Game Development

Hi and welcome to devnet,

As the string suggests, it's base64 encoded. Therefore you can use QByteArray::fromBase64 to load the data that is available after the "base64,".

I just received the information from KDAB that Qt3D support starts with OpenGL ES 2 and ranges to modern versions of the API. In the future the RHI will be supported as well.

@Mquaza said in QPainter drawRects without draging a line behind:

How do you make it so, that 2 rectangles are moving across the scene?

I would say change their coordinates?

Not generally good form to reply to oneself, but it seems OpenGL isn't scaled on hiDpi screens, according to this

So calling QApplication::desktop()->devicePixelRatio() gives me a pixel ratio of 2, which means I guess I just set 'trect' in the code to have w and h scaled by 2.

Interestingly, the screen is not scaled by 2, it's a 3200x1800 display on a native resolution of 5120x2880. The ultra-high DPI is just too much, but I want more than the standard half-resolution.

@aha_1980 said in My Qt creater version is v5.14.1:

@learningOpenGL

My Qt creater version is v5.14.1

No. Surely not.

This mysterious post comes from the future... ;-)

Hi and welcome to devnet,

Since you want to translate to Wt, you might want to ask the authors of that library.

@Alkoou

Hi Alkoou,
can you share your full code? I am currently working on the same topic.. It would be really helpful.

Hi and welcome to devnet,

At what point ? Building the plugin ?
When running your application ?
On what platform ?

Allright, I have got a few answers from other places that are potential options, so here's a list of potential ways to do what I want.

QQuickPaintedItem but will use software rasterizer (or an FBO which will be a texture upload on every frame). QQuickItem and updatePaintNode. More low level then QQuickPaintedItem which will use the SceneGraph API. How this performs is entirely up to how painting is "done". QQuickFrameBufferObject https://doc.qt.io/qt-5/qquickframebufferobject.html lets you use OpenGL directly in your custom item. The QML Canvas element can draw primitives using the Canvas API known from HTML5. Can also use an FBO to draw. "Shapes" in QML can draw lines and, Shapes. But requires dynamically creating the elements and then updating them from C++. QNanoPainter which is an OpenGL accelerated C++ vector drawing library for Qt: https://github.com/QUItCoding/qnanopainter

I haven't explored the suggested options in code yet. But this list looks pretty exhaustive to me. I'm marking this question as solved since I don't expect more alternatives to arise :)

You have to give more details. Otherwise it's pretty much Crystal Ball debugging and not very efficient.

Created a bug report for this problem https://bugreports.qt.io/browse/QTBUG-81087.

@Orad
You could place a progress bar with indefinite status. You can use the QProgressDialog and setting

progressBarDialog->setMaximum(0); progressBarDialog->setMinimum(0);

will show an infinite progress bar.

@haoxiang002 said in OpenGL queries:

Re: Question about OpenGL queries

Hi, what is your question?

All the solutions you listed are correct.

@Cheng-shi-hua
QML ?