Function for drawing a margin around a region #599
Description
📝 Description of the feature
Create a function that can return a region based on an original region that is smaller (or larger) than the original.
💡 Steps for implementing the feature
- Create a method for returning perpendicular lines for an entity of given length:
def get_perpendicular_line(entity, length):
line = Line(entity.start, entity.end)
line.rotate(entity.midpoint, 90)
line.start = line.midpoint
new_end = line.get_coordinate_from_distance(line.start, distance=length)
line.end = new_end
return line
- Use the perpendicular lines to get the vector to shift original lines by:
shifted_entities = []
perpendicular_lines = []
for entity in square_1.entities:
perpendicular_line = get_perpendicular_line(entity, margin)
perpendicular_lines.append(perpendicular_line)
vector_to_shift = perpendicular_line.end - perpendicular_line.start
shifted_entity = Line(entity.start, entity.end)
shifted_entity.translate(vector_to_shift.x, vector_to_shift.y)
shifted_entities.append(shifted_entity)
- Find the intersection points of these shifted lines:
intersection_points = []
entity = shifted_entities[-1]
for i in range(len(shifted_entities)):
next_entity = shifted_entities[i]
intersection_points.append(entity.get_intersection(next_entity)[0])
entity = next_entity
intersection_points.append(intersection_points[0])
- Draw new lines between the intersection points to form the new 'margin region':
point_1 = intersection_points[0]
margin_region = Region()
for i in range(len(intersection_points)-1):
point_2 = intersection_points[i+1]
margin_region.add_entity(Line(point_1, point_2))
point_1 = point_2
