added gui folder

pt2d/__init__.py

 import sys
 from PyQt5.QtWidgets import QApplication
-from .mainWindow import MainWindow
+from .gui.mainWindow import MainWindow
 
 def main():
     app = QApplication(sys.argv)

pt2d/imageGraphicsView.py → pt2d/gui/imageGraphicsView.py

@@ -6,7 +6,7 @@ import math
 import numpy as np
 from .panZoomGraphicsView import PanZoomGraphicsView
 from .labeledPointItem import LabeledPointItem
-from .find_path import find_path
+from ..find_path import find_path
 
 
 class ImageGraphicsView(PanZoomGraphicsView):

pt2d/mainWindow.py → pt2d/gui/mainWindow.py

@@ -5,8 +5,8 @@ from PyQt5.QtWidgets import (
     QVBoxLayout, QWidget, QFileDialog
 )
 from PyQt5.QtGui import QPixmap, QImage, QCloseEvent
-from .compute_cost_image import compute_cost_image
-from .preprocess_image import preprocess_image
+from ..compute_cost_image import compute_cost_image
+from ..preprocess_image import preprocess_image
 from .advancedSettingsWidget import AdvancedSettingsWidget
 from .imageGraphicsView import ImageGraphicsView
 from .circleEditorWidget import CircleEditorWidget