feat: swappable colour schemes

particle-track-and-trace/src/advection/UVGrid.cpp

@@ -31,6 +31,12 @@ UVGrid::UVGrid(string path) {
   for (auto vel: views::zip(us, vs)) {
     uvData.push_back(Vel(vel));
   }
+
+  // FIXME: should really read these from file instead of hard-coding them.
+  this->uMin = -0.381482899188995;
+  this->uMax =  0.566494882106781;
+  this->vMin = -0.381482899188995;
+  this->vMax =  0.470820993185043;
 }
 
 const Vel &UVGrid::operator[](size_t timeIndex, size_t latIndex, size_t lonIndex) const {

particle-track-and-trace/src/advection/UVGrid.h

@@ -25,6 +25,14 @@ public:
   size_t latSize;
   size_t lonSize;
 
+  /**
+    * Minimum and Maximum values of the u and v variables.
+    */
+  double uMin;
+  double uMax;
+  double vMin;
+  double vMax;
+
   /**
    * Assuming grid is a regular grid, gives the longitudinal spacing of grid.
    * @return longitudinal spacing