.NET: Clear the OpenTK namespace
rolfbjarne opened this issue · 2 comments
Types in the OpenTK namespace
We want to remove types from the OpenTK namespace, and these types fall in three categories:
- Types we can replace with an existing .NET type
- Types that don't have an equivalent .NET type, so we have to come up with an alternative type.
- Types we don't need, so we can remove them.
One important question is which namespace to use for 2. Options:
- Keep using
OpenTK. This is not an option, because that's exactly what we're trying to move away from. ObjCRuntime: not really very math-like, and this namespace shouldn't become a catch-all for everything that doesn't fit elsewhere either.CoreNumerics: A mix of Apple's Core* frameworks with System.Numerics.CoreMath: same as 3.CoreGraphics: existing Apple namespace. Con: might end up with a name clash in the future depending on what Apple does.- Something else?
Ref: #2571
Ref: https://bugzilla.xamarin.com/show_bug.cgi?id=58599
Different type
The following types have an equivalent in .NET, so the proposal is to use that type instead:
| OpenTK type | .NET type |
|---|---|
| OpenTK.Matrix4 | System.Numerics.Matrix4x4 |
| OpenTK.Quaternion | System.Numerics.Quaternion |
| OpenTK.Vector2 | System.Numerics.Vector2 |
| OpenTK.Vector2d | System.Numerics.Vector<double> |
| OpenTK.Vector2i | System.Numerics.Vector<int> |
| OpenTK.Vector3 | System.Numerics.Vector3 |
| OpenTK.Vector3d | System.Numerics.Vector<double> |
| OpenTK.Vector3i | System.Numerics.Vector<int> |
| OpenTK.Vector4 | System.Numerics.Vector4 |
| OpenTK.Vector4d | System.Numerics.Vector<double> |
| OpenTK.Vector4i | System.Numerics.Vector<int> |
Different namespace
The following OpenTK types have no equivalent in .NET, so the proposal is to copy the OpenTK implementation, but use a different namespace.
- OpenTK.Matrix2
- OpenTK.Matrix3
- OpenTK.Matrix4d
- OpenTK.Quaterniond
The following are types that we created ourselves, but put in the OpenTK namespace.
- OpenTK.NMatrix4d
- OpenTK.NMatrix2
- OpenTK.NMatrix3
- OpenTK.NMatrix4x3
- OpenTK.NMatrix4
- OpenTK.NVector3d
- OpenTK.NVector3
Types to remove
The following types don't seem to be used by any other API, so they can be removed
- OpenTK.Box2
- OpenTK.Functions
- OpenTK.Half
- OpenTK.Vector2h
- OpenTK.Vector3h
- OpenTK.Vector4h
- OpenTK.BezierCurve
- OpenTK.BezierCurveCubic
- OpenTK.BezierCurveQuadric
Don't know yet
- ❓OpenTK.MathHelper
Ref: #13087
For OpenTK.Matrix2, OpenTK.Matrix3 and OpenTK.Matrix4d I wonder if you could use ValueTuple<Vector3, Vector3, Vector3> etc. instead.
For OpenTK.Matrix2, OpenTK.Matrix3 and OpenTK.Matrix4d I wonder if you could use ValueTuple<Vector3, Vector3, Vector3> etc. instead.
Sadly not, value tuples have auto layout rather than sequential: not suitable for interop...
System.Numerics.Vector
Note: Vector isn't quite akin to Vector2, namely it's variably sized and actually might hold more than 2 Ts in some cases. Because of this, the memory layout probably isn't suitable for your needs (interop, presumably?)
There's a proposal for generic "dimensional" vectors (dotnet/runtime#24168), but these have been postponed to .NET 7. The best solution is probably to whip up your own vectors in a Xamarin namespace. When .NET 7 generic vectors become available, either implicit casts can be added or throw those types out if you still feel in the mood to break things between major releases.
For your reference:
We've been down this road and made our own maths library which fills these holes for us (i.e. MathHelper, called Scalar in our library; and generic vector types like Vector2D). It's possibly a bit overkill for what Xamarin needs, but figured I'd drop it here for your reference (please change the namespace if you use anything): https://github.com/dotnet/Silk.NET/tree/main/src/Maths/Silk.NET.Maths
One more thing to add is please don't call anything VectorN or MatrixNxN regardless of namespace as these will conflict with System.Numerics if ever they get those types as well if users are using both namespaces - this is why the above link uses VectorND for its vectors and a capital X for its matrices.