Small optimizations to Animation Channel creation

[Crauzer]

This PR is an attempt at fixing #71.

Changes:

• Added searchForExisting parameter to UseBufferView which dictates whether the function should search for an already existing buffer with the same content
• • This is especially useful in the context of animations, where there is rarely the same data
• CreateInputAccessor and CreateOutputAccessor now accepts an IEnumerable instead of an IReadOnlyList.
• • Related to change in the Split function which now no longer copies data to new arrays but rather returns references to the inner sorted dictionary Keys and Values

Result

I was able to achieve around a 50% increase in performance while creating animation channels. The time it takes to do this same exact task with the test files provided in the issue in the current version of SharpGLTF takes around 3.5 minutes on my machine. This PR reduces that time to 2 minutes.

Generated file: GeneratedFile.zip

[vpenades]

Hmm... Is changing the IReadOnlyList to IEnumerable required?

Keep in mind that the IEnumerable.Count(); and IEnumerable.ElementAt() methods traverse the enumerable collection every time , so in your particular use case you might have improved the performance, but for other use cases the performance might have worsened.

[Crauzer]

Yes, I agree with you.

I'm currently trying to create a more efficient method that doesn't do as much memory copying. If it does end up being good I will commit that. If it ends up being bad I will change the IEnumerable back to IReadOnlyList.

Do you have any other ideas that might improve the performance of these methods ?

[vpenades]

Do you have any other ideas that might improve the performance of these methods ?

well, I wanted to do a full review of the case first, but this week is being particularly busy...

Also, I wanted to try creating a scene with a lot of animations using the SceneBuilder instead of attacking Schema2 namespace directly.

Keep in mind that SceneBuilder can do a lot of tricks under the hood that Schema2 cannot do by itself

[Crauzer]

I actually took a look at SceneBuilder as you suggested in the issue, but I can't seem to find a way to add animations with it.

[vpenades]

SceneBuilder is quite different to what you're used to with the Schema2.ModelRoot namespace. (At some point I should write tutorials, help!). try looking at some examples using it...

Btw, I created a discord channel.

[vpenades]

I'm closing this pull request since the latest changes already fix the issue.