1"""Ground control points"""
2
3import uuid
4
5
6class GroundControlPoint(object):
7    """A mapping of row, col image coordinates to x, y, z."""
8
9    def __init__(self, row=None, col=None, x=None, y=None, z=None,
10                 id=None, info=None):
11        """Create a new ground control point
12
13        Parameters
14        ----------
15        row, col : float, required
16            The row (or line) and column (or pixel) coordinates that
17            map to spatial coordinate values ``y`` and ``x``,
18            respectively.
19        x, y : float, required
20            Spatial coordinates of a ground control point.
21        z : float, optional
22            Optional ``z`` coordinate.
23        id : str, optional
24            A unique identifer for the ground control point.
25        info : str, optional
26            A short description for the ground control point.
27        """
28        if any(x is None for x in (row, col, x, y)):
29            raise ValueError("row, col, x, and y are required parameters.")
30        if id is None:
31            id = str(uuid.uuid4())
32        self.id = id
33        self.info = info
34        self.row = row
35        self.col = col
36        self.x = x
37        self.y = y
38        self.z = z
39
40    def __repr__(self):
41        args = ', '.join(['{}={}'.format(att, repr(getattr(self, att)))
42                         for att in ('row', 'col', 'x', 'y', 'z', 'id', 'info')
43                         if getattr(self, att) is not None])
44        return "GroundControlPoint({})".format(args)
45
46    def asdict(self):
47        """A dict representation of the GCP"""
48        return {'id': self.id, 'info': self.info, 'row': self.row,
49                'col': self.col, 'x': self.x, 'y': self.y, 'z': self.z}
50
51    @property
52    def __geo_interface__(self):
53        """A GeoJSON representation of the GCP"""
54        coords = [self.x, self.y]
55        if self.z is not None:
56            coords.append(self.z)
57        return {'id': self.id, 'type': 'Feature',
58                'geometry': {'type': 'Point', 'coordinates': tuple(coords)},
59                'properties': self.asdict()}
60