Values for tablet pressure in ArtEffect - Page 2

Michael Sykes · 09 July 2016, 17:53

Another short question.Not only to bump the thread.

Would it make any difference if the API tool would show me -32768 to +32767 instead of 0 to 65280? So only a positive range of 0-32000 is enough.
I bet that causes the software to behave in an erratic way.

The snipet from intuition.h also talks about negative values.
And that pens don't produce them.

At least for the tilt it would make sense to have a positive and negative range on two axis.
And there are also tablets that recognize the distance of the pen.

EDIT 22,5 : This might be the solution....

Found this great tool.
This may be helpfull if you have a tablet and want to tweak it.
http://blackink.cz/tablet-pressure-curve-tool/

If I clip the real output to 0-50% for the full range of the tip with that tool the Amiga API shows only 0 to 32500 if I press my pen to the max!!! Now it works better but still seems to miss the lower 50% in AE4. Strange that the upper half (32-65k) works,too...

For example if I draw a white dot it appears middle gray (pressure enabled for color density) in AE4. But I can draw a nice range from that middle gray to black and back if i release it.
Plus it does not stop drawing anymore even if i lift the pen or klick with the mouse.
IF it realy expects negative values I guess its stuck at 0 and thinks i still press the tip 50% all the time. It would ecpect the value goes back to -32000.
The brush size now starts at 50% and does not grow bigger than 100% of what is set in the prefs. As it did with 65000 set as maximum.

Heres a little picture of how I think it has to be. Take a look how 32000 and 0 are at the same position. And remember the middle gray brush in AE and that it doesnt stop drawing once tip is at position 0. I'd also suggest a little deadzone on both ends.

idrougge · 10 July 2016, 03:16

Quote:

Originally Posted by Michael Sykes

If it supports pressure can you download the testing tool(AmigaOSTabletAPI) from the aminet and give us a hint what the max value for pressure is.
It's in "Wacom_150.lha" in the Develop drawer.

It seems that Wacom 1.50 doesn't support my Wacom ArtPad II, so I use FormAldiHyd instead for a driver. The testing tool does work, though, since it interrogates standard OS structures.

With FormAldiHyd pressure threshold set to 0, minimum to 0 and maximum to 100:
Pressure 0 = 0 (AmigaOSTabletAPI actually prints a string of zeros followed by a random number, but I think that number is just a leftover from the preceding pressure value)
Pressure 638 = -16190013 (this value also has trouble being drawn to screen)

Michael Sykes · 10 July 2016, 05:27

Thanks for the reply, not many people with real hardware and tablet around these days. ^^

Does pressure work in ArtEffect 4 if you enable the R. Schwingel or any other tablet option? Don't forget to enable it for the brush you are using,too.

If you can't get AE there is still the free XiPaint wich also shows lifesigns when it comes to reading the API data.

Whats that random number? Maybe the real zero state of the tip, even if shows not really 0!
Hardware wears out over the years.

That enormous large number in the API tool may be caused by the strange 638 for the pressure state. Seems multiplied by 10 compared to Tonis way.
If you devide that by 10 it's close to 64. And the -16190013/10/256 are also close to -64.
Do you have 64 levels of pressure?
And -16190013/10*2 brings us back to my +-32000 theory. We just ignore the .13 because its an integer.

The question is if that x10 is really needed, just a bug in formaldihyd or the tablet sending the data in that format?
As I wrote the 0-32000 range gave me at least the upper half of the pressure spectrum in AE. Brush size 50-100% and the same goes for color and transparency.

idrougge · 10 July 2016, 20:35

I have both AE4 and XiPaint, but I might not have time to test anything for one or two weeks, what with this being July…

According to Wacom, my tablet should have 2048 levels, but FormAldiHyd reports a resolution of 6400x4800x1023.

Michael Sykes · 03 August 2016, 19:22

I'd still like to see some real values.
Also it would be interesting to know how AE4 scales the size of the brush on real hardware.

09 July 2016, 17:53	#21
Michael Sykes WinUAE end user Join Date: Jan 2014 Location: Bremen Age: 44 Posts: 649	Another short question.Not only to bump the thread. Would it make any difference if the API tool would show me -32768 to +32767 instead of 0 to 65280? So only a positive range of 0-32000 is enough. I bet that causes the software to behave in an erratic way. The snipet from intuition.h also talks about negative values. And that pens don't produce them. At least for the tilt it would make sense to have a positive and negative range on two axis. And there are also tablets that recognize the distance of the pen. EDIT 22,5 : This might be the solution.... Found this great tool. This may be helpfull if you have a tablet and want to tweak it. http://blackink.cz/tablet-pressure-curve-tool/ If I clip the real output to 0-50% for the full range of the tip with that tool the Amiga API shows only 0 to 32500 if I press my pen to the max!!! Now it works better but still seems to miss the lower 50% in AE4. Strange that the upper half (32-65k) works,too... For example if I draw a white dot it appears middle gray (pressure enabled for color density) in AE4. But I can draw a nice range from that middle gray to black and back if i release it. Plus it does not stop drawing anymore even if i lift the pen or klick with the mouse. IF it realy expects negative values I guess its stuck at 0 and thinks i still press the tip 50% all the time. It would ecpect the value goes back to -32000. The brush size now starts at 50% and does not grow bigger than 100% of what is set in the prefs. As it did with 65000 set as maximum. Heres a little picture of how I think it has to be. Take a look how 32000 and 0 are at the same position. And remember the middle gray brush in AE and that it doesnt stop drawing once tip is at position 0. I'd also suggest a little deadzone on both ends. Attached Thumbnails Last edited by Michael Sykes; 10 July 2016 at 12:47.

10 July 2016, 05:27	#23
Michael Sykes WinUAE end user Join Date: Jan 2014 Location: Bremen Age: 44 Posts: 649	Thanks for the reply, not many people with real hardware and tablet around these days. ^^ Does pressure work in ArtEffect 4 if you enable the R. Schwingel or any other tablet option? Don't forget to enable it for the brush you are using,too. If you can't get AE there is still the free XiPaint wich also shows lifesigns when it comes to reading the API data. Whats that random number? Maybe the real zero state of the tip, even if shows not really 0! Hardware wears out over the years. That enormous large number in the API tool may be caused by the strange 638 for the pressure state. Seems multiplied by 10 compared to Tonis way. If you devide that by 10 it's close to 64. And the -16190013/10/256 are also close to -64. Do you have 64 levels of pressure? And -16190013/102 brings us back to my +-32000 theory. We just ignore the .13 because its an integer. The question is if that x10 is really needed, just a bug in formaldihyd or the tablet sending the data in that format? As I wrote the 0-32000 range gave me at least the upper half of the pressure spectrum in AE. Brush size 50-100% and the same goes for color and transparency. Last edited by Michael Sykes; 10 July 2016 at 12:49.*

10 July 2016, 20:35	#24
idrougge Registered User Join Date: Sep 2007 Location: Stockholm Posts: 4,332	I have both AE4 and XiPaint, but I might not have time to test anything for one or two weeks, what with this being July… According to Wacom, my tablet should have 2048 levels, but FormAldiHyd reports a resolution of 6400x4800x1023. Attached Thumbnails

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03 August 2016, 19:22	#25
Michael Sykes WinUAE end user Join Date: Jan 2014 Location: Bremen Age: 44 Posts: 649	I'd still like to see some real values. Also it would be interesting to know how AE4 scales the size of the brush on real hardware.

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