measureInsertionsRing.m
fc47198e3979master

measureInsertionsRing.m
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			function measureInsertionsRing(obj)
			% The insertions ring is the intersection of the plane fitted to the
			% insertions' landmarks with the humeral head fitted sphere.

			insertionsArray = [...
			obj.landmarks.insertions.subscapularis_inferior';...
			obj.landmarks.insertions.supraspinatus_anterior';...
			obj.landmarks.insertions.teres_minor_inferior'];
			insertionsPlane = Plane();
			insertionsPlane.fit(insertionsArray);

			ringNormal = Vector(insertionsPlane.normal);
			humerusCenterToPlanePoint = Vector(obj.center, insertionsPlane.point);

			% The ring's center is the projection of any point of the insertions' plane
			% on the vector starting at the humeral head center and with the same
			% direction as the insertion's plane normal direction.
			ringCenter = obj.center...
			+ (ringNormal.dot(humerusCenterToPlanePoint) * ringNormal.vector);

			humerusCenterToRingCenter = Vector(obj.center, ringCenter);
			ringRadius = sqrt(obj.radius^2 - humerusCenterToRingCenter.norm()^2);

			obj.insertionsRing.center = ringCenter;
			obj.insertionsRing.radius = ringRadius;
			obj.insertionsRing.normal = ringNormal;
			end