Add alpha multiplier to QCustom3DVolume api

Change-Id: I856c4166513f6d6f7b73fd52bc46d52ab1b8fdff
Reviewed-by: Tomi Korpipää <tomi.korpipaa@digia.com>
Reviewed-by: Mika Salmela <mika.salmela@digia.com>

3 files changed, 74 insertions, 15 deletions

diff --git a/examples/datavisualization/volumetric/main.cpp b/examples/datavisualization/volumetric/main.cpp
index 5a90070e..84062969 100644
--- a/examples/datavisualization/volumetric/main.cpp
+++ b/examples/datavisualization/volumetric/main.cpp
@@ -36,16 +36,18 @@ int main(int argc, char **argv)
     QWidget *container = QWidget::createWindowContainer(graph);
 
     QSize screenSize = graph->screen()->size();
-    container->setMinimumSize(QSize(screenSize.width() / 2, screenSize.height() / 1.5));
+    container->setMinimumSize(QSize(screenSize.width() / 3, screenSize.height() / 3));
     container->setMaximumSize(screenSize);
     container->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
     container->setFocusPolicy(Qt::StrongFocus);
 
-    QWidget *widget = new QWidget;
+    QWidget *widget = new QWidget();
     QHBoxLayout *hLayout = new QHBoxLayout(widget);
     QVBoxLayout *vLayout = new QVBoxLayout();
+    QVBoxLayout *vLayout2 = new QVBoxLayout();
     hLayout->addWidget(container, 1);
     hLayout->addLayout(vLayout);
+    hLayout->addLayout(vLayout2);
 
     widget->setWindowTitle(QStringLiteral("Volumetric Object Example"));
 
@@ -122,10 +124,17 @@ int main(int argc, char **argv)
     sliceImageYLabel->setScaledContents(true);
     sliceImageZLabel->setScaledContents(true);
 
-    vLayout->addWidget(fpsCheckBox);
-    vLayout->addWidget(fpsLabel);
-    vLayout->addWidget(textureDetailGroupBox);
-    vLayout->addWidget(colorTableCheckBox);
+    QSlider *alphaMultiplierSlider = new QSlider(Qt::Horizontal, widget);
+    alphaMultiplierSlider->setMinimum(0);
+    alphaMultiplierSlider->setMaximum(139);
+    alphaMultiplierSlider->setValue(100);
+    alphaMultiplierSlider->setEnabled(true);
+    QLabel *alphaMultiplierLabel = new QLabel(QStringLiteral("Alpha multiplier: 1.0"));
+
+    QCheckBox *preserveOpacityCheckBox = new QCheckBox(widget);
+    preserveOpacityCheckBox->setText(QStringLiteral("Preserve opacity"));
+    preserveOpacityCheckBox->setChecked(true);
+
     vLayout->addWidget(sliceXCheckBox);
     vLayout->addWidget(sliceXSlider);
     vLayout->addWidget(sliceImageXLabel);
@@ -135,6 +144,13 @@ int main(int argc, char **argv)
     vLayout->addWidget(sliceZCheckBox);
     vLayout->addWidget(sliceZSlider);
     vLayout->addWidget(sliceImageZLabel, 1, Qt::AlignTop);
+    vLayout2->addWidget(fpsCheckBox);
+    vLayout2->addWidget(fpsLabel);
+    vLayout2->addWidget(textureDetailGroupBox);
+    vLayout2->addWidget(colorTableCheckBox);
+    vLayout2->addWidget(alphaMultiplierLabel);
+    vLayout2->addWidget(alphaMultiplierSlider);
+    vLayout2->addWidget(preserveOpacityCheckBox, 1, Qt::AlignTop);
 
     VolumetricModifier *modifier = new VolumetricModifier(graph);
     modifier->setFpsLabel(fpsLabel);
@@ -142,6 +158,7 @@ int main(int argc, char **argv)
     modifier->setHighDetailRB(highDetailRB);
     modifier->setSliceSliders(sliceXSlider, sliceYSlider, sliceZSlider);
     modifier->setSliceLabels(sliceImageXLabel, sliceImageYLabel, sliceImageZLabel);
+    modifier->setAlphaMultiplierLabel(alphaMultiplierLabel);
 
     QObject::connect(fpsCheckBox, &QCheckBox::stateChanged, modifier,
                      &VolumetricModifier::setFpsMeasurement);
@@ -157,14 +174,18 @@ int main(int argc, char **argv)
                      &VolumetricModifier::adjustSliceY);
     QObject::connect(sliceZSlider, &QSlider::valueChanged, modifier,
                      &VolumetricModifier::adjustSliceZ);
-    QObject::connect(lowDetailRB,  &QRadioButton::toggled, modifier,
+    QObject::connect(lowDetailRB, &QRadioButton::toggled, modifier,
                      &VolumetricModifier::toggleLowDetail);
-    QObject::connect(mediumDetailRB,  &QRadioButton::toggled, modifier,
+    QObject::connect(mediumDetailRB, &QRadioButton::toggled, modifier,
                      &VolumetricModifier::toggleMediumDetail);
-    QObject::connect(highDetailRB,  &QRadioButton::toggled, modifier,
+    QObject::connect(highDetailRB, &QRadioButton::toggled, modifier,
                      &VolumetricModifier::toggleHighDetail);
-    QObject::connect(colorTableCheckBox,  &QCheckBox::stateChanged, modifier,
+    QObject::connect(colorTableCheckBox, &QCheckBox::stateChanged, modifier,
                      &VolumetricModifier::changeColorTable);
+    QObject::connect(preserveOpacityCheckBox, &QCheckBox::stateChanged, modifier,
+                     &VolumetricModifier::setPreserveOpacity);
+    QObject::connect(alphaMultiplierSlider, &QSlider::valueChanged, modifier,
+                     &VolumetricModifier::adjustAlphaMultiplier);
 
     widget->show();
     return app.exec();
diff --git a/examples/datavisualization/volumetric/volumetric.cpp b/examples/datavisualization/volumetric/volumetric.cpp
index a553ccf8..56f02dcb 100644
--- a/examples/datavisualization/volumetric/volumetric.cpp
+++ b/examples/datavisualization/volumetric/volumetric.cpp
@@ -80,7 +80,7 @@ VolumetricModifier::VolumetricModifier(Q3DScatter *scatter)
     // Both tables have a fully transparent colors to fill outer portions of the volume.
 
     // The primary color table.
-    // The first visible layer, red, is somewhat transparent. Rest of to colors are opaque.
+    // The top two layers are transparent.
     m_colorTable1.resize(colorTableSize);
     m_colorTable2.resize(colorTableSize);
 
@@ -88,9 +88,9 @@ VolumetricModifier::VolumetricModifier(Q3DScatter *scatter)
         if (i < cutOffColorIndex)
             m_colorTable1[i] = qRgba(0, 0, 0, 0);
         else if (i < 60)
-            m_colorTable1[i] = qRgba((i * 2) + 120, 0, 0, 20);
+            m_colorTable1[i] = qRgba((i * 2) + 120, 0, 0, 15);
         else if (i < 120)
-            m_colorTable1[i] = qRgba(0, ((i - 60) * 2) + 120, 0, 255);
+            m_colorTable1[i] = qRgba(0, ((i - 60) * 2) + 120, 0, 50);
         else if (i < 180)
             m_colorTable1[i] = qRgba(0, 0, ((i - 120) * 2) + 120, 255);
         else
@@ -98,14 +98,15 @@ VolumetricModifier::VolumetricModifier(Q3DScatter *scatter)
     }
 
     // The alternate color table.
-    // The first visible layer is a thin single color, and rest of the volume uses a smooth gradient.
+    // The first visible layer is a thin opaque color, and rest of the volume uses a smooth
+    // transparent gradient.
     for (int i = 1; i < colorTableSize; i++) {
         if (i < cutOffColorIndex)
             m_colorTable2[i] = qRgba(0, 0, 0, 0);
         else if (i < cutOffColorIndex + 4)
             m_colorTable2[i] = qRgba(75, 150, 0, 255);
         else
-            m_colorTable2[i] = qRgba(i, 0, 255 - i, 255);
+            m_colorTable2[i] = qRgba(i, 0, 255 - i, i);
     }
 
     m_volumeItem->setColorTable(m_colorTable1);
@@ -167,6 +168,11 @@ void VolumetricModifier::setSliceLabels(QLabel *xLabel, QLabel *yLabel, QLabel *
     adjustSliceZ(m_sliceSliderZ->value());
 }
 
+void VolumetricModifier::setAlphaMultiplierLabel(QLabel *label)
+{
+    m_alphaMultiplierLabel = label;
+}
+
 void VolumetricModifier::sliceX(int enabled)
 {
     if (m_volumeItem)
@@ -322,6 +328,34 @@ void VolumetricModifier::changeColorTable(int enabled)
     adjustSliceZ(m_sliceSliderZ->value());
 }
 
+void VolumetricModifier::setPreserveOpacity(bool enabled)
+{
+    m_volumeItem->setPreserveOpacity(enabled);
+
+    // Rerender image labels
+    adjustSliceX(m_sliceSliderX->value());
+    adjustSliceY(m_sliceSliderY->value());
+    adjustSliceZ(m_sliceSliderZ->value());
+}
+
+void VolumetricModifier::adjustAlphaMultiplier(int value)
+{
+    float mult;
+    if (value > 100)
+        mult = float(value - 99) / 2.0f;
+    else
+        mult = float(value) / float(500 - value * 4);
+    m_volumeItem->setAlphaMultiplier(mult);
+    QString labelFormat = QStringLiteral("Alpha multiplier: %1");
+    m_alphaMultiplierLabel->setText(labelFormat.arg(
+                                        QString::number(m_volumeItem->alphaMultiplier(), 'f', 3)));
+
+    // Rerender image labels
+    adjustSliceX(m_sliceSliderX->value());
+    adjustSliceY(m_sliceSliderY->value());
+    adjustSliceZ(m_sliceSliderZ->value());
+}
+
 int VolumetricModifier::createVolume(int textureSize, int startIndex, int count,
                                      QVector<uchar> *textureData)
 {
diff --git a/examples/datavisualization/volumetric/volumetric.h b/examples/datavisualization/volumetric/volumetric.h
index eb8a4172..497506ad 100644
--- a/examples/datavisualization/volumetric/volumetric.h
+++ b/examples/datavisualization/volumetric/volumetric.h
@@ -41,6 +41,7 @@ public:
     void setMediumDetailRB(QRadioButton *button);
     void setHighDetailRB(QRadioButton *button);
     void setSliceLabels(QLabel *xLabel, QLabel *yLabel, QLabel *zLabel);
+    void setAlphaMultiplierLabel(QLabel *label);
 
 public slots:
     void sliceX(int enabled);
@@ -58,6 +59,8 @@ public slots:
     void setFpsMeasurement(bool enabled);
     void setSliceSliders(QSlider *sliderX, QSlider *sliderY, QSlider *sliderZ);
     void changeColorTable(int enabled);
+    void setPreserveOpacity(bool enabled);
+    void adjustAlphaMultiplier(int value);
 
 private:
 
@@ -86,6 +89,7 @@ private:
     QLabel *m_sliceLabelX;
     QLabel *m_sliceLabelY;
     QLabel *m_sliceLabelZ;
+    QLabel *m_alphaMultiplierLabel;
 };
 
 #endif