Fix Sample Clip Reversing Position

[regulus79]

This pr makes it so that when you reverse a trimmed/cropped sample, the cropped section is actually reversed. This is in contrast to the previous behavior, where the original sample would be reversed, causing the clip bounds to be on a different part of the sample.

Fixes #7352

[sakertooth]

Just tested the PR. It seems it didn't fix it for me.

[Gabrielxd195]

I tried this and it didn't work, but it's good that they took this into account.

[Gabrielxd195]

@regulus79 I did the test and now this improvement works, if there is no other problem I think it can be merged.

[messmerd]

If @sakertooth approves, I think it's good to merge

[bratpeki]

This might work, but I noticed that the reversed and forward sample slices don't look the same. On further inspection, I noticed LMMS behaves oddly when different zoom is applied.

These each subsequent step is one zoom-in action. Noticed how the last one looks. Very odd.

[bratpeki]

Notice how the reversed one has this "tail" after the transient.

[bratpeki]

Sounds perfectly fine, so the feature is a success!

However, the sample zoom thing is most odd.

Here's proof that the reverse doesn't match the sound.

https://github.com/user-attachments/assets/c5e1fd63-7c06-4941-8794-62ceaeb64083

This is what ffprobe has to say about the audio file:

Input #0, mp3, from 'MidiMelo2updatedMidi3.mp3':
  Metadata:
    Software        : LMMS (libsndfile-1.0.28)
  Duration: 00:01:03.79, start: 0.025057, bitrate: 294 kb/s
  Stream #0:0: Audio: mp3 (mp3float), 44100 Hz, stereo, fltp, 294 kb/s
      Metadata:
        encoder         : LAME3.100

Should I open a new issue regarding this?

[regulus79]

@bratpeki I cannot reproduce the issue; would you mind providing a sample file/project where the bug happens?

[bratpeki]

Just to note, we discussed this further on Discord.