Controlling cursor speed when using a joystick

[Michiel Spape]

Hiya,
Two points here:
- For one, I'd suggest just going a bit higher into Windows and setting the mouse and/or joystick sensitivity. I remember this was quite common in Win98 or something like that, but it seems to be missing in Windows XP. Nevertheless, I very much doubt you won't be able to find a little programme that sets the cursor and/or mouse sensitivity to a lower resolution. All in all, that would be a lot easier for your purposes. 
- Second, it seems to me that the main issue with joystick vs mouse is the joystick being centred at a certain position. I think - but could be mistaken? - that in order to do this, you might want to change the script so that the X0, Y0 are not overwritten, but rather that you change the cursor position by the deviation with the beginning of the trial. So, if the cursor is at pixel 320,240 in the beginning (i.e. centre at 640x480 resolution), then at next polling the cursor is at 321,240 (1 pixel to the right), the cursor should (as it does currently) move one pixel to the right. However, at the polling after that, given that the subject didn't move the joystick (i.e. polling says it's the same as previous polling), then the difference of 1,0 related to the *startposition* should still cause it to move 1 more to the right (i.e. 322,240). I'm terrible at messing with someone else's code, but if you understand what I'm saying, this shouldn't be too hard to implement (just keep comparing to the start position, rather than the previous position). More hardcore, by the way, and likely better (given that most joysticks tend to be round, rather than square) would be to calculate the angle and amplitude of the joystick, then move the cursor with that information.
 
Hope that helps,
Mich


Michiel Spapé
Research Fellow
Perception & Action group
University of Nottingham
School of Psychology
www.cognitology.eu


-----Original Message-----
From: e-prime at googlegroups.com [mailto:e-prime at googlegroups.com] On Behalf Of David McFarlane
Sent: 12 May 2011 20:38
To: e-prime at googlegroups.com
Subject: Re: Controlling cursor speed when using a joystick

Just thinking through this a bit further, if we knew exactly what 
data the joystick sent to the PC, and where (e.g., what I/O port) 
that data appeared, then in principle we could write code to affect 
the cursor in whatever way we wish.  But at the moment we lack that 
technical information.

-- David McFarlane, Professional Faultfinder


At 5/12/2011 03:34 PM Thursday, you wrote:
>Erin,
>
>Thanks for testing that out, and posting back so quickly.  I don't 
>have any joystick myself, so I don't think I can help any 
>further.  I would not have expected your result, clearly the 
>joystick does not simply emulate the mouse otherwise it would just 
>work (and in that case you would not need a code solution in the 
>first place).  Is there a separate Windows "control panel" for the 
>joystick that you can use to control its settings?  Other than that, 
>if it were me I might try another joystick, or start Googling around 
>for more technical background on joysticks in general and then use 
>that knowledge to devise a solution.
>
>Good luck,
>-- David McFarlane, Professional Faultfinder
>
>
>>hi David,
>>Matt was the one helping me.
>>
>>Thank you very much for the sample code!  I tried it out, and it does
>>change how the cursor moves.  For the mouse, it slows it down quite
>>perfectly.  For the joystick, it also slows down, but there is an
>>interesting effect. The mouse cursor is basically "stuck" to the
>>joystick.  Normally, when you move the joystick left, the cursor
>>continues to move left, even when the joystick handle is held in a
>>constant left position.  With your modification, the mouse cursor
>>moves only when you move the joystick.  So, the cursor will move left
>>as you move the joystick left, but when you stop the joystick, it
>>stops.  And, when you let the joystick go back to it's resting
>>position, the cursor actually backtracks back to it's original
>>position.  This is an interesting feature, but not what will work for
>>my particular application. (However, I'm sure it's exactly what
>>someone else might need).  It would be absolutely perfect if the
>>cursor could be "unstuck"  from the joystick, so that the joystick
>>just directs the cursor to move forward in whatever direction the
>>joystick is pointed.  Any suggestions?  Again, thank you so much!
>>
>>Erin
>>
>>
>>
>>On May 12, 1:58 pm, David McFarlane <mcfar... at msu.edu> wrote:
>> > Erin,
>> >
>> > Thanks for posting the full information from PST, that helped (can
>> > you let us know which staff member helped you?).  I might have come
>> > up with the Mouse.SetCursorPos approach myself, but not the
>> > Mouse.SetCursorLimits approach, that approach seems a little wacky to
>> > me but what do I know?.
>> >
>> > As for Mouse.SetCursorPos, this posed a nice little puzzle, so I
>> > knocked out a quick demo, and here is the inline that I came up
>> > with.  (Just to have a mouse click to respond to, I preceded the
>> > inline with a TextDisplay called StimText, set to Duration of 0 and
>> > mouse with Time Limit of (infinite)):
>> >
>> > /----------------------------------------------------------------------\
>> > ' Code to modify the rate of mouse movement.
>> >
>> > Const  LoopDelay as Long = 0
>> > Const  CursorMoveFactor as Single = 0.5
>> >
>> > Dim  x0 as Long, y0 as Long
>> > Dim  x1 as Long, y1 as Long
>> >
>> > Mouse.GetCursorPos x0, y0  ' initialize
>> > Do While (StimText.RT = 0)  ' replace this with your exit condition
>> >      Mouse.GetCursorPos x1, y1
>> >      x0 = x0 + (CursorMoveFactor * (x1 - x0))
>> >      y0 = y0 + (CursorMoveFactor * (y1 - y0))
>> >      Mouse.SetCursorPos x0, y0
>> >      Sleep LoopDelay
>> > Loop
>> > \----------------------------------------------------------------------/
>> >
>> > I expected to find some cursor movement artifacts, but it really
>> > worked rather smoothly.  As you can see, I didn't even really need
>> > the LoopDelay, but I left it there just in case.
>> >
>> > -- David McFarlane, Professional Faultfinder
>> >
>> > At 5/12/2011 01:03 PM Thursday, you wrote:
>> >
>> > >I want to control the speed the cursor moves when controlling it with
>> > >a joystick.  I set the joystick to emulate the mouse in my experiment
>> > >(inline Joystick.AttachToMouseCursor = True).  The joystick is quite
>> > >touchy, and causes the cursor to move very quickly across the screen.
>> > >For my experiment, I need the cursor to only move slowly, no matter
>> > >how much the joystick is moved.
>> >
>> > >I tried decreasing the mouse sensitivity settings on my computer.
>> > >This slowed the cursor down when using the mouse within my experiment,
>> > >but had no effect on the joystick.  I also tried increasing the
>> > >resolution display of my experiment (giving the cursor "further" to
>> > >travel)- also no effect.  I have also tried adjusting the sensitivity
>> > >of my joystick, but the cursor is still too fast.
>> >
>> > >E-Prime support suggested the following: "E-Prime does have some
>> > >limited options for positioning the mouse cursor and limiting its
>> > >boundaries. We could try to use a combination of the two to make the
>> > >mouse cursor move more slowly. However, this would require significant
>> > >scripting and could result in the cursor movement not being smooth"
>> >
>> > >My main question: Is anyone aware of a simpler way of controlling the
>> > >cursor speed in E-Prime?
>> >
>> > >If not, here is further information on this method:
>> >
>> > >E-Prime help suggested the following:
>> > >"I would recommend taking a look at the MouseDevice.SetCursorLimits
>> > >and MouseDevice.SetCursorPos topics in the E-Basic Help (accessed via
>> > >the Help menu). The former will allow you to specify boundaries for
>> > >the cursor, and the latter will allow you to position the mouse cursor
>> > >in a specific area. You could use a combination of the two to first
>> > >limit the movement of the cursor so that it does not immediately move
>> > >to one edge of the screen, and then use SetCursorPos to move the
>> > >cursor move slowly. You could also slowly expand the cursor limits as
>> > >the cursor hits the maximum in one direction. This would allow you to
>> > >give the appearance of the cursor moving more slowly. To do this, you
>> > >would have a loop that continuously checks the cursor position against
>> > >the limits that are set, and expand the limits in one direction as the
>> > >cursor hits that limit. This would require significant scripting and
>> > >could result in the cursor movement not being smooth."
>> >
>> > >I took a look at the MouseDevice.SetCursorLimits and
>> > >MouseDevice.SetCursorPos help, and I understand how this would work in
>> > >theory.  However, I am very new to programming, and I am afraid that
>> > >the scripting involved is a bit over my head.  If anyone can offer any
>> > >advice or pointers, it would be very appreciated.  thank you!
>> >
>> > >Erin

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