First step towards FXAA based antialiasing.

Change-Id: I40e767373156cf3e7f89c05767846a4949df319c
Reviewed-by: Tomi Korpipää <tomi.korpipaa@digia.com>
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@digia.com>

5 files changed, 258 insertions, 33 deletions

diff --git a/src/datavisualizationqml2/abstractdeclarative.cpp b/src/datavisualizationqml2/abstractdeclarative.cpp
index 2dc600c2..7415df9b 100644
--- a/src/datavisualizationqml2/abstractdeclarative.cpp
+++ b/src/datavisualizationqml2/abstractdeclarative.cpp
@@ -19,6 +19,7 @@
 #include "abstractdeclarative_p.h"
 #include "qvalue3daxis.h"
 #include "declarativetheme_p.h"
+#include "declarativerendernode_p.h"
 
 #include <QThread>
 #include <QGuiApplication>
@@ -33,7 +34,9 @@ static QHash<QQuickWindow *, bool> windowClearList;
 AbstractDeclarative::AbstractDeclarative(QQuickItem *parent) :
     QQuickItem(parent),
     m_controller(0),
-    m_clearWindowBeforeRendering(true)
+    m_renderMode(DirectToBackground),
+    m_node(0),
+    m_initialisedSize(0, 0)
 {
     connect(this, &QQuickItem::windowChanged, this, &AbstractDeclarative::handleWindowChanged);
     setAntialiasing(true);
@@ -45,6 +48,68 @@ AbstractDeclarative::~AbstractDeclarative()
     checkWindowList(0);
 }
 
+void AbstractDeclarative::setRenderingMode(AbstractDeclarative::RenderingMode mode)
+{
+    if (mode == m_renderMode)
+        return;
+
+    m_renderMode = mode;
+
+    switch (mode) {
+    case DirectToBackground:
+        // Intentional flowthrough
+    case DirectToBackground_NoClear:
+        // Delete render node
+        delete m_node;
+        m_node = 0;
+        m_initialisedSize = QSize(0, 0);
+        setAntialiasing(true);
+        setFlag(QQuickItem::ItemHasContents, false);
+        break;
+    case Indirect_NoAA:
+        // Force recreation of render node by resetting the initialized size
+        setAntialiasing(false);
+        m_initialisedSize = QSize(0, 0);
+        setFlag(QQuickItem::ItemHasContents, true);
+        break;
+    }
+
+    updateWindowParameters();
+
+    emit renderingModeChanged(mode);
+}
+
+AbstractDeclarative::RenderingMode AbstractDeclarative::renderingMode() const
+{
+    return m_renderMode;
+}
+
+QSGNode *AbstractDeclarative::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
+{
+    // If old node exists and has right size, reuse it.
+    if (oldNode && m_initialisedSize == boundingRect().size().toSize()) {
+        // Update bounding rectangle (that has same size as before).
+        DeclarativeRenderNode *renderNode = static_cast<DeclarativeRenderNode *>(oldNode);
+        renderNode->setRect(boundingRect());
+        return oldNode;
+    }
+
+    // Create a new render node when size changes or if there is no node yet
+    m_initialisedSize = boundingRect().size().toSize();
+
+    // Delete old node
+    if (oldNode) {
+        m_node = 0;
+        delete oldNode;
+    }
+
+    // Create a new one and set its bounding rectangle
+    DeclarativeRenderNode *node = new DeclarativeRenderNode(window(), m_controller, m_renderMode, this);
+    node->setRect(boundingRect());
+    m_node = node;
+    return node;
+}
+
 Declarative3DScene* AbstractDeclarative::scene() const
 {
     return static_cast<Declarative3DScene *>(m_controller->scene());
@@ -65,19 +130,6 @@ void AbstractDeclarative::clearSelection()
     m_controller->clearSelection();
 }
 
-void AbstractDeclarative::setClearWindowBeforeRendering(bool enable)
-{
-    if (m_clearWindowBeforeRendering != enable) {
-        m_clearWindowBeforeRendering = enable;
-        emit clearWindowBeforeRenderingChanged(enable);
-    }
-}
-
-bool AbstractDeclarative::clearWindowBeforeRendering() const
-{
-    return m_clearWindowBeforeRendering;
-}
-
 void AbstractDeclarative::setSelectionMode(SelectionFlags mode)
 {
     int intmode = int(mode);
@@ -130,7 +182,7 @@ void AbstractDeclarative::setSharedController(Abstract3DController *controller)
 
 void AbstractDeclarative::synchDataToRenderer()
 {
-    if (m_clearWindowBeforeRendering && clearList.size())
+    if (m_renderMode == DirectToBackground && clearList.size())
         clearList.clear();
     m_controller->initializeOpenGL();
     m_controller->synchDataToRenderer();
@@ -143,12 +195,14 @@ void AbstractDeclarative::handleWindowChanged(QQuickWindow *window)
     if (!window)
         return;
 
-    connect(window, &QQuickWindow::beforeSynchronizing, this,
-            &AbstractDeclarative::synchDataToRenderer, Qt::DirectConnection);
-    connect(window, &QQuickWindow::beforeRendering, this,
-            &AbstractDeclarative::render, Qt::DirectConnection);
-    connect(m_controller.data(), &Abstract3DController::needRender, window,
-            &QQuickWindow::update);
+    connect(window, &QQuickWindow::beforeSynchronizing,
+            this, &AbstractDeclarative::synchDataToRenderer,
+            Qt::DirectConnection);
+    connect(window, &QQuickWindow::beforeRendering,
+            this, &AbstractDeclarative::render,
+            Qt::DirectConnection);
+    connect(m_controller.data(), &Abstract3DController::needRender,
+            window, &QQuickWindow::update);
 
     updateWindowParameters();
 }
@@ -184,9 +238,15 @@ void AbstractDeclarative::updateWindowParameters()
             win->update();
         }
 
-        QPointF point = QQuickItem::mapToScene(QPointF(0.0f, 0.0f));
-        scene->d_ptr->setViewport(QRect(point.x(), point.y(), m_cachedGeometry.width(),
-                                        m_cachedGeometry.height()));
+        if (m_renderMode == DirectToBackground || m_renderMode == DirectToBackground_NoClear) {
+            // Origo mapping is needed when rendering directly to background
+            QPointF point = QQuickItem::mapToScene(QPointF(0.0f, 0.0f));
+            scene->d_ptr->setViewport(QRect(point.x(), point.y(), m_cachedGeometry.width(),
+                                            m_cachedGeometry.height()));
+        } else {
+            // No translation needed when rendering to FBO
+            scene->d_ptr->setViewport(m_cachedGeometry.toRect());
+        }
     }
 }
 
@@ -205,9 +265,13 @@ void AbstractDeclarative::render()
 {
     updateWindowParameters();
 
+    // If we're not rendering directly to the background, return
+    if (m_renderMode != DirectToBackground && m_renderMode != DirectToBackground_NoClear)
+        return;
+
     // Clear the background once per window as that is not done by default
     const QQuickWindow *win = window();
-    if (m_clearWindowBeforeRendering && !clearList.contains(win)) {
+    if (m_renderMode == DirectToBackground && !clearList.contains(win)) {
         clearList.append(win);
         QColor clearColor = win->color();
         glClearColor(clearColor.redF(), clearColor.greenF(), clearColor.blueF(), 1.0f);
diff --git a/src/datavisualizationqml2/abstractdeclarative_p.h b/src/datavisualizationqml2/abstractdeclarative_p.h
index 16effca0..83a1bbdb 100644
--- a/src/datavisualizationqml2/abstractdeclarative_p.h
+++ b/src/datavisualizationqml2/abstractdeclarative_p.h
@@ -42,17 +42,20 @@
 
 QT_BEGIN_NAMESPACE_DATAVISUALIZATION
 
+class DeclarativeRenderNode;
+
 class AbstractDeclarative : public QQuickItem
 {
     Q_OBJECT
     Q_ENUMS(ShadowQuality)
+    Q_ENUMS(RenderingMode)
     Q_FLAGS(SelectionFlag SelectionFlags)
     Q_PROPERTY(SelectionFlags selectionMode READ selectionMode WRITE setSelectionMode NOTIFY selectionModeChanged)
     Q_PROPERTY(ShadowQuality shadowQuality READ shadowQuality WRITE setShadowQuality NOTIFY shadowQualityChanged)
     Q_PROPERTY(Declarative3DScene* scene READ scene NOTIFY sceneChanged)
     Q_PROPERTY(QAbstract3DInputHandler* inputHandler READ inputHandler WRITE setInputHandler NOTIFY inputHandlerChanged)
     Q_PROPERTY(Q3DTheme* theme READ theme WRITE setTheme NOTIFY themeChanged)
-    Q_PROPERTY(bool clearWindowBeforeRendering READ clearWindowBeforeRendering WRITE setClearWindowBeforeRendering NOTIFY clearWindowBeforeRenderingChanged)
+    Q_PROPERTY(RenderingMode renderingMode READ renderingMode WRITE setRenderingMode NOTIFY renderingModeChanged)
 
 public:
     enum SelectionFlag {
@@ -79,10 +82,19 @@ public:
         ShadowQualitySoftHigh
     };
 
+    enum RenderingMode {
+        DirectToBackground = 0,
+        DirectToBackground_NoClear,
+        Indirect_NoAA
+    };
+
 public:
     explicit AbstractDeclarative(QQuickItem *parent = 0);
     virtual ~AbstractDeclarative();
 
+    virtual void setRenderingMode(RenderingMode mode);
+    virtual AbstractDeclarative::RenderingMode renderingMode() const;
+
     virtual void setSelectionMode(SelectionFlags mode);
     virtual AbstractDeclarative::SelectionFlags selectionMode() const;
 
@@ -99,9 +111,6 @@ public:
 
     Q_INVOKABLE virtual void clearSelection();
 
-    virtual void setClearWindowBeforeRendering(bool enable);
-    virtual bool clearWindowBeforeRendering() const;
-
     virtual void geometryChanged(const QRectF & newGeometry, const QRectF & oldGeometry);
 
     void setSharedController(Abstract3DController *controller);
@@ -128,6 +137,7 @@ protected:
     virtual void updateWindowParameters();
     virtual void handleSelectionModeChange(QAbstract3DGraph::SelectionFlags mode);
     virtual void handleShadowQualityChange(QAbstract3DGraph::ShadowQuality quality);
+    virtual QSGNode *updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *);
 
 signals:
     void selectionModeChanged(SelectionFlags mode);
@@ -135,12 +145,14 @@ signals:
     void sceneChanged(Q3DScene *scene);
     void inputHandlerChanged(QAbstract3DInputHandler *inputHandler);
     void themeChanged(Q3DTheme *theme);
-    void clearWindowBeforeRenderingChanged(bool enable);
+    void renderingModeChanged(RenderingMode mode);
 
 private:
     QPointer<Abstract3DController> m_controller;
     QRectF m_cachedGeometry;
-    bool m_clearWindowBeforeRendering;
+    AbstractDeclarative::RenderingMode m_renderMode;
+    DeclarativeRenderNode *m_node;
+    QSize m_initialisedSize;
 };
 Q_DECLARE_OPERATORS_FOR_FLAGS(AbstractDeclarative::SelectionFlags)
 
diff --git a/src/datavisualizationqml2/datavisualizationqml2.pro b/src/datavisualizationqml2/datavisualizationqml2.pro
index d6e8570c..254fefde 100644
--- a/src/datavisualizationqml2/datavisualizationqml2.pro
+++ b/src/datavisualizationqml2/datavisualizationqml2.pro
@@ -25,7 +25,8 @@ SOURCES += \
     declarativeseries.cpp \
     declarativetheme.cpp \
     declarativecolor.cpp \
-    declarativescene.cpp
+    declarativescene.cpp \
+    declarativerendernode.cpp
 
 HEADERS += \
     datavisualizationqml2_plugin.h \
@@ -37,7 +38,8 @@ HEADERS += \
     declarativeseries_p.h \
     declarativetheme_p.h \
     declarativecolor_p.h \
-    declarativescene_p.h
+    declarativescene_p.h \
+    declarativerendernode_p.h
 
 OTHER_FILES = qmldir
 
diff --git a/src/datavisualizationqml2/declarativerendernode.cpp b/src/datavisualizationqml2/declarativerendernode.cpp
new file mode 100644
index 00000000..612d11df
--- /dev/null
+++ b/src/datavisualizationqml2/declarativerendernode.cpp
@@ -0,0 +1,83 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc
+** All rights reserved.
+** For any questions to Digia, please use contact form at http://qt.digia.com
+**
+** This file is part of the QtDataVisualization module.
+**
+** Licensees holding valid Qt Enterprise licenses may use this file in
+** accordance with the Qt Enterprise License Agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.
+**
+** If you have questions regarding the use of this file, please use
+** contact form at http://qt.digia.com
+**
+****************************************************************************/
+
+#include "declarativerendernode_p.h"
+#include <QtQuick/QQuickWindow>
+#include <QtGui/QOpenGLFramebufferObject>
+
+QT_BEGIN_NAMESPACE_DATAVISUALIZATION
+
+DeclarativeRenderNode::DeclarativeRenderNode(QQuickWindow *window, Abstract3DController *controller, AbstractDeclarative::RenderingMode mode, QObject *parent)
+    : QObject(parent),
+      m_fbo(0),
+      m_texture(0),
+      m_window(window),
+      m_controller(controller),
+      m_mode(mode)
+{
+    connect(window, &QQuickWindow::beforeRendering,
+            this, &DeclarativeRenderNode::renderFBO,
+            Qt::DirectConnection);
+}
+
+DeclarativeRenderNode::~DeclarativeRenderNode()
+{
+    delete m_texture;
+    delete m_fbo;
+}
+
+void DeclarativeRenderNode::renderFBO()
+{
+    QSize size = rect().size().toSize();
+
+    // Create FBO
+    if (!m_fbo) {
+        QOpenGLFramebufferObjectFormat format;
+        format.setAttachment(QOpenGLFramebufferObject::Depth);
+        m_fbo = new QOpenGLFramebufferObject(size, format);
+        m_texture = m_window->createTextureFromId(m_fbo->texture(), size);
+
+        setTexture(m_texture);
+
+        // Flip texture
+        QSize ts = m_texture->textureSize();
+        QRectF sourceRect(0, 0, ts.width(), ts.height());
+        float tmp = sourceRect.top();
+        sourceRect.setTop(sourceRect.bottom());
+        sourceRect.setBottom(tmp);
+        QSGGeometry *geometry = this->geometry();
+        QSGGeometry::updateTexturedRectGeometry(geometry, rect(),
+                                                m_texture->convertToNormalizedSourceRect(sourceRect));
+        markDirty(DirtyMaterial);
+    }
+
+    // Call the shared rendering function
+    m_fbo->bind();
+    glDisable(GL_BLEND);
+
+    m_controller->render(m_fbo->handle());
+
+    glEnable(GL_BLEND);
+
+    m_fbo->release();
+
+    // New view is in the FBO, request repaint of scene graph
+    m_window->update();
+}
+
+QT_END_NAMESPACE_DATAVISUALIZATION
diff --git a/src/datavisualizationqml2/declarativerendernode_p.h b/src/datavisualizationqml2/declarativerendernode_p.h
new file mode 100644
index 00000000..b8250512
--- /dev/null
+++ b/src/datavisualizationqml2/declarativerendernode_p.h
@@ -0,0 +1,64 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc
+** All rights reserved.
+** For any questions to Digia, please use contact form at http://qt.digia.com
+**
+** This file is part of the QtDataVis3D module.
+**
+** Licensees holding valid Qt Enterprise licenses may use this file in
+** accordance with the Qt Enterprise License Agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.
+**
+** If you have questions regarding the use of this file, please use
+** contact form at http://qt.digia.com
+**
+****************************************************************************/
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the QtDataVis3D 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 DECLARATIVERENDERNODE_P_H
+#define DECLARATIVERENDERNODE_P_H
+
+#include <QObject>
+#include "datavisualizationglobal_p.h"
+#include "abstract3dcontroller_p.h"
+#include "abstractdeclarative_p.h"
+#include <qsgsimpletexturenode.h>
+
+class QOpenGLFramebufferObject;
+class QSGTexture;
+class QQuickWindow;
+
+QT_BEGIN_NAMESPACE_DATAVISUALIZATION
+
+class DeclarativeRenderNode : public QObject, public QSGSimpleTextureNode
+{
+    Q_OBJECT
+public:
+    explicit DeclarativeRenderNode(QQuickWindow *window, Abstract3DController *controller, AbstractDeclarative::RenderingMode mode, QObject *parent = 0);
+    virtual ~DeclarativeRenderNode();
+
+    // Renders view to FBO before render cycle starts.
+    void renderFBO();
+
+private:
+    QOpenGLFramebufferObject *m_fbo;
+    QSGTexture *m_texture;
+    QQuickWindow *m_window;
+    QPointer<Abstract3DController> m_controller;
+    AbstractDeclarative::RenderingMode m_mode;
+};
+
+QT_END_NAMESPACE_DATAVISUALIZATION
+
+#endif // DECLARATIVERENDERNODE_P_H