OpenVG Scenegraph Adaptation

This is an OpenVG backend for the Qt Quick 2 scenegraph.

Should be feature complete now, but there are still some issues that
could be improved in future commits:

If Rectangle nodes are rendered with a non-affine transform, they will
be rendered incorrectly.  This is because paths expect affine
transformations.

The Glyph cache is a bit cheeky in that it's caching paths, but doing
so per font size.  It shoudln't need to, but right now I've not though
up a good way of getting the transform/scale needed when rendering yet.

Change-Id: Ie3c4f2df35d14279b0f9f55e0e10a873328c025b
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

1 files changed, 115 insertions, 0 deletions

diff --git a/src/plugins/scenegraph/openvg/qsgopenvglayer.h b/src/plugins/scenegraph/openvg/qsgopenvglayer.h
new file mode 100644
index 0000000000..ee9984b9d9
--- /dev/null
+++ b/src/plugins/scenegraph/openvg/qsgopenvglayer.h
@@ -0,0 +1,115 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQuick 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 The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://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.LGPL3 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-3.0.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 (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QSGOPENVGLAYER_H
+#define QSGOPENVGLAYER_H
+
+#include <private/qsgadaptationlayer_p.h>
+#include <private/qsgcontext_p.h>
+
+#include "qopenvgcontext_p.h"
+
+QT_BEGIN_NAMESPACE
+
+class QSGOpenVGRenderer;
+class QSGOpenVGRenderContext;
+
+class QSGOpenVGLayer : public QSGLayer
+{
+public:
+    QSGOpenVGLayer(QSGRenderContext *renderContext);
+    ~QSGOpenVGLayer();
+
+    // QSGTexture interface
+public:
+    int textureId() const override;
+    QSize textureSize() const override;
+    bool hasAlphaChannel() const override;
+    bool hasMipmaps() const override;
+    void bind() override;
+
+    // QSGDynamicTexture interface
+public:
+    bool updateTexture() override;
+
+    // QSGLayer interface
+public:
+    void setItem(QSGNode *item) override;
+    void setRect(const QRectF &rect) override;
+    void setSize(const QSize &size) override;
+    void scheduleUpdate() override;
+    QImage toImage() const override;
+    void setLive(bool live) override;
+    void setRecursive(bool recursive) override;
+    void setFormat(uint format) override;
+    void setHasMipmaps(bool mipmap) override;
+    void setDevicePixelRatio(qreal ratio) override;
+    void setMirrorHorizontal(bool mirror) override;
+    void setMirrorVertical(bool mirror) override;
+
+public slots:
+    void markDirtyTexture() override;
+    void invalidated() override;
+
+private:
+    void grab();
+
+    QSGNode *m_item;
+    QSGOpenVGRenderContext *m_context;
+    QSGOpenVGRenderer *m_renderer;
+    QRectF m_rect;
+    QSize m_size;
+    qreal m_device_pixel_ratio;
+    bool m_mirrorHorizontal;
+    bool m_mirrorVertical;
+    bool m_live;
+    bool m_grab;
+    bool m_recursive;
+    bool m_dirtyTexture;
+
+    QOpenVGContext *m_vgContext;
+    VGImage m_image;
+    QSize m_imageSize;
+    EGLSurface m_renderTarget;
+    EGLContext m_layerContext;
+};
+
+QT_END_NAMESPACE
+
+#endif // QSGOPENVGLAYER_H