Re: master e37eb7f: Add support for pixel wheel deltas on NS

[Po Lu <luangruo@yahoo.com>]

Eli Zaretskii <eliz@gnu.org> writes:

>> > What pixel-delta values are typically reported on X for a single
>> > click of the mouse wheel?
     ^^^^^

>> A click (i.e. a movement where precise information is unavailable)?

> Why are you saying "click" when we are talking about mouse wheel.  The
> wheel is not clicked when the user wants to scroll, the wheel is
> turned.

That is what you said, right?

>> Typically 1 scroll unit is reported, which would be:
>> 
>>     1.0 * pow (FRAME_PIXEL_HEIGHT (f), 2.0 / 3.0)

> ??? That's about 100 pixels on a reasonably-sized frame.  How can such
> large values support "precision pixelwise scrolling"?

> Are we talking about the same thing?  I was asking about the smallest
> values of the deltas reported in the mouse wheel-up and wheel-down
> events when the user turns the wheel the smallest amount possible.

Ahh, I understand what you're asking now.  The smallest value reported
is usually to 0.01 or so, after conversion into scroll units.

On a reasonably sized frame that would be 1 to 2 pixels.

I thought you were asking about the value reported before X sends a
legacy ButtonPress event for button 4/5/6/7.

Thanks.