We have a C++ application that uses imgui extensively with very good results. We want to offer our users the possibility to write plugins in python, and to provide own controls for the plugins we would prefer that rendering of the plugin controls is done with the already active imgui context. Python has various imgui bindings (e.g. pyimgui, dearpygui). Is it possible to pass the already existing C++ imgui context to Python and draw windows, draw controls there, so they all show up in the common ui (in the same swap, with the same font ... etc)?
Related
I'm trying to port the code from https://github.com/eryar/occQt to gtkmm, by creating a custom widget and overriding the Gtk::widget::on_realize() method like
void OccView::on_realize() {
// Create Aspect_DisplayConnection
Handle(Aspect_DisplayConnection) display_connection = new Aspect_DisplayConnection();
// Get graphic driver if it exists, otherwise initialize it.
Handle(Graphic3d_GraphicDriver) graphic_driver;
if (!graphic_driver) {
graphic_driver = new OpenGl_GraphicDriver(display_connection);
}
// Get window handle. This returns something suitable for all platforms.
Window x_window = GDK_SURFACE_XID(get_native()->get_surface()->gobj());
// Create window for platform.
Handle(Xw_Window) xw_window = new Xw_Window(display_connection, x_window);
// Create V3dViewer and V3d_View
mViewer = new V3d_Viewer(graphic_driver, Standard_ExtString("viewer3d"));
mView = mViewer->CreateView();
// Set window for the view
mView->SetWindow(xw_window);
if (!xw_window->IsMapped()) {
xw_window->Map();
}
// Create AISInteractiveContext
mContext = new AIS_InteractiveContext(mViewer);
// Set up lights etc
mViewer->SetDefaultLights();
mViewer->SetLightOn();
mView->SetBackgroundColor(Quantity_NOC_BLACK);
mView->MustBeResized();
mView->TriedronDisplay(Aspect_TOTP_LEFT_LOWER, Quantity_NOC_GOLD, 0.08, V3d_ZBUFFER);
mContext->SetDisplayMode(AIS_Shaded, Standard_True);
// Call base method
Gtk::Widget::on_realize();
}
but the Gtk::Window stays empty after appending the OccView object. What am I doing wrong? Is there a working example on how to integrate the Opencascade V3d_View into a Gtk::Widget, or the gtkmm framework in general?
I haven't used GTK since university, so my experience is pretty basic here.
There are two basic approaches for embedding OpenGL-based viewer into GTK:
Ask OCCT to create OpenGL context for a native window taken from a normal Widget or entire window.
Wrap existing OpenGL context created by GUI library itself, e.g. Gtk::GLArea.
Your current code tries to follow the first approach used by conventional samples for Qt Widgets and MFC coming with OCCT. I guess it should be feasible, but implies some limitations and issues with mixing GTK widgets, as GTK will not be aware of OpenGL usage.
In contrast, Gtk::GLArea looks like a "modern" way for embedding OpenGL renderer designed by GTK developers and expected to work transparently.
Therefore, I've tried implementing a Hello-World sample using Gtk::GLArea (based on a development snapshot of OCCT 7.6.0dev):
https://github.com/gkv311/occt-samples-gtk
I don't bring the whole code of the sample here, as it is quite large in size.
Putting OCCT Viewer into Gtk::GLArea includes some tricky parts like:
Wrapping native Window into Aspect_Window (it could be also Xw_Window like in your sample, more general Aspect_NeutralWindow or another subclass).
Wrapping OpenGL context created by Gtk::GLArea into Aspect_RenderingContext/OpenGl_Context.
Wrapping offscreen buffer (FBO) used by Gtk::GLArea for rendering content into OpenGl_FrameBuffer.
Putting all viewer redraws into dedicated callback for Gtk::GLArea::signal_render().
Redirecting user input to viewer (with help of AIS_ViewController).
It is important to note, that GTK may be run in different context:
X11 server - X Window is created and GLX is used for OpenGL.
This is default OCCT configuration for Linux;
Wayland - native window is not X Window and EGL is used for OpenGL context.
OCCT does support EGL but as a dedicated configuration as alternative to GLX, while GTK handles this in runtime somehow. In addition, OCCT does not (yet) provide any wrapper for a Wayland native window, though it might be not critical for using.
GTK also has an option to use OpenGL ES instead of OpenGL.
Initially I expected Gtk::GLArea to work natively, but instead a very basic sample (without OCCT viewer) displays artifacts to me (widgets randomly blacked) on Xubuntu 18.04, though it works as expected on Ubuntu 21.04 (within Xorg session). I don't know if it is a bug fixed in GTK implementation, or there is something that should be fixed in a sample to workaround problem on older Linux.
How do i just create a window with just some controls like menus , check button , radio button , scroll bar ..just with c++ and OpenGL?
It depends.
1) You can't use any external libraries.
In this case you would need to create whole framework for creating controls, handling events, hit tests, state changes... Shortly speaking, you would need to write a GUI library like Qt or wxWidgets, but with all controls drawing implemented in OpenGL.
2) You can use 3rd party libs.
Well, simply read the spec and use them. Examples:
GiGi
GLUI
Also, you may want to read this: OpenGL Forum
However, if you don't have to use OpenGL-based solution, I would suggest you use wxWidgets. I've been using it for years. It's my favourite cross-platform GUI library with solid support, quite big community and reliable, up-to-date online/offline documentation.
I am working with an existing OpenGL library which needs to be augmented with other UI functions (better keyboard input, mouse handling, etc). I was hoping to use SDL, SFML or GLFW with the existing OpenGL API to facilitate this. Using any of these frameworks, is it possible to hook UI functions from any of these frameworks into an existing window, rather than a window directly created from these frameworks?
-The existing OpenGL window is already created by the library I'm forced to use.
-I'm aware of the SDL_WINDOW_FOREIGN bit set but am not sure how this is supposed to work.
-Is there a better strategy for simply detecting mouse/keyboard input?
The SDL 2.0 function SDL_CreateWindowFrom() can set up SDL for input and rendering from a given native window.
https://wiki.libsdl.org/SDL_CreateWindowFrom
I'm making an editor for 3d worlds in opengl using the windows forms UI. I'm developing on visual studio 2012 express and i would like to embed a GLFW window/context inside a windows form. just like done in this tutorial http://www.codeproject.com/Articles/16051/Creating-an-OpenGL-view-on-a-Windows-Form except working. And with GLFW for opengl context.
Is this possible? should i use Qt instead? and how would i got about doing this? I'm not bound to using windows forms i just need a simple good-looking functional UI for my project.
That are three different frameworks (Windows Forms, GLFW, Qt) which can all do the same thing, i.e. creating a window and an OpenGL context in it.
See here for an easy example how to create a window with OpenGL context with GLFW.
Or see here for the Qt example.
So, you have to choose between one of them. GLFW and Qt have the advantages that your code will also work on MacOSX and on Linux; with some work even on iPhone.
If you want to do the window creation and event handling and other stuff with GLFW but the GUI still with Qt, there is some way to do offline drawing (some ref here or here or here) the Qt widgets and then draw it onto some OpenGL texture. Or you might also be able to directly draw them via OpenGL (not exactly sure).
I have a bare-bones Linux distro running on a machine connected to a laser. I want to develop an interface which allows me to:
Configure settings for the laser (e.g. toolbars and buttons)
Display the current path of the laser (e.g. graphics window)
Since these are bare-bones machines, I don't have X11 installed. I figured that perhaps I could use ncurses to develop a cross-platform interface to configure the settings for the laser, and use SDL to draw arcs and lines to represent the path of the laser.
While I'm comfortable using ncurses and SDL independently, I'm having trouble figuring out how to embed the SDL graphics within an ncurses window.
Is it possible to embed a graphics window (not necessarily SDL) into an ncurses application? If not, is there a cross-platform alternative to ncurses which will do what I need without X11?
The Ncurses project appears focused on developing a library for the construction of text-based user interfaces. As such, I do not believe there currently is, nor is planned to be, support for embedding an SDL graphical context.
I would suggest looking into other options such as the AGAR library which enables the creation of graphical user interfaces within SDL.