Cluster: add function to retrieve earliest pixel + split getSeedPixel()
This MR is in preparation for an improvement of the timewalk correction:
Before:
-
Clustering4D
: cluster timestamp = earliest pixel (or largest ToT) -
Timing Analysis
: timewalk correction based on seed pixel, but seed pixel = largest ToT ≠ cluster timestamp
Now one can retrieve both from the cluster:
-
getSeedPixel()
-> pixel with largest charge (or earliest pixel if no charge available) -
getEarliestPixel()
-> pixel with earliest timestamp