Can't seem to draw from the center of two rectangles....

JoeJoe_000

Hello I can't see my line if I draw it from the center of two rectangles.......

However If I draw line then a rectangle all that looks ok.......

Can you tell me how to get my line to be under the rectangles?

void MainWindow::paintEvent(QPaintEvent *event)
{
    QPainter pathPainter(this);
    pathPainter.setPen(QPen(Qt::black, 1, Qt::SolidLine, Qt::FlatCap, Qt::MiterJoin));
    pathPainter.setBrush(Qt::yellow);

   
    QPainterPath rectPath;
    QRect fRect(200,70,100,50);
    rectPath.addRect(fRect);
    pathPainter.drawPath(rectPath);

 

    QRect sRect(500,370,100,50);
    rectPath.addRect(sRect);
    pathPainter.drawPath(rectPath);

    QPainter lineDrawer(this);

    QPoint fCP((fRect.width()/2),(fRect.height()/2));
    QPoint sCP((sRect.width()/2), (sRect.height()/2));
    lineDrawer.setPen(QPen(Qt::black, 1, Qt::SolidLine));
    lineDrawer.setBrush(Qt::yellow);
    QLine test(fCP, sCP);
     lineDrawer.drawLine(test);


    QRect otrRect(50,50,100,100);
    rectPath.addRect(otrRect);
    pathPainter.drawPath(rectPath);


    lineDrawer.drawLine(10,10,250,250);


}

mpergand

QPoint fCP((fRect.width()/2),(fRect.height()/2));
QPoint sCP((sRect.width()/2), (sRect.height()/2));

This draw a single point :)
You draw the first rectangle two times.

JoeJoe_000

This post is deleted!

JoeJoe_000

I believe you're mistaken sir.

QPoint doesnt draw anything it holds values for a point, points that can be used to draw a line.

mpergand

QPoint fCP((fRect.width()/2),(fRect.height()/2));
QPoint sCP((sRect.width()/2), (sRect.height()/3));

Now it draws a line.
At first glance i don't see the point, but it's there ;)

JoeJoe_000

awww man...what world are you from?? :'(

JoeJoe_000

Please somebody help.

Devopia53

@JoeJoe_000

QPoint fCP((fRect.width()/2),(fRect.height()/2));
QPoint sCP((sRect.width()/2), (sRect.height()/2));

The fCP and sCP are the same point(50, 25) as @JoeJoe_000 mentioned. So it does not look good, but it appears as a dot on the screen.

If you want to draw a line connecting the centers of two rectangles, try the following:

painter.drawLine(fRect.center(), sRect.center());

JoeJoe_000

Thanks a lot. I didnt know about those two functions. I finally figured out my idiocy. Thanks.

//This does the same thing as painter.drawLine(fRect.center(), sRect.center());
   QPoint pCP((parent.width()/2)+parent.left(),(parent.height()/2)+parent.top());
    QPoint cCP((child.width()/2)+child.left(), (child.height()/2)+child.top());

JoeJoe_000

Do you know how to specify which object/shape is at a high layer (drawing over) or lower layer (drawing under)?

jsulm

@JoeJoe_000 I would say what you draw first is lower layer

mrjj

Hi
When using QPainter there is no layers.
So what you draw last, will be on top.