Add a specialised QwtRasterData for views with only 2 dimensions

It also doesn't use any overlays.
Refs #9319

Code/Mantid/MantidPlot/src/Spectrogram.cpp

@@ -72,15 +72,17 @@ Spectrogram::Spectrogram(const Mantid::API::IMDWorkspace_const_sptr &workspace)
       color_axis(QwtPlot::yRight),
       color_map_policy(Default),mColorMap()
 {
-  d_wsData = new MantidQt::API::QwtRasterDataMD;
+  d_wsData = new MantidQt::API::NoOverlayRaster2D;
   d_wsData->setWorkspace(workspace);
   d_wsData->setFastMode(false);
   d_wsData->setNormalization(Mantid::API::NoNormalization);
   d_wsData->setZerosAsNan(false);
 
+  // colour range
   QwtDoubleInterval fullRange = MantidQt::API::SignalRange(*workspace).interval();
   d_wsData->setRange(fullRange);
 
+  // X/Y axis ranges
   auto dim0 = workspace->getDimension(0);
   auto dim1 = workspace->getDimension(1);
   Mantid::coord_t minX(dim0->getMinimum()), minY(dim1->getMinimum());
@@ -927,19 +929,19 @@ bool Spectrogram::isIntensityChanged()
 
 /**
  * Override QwtPlotSpectrogram::renderImage to draw ragged spectrograms. It is almost
- * a copy of QwtPlotSpectrogram::renderImage except that pixels of the image that are 
+ * a copy of QwtPlotSpectrogram::renderImage except that pixels of the image that are
  * outside the boundaries of the histograms are set to a special colour (white).
  */
 QImage Spectrogram::renderImage(
-    const QwtScaleMap &xMap, const QwtScaleMap &yMap, 
+    const QwtScaleMap &xMap, const QwtScaleMap &yMap,
     const QwtDoubleRect &area) const
 {
+  // Mantid workspace handled in QwtRasterDataMD
+  if(d_wsData) return QwtPlotSpectrogram::renderImage(xMap,yMap,area);
 
-  MantidMatrixFunction* mantidFun = dynamic_cast<MantidMatrixFunction*>(d_funct);
-  if (!mantidFun)
-  {
-    return QwtPlotSpectrogram::renderImage(xMap,yMap,area);
-  }
+  // Not Mantid function so just use base class
+  auto *mantidFun = dynamic_cast<MantidMatrixFunction*>(d_funct);
+  if (!mantidFun) return QwtPlotSpectrogram::renderImage(xMap,yMap,area);
 
   if ( area.isEmpty() )
     return QImage();

Code/Mantid/MantidQt/API/inc/MantidQtAPI/QwtRasterDataMD.h

@@ -104,6 +104,16 @@ class QWT_EXPORT QwtRasterDataMD : public QwtRasterData
   Mantid::API::MDNormalization m_normalization;
 };
 
+//-----------------------------------------------------------------
+// Specialised class for 2D data with no overlays
+//-----------------------------------------------------------------
+class QWT_EXPORT NoOverlayRaster2D : public QwtRasterDataMD
+{
+public:
+  NoOverlayRaster2D* copy() const;
+  double value(double x, double y) const;
+};
+
 } // namespace SliceViewer
 } // namespace Mantid
 

Code/Mantid/MantidQt/API/src/QwtRasterDataMD.cpp

@@ -3,6 +3,7 @@
 #include "MantidGeometry/MDGeometry/MDTypes.h"
 #include "MantidGeometry/MDGeometry/IMDDimension.h"
 #include "MantidAPI/IMDWorkspace.h"
+#include "MantidAPI/MatrixWorkspace.h"
 
 namespace MantidQt
 {
@@ -279,5 +280,62 @@ void QwtRasterDataMD::setSliceParams(size_t dimX, size_t dimY,
   }
 }
 
+//===================================================================================
+// NoOverlayRaster2D
+//===================================================================================
+
+/**
+ * Create a new object with the same state as this
+ * @return A pointer to a new object
+ */
+NoOverlayRaster2D *NoOverlayRaster2D::copy() const
+{
+  auto* out = new NoOverlayRaster2D();
+  //base bounding box
+  out->setBoundingRect(this->boundingRect());
+
+  out->m_ws = this->m_ws;
+  out->m_dimX = this->m_dimX;
+  out->m_dimY = this->m_dimY;
+  out->m_nd = this->m_nd;
+  out->m_range = this->m_range;
+  out->m_slicePoint = new coord_t[m_nd];
+  for (size_t d=0; d<m_nd; d++)
+    out->m_slicePoint[d] = this->m_slicePoint[d];
+  out->m_ws = this->m_ws;
+  out->m_fast = this->m_fast;
+  out->m_zerosAsNan = this->m_zerosAsNan;
+  out->m_normalization = this->m_normalization;
+
+  out->m_overlayWS = this->m_overlayWS;
+  out->m_overlayXMin = this->m_overlayXMin;
+  out->m_overlayXMax = this->m_overlayXMax;
+  out->m_overlayYMin = this->m_overlayYMin;
+  out->m_overlayYMax = this->m_overlayYMax;
+  out->m_overlayInSlice = this->m_overlayInSlice;
+  return out;
+
+}
+
+/**
+ * Return the data value to plot at the given position specialized
+ * for a matrix workspace. There is no consideration for a
+ * slicing point. It simply plots the signal from the given
+ * coordinates
+ * @param x :: position in coordinates of the MDWorkspace
+ * @param y :: position in coordinates of the MDWorkspace
+ * @return signal to plot
+ */
+double NoOverlayRaster2D::value(double x, double y) const
+{
+  coord_t lookPoint[2] = {static_cast<coord_t>(x), static_cast<coord_t>(y)};
+  signal_t value = m_ws->getSignalAtCoord(lookPoint, m_normalization);
+  if(value != value) // out of range
+  {
+    value = m_range.maxValue()*1.1;
+  }
+  return value;
+}
+
 } //namespace
 } //namespace