Add an example showing instancing using VBO with divisor of 1

Change-Id: I710df314902ca592c236e2120119718fc3b90c2c
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

1 files changed, 80 insertions, 0 deletions

diff --git a/examples/qt3d/instanced-arrays-qml/instancebuffer.cpp b/examples/qt3d/instanced-arrays-qml/instancebuffer.cpp
new file mode 100644
index 000000000..f457c96b9
--- /dev/null
+++ b/examples/qt3d/instanced-arrays-qml/instancebuffer.cpp
@@ -0,0 +1,80 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Klaralvdalens Datakonsult AB (KDAB).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/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 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later 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 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "instancebuffer.h"
+
+#include <QtGui/qvector3d.h>
+
+static const int rowCount = 20;
+static const int colCount = 20;
+static const int maxInstanceCount = rowCount * colCount;
+
+InstanceBuffer::InstanceBuffer(Qt3DCore::QNode *parent)
+    : Qt3DRender::QBuffer(QBuffer::VertexBuffer, parent)
+    , m_instanceCount(maxInstanceCount)
+{
+    // Create some per instance data - position of each instance
+    QByteArray ba;
+    ba.resize(maxInstanceCount * sizeof(QVector3D));
+    QVector3D *posData = reinterpret_cast<QVector3D *>(ba.data());
+    for (int j = 0; j < rowCount; ++j) {
+        const float z = float(j);
+        for (int i = 0; i < colCount; ++i) {
+            const float x = float(i);
+            const QVector3D pos(x, 0.0f, z);
+            *posData = pos;
+            ++posData;
+        }
+    }
+
+    // Put the data into the buffer
+    setData(ba);
+}
+
+int InstanceBuffer::instanceCount() const
+{
+    return m_instanceCount;
+}
+
+void InstanceBuffer::setInstanceCount(int instanceCount)
+{
+    if (m_instanceCount == instanceCount)
+        return;
+
+    m_instanceCount = instanceCount;
+    emit instanceCountChanged(instanceCount);
+}
+