Stippled Pattern when Painting with mouse/tablet

[DanqueDynasty]

Hello all,

I am experience a problem where if I try to draw with pen/tablet input, the widget will draw a line along with circles at points periodically. Such as the following:
10158
The code(in context of QTabletEvent, QMouseEvent is coded the same way):



bool deviceDown = false;
QPoint drawPath[3];

void Editor::TabletEvent(QTabletEvent* event)
{
if(event->type() == QEvent::TabletPress)
{
deviceDown = true;
drawPath[2] = drawPath[1] = drawPath[0] = event->pos();
}
if(event->type() == QEvent::TabletRelease)
{
if(deviceDown == true){deviceDown = false;}
}

if(event->type() == QEvent::TabletMove)
{
drawPath[2] = drawPath[1];
drawPath[1] = drawPath[0];
drawPath[0] = event->pos();

/* DRAW CODE - Commented out due to actual code residing in another class/function.
QPainter painter(&pixmap);
painter.drawLine(drawPath[1], event->pos());
*/
}
}


I have attempted to use a single point as the last known point, but that failed. Using a QPoint array seams to be the only way to get the widget to draw any lines correctly.

[ChrisW67]

You paint a translucent (alpha < 1.0) line from A to B, then B to C, C to D etc. The point B is painted twice, once for each line it is part of. The result is that the brush area on top of point B is now darker. Same goes for C etc.

Options:

Accumulate points from press to release and then draw a single poly-line (QPainter::drawPolyLine())
Accumulate points from press and draw a single polyline onto a transparent overlay image that you then compose with the base image onto the display. When the finger is raised draw the entire polyline into the base image.

[DanqueDynasty]

Alright I'll try that out. Will the same method work if I invoke "painter.drawPixmap()" or "painter.drawEllipse"?