Fix: Allow negative frame id in scene.setCell (scripting).

[Banbury]

This fix is necessary for creating animations in Javascript from raster images
with only one frame. For this Opentoonz expects a frame id of -2.
A frame id of -1 is an empty frame.
The original implementation only allows positive numbers.

I'm planning to release a converter from Papagayo to Opentoonz script. The script will create a new level with all the mouth shapes. But without this patch the script won't work.

[kogaki]

Jenkins, confirm this

[kogaki]

@Banbury I want know more detailed situation where negative indices are rquired. I tried following script, and of course, it works. I will be glad if you can show small sample script using negative indices.

>> l = new Level("/Applications/OpenToonz/OpenToonz_1.0_stuff/sandbox/drawings/fafaefaeafeae.tlv");
Toonz level (fafaefaeafeae, 1 frames)
>> l.getFrame("1")
Toonz raster image ( 768 x 576 ) # ok to access to frame1
>> l.getFrame("0")
undefined
>> l.getFrame("2")
undefined # only one frame
>> 

I am excited to hear about your plan to use Papagayo. So I will merge this as soon as I can understand your request.

[kogaki]

Now I understood the problem.

In ver.1.0.2,

>> l = new Level("/Users/keisuke_ogaki/Desktop/ottest4.png")
Raster level (ottest4, 1 frames)
>> fids = l.getFrameIds();
["-"]
>> l.getFrame("-")
Error: Argument '-' does not look like a FrameId

[kogaki]

OK, I confirmed this PR can solve the problem partially (I found another bug).

>> l = new Level("/Users/keisuke_ogaki/Desktop/ottest4.png") 
Raster level (ottest4, 1 frames)
>> fids = l.getFrameIds();
["-"]
>> l.getFrame("-") #I changed regexp
undefined
>> l.getFrame("-2")
Raster image ( 1920 x 1080 )

Thanks @Banbury . And we are looking forward to seeing your converter !!

[Banbury]

Thanks for merging this. The converter itself is finished. But I've postponed packaging and releasing it, until Opentoonz supports it.

Below you'll find a part of the script for this animation.

scene = new Scene()
scene.insertColumn(0)
AI = scene.loadLevel("AI", "d:/OpenToonz 1.0_stuff/projects/OotS/drawings/mouth1/AI.tif")
E = scene.loadLevel("E", "d:/OpenToonz 1.0_stuff/projects/OotS/drawings/mouth1/E.tif")
etc = scene.loadLevel("etc", "d:/OpenToonz 1.0_stuff/projects/OotS/drawings/mouth1/etc.tif")
FV = scene.loadLevel("FV", "d:/OpenToonz 1.0_stuff/projects/OotS/drawings/mouth1/FV.tif")
L = scene.loadLevel("L", "d:/OpenToonz 1.0_stuff/projects/OotS/drawings/mouth1/L.tif")
MBP = scene.loadLevel("MBP", "d:/OpenToonz 1.0_stuff/projects/OotS/drawings/mouth1/MBP.tif")
O = scene.loadLevel("O", "d:/OpenToonz 1.0_stuff/projects/OotS/drawings/mouth1/O.tif")
rest = scene.loadLevel("rest", "d:/OpenToonz 1.0_stuff/projects/OotS/drawings/mouth1/rest.tif")
U = scene.loadLevel("U", "d:/OpenToonz 1.0_stuff/projects/OotS/drawings/mouth1/U.tif")
WQ = scene.loadLevel("WQ", "d:/OpenToonz 1.0_stuff/projects/OotS/drawings/mouth1/WQ.tif")
scene.setCell(0, 0, { level:"etc", fid:'-2' })
scene.setCell(1, 0, { level:"etc", fid:'-2' })
scene.setCell(2, 0, { level:"AI", fid:'-2' })
scene.setCell(3, 0, { level:"AI", fid:'-2' })
scene.setCell(4, 0, { level:"etc", fid:'-2' })
scene.setCell(5, 0, { level:"etc", fid:'-2' })
scene.setCell(6, 0, { level:"etc", fid:'-2' })
scene.setCell(7, 0, { level:"E", fid:'-2' })
scene.setCell(8, 0, { level:"E", fid:'-2' })
scene.setCell(9, 0, { level:"etc", fid:'-2' })
scene.setCell(10, 0, { level:"etc", fid:'-2' })
scene.setCell(11, 0, { level:"U", fid:'-2' })
scene.setCell(12, 0, { level:"etc", fid:'-2' })
scene.setCell(13, 0, { level:"etc", fid:'-2' })
scene.setCell(14, 0, { level:"E", fid:'-2' })
scene.setCell(15, 0, { level:"etc", fid:'-2' })
scene.setCell(16, 0, { level:"etc", fid:'-2' })
scene.setCell(17, 0, { level:"etc", fid:'-2' })
scene.setCell(18, 0, { level:"etc", fid:'-2' })
scene.setCell(19, 0, { level:"U", fid:'-2' })
scene.setCell(20, 0, { level:"AI", fid:'-2' })