Hi,
If I run the “testrelative” SDL demo with “–info all”, I’m noticing
that rolling the scroll wheel one “notch” doesn’t generate a scroll
event. If I keep rolling it, I will start to see scroll events logged.
This is with a logitech G400, or a microsoft ergonomic mouse.
What’s happening is, in Cocoa_HandleMouseWheel the deltaY for
scrolling the scroll wheel one notch is 0.00172424316. SDL adds 0.9 to
that, and the resuting value is truncated to an int which results in
0.
I don’t think this happened in OS X 10.11.
As an immediate fix, if the delta is non-zero, we could snap it to 1
or -1. Maybe this needs a runtime macOS version check to avoid
changing the scroll behaviour on previous mac versions?
Eric
Posted to the bugtracker with a possible fix here:
https://bugzilla.libsdl.org/show_bug.cgi?id=3432On Wed, Sep 21, 2016 at 11:36 AM, Eric Wasylishen <@Eric_Wasylishen> wrote:
Hi,
If I run the “testrelative” SDL demo with “–info all”, I’m noticing
that rolling the scroll wheel one “notch” doesn’t generate a scroll
event. If I keep rolling it, I will start to see scroll events logged.
This is with a logitech G400, or a microsoft ergonomic mouse.
What’s happening is, in Cocoa_HandleMouseWheel the deltaY for
scrolling the scroll wheel one notch is 0.00172424316. SDL adds 0.9 to
that, and the resuting value is truncated to an int which results in
0.
I don’t think this happened in OS X 10.11.
As an immediate fix, if the delta is non-zero, we could snap it to 1
or -1. Maybe this needs a runtime macOS version check to avoid
changing the scroll behaviour on previous mac versions?
Eric