update: perhaps some improvement

server/map/get_relation.py

@@ -19,7 +19,7 @@ def get_relation(self, body_of_water: str):  # NB: implement body_of_water
     # Divide all polygons into sections
     for polygon in polygons:
 
-        cell_size = 0.4
+        cell_size = 1.5
         # Divide the length and with of polygon into a grid of equally sized parts
         grid_lines = create_grid_coords(polygon, cell_size)
 
@@ -28,7 +28,6 @@ def get_relation(self, body_of_water: str):  # NB: implement body_of_water
 
         # Cut polygon into horizontal sections, bottom to top
         for hrz_line in hrz_lines:
-
             # Split shape into upper and lower section as hrz_line as divider
             divided_poly = cut_polygon_by_points(polygon, hrz_line, cell_size)
             horizontal_section = divided_poly[0]  # Save upper horizontal section
@@ -122,10 +121,13 @@ def cut_polygon_by_points(polygon: Polygon, divisor: float, cell_size: float):
                 remaining_shape.append((point2.x, point2.y))
 
     # Populate newly created edges with points to facilitate vertical cutting
-    populated_shapes = populate_new_edge(split_shape, remaining_shape, cell_size, divisor)
-    if populated_shapes is not None:
-        split_shape = populated_shapes[0]
-        remaining_shape = populated_shapes[1]
+    populated_split = populate_new_edge(split_shape, cell_size, divisor)
+    if populated_split is not None:
+        split_shape = populated_split
+
+    populated_rem = populate_new_edge(remaining_shape, cell_size, divisor)
+    if populated_rem is not None:
+        remaining_shape = populated_rem
 
     # Ensure that the shapes are closed loops
     if len(split_shape) > 0 and split_shape[0] != split_shape[-1]:
@@ -137,7 +139,6 @@ def cut_polygon_by_points(polygon: Polygon, divisor: float, cell_size: float):
     return Polygon(split_shape), Polygon(remaining_shape)
 
 
-
 # Generate grid of equally spaced x and y coordinates where the grid size is determined by cell_size
 def create_grid_coords(polygon: Polygon, cell_size: float):
     # Define boundaries of grid
@@ -174,7 +175,7 @@ def circle_polygon():
 
 
 # Adds equally spaced points along an edge that is created after a polygon is cut.
-def populate_new_edge(split_shape, remaining_shape, cell_size: float, divisor: float):
+def populate_new_edge(split_shape, cell_size: float, divisor: float):
     # Prepend new points onto the newly created edge to facilitate vertical splitting
     if split_shape is not None and polygon_min_x is not None:
         # Define starting point with an x-value that will be common for all polygons
@@ -183,11 +184,9 @@ def populate_new_edge(split_shape, remaining_shape, cell_size: float, divisor: f
         # Create list of corners
         corners = []
 
-        divisor_range = ((divisor - 0.1),(divisor + 0.1))  # Define tolerance NB: must find appropriate value
-
         # Find all corners of split shape. Corner = point that intersects divisor
         for point in split_shape:
-            if divisor_range[0] < point[1] < divisor_range[1]:
+            if point[1] == divisor:
                 corners.append(point)
 
         if not corners or len(corners) < 2:
@@ -199,16 +198,9 @@ def populate_new_edge(split_shape, remaining_shape, cell_size: float, divisor: f
         while starting_point < sorted_corners[0][0]:  # Increment starting point until it is withing the polygons bounds
             starting_point += cell_size
 
-        # if starting_point < left_corner.x: # NB: optimised substitute for previous while loop, requires testing
-        #    starting_point += cell_size * math.floor(starting_point - left_corner.x)
-
         # Insert new points with cell_size spacing while starting_point is within bounds
         while starting_point < sorted_corners[-1][0]:
             split_shape.insert(0, (starting_point, divisor))  # NB may have to add/subtract small offset of 0.00001
-            remaining_shape.insert(-1, (starting_point, divisor))  # Prepend new point to shape
-
             starting_point += cell_size
 
-        return split_shape, remaining_shape
-
-
+        return split_shape