feat (WIP): base VTK visualisation of Eulerian flow fields

vtk/src/CMakeLists.txt

@@ -0,0 +1,55 @@
+cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
+
+project(VtkBase)
+
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+find_package(VTK COMPONENTS 
+  CommonColor
+  CommonCore
+  CommonDataModel
+  FiltersGeneral
+  InteractionStyle
+  RenderingContextOpenGL2
+  RenderingCore
+  RenderingFreeType
+  RenderingGL2PSOpenGL2
+  RenderingOpenGL2
+    CommonColor
+    FiltersGeometry
+    RenderingCore)
+
+if (NOT VTK_FOUND)
+  message(FATAL_ERROR "VtkBase: Unable to find the VTK build folder.")
+endif()
+
+# netcdf setup
+find_package(netCDF REQUIRED)
+
+add_executable(VtkBase MACOSX_BUNDLE main.cpp )
+
+execute_process(
+    COMMAND nc-config --includedir
+    OUTPUT_VARIABLE NETCDF_INCLUDE_DIR
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+)
+
+execute_process(
+    COMMAND ncxx4-config --libdir
+    OUTPUT_VARIABLE NETCDFCXX_LIB_DIR
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+)
+
+target_include_directories(VtkBase PUBLIC ${netCDF_INCLUDE_DIR})
+
+find_library(NETCDF_LIB NAMES netcdf-cxx4 netcdf_c++4 PATHS ${NETCDFCXX_LIB_DIR} NO_DEFAULT_PATH)
+
+# Prevent a "command line is too long" failure in Windows.
+set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
+target_link_libraries(VtkBase ${NETCDF_LIB} ${VTK_LIBRARIES})
+
+# vtk_module_autoinit is needed
+vtk_module_autoinit(
+  TARGETS VtkBase
+  MODULES ${VTK_LIBRARIES}
+)

vtk/src/main.cpp

@@ -0,0 +1,94 @@
+#include <vtkActor.h>
+#include <vtkActor2D.h>
+#include <vtkCamera.h>
+#include <vtkDoubleArray.h>
+#include <vtkMapper2D.h>
+#include <vtkNamedColors.h>
+#include <vtkNew.h>
+#include <vtkPolyDataMapper.h>
+#include <vtkPolyDataMapper2D.h>
+#include <vtkProperty.h>
+#include <vtkRectilinearGrid.h>
+#include <vtkRectilinearGridGeometryFilter.h>
+#include <vtkRenderWindow.h>
+#include <vtkRenderWindowInteractor.h>
+#include <vtkRenderer.h>
+
+#include <netcdf>
+
+#define NLATS 67
+#define NLONS 116
+
+using namespace std;
+using namespace netCDF;
+
+template <typename T>
+vector<T> getVarVector(const NcVar &var) {
+    int length = 1;
+    for (NcDim dim : var.getDims()) {
+        length *= dim.getSize();
+    }
+
+    vector<T> vec(length);
+
+    var.getVar(vec.data());
+
+    return vec;
+}
+
+tuple<vector<int>, vector<double>, vector<double>> readGrid() {
+    netCDF::NcFile data("../../../../data/grid.h5", netCDF::NcFile::read);
+    multimap< string, NcVar > vars = data.getVars();
+    vector<int> time = getVarVector<int>(vars.find("times")->second);
+    vector<double> longitude = getVarVector<double>(vars.find("longitude")->second);
+    vector<double> latitude = getVarVector<double>(vars.find("latitude")->second);
+
+    return {time, latitude, longitude};
+}
+
+int main() {
+  vtkNew<vtkNamedColors> colors;
+
+
+  vtkNew<vtkDoubleArray> pCoords;
+  pCoords->SetNumberOfComponents(3);
+  pCoords->SetNumberOfTuples(NLATS*NLONS);
+  auto [times, lats, lons] = readGrid();
+
+  double i = 0;
+  for (double lat : lats) {
+    for (double lon : lons) {
+      pCoords->InsertTuple3(i++, 0, lat, lon);
+    }
+  }
+
+
+  vtkNew<vtkPoints> points;
+  points->SetData(pCoords);
+
+  vtkNew<vtkPolyData> polydata;
+  polydata->SetPoints(points);
+
+
+  vtkNew<vtkPolyDataMapper2D> mapper;
+  mapper->SetInputData(polydata);
+  mapper->SetScalarRange(0, 40);
+
+  vtkNew<vtkActor2D> actor;
+  actor->SetMapper(mapper);
+
+  vtkNew<vtkRenderer> ren;
+  ren->AddActor(actor);
+  ren->SetBackground(colors->GetColor3d("DarkSlateGray").GetData());
+
+  vtkNew<vtkRenderWindow> renWin;
+  renWin->AddRenderer(ren);
+  renWin->SetSize(900, 600);
+
+  vtkNew<vtkRenderWindowInteractor> iren;
+  iren->SetRenderWindow(renWin);
+  iren->Start();
+
+  return EXIT_SUCCESS;
+}
+