1.18.00.00 Square waveform in IT Compat Mode

[Harbinger]

Full Version:
OpenMPT v1.18.00.00

Has the bug occured in previous versions? If yes, please specify version(s): Possibly.

Description of the bug:1st BUG: While testing the difference between IT in Compat Mode and ModPlug Mode, i noticed that in Compat Mode the square wave in Tremolo (Rxy) does not work, or IT's tables make the tremolo sound weak (the channel VUs did not detect a difference).
2nd BUG: Again, while testing the difference between IT in Compat Mode and ModPlug Mode, i noticed that in Compat Mode, when using the square wave on Panbrello (Yxy), the pan had to be set at p16 in order to center the panning (32 for ModPlug mode).

Wanted to make sure these are working as intended. Please check the behavior specs.

How often does it happen?: Always, depending on flags

How to reproduce (step by step description):
Set up a sample-based instrument in an IT track. Use S3x to set up a square waveform for the vibrato. Then apply an Rxy command that will allow you to hear the vibrato fluctuation in the note. (Of course apply it for every row the note plays.) Listen to the difference in both Modplug and Compat mode, and show the Channel VUs so you can see what's going on. Try the same thing with Yxy in both modes.

[Saga Musix]

That's the way the IT square table works, yes. it has a "zero" value and a "+x" value. Therefore, you won't notice square tremolo at maximum volume, but at lowest volume, you will notice a on-off effect. Same applies to panbrello. Just try it out yourself and compare with XMPlay:

Code Select Expand



ModPlug Tracker  IT

|C-501v00S42

|........R1F

|........R1F

|........R1F

.....repeat........

Code Select Expand

ModPlug Tracker  IT

|C-501...S52

|........Y1F

|........Y1F

|........Y1F

.....repeat........



The behaviour is correct and therefore, I'm going to close this report.