindow_p.h \
@@ -128,7 +129,8 @@ SOURCES += \
         kernel/qpaintdevicewindow.cpp \
         kernel/qrasterwindow.cpp \
         kernel/qplatformgraphicsbuffer.cpp \
-        kernel/qplatformgraphicsbufferhelper.cpp
+        kernel/qplatformgraphicsbufferhelper.cpp \
+        kernel/qplatformhardwarecompositor.cpp
 
 contains(QT_CONFIG, opengl)|contains(QT_CONFIG, opengles2) {
     HEADERS += \
diff --git a/src/gui/kernel/qplatformhardwarecompositor.cpp b/src/gui/kernel/qplatformhardwarecompositor.cpp
new file mode 100644
index 0000000000..6c010a7d7c
--- /dev/null
+++ b/src/gui/kernel/qplatformhardwarecompositor.cpp
@@ -0,0 +1,98 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Jolla Ltd, author: <gunnar.sletta@jollamobile.com>
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qplatformhardwarecompositor.h"
+
+QT_BEGIN_NAMESPACE
+
+/*
+    Layer:
+
+    'transform' is a generic transform which can position the layer at
+    any given position with optional scale and rotation. It is quite likely that
+    the hardware compositor does not support arbitrary rotations and projective
+    transforms, but this is an easy way of expressing a number of different
+    scale/rotations in a generic way so deal with it.
+
+    'opacity' is the opacity of the layer
+
+    'subRect' is the region of the layer to actually draw. By default
+    this is (0,0)->(1,1). The values are relative to size and can
+    thus support subpixels.
+
+    'color' If color is a valid color and handle is 0, render the layer as
+    a solid color layer.
+
+    'buffer' The buffer to compose. Please note that the compositor might
+    lock buffers for read access and retain that lock after the composition
+    step has finished.
+
+   // Screen geometry (in pixels)
+   +-----------------------------------------
+   |\
+   | \ transform
+   |  \  (0, 0) is top left in "layer coordinates"
+   |   +-----------------------------------------+ size.width (in pixels)
+   |   |                                         |
+   |   |                                         |
+   |   |                                         |
+   |   |           subRect                       |
+   |   |      +---------------------------+      |
+   |   |      | float coords in the range |      |
+   |   |      | 0-1. 0 is top/left. 1 is  |      |
+   |   |      | bottom/right. Relative to |      |
+   |   |      | size.                     |      |
+   |   |      +---------------------------+      |
+   |   |                                         |
+   |   +-----------------------------------------+
+   |   size.height (in pixels)
+   |
+
+*/
+
+QPlatformHardwareCompositor::Layer::Layer()
+    : opacity(1)
+    , subRect(0, 0, 1, 1)
+    , buffer(0)
+{
+}
+
+QT_END_NAMESPACE
diff --git a/src/gui/kernel/qplatformhardwarecompositor.h b/src/gui/kernel/qplatformhardwarecompositor.h
new file mode 100644
index 0000000000..89c98a6262
--- /dev/null
+++ b/src/gui/kernel/qplatformhardwarecompositor.h
@@ -0,0 +1,80 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Jolla Ltd, author: <gunnar.sletta@jollamobile.com>
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is part of the QPA API and is not meant to be used
+// in applications. Usage of this API may make your code
+// source and binary incompatible with future versions of Qt.
+//
+
+#ifndef QPLATFORMHARDWARECOMPOSITOR_H
+#define QPLATFORMHARDWARECOMPOSITOR_H
+
+#include <QtGui/QMatrix4x4>
+#include <QtGui/QColor>
+
+QT_BEGIN_NAMESPACE
+
+class QPlatformGraphicsBuffer;
+
+class Q_GUI_EXPORT QPlatformHardwareCompositor : public QObject
+{
+    Q_OBJECT
+
+public:
+    struct Layer {
+        Layer();
+        QMatrix4x4 transform;
+        qreal opacity;
+        QRectF subRect;
+        QColor color;
+        QPlatformGraphicsBuffer *buffer;
+    };
+    virtual ~QPlatformHardwareCompositor() {}
+    virtual bool compose(const QVector<Layer> &layers) = 0;
+};
+
+QT_END_NAMESPACE
+
+#endif // QPLATFORMHARDWARECOMPOSITOR_H
diff --git a/src/gui/kernel/qplatformintegration.cpp b/src/gui/kernel/qplatformintegration.cpp
index 86edb9bd28..98755c3a5e 100644
--- a/src/gui/kernel/qplatformintegration.cpp
+++ b/src/gui/kernel/qplatformintegration.cpp
@@ -539,4 +539,9 @@ QOpenGLContext::OpenGLModuleType QPlatformIntegration::openGLModuleType()
 }
 #endif
 
+QPlatformHardwareCompositor *QPlatformIntegration::hardwareCompositor(QScreen *) const
+{
+    return 0;
+}
+
 QT_END_NAMESPACE
diff --git a/src/gui/kernel/qplatformintegration.h b/src/gui/kernel/qplatformintegration.h
index dbef939b8b..adc9c98c37 100644
--- a/src/gui/kernel/qplatformintegration.h
+++ b/src/gui/kernel/qplatformintegration.h
@@ -71,6 +71,7 @@ class QPlatformSessionManager;
 class QKeyEvent;
 class QPlatformOffscreenSurface;
 class QOffscreenSurface;
+class QPlatformHardwareCompositor;
 
 class Q_GUI_EXPORT QPlatformIntegration
 {
@@ -169,6 +170,8 @@ public:
     virtual QOpenGLContext::OpenGLModuleType openGLModuleType();
 #endif
 
+    virtual QPlatformHardwareCompositor *hardwareCompositor(QScreen *) const;
+
 protected:
     void screenAdded(QPlatformScreen *screen);
     void destroyScreen(QPlatformScreen *screen);