Fix rotated size when rotating 180

Author: mcm001

photon-core/src/main/java/org/photonvision/vision/calibration/CameraCalibrationCoefficients.java

@@ -116,6 +116,8 @@ public CameraCalibrationCoefficients rotateCoefficients(ImageRotationMode rotati
         double p1 = getDistCoeffsMat().get(0, 2)[0];
         double p2 = getDistCoeffsMat().get(0, 3)[0];
 
+        Size rotatedImageSize = null;
+
         // A bunch of horrifying opaque rotation black magic. See image-rotation.md for more details.
         switch (rotation) {
             case DEG_0:
@@ -136,6 +138,8 @@ public CameraCalibrationCoefficients rotateCoefficients(ImageRotationMode rotati
                 // P2
                 rotatedDistCoeffs.put(0, 3, -p1);
 
+                // The rotated image size is the same as the unrotated image size, but the width and height are flipped
+                rotatedImageSize = new Size(unrotatedImageSize.height, unrotatedImageSize.width);
                 break;
             case DEG_180_CCW:
                 // CX
@@ -147,6 +151,9 @@ public CameraCalibrationCoefficients rotateCoefficients(ImageRotationMode rotati
                 rotatedDistCoeffs.put(0, 2, -p1);
                 // P2
                 rotatedDistCoeffs.put(0, 3, -p2);
+
+                // The rotated image size is the same as the unrotated image size
+                rotatedImageSize = unrotatedImageSize;
                 break;
             case DEG_90_CCW:
                 // FX
@@ -164,6 +171,8 @@ public CameraCalibrationCoefficients rotateCoefficients(ImageRotationMode rotati
                 // P2
                 rotatedDistCoeffs.put(0, 3, p1);
 
+                // The rotated image size is the same as the unrotated image size, but the width and height are flipped
+                rotatedImageSize = new Size(unrotatedImageSize.height, unrotatedImageSize.width);
                 break;
         }
 
@@ -174,7 +183,6 @@ public CameraCalibrationCoefficients rotateCoefficients(ImageRotationMode rotati
         rotatedIntrinsics.release();
         rotatedDistCoeffs.release();
 
-        var rotatedImageSize = new Size(unrotatedImageSize.height, unrotatedImageSize.width);
 
         return new CameraCalibrationCoefficients(
                 rotatedImageSize,

photon-core/src/test/java/org/photonvision/vision/pipeline/CalibrationRotationPipeTest.java

@@ -174,6 +174,65 @@ public void testUndistortImagePointsWithRotation(@Enum ImageRotationMode rot) {
         }
     }
 
+    @Test
+    public void testRotateCoefficients180multiple() {
+        ImageRotationMode rot = ImageRotationMode.DEG_180_CCW;
+
+        // GIVEN A camera calibration
+        var res = new Size(1270, 720);
+        double fx = 900;
+        double fy = 951;
+        double cx = 500;
+        double cy = 321;
+        double[] intrinsics = {
+            fx, 0, cx,
+            0, fy, cy,
+            0, 0, 1
+        };
+        double[] distCoeffs = {
+            0.25,
+            -1.5,
+            0.0017808248356550637,
+            .00004,
+            2.179764689221826,
+            -0.034952777924711353,
+            0.09625562194891251,
+            -0.1860797479660746
+        };
+        CameraCalibrationCoefficients coeffs =
+                new CameraCalibrationCoefficients(
+                        res,
+                        new JsonMatOfDouble(3, 3, intrinsics),
+                        new JsonMatOfDouble(1, 8, distCoeffs),
+                        new double[] {},
+                        List.of(),
+                        new Size(),
+                        1,
+                        CameraLensModel.LENSMODEL_OPENCV);
+
+        // WHEN the camera calibration is rotated 180 degrees
+        var coeffs2 = coeffs.rotateCoefficients(rot);
+
+        // THEN the optical center should be rotated 180 degrees
+        double[] rotatedCamMat = {
+            fx, 0, res.width-cx,
+            0, fy, res.height-cy,
+            0, 0, 1
+        };
+        assertArrayEquals(rotatedCamMat, coeffs2.cameraIntrinsics.data);
+        // AND the image size should be the same
+        assertEquals(res, coeffs2.unrotatedImageSize);
+
+        // WHEN the camera calibration is rotated 180 degrees
+        var coeffs3 = coeffs2.rotateCoefficients(rot);
+
+        // THEN the camera matrix will be the same as the original
+        assertArrayEquals(intrinsics, coeffs3.cameraIntrinsics.data);
+        // AND the image size should be the same
+        assertEquals(res, coeffs2.unrotatedImageSize);
+    }
+    
+
     @CartesianTest
     public void testCalibrationDataIsValidWithRotation(@Enum ImageRotationMode rot) {
         double[] intrinsics = {