Added a bar chart.

* HistoryGraph replaced by BarChart
* HistoryGraph not removed from code, might be useful in the future

5 files changed, 179 insertions, 10 deletions

diff --git a/barchart.cpp b/barchart.cpp
new file mode 100644
index 0000000..02509ae
--- /dev/null
+++ b/barchart.cpp
@@ -0,0 +1,123 @@
+#include "barchart.h"
+
+#include <algorithm>
+
+#include "geometry.h"
+#include "scale.h"
+
+static const QColor OUTLINE_COLOR(0, 0, 0);
+static const QColor BAR_COLOR(128, 128, 128);
+static const float DEFAULT_OPACITY = 0.8f;
+
+BarChart::BarChart(QQuickItem *parent)
+    : QQuickItem(parent)
+    , m_shouldUpdateBars(false)
+{
+    setClip(true);
+    setFlag(QQuickItem::ItemHasContents);
+    // setAcceptedMouseButtons(Qt::LeftButton);
+    setAcceptHoverEvents(true);
+}
+
+BarChart::~BarChart()
+{
+}
+
+void BarChart::setValues(const arma::vec &values)
+{
+    m_values = values;
+    m_shouldUpdateBars = true;
+    emit valuesChanged(values);
+}
+
+QSGNode *BarChart::newBarNode()
+{
+    // A bar node is:
+    // opacityNode [outlineGeomNode barGeomNode]
+
+    QSGGeometryNode *outlineGeomNode = new QSGGeometryNode;
+    QSGGeometry *outlineGeometry =
+        new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), 4);
+    outlineGeometry->setDrawingMode(GL_LINE_LOOP);
+    outlineGeomNode->setGeometry(outlineGeometry);
+    outlineGeomNode->setFlag(QSGNode::OwnsGeometry);
+    QSGFlatColorMaterial *material = new QSGFlatColorMaterial;
+    material->setColor(OUTLINE_COLOR);
+    outlineGeomNode->setMaterial(material);
+    outlineGeomNode->setFlag(QSGNode::OwnsMaterial);
+
+    QSGGeometryNode *barGeomNode = new QSGGeometryNode;
+    QSGGeometry *barGeometry =
+        new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), 4);
+    barGeometry->setDrawingMode(GL_POLYGON);
+    barGeomNode->setGeometry(barGeometry);
+    barGeomNode->setFlag(QSGNode::OwnsGeometry);
+    material = new QSGFlatColorMaterial;
+    material->setColor(BAR_COLOR);
+    barGeomNode->setMaterial(material);
+    barGeomNode->setFlag(QSGNode::OwnsMaterial);
+
+    QSGOpacityNode *opacityNode = new QSGOpacityNode;
+    opacityNode->setOpacity(DEFAULT_OPACITY);
+    opacityNode->appendChildNode(barGeomNode);
+    opacityNode->appendChildNode(outlineGeomNode);
+
+    return opacityNode;
+}
+
+void BarChart::updateBarNodeGeom(QSGNode *barNode, float x, float barWidth, float barHeight)
+{
+    QSGGeometryNode *outlineGeomNode =
+        static_cast<QSGGeometryNode *>(barNode->firstChild());
+    QSGGeometryNode *barGeomNode =
+        static_cast<QSGGeometryNode *>(barNode->firstChild()->nextSibling());
+
+    float y = height() - barHeight;
+    updateRectGeometry(outlineGeomNode->geometry(), x, y, barWidth, barHeight);
+    updateRectGeometry(barGeomNode->geometry(), x, y, barWidth, barHeight);
+}
+
+void BarChart::updateBars(QSGNode *root)
+{
+    QSGNode *node = root->firstChild();
+    float x = 0;
+    float barWidth = width() / m_values.n_elem;
+    LinearScale<float> heightScale(m_values.min(), m_values.max(), 0, height());
+
+    for (auto it = m_values.cbegin(); it != m_values.cend(); it++) {
+        updateBarNodeGeom(node, x, barWidth, heightScale((float) *it));
+        x += barWidth;
+        node = node->nextSibling();
+    }
+}
+
+QSGNode *BarChart::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
+{
+    QSGNode *root = oldNode ? oldNode : new QSGNode;
+    if (m_shouldUpdateBars) {
+        // First, make sure we have the same number of values & bars
+        while (m_values.n_elem > root->childCount()) {
+            QSGNode *barNode = newBarNode();
+            root->appendChildNode(barNode);
+        }
+        while (m_values.n_elem < root->childCount()) {
+            // NOTE: as stated in docs, QSGNode's children are stored in a
+            // linked list. Hence, this operation should be as fast as expected
+            root->removeChildNode(root->firstChild());
+        }
+
+        // Then, update the geometry of bars to reflect the values
+        updateBars(root);
+        m_shouldUpdateBars = false;
+    }
+
+    return root;
+}
+
+void BarChart::hoverMoveEvent(QHoverEvent *event)
+{
+}
+
+void BarChart::mousePressEvent(QMouseEvent *event)
+{
+}
diff --git a/barchart.h b/barchart.h
new file mode 100644
index 0000000..ccbb13e
--- /dev/null
+++ b/barchart.h
@@ -0,0 +1,34 @@
+#ifndef BARCHART_H
+#define BARCHART_H
+
+#include <QtQuick>
+#include <armadillo>
+
+class BarChart : public QQuickItem
+{
+    Q_OBJECT
+public:
+    BarChart(QQuickItem *parent = 0);
+    ~BarChart();
+
+signals:
+    void valuesChanged(const arma::vec &values);
+
+public slots:
+    void setValues(const arma::vec &values);
+
+protected:
+    QSGNode *updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *);
+    void hoverMoveEvent(QHoverEvent *event);
+    void mousePressEvent(QMouseEvent *event);
+
+private:
+    QSGNode *newBarNode();
+    void updateBarNodeGeom(QSGNode *barNode, float x, float width, float height);
+    void updateBars(QSGNode *root);
+
+    arma::vec m_values;
+    bool m_shouldUpdateBars;
+};
+
+#endif // BARCHART_H
diff --git a/main.cpp b/main.cpp
index b9d7232..41d0ed0 100644
--- a/main.cpp
+++ b/main.cpp
@@ -14,6 +14,7 @@
 #include "scatterplot.h"
 #include "voronoisplat.h"
 #include "historygraph.h"
+#include "barchart.h"
 #include "interactionhandler.h"
 #include "selectionhandler.h"
 #include "effectivenessobserver.h"
@@ -158,6 +159,7 @@ int main(int argc, char **argv)
 
     qmlRegisterType<Scatterplot>("PM", 1, 0, "Scatterplot");
     qmlRegisterType<HistoryGraph>("PM", 1, 0, "HistoryGraph");
+    qmlRegisterType<BarChart>("PM", 1, 0, "BarChart");
     qmlRegisterType<InteractionHandler>("PM", 1, 0, "InteractionHandler");
     qmlRegisterSingletonType<Main>("PM", 1, 0, "Main", mainProvider);
 
@@ -222,11 +224,14 @@ int main(int argc, char **argv)
             plot, SLOT(setSelection(const QSet<int> &)));
 
     // Connections between history graph and subsample plot
-    HistoryGraph *history = engine.rootObjects()[0]->findChild<HistoryGraph *>("history");
-    QObject::connect(subsamplePlot, SIGNAL(xyInteractivelyChanged(const arma::mat &)),
-            history, SLOT(addHistoryItem(const arma::mat &)));
-    QObject::connect(history, SIGNAL(currentItemChanged(const arma::mat &)),
-            subsamplePlot, SLOT(setXY(const arma::mat &)));
+    //HistoryGraph *history = engine.rootObjects()[0]->findChild<HistoryGraph *>("history");
+    //QObject::connect(subsamplePlot, SIGNAL(xyInteractivelyChanged(const arma::mat &)),
+    //        history, SLOT(addHistoryItem(const arma::mat &)));
+    //QObject::connect(history, SIGNAL(currentItemChanged(const arma::mat &)),
+    //        subsamplePlot, SLOT(setXY(const arma::mat &)));
+
+    BarChart *barChart = engine.rootObjects()[0]->findChild<BarChart *>("barChart");
+    barChart->setValues(arma::randn<arma::vec>(100));
 
     // Map distortion as the glyph color
     //DistortionObserver distortionObs(X, sampleIndices);
@@ -245,8 +250,7 @@ int main(int argc, char **argv)
     //QObject::connect(&enforcer, SIGNAL(effectivenessChanged(const arma::vec &)),
     //        subsamplePlot, SLOT(setColorData(const arma::vec &)));
 
-
-    history->addHistoryItem(Ys);
+    //history->addHistoryItem(Ys);
     subsamplePlot->setXY(Ys);
     subsamplePlot->setColorData(labels(sampleIndices));
     plot->setColorScale(&colorScale);
diff --git a/main_view.qml b/main_view.qml
index a9c1c18..1be06d0 100644
--- a/main_view.qml
+++ b/main_view.qml
@@ -107,11 +107,17 @@ ApplicationWindow {
             border.width: 1
             border.color: "#cccccc"
 
-            HistoryGraph {
-                id: history
-                objectName: "history"
+            BarChart {
+                id: barChart
+                objectName: "barChart"
                 anchors.fill: parent
             }
+
+            //HistoryGraph {
+            //    id: history
+            //    objectName: "history"
+            //    anchors.fill: parent
+            //}
         }
     }
 
diff --git a/pm.pro b/pm.pro
index 0a76551..54476c8 100644
--- a/pm.pro
+++ b/pm.pro
@@ -12,6 +12,7 @@ HEADERS += main.h \
     scatterplot.h \
     voronoisplat.h \
     historygraph.h \
+    barchart.h \
     interactionhandler.h \
     selectionhandler.h \
     effectivenessobserver.h \
@@ -28,6 +29,7 @@ SOURCES += main.cpp \
     scatterplot.cpp \
     voronoisplat.cpp \
     historygraph.cpp \
+    barchart.cpp \
     interactionhandler.cpp \
     selectionhandler.cpp \
     effectivenessobserver.cpp \