renamed and stuff

particle-track-and-trace/src/layers/BackgroundImage.cpp

@@ -0,0 +1,62 @@
+#include "BackgroundImage.h"
+#include <vtkCamera.h>
+#include <vtkImageActor.h>
+#include <vtkImageData.h>
+#include <vtkImageReader2.h>
+
+using std::string;
+
+BackgroundImage::BackgroundImage(string imagePath) : imagePath(imagePath) {
+  this->ren = vtkSmartPointer<vtkRenderer>::New();
+  this->ren->SetLayer(0);
+  this->ren->InteractiveOff();
+  updateImage();
+}
+
+
+void BackgroundImage::updateImage() {
+  vtkSmartPointer<vtkImageData> imageData;
+
+  vtkSmartPointer<vtkImageReader2> imageReader;
+  
+  imageReader.TakeReference(this->readerFactory->CreateImageReader2(this->imagePath.c_str()));
+  imageReader->SetFileName(this->imagePath.c_str());
+  imageReader->Update();
+  imageData = imageReader->GetOutput();
+
+  vtkNew<vtkImageActor> imageActor;
+  imageActor->SetInputData(imageData);
+
+  this->ren->AddActor(imageActor);
+
+
+  // camera stuff
+  // essentially sets the camera to the middle of the background, and points it at the background
+  // TODO: extract this to its own function, separate from the background class.
+  double origin[3], spacing[3];
+  int extent[6];
+  imageData->GetOrigin(origin);
+  imageData->GetSpacing(spacing);
+  imageData->GetExtent(extent);
+
+  vtkCamera *camera = this->ren->GetActiveCamera();
+  camera->ParallelProjectionOn();
+
+  double xc = origin[0] + 0.5 * (extent[0] + extent[1]) * spacing[0];
+  double yc = origin[1] + 0.5 * (extent[2] + extent[3]) * spacing[1];
+  double yd = (extent[3] - extent[2] + 1) * spacing[1];
+  double d = camera->GetDistance();
+  camera->SetParallelScale(0.5 * yd);
+  camera->SetFocalPoint(xc, yc, 0.0);
+  camera->SetPosition(xc, yc, d);
+}
+
+
+string BackgroundImage::getImagePath() {
+  return this->imagePath;
+}
+
+void BackgroundImage::setImagePath(string imagePath) {
+  this->imagePath = imagePath;
+  updateImage();
+}