Remove using dxt.js, added custom decoding, support VC/III formats

[AnriTool]

Removed dxt-js. Decompression of DXT, as well as conversion of different palettes and raster formats is done through a helper class.

Based on: DragonFF/blob/master/gtaLib/txd.py

jest TXD test - passes successfully

Tested on canvas in browser

txd - files filled through MagicTxd selecting different formats and versions (only PC GTA III/VC/SA)

[AnriTool]

maybe try to describe the code more explicitly, and add comments in order to make it more clear how the algorithms work?

[Timic3]

Hey, thanks for the PR, the code looks great! You can add documentation on how the code works, but it's not that critical. Do it only if you have time. :)

Also, I would do some benchmarks and check the difference between dxt-js and your own implementation. If dxt-js is faster, then people might prefer to sacrifice bundle size and use it to speed up parsing. In this case, dxt-js would be added to optionalDependencies and would not get installed by default. Of course, dxt-js will then be imported and used only if it is installed. If performance is negligible, then this isn't really needed.

[AnriTool]

lso, I would do some benchmarks and check the difference between dxt-js and your own implementation.

Ok, well, I wonder how strong the differences are, I'll do performance tests.
Should I mark the request as draft for now?

[Timic3]

Should I mark the request as draft for now?

Not needed, I think it's fine the way it is, just some research regarding performance is required.

Thanks :)

[AnriTool]

@Timic3 I ran speed tests and the result was not comforting. The code was very slow.

After that I made some optimizations and fixes (dxt4/dxt5 implementation had artifacts)
And now the performance is decent!

How the testing was done:
I ran decoding 1024x1024 images dxt1, dxt3, dxt5, 1000 times, 10 iterations.

Comparative table:
The table shows decoding time of 1000 images (input data is always the same), in ms

result screen with opacity

[Timic3]

Perfect! Everything looks good, just one minor change.

[Timic3]

Looks good, we can add tests in another PR.

Thanks for the contribution!

[Timic3]

I will make a release once I get home.