Introduce QRasterWindow

A simple convenience class providing a QWindow that has a
paintEvent and supports opening a painter on itself. It
behaves exactly like QOpenGLWindow in this respect, which is not
surprising since they share the same base class (QPaintDeviceWindow).

QRasterWindow does not however have any OpenGL dependencies and will
be present in -no-opengl builds too.

[ChangeLog] Added QRasterWindow, a thin convenience wrapper for a
QWindow on which a QPainter can be opened.

Done-with: Jorgen Lind <jorgen.lind@digia.com>
Change-Id: I37e82720492945d7b85d5f713eea8d5f7556e511
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@digia.com>

3 files changed, 133 insertions, 1 deletions

diff --git a/examples/qpa/qpa.pro b/examples/qpa/qpa.pro
index 27293482ef..85b51dc5f4 100644
--- a/examples/qpa/qpa.pro
+++ b/examples/qpa/qpa.pro
@@ -1,4 +1,5 @@
 requires(qtHaveModule(gui))
 
 TEMPLATE      = subdirs
-SUBDIRS       = windows
+SUBDIRS       = windows \
+                qrasterwindow
diff --git a/examples/qpa/qrasterwindow/main.cpp b/examples/qpa/qrasterwindow/main.cpp
new file mode 100644
index 0000000000..0e87d41682
--- /dev/null
+++ b/examples/qpa/qrasterwindow/main.cpp
@@ -0,0 +1,127 @@
+/****************************************************************************
+ **
+ ** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+ ** Contact: http://www.qt-project.org/legal
+ **
+ ** This file is part of the examples of the Qt Toolkit.
+ **
+ ** $QT_BEGIN_LICENSE:BSD$
+ ** You may use this file under the terms of the BSD license as follows:
+ **
+ ** "Redistribution and use in source and binary forms, with or without
+ ** modification, are permitted provided that the following conditions are
+ ** met:
+ **   * Redistributions of source code must retain the above copyright
+ **     notice, this list of conditions and the following disclaimer.
+ **   * Redistributions in binary form must reproduce the above copyright
+ **     notice, this list of conditions and the following disclaimer in
+ **     the documentation and/or other materials provided with the
+ **     distribution.
+ **   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
+ **     of its contributors may be used to endorse or promote products derived
+ **     from this software without specific prior written permission.
+ **
+ **
+ ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+ **
+ ** $QT_END_LICENSE$
+ **
+ ****************************************************************************/
+
+#include <QRasterWindow>
+#include <QPainter>
+#include <QGuiApplication>
+#include <QMatrix4x4>
+#include <QTimer>
+
+static QPainterPath painterPathForTriangle()
+{
+    static const QPointF bottomLeft(-1.0, -1.0);
+    static const QPointF top(0.0, 1.0);
+    static const QPointF bottomRight(1.0, -1.0);
+
+    QPainterPath path(bottomLeft);
+    path.lineTo(top);
+    path.lineTo(bottomRight);
+    path.closeSubpath();
+    return path;
+}
+
+class PaintedWindow : public QRasterWindow
+{
+    Q_OBJECT
+
+public:
+    PaintedWindow()
+    {
+        m_view.lookAt(QVector3D(3,1,1),
+                      QVector3D(0,0,0),
+                      QVector3D(0,1,0));
+        m_timer.setInterval(16);
+        connect(&m_timer, SIGNAL(timeout()), this, SLOT(update()));
+        m_timer.start();
+    }
+
+protected:
+    void paintEvent(QPaintEvent *)
+    {
+        QPainter p(this);
+        p.fillRect(QRect(0,0,width(),height()),Qt::gray);
+
+        p.setWorldTransform(m_window_matrix.toTransform());
+
+        QMatrix4x4 mvp = m_projection * m_view * m_model;
+        p.setTransform(mvp.toTransform(), true);
+
+        p.fillPath(painterPathForTriangle(), m_brush);
+
+        m_model.rotate(1, 0, 1, 0);
+    }
+
+    void resizeEvent(QResizeEvent *)
+    {
+        m_window_matrix = QTransform();
+        m_window_matrix.translate(width() / 2.0, height() / 2.0);
+        m_window_matrix.scale(width() / 2.0, -height() / 2.0);
+
+        m_projection.setToIdentity();
+        m_projection.perspective(45.f, qreal(width()) / qreal(height()), 0.1f, 100.f);
+
+        QLinearGradient gradient(QPointF(-1,-1), QPointF(1,1));
+        gradient.setColorAt(0, Qt::red);
+        gradient.setColorAt(1, Qt::green);
+
+        m_brush = QBrush(gradient);
+    }
+
+private:
+    QMatrix4x4 m_window_matrix;
+    QMatrix4x4 m_projection;
+    QMatrix4x4 m_view;
+    QMatrix4x4 m_model;
+    QBrush m_brush;
+    QTimer m_timer;
+};
+
+int main (int argc, char **argv)
+{
+    QGuiApplication app(argc, argv);
+
+    PaintedWindow window;
+    window.create();
+    window.show();
+
+    return app.exec();
+}
+
+#include "main.moc"
diff --git a/examples/qpa/qrasterwindow/qrasterwindow.pro b/examples/qpa/qrasterwindow/qrasterwindow.pro
new file mode 100644
index 0000000000..e5bf34f25c
--- /dev/null
+++ b/examples/qpa/qrasterwindow/qrasterwindow.pro
@@ -0,0 +1,4 @@
+SOURCES += main.cpp
+
+target.path = $$[QT_INSTALL_EXAMPLES]/qpa/qrasterwindow
+INSTALLS += target