Reading scenePos by small step

[maverick_pol]

Hi gusy,

I would like to read sceene position to see the second digit after the coma.
POS -> 00.00.
I am currently using the mouseMoveEvent->sceenePos(), but after converting it to String, I get only an int number( not value after the ',' ). What can I do to read the sceenePos() as a decimal fraction with number after the comma? Maybe the fraction is being casted after creating the QString object?

Thank you for help.

Maverick

[wysota]

Can we see the code? QString::number() should work fine in conjunction with QPointF::x and QPointF::y.

[maverick_pol]

I have used a simple QString("%1").arg(QPointF::x());
Ok. will try your idea.

THank you.

Maverick


P.S

I have used this:
QString(QString::number(mouseEvent->scenePos().x())))

but also show only the int part.

Any ideas?

[rajesh]

I think you write:
QPointF pt = mouseEvent->scenePos();
QString str = QString("%1,%2").arg(pt.x()).arg(pt.y());

[maverick_pol]

Hi,

I have tried this solution in the first place. It shows only INT values.
Maybe the INT value is read from the scene, and it's not the case of converting it to string. How to read scenePOS with high precision?

Beforehand thanks!

Maverick

[marcel]

Try QString::setNum(float, char format, int precision).

[maverick_pol]

Hi,

I will try the QString::setNUM, but I have just used qDebug() to show mouseMoveEvent->scenePos().x(), and it show INT values. It seems that I am reading coordinates as INT values. THe question is: how to read coordinates with higer precision?

Beforehand thanks!

Maverick

P.S.

I have tried using this:

QString	wspX;
wspX.setNum(mouseEvent->scenePos().x(),'g',10);
qDebug()<<wspX;

QString	wspX;
wspX.setNum(mouseEvent->scenePos().x(),'g',10);
qDebug()<<wspX;

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shows only the Decimal values(INTs).

[wysota]

I think your "problem" is that the fraction part of your coordinates are simply "0" thus the decimal point and zeros that follow are simply discarded. Are you sure the coordinates have non integer values?

[maverick_pol]

Hi,

I draw a custom background using some VPF data. I create polygon from pair coordinates. There is a lot of coor. like: 3.234, 1.234...etc When I print coord before drawing the background. Because I draw using( example 3.234) coordinate I would like to read the same coordinates with the same precision.
But now I am a bit confused. I need to have a good precision because after zooming the scene 10 times I should be able to see high precision coordinates(3.234) not only the jump from 3->4->5...etc.

Maverick

[wysota]

Can we see the exact code reproducing the problem?

[maverick_pol]

I belive that the code is not a problem, rather the understanding of coordinates system.
I am passing from signal to slot the:

mouseEvent->scenePos();

mouseEvent->scenePos();

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scenePos().x() in the qDebug() show the int, so I belive that I am reading only int values, but need to also read the decimal fraction.

How to do it is the problem.


But...when I zoom, let's say 3 times, I get high precision coordinates.(because the distance between 2 point is bigger, and this maybe be the reason).