def test_add_points_to_empty_bounding_box(self):
box = Bounds()
p1 = Point(-5, 2, 0)
p2 = Point(7, 0, -3)
box.add_point(p1)
box.add_point(p2)
self.assertEqual(box.min, Point(-5, 0, -3))
self.assertEqual(box.max, Point(7, 2, 0))
def bounds_of(self) -> Bounds:
box = Bounds()
box.add_point(self.p1)
box.add_point(self.p2)
box.add_point(self.p3)
return box
class SvgLoopTracer(object):
def __init__(self):
self.loops = []
self.bounds = Bounds()
def get_point(self, command):
x = command[1]
y = -command[2]
self.bounds.add_point(x, y)
return x, y
def onMove(self, command):
x, y = self.get_point(command)
self.current_path = [(x, y)]
def onLine(self, command):
x, y = self.get_point(command)
self.current_path.append((x, y))
def onClose(self, command):
if self.current_path[0] == self.current_path[-1]:
self.current_path = self.current_path[:-1]
if len(self.current_path) < 3:
raise ParseError('loop needs 3 or more verts')
self.loops.append(self.current_path)
self.current_path = None
def onBadCommand(self, action):
msg = 'unsupported svg path command: %s' % (action,)
raise ParseError(msg)
def to_loops(self, commands):
'''
commands : list of tuples, as output from to_tuples() method, eg:
[('M', 1, 2), ('L', 3, 4), ('L', 5, 6), ('z')]
Interprets the command characters at the start of each tuple to return
a list of loops, where each loop is a closed list of verts, and each
vert is a pair of ints or floats, eg:
[[1, 2, 3, 4, 5, 6]]
Note that the final point of each loop is eliminated if it is equal to
the first.
SVG defines commands:
M x,y: move, start a new loop
L x,y: line, draw boundary
H x: move horizontal
V y: move vertical
Z: close current loop - join to start point
Lower-case command letters (eg 'm') indicate a relative offset.
See http://www.w3.org/TR/SVG11/paths.html
'''
lookup = {
'M': self.onMove,
'L': self.onLine,
'Z': self.onClose,
'z': self.onClose,
}
self.loops = []
self.current_path = None
self.bounds.reset()
for command in commands:
action = command[0]
if action in lookup:
lookup[action](command)
else:
self.onBadCommand(action)
return self.loops
