reaper.SnapToGrid(), which grid does it refer to?

[_Stevie_]

Can anyone shed some light on this?
Does this function refer to the MIDI editor grid and does it also obey the grid setting (1/8, 1/16....)?
Or does it always snap to 1/16?

[Lokasenna]

It returns the time of the nearest "visible" gridline in the arrange view - if your grid is set to 1/128, but you zoom out far enough that the smallest division shown is 1/4, it will snap to 1/4.

[_Stevie_]

Oh snap! (pun intended)
Is there a way to get the closest grid in dependency to the grid currently set in the MIDI editor?
I want to use this for a quantize script.

(I know it's possible to link the arrangement and MIDI editor grid, but I would
like to keep them seperate)

[Lokasenna]

You can get the current grid settings with:

 retval, swing, noteLen = reaper.MIDI_GetGrid( take )

Don't have time to try it, but I think if you got the grid, then got the item's start time, you could add multiples of the grid size until you pass the given position and then round up/down appropriately.

[_Stevie_]

Ah that worked, thanks! But, I used the modulo operator. It somehow felt easier that way. But maybe, I'm overlooking something.

[Lokasenna]

That's pretty much what I meant. I use this:

    -- Returns 'val', rounded to the nearest multiple of 'snap'
    local function nearestmultiple(val, snap)
        
        local int, frac = math.modf(val / snap)
        return (math.floor( frac + 0.5 ) == 1 and int + 1 or int) * snap
        
    end

[_Stevie_]

Thanks, have to check this out! Looks way more sophisticated than my solution

[_Stevie_]

Wow, I just tried it out and it works perfectly, thanks again man!
I'm far from understanding the whole algorithm, though

Do you have any idea, what I would need to add to create a humanize quantize of 50%?

[Lokasenna]

Scaling between two values is done by:

A = Current note position
B = 100% snapped position
S = .5

C = A + (B - A) * S

Works for pretty much anything - figuring out a certain position along a color gradient, for instance.

[Lokasenna]

Readable version of the algorithm above, with more comments:

        -- math.modf just gives the whole and decimal parts of a number
        local int, frac = math.modf(val / snap)

        -- Simple rounding logic. If you can add 0.5 and it still rounds down (math.floor) 
        -- to 0 then it should round down. If adding 0.5 causes it to round down to 1 then
        -- it was >= 0.5 and should round up.
        local updown = math.floor( frac + 0.5 )

        if updown == 1 then
            int = int + 1
        end

        -- "int" is just the number of multiples of "snap" that we have, so we have to multiply
        -- snap back in.
        return int * snap

[_Stevie_]

You rock man, thanks for all that useful info! That definitely sheds a lot of light.
Gotta love the Reaper community

[Thonex]

Nice Loka!!

Yeah... the +.5 is a an elegant way to round to the nearest integer. My friend did coding for the military where they were using some language that had limited math functions... and the Integer Val of X + .5 would yield the correct rounding. I always thought that was a clever solution.

Also, he was working on heads-up displays for the air force, and had to find a simple solution for if an object was inside or outside the circle in the display.

His solution was to calculate a ray (straight line) from the point (in any direction... didn't matter) and if the line intersected the circle only once, it was inside the circle. Conversely, if it intersected the circle twice or zero times, it was outside the circle. But only the first calculation was needed. I thought that was clever.

Cheers,

Andrew K

[Lokasenna]

I wish I could take credit for it. Found it a couple of years ago after discovering that Lua doesn't have a round function.

That circle solution is pretty clever. I'm spoiled by having trig functions, I guess.

[_Stevie_]

For getting the snap ticks I'm using this method here (to advance the note by one grid)

editorGridQN = reaper.MIDI_GetGrid(take)
ticksPerBeat = reaper.SNM_GetIntConfigVar('miditicksperbeat', 0) -- get ticks per beat from Reaper project settings
grid = ticksPerBeat * editorGridQN -- calculate grid steps in ticks

Am I overcomplicating things, is there a simpler method?

[Lokasenna]

I can't see a more direct way to do it.

Depending on the task, it's worth looking at the various PPQ functions in the API - Project time from PPQ, PPQ from project time, that sort of stuff. Handy to have.

[_Stevie_]

Okay, good to know! Then I'll keep it that way
Yeah, I tried the PPQ conversion stuff. It's very handy indeed! But it's only helpful for specific positions in the timeline.

[_Stevie_]

So snapToGrid() does not only refer to the visible grid. It depends on the setting in the grid dialog. Leaving this here for everyone:

https://forum.cockos.com/showpost.ph...7&postcount=23