I am making a 3D game with OpenGL ES 2.0 and want to use QML as an overlay for the user interfaces.
I know that I can embed my OpenGL code inside a QGLWidget but how can I force QML to redraw the view as often as possible?
Additionally will I get performance issues because I am embedding the OpenGL view?
If you want to render your game with OpenGL and use QML for the UI, consider using the Qt Quick Scene Graph:
Mixing Scene Graph and OpenGL
Scene Graph - OpenGL Under QML
Related
When using the Qt OpenGL back-end then it is possible to render custom OpenGL code during Qml scenegraph rendering using the QQuickWindow::beforeRenderPassRecording signal, as described in the Qt documentation: https://doc.qt.io/qt-5/qtquick-scenegraph-openglunderqml-example.html
Is a similar functionality available for the Apple Metal back-end? How can I use native Metal code in the scene graph?
I need to create a GUI with a file menu and menu in which the user can input parameters. The parameters are then used for drawing rectangles in a canvas which is part of the application window. Is there a way to scale the OpenGL subwindow to just one part of the screen and the parameter input to the other? The application needs to be written in C++.
Is it possible to create a GUI with QT and draw the rectangles in the same window using OpenGL? If not, what is the common way to integrate a GUI with OpenGL? (or any other graphics library which I can use to draw rectangles from points as easy as possible)
EDIT: I am not sure If OpenGL is necessary or there is a way to paint the rectangles on the canvas like you can in Java with paintComponent().
I have never used QT before so I am not aware of its capabilites.
you can use opengl window singly or use this in the common mainwindow. previous example (in first answer) show how to use opengl window in qt singly and without communication with other components of Qt (like menu, toolbar and ...). but you can add a opengl window to a mainwindow (like other widget) and use it alongside other widgets . this example can help you.
Yes, using OpenGL together with Qt is absolutely possible. There is even an example for that and Qt provides classes for a more object oriented way of using OpenGL. Have a look here (Section "OpenGL and OpenGL ES Integration") for more details.
I have been looking for ways to render a 3d scene using Qt QML controls. I saw there is a framebuffer example which uses Canvas3D control to get OpenGL 3d scene rendered. However this example uses JavaScript for the rendering logic.
I was looking for a way to do the same but via a C++ class. Is there any way to do so? Or any example available?
Ideally, I would like to use 3rd party renderer to create a scene. Any ideas?
I'm developing a Qt app which uses Cocoa on the Mac and am using PowerVR SDK to enable OpenGL ES 2.0 on Mac Desktop.
I've managed to get it working, everything renders perfectly, the problem is
that when I'm creating a widget in that window, OpenGL renders over it, e.g
I'm creating a QLabel and it renders over it, making the label invisible.
I tried calling QLabel's repaint() method after rendering a single OpenGL frame, but that didn't help.
Has anyone encountered such or similar issue and has any suggestions?
Thanks!
If you wish widgets to interoperate with OpenGL content, you must use the QOpenGLWidget. It draws to an offscreen buffer that then gets composited with the widgets.
Alternatively, you must yourself render the label into a texture, and apply the texture to a quad.
I wonder if it's possible to use Awesomium to render the GUI over the DirectX 11 game (I do NOT use .NET, it's C++/DirectX 11 game)?
It would involve:
Rendering the scene on the window with DirectX 11 (just as I am doing it now).
Rendering the GUI with Awesomium from HTML/CSS over the previously rendered scene.
Note that some GUI elements should be semi-transparent or rounded - so it's not only rendering on some rect, but also blending.
Is it possible? Or maybe I could make it another way (e.g. telling Awesomium to use DirectX for rendering somehow)?
Or maybe I could draw an semi-transparent DirectX texture in Awesomium, and then render it over the scene with DirectX? I know that rendering to texture resource is possible with Awesomium, but does it supports transparency & semi-transparency?
If not, are the good alternatives for what I wanted to achive with Awesomium?
Yes. It can be done.
If you look at the documentation of the Awesomium WebView class it has a surface() method which will return the views backing bitmap.
Here is some c++ documentation for the class.
http://awesomium.com/docs/1_7_0/cpp_api/class_awesomium_1_1_web_view.html
You can copy this bitmap to a texture in DirectX and render it as layer on top of your game creating your UI.
You also have to route and translate input into Awesomium. You can style your UI however you like using HTML, CSS and Javascript. You can make it rounded in this way and introduce transparency.
I won't repeat a perfectly good tutorial on doing this. You can find one here.
http://www.gamedev.net/blog/32/entry-2260646-sweet-snippets-rendering-web-pages-to-texture-using-awesomium-and-direct3d/
How you render your texture after it is written doesn't have anything to do with Awesomium. Choose your blend modes and/or use shaders with output texture for desired effect.