Add gamma to QViewport's API

Change-Id: Ieced911cf1e51c0befc5ce91e8529a421b5c5a80
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

6 files changed, 131 insertions, 35 deletions

diff --git a/src/render/framegraph/qviewport.cpp b/src/render/framegraph/qviewport.cpp
index a78e260a5..8c1ebe67c 100644
--- a/src/render/framegraph/qviewport.cpp
+++ b/src/render/framegraph/qviewport.cpp
@@ -50,6 +50,7 @@ namespace Qt3DRender {
 QViewportPrivate::QViewportPrivate()
     : QFrameGraphNodePrivate()
     , m_normalizedRect(QRectF(0.0f, 0.0f, 1.0f, 1.0f))
+    , m_gamma(2.2f)
 {
 }
 
@@ -62,7 +63,8 @@ QViewportPrivate::QViewportPrivate()
     \inherits Qt3DRender::QFrameGraphNode
 
     Qt3DRender::QViewport of the scene specifies at which portion of the render surface Qt3D
-    is rendering to. Area outside the viewport is left untouched.
+    is rendering to. Area outside the viewport is left untouched. It also controls global parameters
+    to the rendering in that viewport like gamma.
  */
 
 /*!
@@ -74,7 +76,8 @@ QViewportPrivate::QViewportPrivate()
     \brief A viewport on the Qt3D Scene
 
     Viewport of the scene specifies at which portion of the render surface Qt3D is
-    rendering to. Area outside the viewport is left untouched.
+    rendering to. Area outside the viewport is left untouched. It also controls global parameters
+    to the rendering in that viewport like gamma.
  */
 
 /*!
@@ -86,6 +89,12 @@ QViewportPrivate::QViewportPrivate()
  */
 
 /*!
+    \qmlproperty rect Viewport::gamma
+
+    Specifies the gamma factor for the viewport. The default is 2.2 which should give proper result on most screens.
+ */
+
+/*!
     Constructs QViewport with given \a parent.
  */
 QViewport::QViewport(QNode *parent)
@@ -111,6 +120,12 @@ QRectF QViewport::normalizedRect() const
     return d->m_normalizedRect;
 }
 
+float QViewport::gamma() const
+{
+    Q_D(const QViewport);
+    return d->m_gamma;
+}
+
 /*!
     \property QViewport::normalizedRect
 
@@ -127,12 +142,27 @@ void QViewport::setNormalizedRect(const QRectF &normalizedRect)
     }
 }
 
+/*!
+    \property QViewport::gamma
+
+    Specifies the gamma factor for the viewport. The default is 2.2 which should give proper result on most screens.
+ */
+void QViewport::setGamma(float gamma)
+{
+    Q_D(QViewport);
+    if (gamma != d->m_gamma) {
+        d->m_gamma = gamma;
+        emit gammaChanged(gamma);
+    }
+}
+
 Qt3DCore::QNodeCreatedChangeBasePtr QViewport::createNodeCreationChange() const
 {
     auto creationChange = QFrameGraphNodeCreatedChangePtr<QViewportData>::create(this);
     auto &data = creationChange->data;
     Q_D(const QViewport);
     data.normalizedRect = d->m_normalizedRect;
+    data.gamma = d->m_gamma;
     return creationChange;
 }
 
diff --git a/src/render/framegraph/qviewport.h b/src/render/framegraph/qviewport.h
index 5959ed791..abe423cf4 100644
--- a/src/render/framegraph/qviewport.h
+++ b/src/render/framegraph/qviewport.h
@@ -54,18 +54,22 @@ class QT3DRENDERSHARED_EXPORT QViewport : public QFrameGraphNode
 {
     Q_OBJECT
     Q_PROPERTY(QRectF normalizedRect READ normalizedRect WRITE setNormalizedRect NOTIFY normalizedRectChanged)
+    Q_PROPERTY(float gamma READ gamma WRITE setGamma NOTIFY gammaChanged)
 
 public:
     explicit QViewport(Qt3DCore::QNode *parent = nullptr);
     ~QViewport();
 
     QRectF normalizedRect() const;
+    float gamma() const;
 
 public Q_SLOTS:
     void setNormalizedRect(const QRectF& normalizedRect);
+    void setGamma(float gamma);
 
 Q_SIGNALS:
     void normalizedRectChanged(const QRectF& normalizedRect);
+    void gammaChanged(float gamma);
 
 protected:
     explicit QViewport(QViewportPrivate &dd, Qt3DCore::QNode *parent = nullptr);
diff --git a/src/render/framegraph/qviewport_p.h b/src/render/framegraph/qviewport_p.h
index 790cd3d06..4c82f38b3 100644
--- a/src/render/framegraph/qviewport_p.h
+++ b/src/render/framegraph/qviewport_p.h
@@ -67,11 +67,13 @@ public :
     Q_DECLARE_PUBLIC(QViewport)
     QRectF m_normalizedRect;
     QColor m_clearColor;
+    float m_gamma;
 };
 
 struct QViewportData
 {
     QRectF normalizedRect;
+    float gamma;
 };
 
 } // namespace Qt3DRender
diff --git a/src/render/framegraph/viewportnode.cpp b/src/render/framegraph/viewportnode.cpp
index ccdb68918..c16a660b0 100644
--- a/src/render/framegraph/viewportnode.cpp
+++ b/src/render/framegraph/viewportnode.cpp
@@ -55,6 +55,7 @@ ViewportNode::ViewportNode()
     , m_yMin(0.0f)
     , m_xMax(1.0f)
     , m_yMax(1.0f)
+    , m_gamma(2.2f)
 {
 }
 
@@ -67,6 +68,7 @@ void ViewportNode::initializeFromPeer(const Qt3DCore::QNodeCreatedChangeBasePtr
     m_xMax = data.normalizedRect.width();
     m_yMin = data.normalizedRect.y();
     m_yMax = data.normalizedRect.height();
+    m_gamma = data.gamma;
 }
 
 float ViewportNode::xMin() const
@@ -106,6 +108,16 @@ void ViewportNode::setYMax(float yMax)
     m_yMax = yMax;
 }
 
+float ViewportNode::gamma() const
+{
+    return m_gamma;
+}
+
+void ViewportNode::setGamma(float gamma)
+{
+    m_gamma = gamma;
+}
+
 void ViewportNode::sceneChangeEvent(const Qt3DCore::QSceneChangePtr &e)
 {
     if (e->type() == PropertyUpdated) {
@@ -116,6 +128,8 @@ void ViewportNode::sceneChangeEvent(const Qt3DCore::QSceneChangePtr &e)
             setYMin(normalizedRect.y());
             setXMax(normalizedRect.width());
             setYMax(normalizedRect.height());
+        } else if (propertyChange->propertyName() == QByteArrayLiteral("gamma")) {
+            setGamma(propertyChange->value().toFloat());
         }
         markDirty(AbstractRenderer::AllDirty);
     }
diff --git a/src/render/framegraph/viewportnode_p.h b/src/render/framegraph/viewportnode_p.h
index 882aa4d86..85003ff36 100644
--- a/src/render/framegraph/viewportnode_p.h
+++ b/src/render/framegraph/viewportnode_p.h
@@ -81,6 +81,9 @@ public:
     float yMax() const;
     void setYMax(float yMax);
 
+    float gamma() const;
+    void setGamma(float gamma);
+
     void sceneChangeEvent(const Qt3DCore::QSceneChangePtr &e) Q_DECL_OVERRIDE;
 
 private:
@@ -90,6 +93,7 @@ private:
     float m_yMin;
     float m_xMax;
     float m_yMax;
+    float m_gamma;
 };
 
 QRectF computeViewport(const QRectF &childViewport, const ViewportNode *parentViewport);
diff --git a/tests/auto/render/qviewport/tst_qviewport.cpp b/tests/auto/render/qviewport/tst_qviewport.cpp
index 87b22e22b..93a2735f2 100644
--- a/tests/auto/render/qviewport/tst_qviewport.cpp
+++ b/tests/auto/render/qviewport/tst_qviewport.cpp
@@ -46,14 +46,15 @@ private Q_SLOTS:
     {
         QTest::addColumn<Qt3DRender::QViewport *>("viewport");
         QTest::addColumn<QRectF>("normalizedRect");
+        QTest::addColumn<float>("gamma");
 
         Qt3DRender::QViewport *defaultConstructed = new Qt3DRender::QViewport();
-        QTest::newRow("defaultConstructed") << defaultConstructed << QRectF(0.0f, 0.0f, 1.0f, 1.0f);
+        QTest::newRow("defaultConstructed") << defaultConstructed << QRectF(0.0f, 0.0f, 1.0f, 1.0f) << 2.2f;
 
         Qt3DRender::QViewport *smallGreenViewport = new Qt3DRender::QViewport();
         smallGreenViewport->setNormalizedRect(QRectF(0.2f, 0.2f, 0.6f, 0.6f));
-        QTest::newRow("smallGreenViewport") << smallGreenViewport << QRectF(0.2f, 0.2f, 0.6f, 0.6f);
-
+        smallGreenViewport->setGamma(1.8f);
+        QTest::newRow("smallGreenViewport") << smallGreenViewport << QRectF(0.2f, 0.2f, 0.6f, 0.6f) << 1.8f;
     }
 
     void checkCloning()
@@ -61,9 +62,11 @@ private Q_SLOTS:
         // GIVEN
         QFETCH(Qt3DRender::QViewport *, viewport);
         QFETCH(QRectF, normalizedRect);
+        QFETCH(float, gamma);
 
         // THEN
         QCOMPARE(viewport->normalizedRect(), normalizedRect);
+        QCOMPARE(viewport->gamma(), gamma);
 
         // WHEN
         Qt3DCore::QNodeCreatedChangeGenerator creationChangeGenerator(viewport);
@@ -80,6 +83,7 @@ private Q_SLOTS:
         QCOMPARE(viewport->isEnabled(), creationChangeData->isNodeEnabled());
         QCOMPARE(viewport->metaObject(), creationChangeData->metaObject());
         QCOMPARE(viewport->normalizedRect(), cloneData.normalizedRect);
+        QCOMPARE(viewport->gamma(), cloneData.gamma);
 
         delete viewport;
     }
@@ -91,39 +95,77 @@ private Q_SLOTS:
         QScopedPointer<Qt3DRender::QViewport> viewport(new Qt3DRender::QViewport());
         arbiter.setArbiterOnNode(viewport.data());
 
-        // WHEN
-        viewport->setNormalizedRect(QRectF(0.5f, 0.5f, 1.0f, 1.0f));
-        QCoreApplication::processEvents();
-
-        // THEN
-        QCOMPARE(arbiter.events.size(), 1);
-        Qt3DCore::QPropertyUpdatedChangePtr change = arbiter.events.first().staticCast<Qt3DCore::QPropertyUpdatedChange>();
-        QCOMPARE(change->propertyName(), "normalizedRect");
-        QCOMPARE(change->subjectId(), viewport->id());
-        QCOMPARE(change->value().value<QRectF>(), QRectF(0.5f, 0.5f, 1.0f, 1.0f));
-        QCOMPARE(change->type(), Qt3DCore::PropertyUpdated);
+        {
+            // WHEN
+            viewport->setNormalizedRect(QRectF(0.5f, 0.5f, 1.0f, 1.0f));
+            QCoreApplication::processEvents();
+
+            // THEN
+            QCOMPARE(arbiter.events.size(), 1);
+            Qt3DCore::QPropertyUpdatedChangePtr change = arbiter.events.first().staticCast<Qt3DCore::QPropertyUpdatedChange>();
+            QCOMPARE(change->propertyName(), "normalizedRect");
+            QCOMPARE(change->subjectId(), viewport->id());
+            QCOMPARE(change->value().value<QRectF>(), QRectF(0.5f, 0.5f, 1.0f, 1.0f));
+            QCOMPARE(change->type(), Qt3DCore::PropertyUpdated);
+
+            arbiter.events.clear();
+
+            // WHEN
+            viewport->setNormalizedRect(QRectF(0.5f, 0.5f, 1.0f, 1.0f));
+            QCoreApplication::processEvents();
+
+            // THEN
+            QCOMPARE(arbiter.events.size(), 0);
+
+            // WHEN
+            viewport->setNormalizedRect(QRectF(0.0f, 0.0f, 1.0f, 1.0f));
+            QCoreApplication::processEvents();
+
+            // THEN
+            QCOMPARE(arbiter.events.size(), 1);
+            change = arbiter.events.first().staticCast<Qt3DCore::QPropertyUpdatedChange>();
+            QCOMPARE(change->propertyName(), "normalizedRect");
+            QCOMPARE(change->subjectId(), viewport->id());
+            QCOMPARE(change->value().value<QRectF>(), QRectF(0.0f, 0.0f, 1.0f, 1.0f));
+            QCOMPARE(change->type(), Qt3DCore::PropertyUpdated);
+        }
 
         arbiter.events.clear();
 
-        // WHEN
-        viewport->setNormalizedRect(QRectF(0.5f, 0.5f, 1.0f, 1.0f));
-        QCoreApplication::processEvents();
-
-        // THEN
-        QCOMPARE(arbiter.events.size(), 0);
-
-        // WHEN
-        viewport->setNormalizedRect(QRectF(0.0f, 0.0f, 1.0f, 1.0f));
-        QCoreApplication::processEvents();
-
-        // THEN
-        QCOMPARE(arbiter.events.size(), 1);
-        change = arbiter.events.first().staticCast<Qt3DCore::QPropertyUpdatedChange>();
-        QCOMPARE(change->propertyName(), "normalizedRect");
-        QCOMPARE(change->subjectId(), viewport->id());
-        QCOMPARE(change->value().value<QRectF>(), QRectF(0.0f, 0.0f, 1.0f, 1.0f));
-        QCOMPARE(change->type(), Qt3DCore::PropertyUpdated);
-
+        {
+            // WHEN
+            viewport->setGamma(1.8f);
+            QCoreApplication::processEvents();
+
+            // THEN
+            QCOMPARE(arbiter.events.size(), 1);
+            Qt3DCore::QPropertyUpdatedChangePtr change = arbiter.events.first().staticCast<Qt3DCore::QPropertyUpdatedChange>();
+            QCOMPARE(change->propertyName(), "gamma");
+            QCOMPARE(change->subjectId(), viewport->id());
+            QCOMPARE(change->value().toFloat(), 1.8f);
+            QCOMPARE(change->type(), Qt3DCore::PropertyUpdated);
+
+            arbiter.events.clear();
+
+            // WHEN
+            viewport->setGamma(1.8f);
+            QCoreApplication::processEvents();
+
+            // THEN
+            QCOMPARE(arbiter.events.size(), 0);
+
+            // WHEN
+            viewport->setGamma(2.0f);
+            QCoreApplication::processEvents();
+
+            // THEN
+            QCOMPARE(arbiter.events.size(), 1);
+            change = arbiter.events.first().staticCast<Qt3DCore::QPropertyUpdatedChange>();
+            QCOMPARE(change->propertyName(), "gamma");
+            QCOMPARE(change->subjectId(), viewport->id());
+            QCOMPARE(change->value().toFloat(), 2.0f);
+            QCOMPARE(change->type(), Qt3DCore::PropertyUpdated);
+        }
     }
 };