System.Numerics conversions

[ykafia]

PR Details

Adds implicit conversions between System.Numerics and Stride.Maths vectors
Some casts use Unsafe.As for better performance, haven't done any tests though.

Motivation and Context

A lot nugets use System.Numerics, it would be nice to be able to cast implicitely between Sys Nums and Stride Maths

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My change requires a change to the documentation.
• I have added tests to cover my changes.
• All new and existing tests passed.

[Eideren]

Thanks, not sure if you're done but you might want to cover matrix as well. Will have to verify whether they are row major or column major though.

[ykafia]

Of course, there are other conversions i will add too that can be useful

[manio143]

Can you also do the conversions the other way from Stride vectors into System.Numerics?

[ykafia]

Didn't think of it but will do, shouldn't be much of a trouble!

[Eideren]

Are you sure that stride and dotnet's matrix have the same memory layout ? (more info #291)

[ykafia]

OOH, i shouldn't have assumed it, will correct this !
It's a bummer but i guess we don't have the need for big perfs right there. (What's weirder is the System.Numerics ctor is in the same order as Stride's matrix).

[Eideren]

Thanks !

[Eideren]

As we've discussed on Discord, this PR breaks UWP, iOS and Android build. Someone will have to take a look at this and provide a fix before we can merge this back in