Two bugs are present in the IT importer, and one bug is present when playing anything with a loop segment in a pattern.
1. Any effect with all zeros are ignored when imported from IT, effect or volume coloum. Unless the effect is unsupported, this usually happens.
What should have happened is that when two zeroes are found, it should look for the last parameter from that effect and use that instead. Here are some cases I have put out:
Case 1: On a retrigger with a volume change, the volume change should remain untouched if a zero is used unless two zeros are found, then you use the last parameter. If the retrigger time in ticks is a zero, it should either use a 1 if there's no previous parameter, or it should use the last parameter it finds.
Case 2: Jump to orders and break to row xx on next pattern should stay as is, even with two zeros in it.
Case 3: Any other effect, if I can recall correctly. If it has two zeros, then just use the last paramenter the effect uses.
2. All notes and insturments are transposed down by one octave, losing the lowest octave and making the ninth octave unused when imported from IT.
What should have happened is that the insturments should have retained its default note one octave higher, therefore transposing all notes one octave higher as well. Now instead of losing one octave, you only lose one note; B9.
3. There's a bug on the loop segments in a pattern. When placed at the end of a pattern, instead of jumping to row zero on the next pattern like IT does, it continunes on the next pattern with the next row number being the number after the repeat. The only case I've found is in two of my own creations, both IT files, and with both having more rows in the next pattern than the previous pattern.
If you need help on how IT works, try Schism Tracker to give you some help. The XM export function is buggy, but it should give you a clue as to how IT works, and should give you a better understanding on some of the formats and how to give them compatibilty with XM-supported effects.
See here and pick a build, depending on what OS you run. I apologize if this is taking it the wrong way.
