Important: Please read the Qt Code of Conduct -

drawLine Bug

  • Hi everybody
    I am writing a CAD program and I found a strange bug, to cut the long story short, the following code shows the bug:

    p.setPen(QPen(Qt::white, 3));
    p.drawLine(410.738, 364.399, -63151.2, -63197.6);
    p.setPen(QPen(Qt::cyan, 1));
    p.drawLine(410.738, 364.399, -63151.2, -63197.6);

    although start and end coordinates are exactly the same, these two lines slopes are different (first line has the correct slope while cyan line is incorrect). is there any suggestion?

    P.S: I use Qt 4.72

  • Lifetime Qt Champion


    Are you locked to that version of Qt ? It pretty old and outdated. Even if you don't want to switch to Qt 5 you should at least consider 4.8.6 to see if you still have that problem.

Log in to reply