Update Time.cs

[DemoXinMC]

Added conversions to and from .NET's TimeSpan struct
Significantly reduced P/Invoke calls, which now only happen during construction and conversion

This should yield performance gains in any place where Time is being used. Additionally, this is a bit of futureproofing for SFML3, as Time is likely to be removed, and the TimeSpan struct has existed in .NET since Framework 1.0

[LaurentGomila]

This should yield performance gains in any place where Time is being used

Is this something that you have measured? Rewriting parts of SFML instead of direct calls, has a maintenance cost and should only be done if really necessary.

[DemoXinMC]

I specifically discovered the performance hit when using SFML.System.Time as part of my animating sprite setup and discovered it to be the single largest bottle neck I have. P/Invoke calls add up very quickly, and considering that this is a very minor change for a class that isn't very volatile, I think this is a worthwhile bit of code copying.

TimeSpan exists within .NET, and serves an identical purpose, but this is the simplest way to allow the use of TimeSpan without rewriting existing signatures to cover a custom marshaler.

When SFML 3 becomes available, I plan to remove the use of sfTime in favor of TimeSpan and a custom marshaler.

[eXpl0it3r]

While I see the cost for re-implementing code, I do think this one is justified, given that it's quite common to call the conversion functions a lot and you wouldn't expect P/Invoke calls for such a simple operation.

[DemoXinMC]

Any further thoughts on this?

[LaurentGomila]

timeSpan.Ticks / (TimeSpan.TicksPerMillisecond / 1000)

I know it's not the case here, but if TimeSpan.TicksPerMillisecond was not an exact multiple of 1000, this would be incorrect. A 100% safe (future-proof) version would simply be:

timeSpan.Ticks * 1000 / TimeSpan.TicksPerMillisecond

[DemoXinMC]

Those 2 formulas yield the same result even with non-multiples of 1000

timeSpan.Ticks / (TimeSpan.TicksPerMillisecond / 1000)
20 / (13340 / 1000)
20 / 13.34
1.499250374812594

timeSpan.Ticks * 1000 / TimeSpan.TicksPerMillisecond
20 * 1000 / 13340
20000 / 13340
1.499250374812594

[LaurentGomila]

In floating-point arithmetic yes, not with integer division -- unless C# has different rules than C++ for that.

[DemoXinMC]

Fair enough. Formula changed and PR updated.