Update TFT_eSPI touch comments
@@ -1205,6 +1205,17 @@ bool gslc_DrvGetTouch(gslc_tsGui* pGui, int16_t* pnX, int16_t* pnY, uint16_t* pn
nOutputX = map(nInputX, pGui->nTouchCalXMin, pGui->nTouchCalXMax, 0, nDispOutMaxX);
nOutputY = map(nInputY, pGui->nTouchCalYMin, pGui->nTouchCalYMax, 0, nDispOutMaxY);
// Perform constraining to OUTPUT boundaries
+ // NOTE: TFT_eSPI's getTouch readings occasionally return spurious touch
+ // events. These are often at the limit of the calibrated X/Y
+ // space. Post constraint, this may appear as events with one
+ // coordinate clipped to 0, for example. Bodmer provides
+ // one additional check in that if the mapped coordinate
+ // exceeds the positive bounds of the display (eg. 320px)
+ // then he marks the touch event invalid. Doing this may
+ // block some of the spurious events but not all (it would be
+ // calibration dependent). If we do decide to add in a similar
+ // check here, then we would want to force (bValid=false) here
+ // and then only proceed after re-checking (bValid==true).
nOutputX = constrain(nOutputX, 0, nDispOutMaxX);
nOutputY = constrain(nOutputY, 0, nDispOutMaxY);
} else {
