This is a helper function called by GetMouse. Do not call
Screen(‘GetMouseHelper’), use GetMouse instead.
“numButtons” is the number of mouse buttons to return in buttonValueArray. 1 <=
numButtons <= 32. Ignored on Linux and Windows.
“screenNumber” is the number of the PTB screen whose mouse should be queried on
setups with multiple connected mice. This value is optional (defaults to zero)
and only honored on GNU/Linux. It’s meaningless on OS-X or Windows.
Well, not quite. If you pass in an onscreen window handle instead of a
screenNumber, then the 4th optional return argument “hsKbFocus” will return 1 if
the given onscreen window has keyboard input focus, 0 otherwise.
“mouseIndex” is the optional index of the (mouse)pointer device. Defaults to
system pointer. Only honored on Linux.
“valuators” If the input device has more than two axis (x and y position), e.g.,
in the case of a touch input device or digitizer tablet, this will be a vector
of double values, returning the values of those axis. Return values could be,
e.g., distance to surface, pen pressure, touch area, or pen orientation on a pen
input device or touchscreen.
On OSX the first two valuators currently return relative mouse delta movement
deltaX and deltaY.