On Wed, Jul 22, 2015 at 03:51:09PM +0200, Hans de Goede wrote:
> Hi,
>
> On 22-07-15 07:09, Peter Hutterer wrote:
> >That's the most likely area it will be resting in, if it's sitting anywhere
> >above that it's likely part of an interaction.
> >
> >A thumb in the lowest 15mm needs to trigger the pressure threshold before
> >it's
> >labelled a thumb. A thumb in the lowest 8mm is considered a thumb if it
> >remains there for 300ms. Regardless of the pressure, since we can't reliably
> >get pressure here. If a thumb moves out of the area, or starts outside of
> >that
> >area it is never a thumb.
>
> "If a thumb moves out of the area" -> not so in the code:
>
> <snip>
>
> > static void
> >-tp_thumb_detect(struct tp_dispatch *tp, struct tp_touch *t)
> >+tp_thumb_detect(struct tp_dispatch *tp, struct tp_touch *t, uint64_t time)
> > {
> >- /* once a thumb, always a thumb */
> >- if (!tp->thumb.detect_thumbs || t->is_thumb)
> >+ enum tp_thumb_state state = t->thumb.state;
> >+
> >+ /* once a thumb, always a thumb, once ruled out always ruled out */
> >+ if (!tp->thumb.detect_thumbs ||
> >+ t->thumb.state != THUMB_STATE_MAYBE)
> > return;
> >
>
> This check make it so that a touch labeled a thumb (THUMB_STATE_YES)
> will stay a thumb even if it moves above the upper_thumb_line.
I'll change the commit message to clarify this. The reason for this check is
to simplify the code, once something is a thumb, it will remain a thumb even
when it moves about or changes pressure. it means we don't have to put code
into everything to check if something is _still_ a thumb and potentially get
odd behaviour. If that causes issues we can add the extra code required, but
until then I prefer the simple solution.
so the commit message should say "if a thumb moves out of the area _within a
timeout_ ..."
Cheers,
Peter
>
> >+ if (t->point.y < tp->thumb.upper_thumb_line) {
> >+ /* if a potential thumb is above the line, it won't ever
> >+ * label as thumb */
> >+ t->thumb.state = THUMB_STATE_NO;
> >+ goto out;
> >+ }
> >+
>
> This can be fixed by moving this check above the previous one.
>
> Otherwise looks good.
>
> Regards,
>
> Hans
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