Quote Originally Posted by lni View Post
You are right about the device being painted on has a finite and fixed resolution, but you are wrong that the zoom should not improve the resolution.
It will not improve the resolution of the output device, it will improve resolution (number of details you can distinguish) of the scene. It is the resolution of the device that determines the number of details of the scene you can see - the better your eye sight the more details you will see in the same weather conditions.

[quote[If you plot 1000 points in a small area, you see a cloud of a mess, if you plot the same amount of data in larger area, you can tell which point is which, and that is what the zoom should be.[/quote]
And it is exactly the way it is.

I think you have not been involved in many application development so you may not have understood what the end users really want.
Right Let's make a poll and see what others think about graphics view zooming.

In your particular example, you made a very simple plot, so you only see a small side of the rule, but try to replace with the following codes, you should see the markers grow as you zoom in, and no matter how much you zoom, you can't tell that I am plotting 10 points.
Right... you can call QPainter::drawLine() as many times as you want and it won't draw a circle. Why? Because it's not supposed to... If you call drawEllipse() on the other hand, it will draw an ellipse. If your code is not correct, it won't do what you want it to.

Actually I don't see your point. You are plotting lines and expect to see points? Would you care to explain that?

And When user zooms in, what users want to see is the data, not the huge text string that got blown out of the screen. So please provide an QPen::setCosmetic equivalent QFont.
Make it yourself, Qt is Open Source I understand there could be an option which you suggest available but I don't say the lack of it makes Graphics View work incorrectly. Especially that you can obtain the effect you want using ItemIgnoresTransformations. Even the docs say:

This flag is useful for keeping text label items horizontal and unscaled, so they will still be readable if the view is transformed. When set, the item's view geometry and scene geometry will be maintained separately. You must call deviceTransform() to map coordinates and detect collisions in the view.
I have also looked into QGraphicsWidget, and it has no difference.
Why would you expect it behaved differently?

As I said, the best example that the end users want are example shown in Qwt, try Qwt's realtime example. It is the one people are looking for. Unfortunately, Qwt doesn't have all we want...
Qwt is for something more specific than Graphics View.

You guys spent a lot of effort already, with some improvement, I think Qt graphics can really become a power house.
It's not us It's Andreas Hanssen and his team mostly