Accelerating lineseries with OpenGL

Added support for QAbstractSeries::useOpenGL property.
When true, the series in question is drawn on a separate
offscreen buffer using OpenGL and then superimposed on
the chart. Currently this property is only supported
for line and scatter series.

Change-Id: I174fec541f9f3c23464270c1fe08f824af16a0fb
Reviewed-by: Titta Heikkala <titta.heikkala@theqtcompany.com>
Reviewed-by: Tomi Korpipää <tomi.korpipaa@theqtcompany.com>

1 files changed, 80 insertions, 0 deletions

diff --git a/src/charts/glwidget_p.h b/src/charts/glwidget_p.h
new file mode 100644
index 00000000..209c634f
--- /dev/null
+++ b/src/charts/glwidget_p.h
@@ -0,0 +1,80 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd
+** All rights reserved.
+** For any questions to The Qt Company, please use contact form at http://qt.io
+**
+** This file is part of the Qt Charts module.
+**
+** Licensees holding valid commercial license for Qt may use this file in
+** accordance with the Qt License Agreement provided with the Software
+** or, alternatively, in accordance with the terms contained in a written
+** agreement between you and The Qt Company.
+**
+** If you have questions regarding the use of this file, please use
+** contact form at http://qt.io
+**
+****************************************************************************/
+
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt Chart API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+
+#ifndef GLWIDGET_H
+#define GLWIDGET_H
+
+#ifndef QT_NO_OPENGL
+
+#include <QtWidgets/QOpenGLWidget>
+#include <QtGui/QOpenGLFunctions>
+#include <QtGui/QOpenGLVertexArrayObject>
+#include <QtCore/QHash>
+#include <QtCharts/QAbstractSeries>
+#include <QtCharts/QXYSeries>
+
+QT_FORWARD_DECLARE_CLASS(QOpenGLShaderProgram)
+
+class QOpenGLBuffer;
+
+QT_CHARTS_BEGIN_NAMESPACE
+
+class GLXYSeriesDataManager;
+
+class GLWidget : public QOpenGLWidget, protected QOpenGLFunctions
+{
+    Q_OBJECT
+
+public:
+    GLWidget(GLXYSeriesDataManager *xyDataManager, QWidget *parent = 0);
+    ~GLWidget();
+
+public Q_SLOTS:
+    void cleanup();
+    void cleanXYSeriesResources(const QXYSeries *series);
+
+protected:
+    void initializeGL() Q_DECL_OVERRIDE;
+    void paintGL() Q_DECL_OVERRIDE;
+    void resizeGL(int width, int height) Q_DECL_OVERRIDE;
+
+private:
+    QOpenGLShaderProgram *m_program;
+    int m_shaderAttribLoc;
+    int m_colorUniformLoc;
+    int m_minUniformLoc;
+    int m_deltaUniformLoc;
+    int m_pointSizeUniformLoc;
+    QOpenGLVertexArrayObject m_vao;
+
+    QHash<const QAbstractSeries *, QOpenGLBuffer *> m_seriesBufferMap;
+    GLXYSeriesDataManager *m_xyDataManager;
+};
+
+QT_CHARTS_END_NAMESPACE
+#endif
+#endif