Updated UI.

- Removed unnecessary UI elements from QML file;
- Added the ColorScale class and implemented glyph color mapping from class
  labels;
- Mark geometry nodes of individual glyphs as dirty when updating the scene
  graph.

1 files changed, 23 insertions, 22 deletions

diff --git a/scatterplot.cpp b/scatterplot.cpp
index b5e8261..a3a0dfc 100644
--- a/scatterplot.cpp
+++ b/scatterplot.cpp
@@ -1,18 +1,22 @@
 #include "scatterplot.h"
 
+#include <iostream>
+
 #include <cmath>
-#include <cstdio>
 #include <QSGNode>
 #include <QSGGeometry>
 #include <QSGGeometryNode>
 #include <QSGMaterial>
 #include <QSGFlatColorMaterial>
+#include <QSGSimpleRectNode>
 
-const int GLYPH_SIZE = 4;
-const float PADDING = 5;
+const int GLYPH_SIZE = 5;
+const float PADDING = 10;
 const float PI = 3.1415f;
 
-Scatterplot::Scatterplot()
+Scatterplot::Scatterplot(QQuickItem *parent)
+    : QQuickItem(parent)
+    , m_colorScale{QColor("red"), QColor("green"), QColor("blue")}
 {
     setFlag(QQuickItem::ItemHasContents);
 }
@@ -23,10 +27,11 @@ Scatterplot::~Scatterplot()
 
 void Scatterplot::setData(const arma::mat &data)
 {
-    if (data.n_cols != 2)
+    if (data.n_cols != 3)
         return;
 
     m_data = data;
+    m_colorScale.setExtents(m_data.col(2).min(), m_data.col(2).max());
     update();
 }
 
@@ -68,10 +73,10 @@ void updateSquareGeometry(QSGGeometry *geometry, float size, float cx, float cy)
 
 QSGNode *Scatterplot::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
 {
+    if (m_data.n_rows < 1)
+        return 0;
+
     QSGNode *node = 0;
-    QSGGeometryNode *childNode = 0;
-    QSGGeometry *geometry = 0;
-    QSGFlatColorMaterial *material = 0;
     int vertexCount = calculateCircleVertexCount(GLYPH_SIZE / 2);
     qreal xmin = m_data.col(0).min(),
           xmax = m_data.col(0).max(),
@@ -82,19 +87,15 @@ QSGNode *Scatterplot::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
     if (!oldNode) {
         node = new QSGNode;
         for (arma::uword i = 0; i < m_data.n_rows; i++) {
-            arma::rowvec row = m_data.row(i);
-            x = (row[0] - xmin) / (xmax - xmin) * width();
-            y = (row[1] - ymin) / (ymax - ymin) * height();
-
-            childNode = new QSGGeometryNode;
+            QSGGeometryNode *childNode = new QSGGeometryNode;
 
-            geometry = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), vertexCount);
+            QSGGeometry *geometry = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), vertexCount);
             geometry->setDrawingMode(GL_POLYGON);
             childNode->setGeometry(geometry);
             childNode->setFlag(QSGNode::OwnsGeometry);
 
-            material = new QSGFlatColorMaterial;
-            material->setColor(QColor());
+            QSGFlatColorMaterial *material = new QSGFlatColorMaterial;
+            material->setColor(m_colorScale.color(m_data(i, 2)));
             childNode->setMaterial(material);
             childNode->setFlag(QSGNode::OwnsMaterial);
 
@@ -104,17 +105,17 @@ QSGNode *Scatterplot::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
         node = oldNode;
     }
 
-    childNode = static_cast<QSGGeometryNode *>(node->firstChild());
+    QSGNode *childNode = node->firstChild();
     for (arma::uword i = 0; i < m_data.n_rows; i++) {
         arma::rowvec row = m_data.row(i);
-        x = (row[0] - xmin) / (xmax - xmin) * width();
-        y = (row[1] - ymin) / (ymax - ymin) * height();
+        x = PADDING + (row[0] - xmin) / (xmax - xmin) * (width() - 2*PADDING);
+        y = PADDING + (row[1] - ymin) / (ymax - ymin) * (height() - 2*PADDING);
 
-        geometry = childNode->geometry();
+        QSGGeometry *geometry = static_cast<QSGGeometryNode *>(childNode)->geometry();
         updateCircleGeometry(geometry, GLYPH_SIZE, x, y);
-        childNode = static_cast<QSGGeometryNode *>(childNode->nextSibling());
+        childNode->markDirty(QSGNode::DirtyGeometry);
+        childNode = childNode->nextSibling();
     }
-    node->markDirty(QSGNode::DirtyGeometry);
 
     return node;
 }