Coordinates.cs

namespace StereoKit
{
	/// <summary>Some utility functions for converting coordinate data to and
	/// from some commonly used tools!
	/// 
	/// StereoKit uses a right-handed coordinate system, where +x is to the
	/// right, +y is upwards, and -z is forward. This is the exact same
	/// coordinate system as OpenXR, so no conversions are necessary there :)
	/// 
	/// Unity uses a left-handed coordinate system, where +x is to the right,
	/// +y is upwards, and +z is forward.
	/// 
	/// Blender uses a right-handed coordinate system, where +x is  to the
	/// right, +z is upward, and -z is forward.
	/// </summary>
	public static class Coordinates
	{
		/// <summary>Convert a point from Unity's coordinate system to
		/// StereoKit's.</summary>
		/// <param name="unityPoint">A point in Unity's coordinate system.
		/// </param>
		/// <returns>A point in StereoKit's coordinate system.</returns>
		public static Vec3 FromUnity(Vec3 unityPoint) => new Vec3(unityPoint.x, unityPoint.y, -unityPoint.z);
		public static Quat FromUnity(Quat unityRotation) => new Quat(unityRotation.x, unityRotation.y, -unityRotation.z, -unityRotation.w);
		public static Pose FromUnity(Pose unityPose) => new Pose(FromUnity(unityPose.position), FromUnity(unityPose.orientation));

		public static Vec3 ToUnity(Vec3 stereokitPoint) => new Vec3(stereokitPoint.x, stereokitPoint.y, -stereokitPoint.z);
		public static Quat ToUnity(Quat stereokitRotation) => new Quat(stereokitRotation.x, stereokitRotation.y, -stereokitRotation.z, -stereokitRotation.w);
		public static Pose ToUnity(Pose stereokitPose) => new Pose(ToUnity(stereokitPose.position), ToUnity(stereokitPose.orientation));

		/// <summary>Convert a point from Blender's coordinate system to
		/// StereoKit's.</summary>
		/// <param name="blenderPoint">A point in Blender's coordinate system.
		/// </param>
		/// <returns>A point in StereoKit's coordinate system.</returns>
		public static Vec3 FromBlender(Vec3 blenderPoint) => new Vec3(blenderPoint.x, blenderPoint.z, -blenderPoint.y);
		public static Quat FromBlender(Quat blenderRotation) => new Quat(blenderRotation.x, blenderRotation.z, -blenderRotation.y, blenderRotation.w);
		public static Pose FromBlender(Pose blenderPose) => new Pose(FromBlender(blenderPose.position), FromBlender(blenderPose.orientation));

		public static Vec3 ToBlender(Vec3 stereokitPoint) => new Vec3(stereokitPoint.x, stereokitPoint.z, -stereokitPoint.y);
		public static Quat ToBlender(Quat stereokitRotation) => new Quat(stereokitRotation.x, stereokitRotation.z, -stereokitRotation.y, stereokitRotation.w);
		public static Pose ToBlender(Pose stereokitPose) => new Pose(ToBlender(stereokitPose.position), ToBlender(stereokitPose.orientation));
	}
}