libts / tslib

Touchscreen access library
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Further parameter in ts_calibrate / getxy() for more robust calibration/validation #190

Open svlstriker opened 2 years ago

svlstriker commented 2 years ago

Hi @ all, did you think about adding a further optional parameter to ts_calibrate / function getxy() ? I thought about something like "min_samples", so that a minimal count of samples needs to be recognized within calibration (and maybe validation as well?). By testing v1.22 of tslib, sometimes there are faulty touch-events on the touchscreen (could be because of old resistiv touchscreen). This could generate a faulty calibration and let validations fail more often. If there is a minimal count of 'samples' needed for calibration / validation, these faulty-events could be ignored and would not take big effect to the calculated, touched point.

These 'min_samples' could have a default value given and overridden by another optional parameter within terminal calls.

What do you think about that?

merge commented 4 months ago

that's a good idea in general, but not so easy. 1st: some touchscreens (firmware) doesn't send multiple (or many) sample when "tapping". 2nd: I think ts_calibrate has to rely on the input to be correct. It creates it's filtering from the raw input. Try not to let endusers to the calibration, but create a known-good one and resue it, maybe. Verify what's going on by watching evtest maybe, while doing the calibration.