I am trying to modify the fingerPaint app that comes with the MultiTouch example of the SDK, so that it does not display the whole history of events and avoid making it a solid line.
Instead I am using Qt::NoBrush with drawEllipse so that only finger points are painted. But again, I do not want the history displayed. If I am using 5 fingers, I just want 5 rings moving around in the window.
To try this, I have been using the QPainter::eraseRect method with the rect corresponding to the QPoint touchPoint.lastPos(), before painting the current touchPoint. I am doing this in the TouchPointMoved case, so the previous rect is erased.
This is leaving a lot of residue and not very accurate. There's got to be a better way for this, right?
I am 1 day old with QT, so please bear if this question does not make sense.