#1803 New percussion note length does not match Percussion Matrix Editor Grid duration

[musewhirl]

Steps to reproduce percussion note:

1. On a percussion track, create a one-measure segment
2. Open the Percussion Matrix Editor (D) on the segment
3. Set Grid size to 1/16 or smaller
4. Create a snare note at the start of the segment
5. Double-click the note and its duration is a whole note (3840)
6. Even stranger, now create another snare hit at the quarter beat location
7. The first note changes to duration (960), while the new one stretches to the end of the segment

In other words, adding new notes affects previous note values. I've seen this before, and although just a side-effect, it was those long stretches of percussion notes to the end of the segment that more easily involved percussion notes in bug #1802.

On the other hand, non-percussion notes have an entirely different behavior. They do match the Grid when created, i.e. never automatically stretch to fill space to the end of the segment. However, I noticed a peculiarity which may or may not be a separate bug:

Steps to reproduce non-percussion note:

1. On a non-percussion track, create a one-measure segment
2. Open the Matrix Editor (M) on the segment
3. Create a whole note
4. Using the Draw tool (F3) try to create a 1/16 note of the same note i.e. click anywhere on the note above. You can't.
5. Now create that 1/16 note as a higher or lower note, then drag it onto the whole note. You can!
6. So they can coexist and the notes behave normally

Obvious question, why can't one just create the note in the first place, if you can do so by the long route? Bug?

[Philip Leishman]

I believe the duration of a percussion note is irrelevant. Certainly with General Midi I believe the note on causes the percussive effect and the sound decays independently of the note off.
Indeed MatrixPercussionInsertionCommand adjusts the length of the previous note.
Creating two notes at the same pitch at the same time seems rather an odd idea so I suppose the matrix editor discourages it. But it is not forbidden.
Is there a bug here ? I am not sure.

[musewhirl]

I only mention this artifact here because during [bugs:#1802], the play-stop-play sequence also causes the percussion to play well after the intended point, and for a snare and kick the delay really stands out like a crazy drummer who "lost it for a moment".

So, it sounds like a bug to the uninitiated, but only occurs for the new logic, not the old. Or more precisely, I never noticed the problem with the old logic or its randomness in that case could have just been more rare.

[musewhirl]

Normally, I would open a new bug called: MIDI snare heard from previous segment. Let me know if you want that or will handle it here.

But I am mentioning this problem here as yet another artifact possibly related to [bugs:#1802], since that bug is proving difficult for you (@lman) to reproduce. I am hoping that consistently pointing out how the old logic differs unexpectedly from the new, will also reveal why bug #1802 only occurs for the new logic.

Steps to reproduce:

1. Check "Use Jack Logic"
2. Uncheck "New Jack Transport Logic"
3. Create a 1 measure long segment at bar 2
4. Open Percussion Matrix Editor on the segment
5. Set default Grid to 1/16
6. Create a single snare hit 1/16 BEFORE end of segment
7. Place playback cursor at start of bar 3 i.e. at end of segment
8. Hit play, and as expected, the snare hit is not heard
9. Now place the playback cursor at start of bar 3 again
10. Check the "New Jack Transport Logic"
11. Hit play, now the snare hit is heard

Since that snare hit is in the last measure, I don't believe it should be heard if play is started from the next measure. That holds, even if by default the snare hit length is created to stretch to the end of the a segment when no notes appear after it. Basically, why does this happen for only the new logic, and is it therefore a bug introduced inadvertently by it?

[Philip Leishman]

I tried the above steps and despaired trying to reproduce the effect you describe.
Then I remembered bug 1795 where you state that your default tempo is 70. So I set my tempo to 70 and ---- I get the same effect.
So the problem is with jack time rounding leading to the song position being just before the bar line.
I guess with my fix for bug 1795 I fixed the symptom but not the underlying problem.
I have a new fix in my bug-1795-jack-transport-positioning branch.