On Mon, Feb 17, 2014 at 11:26:49AM +0100, Egbert Eich wrote: > From: Egbert Eich <e...@suse.com> > > Worn out pens have an initial pressure != 0. If this pressure > persists while the pen is in proximity and still exists when > going out of proximity, warn about worn out tool. > Some devices seem to send a zero pressure when going out of > proximity. Thus we record the last pressure when still in > proximity. > Also we count the number of events we have received while in > proximity so the risk of false reports on 'quick taps' is lower. > > This condition may also occur intermittently on abusive operation. > > Signed-off-by: Egbert Eich <e...@suse.com> > --- > Algorithm has been reworked, suggestions have been incorporated. > I'm not sure about the Wiki page, though, it seems that one cannot > link to any but the main page using http://linuxwacom.sourceforge.net.
The full link would be something along the line of: http://sourceforge.net/apps/mediawiki/linuxwacom/index.php?title=Main_Page with the obvious change to the wiki page explaining this issue. You'll need a wiki account, ping me when you have one so I can give you edit rights. > src/wcmCommon.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ > src/xf86WacomDefs.h | 3 ++- > 2 files changed, 47 insertions(+), 1 deletion(-) > > diff --git a/src/wcmCommon.c b/src/wcmCommon.c > index 209565c..73aeeea 100644 > --- a/src/wcmCommon.c > +++ b/src/wcmCommon.c > @@ -1121,6 +1121,50 @@ setPressureButton(const WacomDevicePtr priv, const > WacomDeviceState *ds) > return buttons; > } > > +/* > + * Broken pen with a broken tip might give high pressure values > + * all the time. We want to warn about this. To avoid getting > + * spurious warnings when the tablet is hit quickly will wait > + * until the device goes out of proximity and check if the minimum > + * pressure is still above a threshold of 20 percent of the maximum > + * pressure. Also we make sure the device has seen a sufficient number > + * of events while in proximity that it had a chance to see decreasing > + * pressure values. > + */ > +#define LIMIT_LOW_PRESSURE 20 /* percentage of max value */ extra space here > +#define PERCENT_TOLERANCE 10 you don't seem to be using this define > +#define MIN_EVENT_COUNT 15 > + > +static void detectPressureIssue(WacomDevicePtr priv, > + WacomCommonPtr common, > + WacomDeviceStatePtr ds) > +{ > + /* pen is just going out of proximity */ > + if (priv->oldProximity && !ds->proximity) { > + > + int pressureThreshold = common->wcmMaxZ * LIMIT_LOW_PRESSURE / > 100; > + /* check if minPressure has persisted all the time > + and is too close to the maximum pressure */ > + if (priv->oldMinPressure > pressureThreshold && > + priv->eventCount > MIN_EVENT_COUNT) > + LogMessageVerbSigSafe( > + X_WARNING, 0, > + "%s(%d) has seen an initial pressure > 0\n\t" > + "there is a base pressure of %d which > persists\n\t" > + "while the pen is in proximity and " > + "which is too close\n\tto the maximum value > (%d).\n\t" > + "This indicates a worn out pen, " > + "Time to change your tool. Also see:\n\t" > + "http://linuxwacom.sourceforge.net/Pen_Wear.\n";, > + priv->pInfo->name, priv->serial, > priv->minPressure, > + common->wcmMaxZ); This is a personal preference but I'd prefer a printf line to go >80 lines and ends with a \n over a line that wraps and has the \n\t inside. Makes it easier to grep for and most of us have screens that can handle the odd 80+ line :) I think the algorithm is fine and should work well enough, thanks. > + } else if (!priv->oldProximity) > + priv->eventCount = 0; > + > + priv->oldMinPressure = priv->minPressure; > + priv->eventCount++; > +} > + > static void commonDispatchDevice(WacomCommonPtr common, unsigned int channel, > const WacomChannelPtr pChannel, > enum WacomSuppressMode suppress) > @@ -1203,6 +1247,7 @@ static void commonDispatchDevice(WacomCommonPtr common, > unsigned int channel, > > if ((IsPen(priv) || IsTouch(priv)) && common->wcmMaxZ) > { > + detectPressureIssue(priv, common, &filtered); > priv->minPressure = rebasePressure(priv, &filtered); > filtered.pressure = normalizePressure(priv, &filtered); > if (IsPen(priv)) > diff --git a/src/xf86WacomDefs.h b/src/xf86WacomDefs.h > index 6de9645..09597a0 100644 > --- a/src/xf86WacomDefs.h > +++ b/src/xf86WacomDefs.h > @@ -303,7 +303,8 @@ struct _WacomDeviceRec > int pPressCurve[FILTER_PRESSURE_RES + 1]; /* pressure curve */ > int nPressCtrl[4]; /* control points for curve */ > int minPressure; /* the minimum pressure a pen may hold */ > - > + int oldMinPressure; /* to record the last minPressure before going > out of proximity */ > + unsigned int eventCount; /* count number of events while in proximity */ bit more alignment of comments would be nice but I suspect the rest of the file is messed up already, so with the above addressed Reviewed-by: Peter Hutterer <peter.hutte...@who-t.net> Cheers, Peter > WacomToolPtr tool; /* The common tool-structure for this device > */ > > int isParent; /* set to 1 if the device is not > auto-hotplugged */ > -- > 1.8.1.4 > ------------------------------------------------------------------------------ Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121054471&iu=/4140/ostg.clktrk _______________________________________________ Linuxwacom-devel mailing list Linuxwacom-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxwacom-devel
