Coverage for python/lsst/afw/cameraGeom/rotateBBoxBy90.py : 5%

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1# This file is part of afw.
2#
3# Developed for the LSST Data Management System.
4# This product includes software developed by the LSST Project
5# (https://www.lsst.org).
6# See the COPYRIGHT file at the top-level directory of this distribution
7# for details of code ownership.
8#
9# This program is free software: you can redistribute it and/or modify
10# it under the terms of the GNU General Public License as published by
11# the Free Software Foundation, either version 3 of the License, or
12# (at your option) any later version.
13#
14# This program is distributed in the hope that it will be useful,
15# but WITHOUT ANY WARRANTY; without even the implied warranty of
16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17# GNU General Public License for more details.
18#
19# You should have received a copy of the GNU General Public License
20# along with this program. If not, see <https://www.gnu.org/licenses/>.
22__all__ = ["rotateBBoxBy90"]
24import numpy
26import lsst.geom
29def rotateBBoxBy90(bbox, n90, dimensions):
30 """Rotate a bounding box by an integer multiple of 90 degrees.
32 Parameters
33 ----------
34 bbox : `lsst.geom.Box2I`
35 Bounding box to rotate.
36 n90 : `int`
37 Number of quarter rotations to perform
38 dimensions : `tuple` of `int`
39 Dimensions of the parent grid.
41 Returns
42 -------
43 newBbox : `lsst.geom.Box`
44 Rotated bounding box.
46 Notes
47 -----
48 **TODO:**
49 document dimensions better; what does it specify?
50 """
51 while n90 < 0:
52 n90 += 4
53 n90 %= 4
55 # sin/cos of the rotation angle
56 s = 0
57 c = 0
58 if n90 == 0:
59 s = 0
60 c = 1
61 elif n90 == 1:
62 s = 1
63 c = 0
64 elif n90 == 2:
65 s = 0
66 c = -1
67 elif n90 == 3:
68 s = -1
69 c = 0
70 else:
71 raise ValueError("n90 must be an integer")
73 centerPixel = lsst.geom.Point2I(int(dimensions[0]/2), int(dimensions[1]/2))
75 xCorner = numpy.array([(corner.getX() - centerPixel[0])
76 for corner in bbox.getCorners()])
77 yCorner = numpy.array([(corner.getY() - centerPixel[1])
78 for corner in bbox.getCorners()])
79 x0 = int((c*xCorner - s*yCorner).min())
80 y0 = int((s*xCorner + c*yCorner).min())
81 x1 = int((c*xCorner - s*yCorner).max())
82 y1 = int((s*xCorner + c*yCorner).max())
84 # Fiddle things a little if the detector has an even number of pixels so that square BBoxes
85 # will map into themselves
87 if n90 == 1:
88 if dimensions[0]%2 == 0:
89 x0 -= 1
90 x1 -= 1
91 elif n90 == 2:
92 if dimensions[0]%2 == 0:
93 x0 -= 1
94 x1 -= 1
95 if dimensions[1]%2 == 0:
96 y0 -= 1
97 y1 -= 1
98 elif n90 == 3:
99 if dimensions[1]%2 == 0:
100 y0 -= 1
101 y1 -= 1
103 LLC = lsst.geom.Point2I(centerPixel[0] + x0, centerPixel[1] + y0)
104 URC = lsst.geom.Point2I(centerPixel[0] + x1, centerPixel[1] + y1)
106 newBbox = lsst.geom.Box2I(LLC, URC)
108 dxy0 = centerPixel[0] - centerPixel[1]
109 if n90%2 == 1 and not dxy0 == 0:
110 newBbox.shift(lsst.geom.Extent2I(-dxy0, dxy0))
112 return newBbox