Applications in the RealSense SDK such as the RealSense Viewer use a system called Imgui to generate the interface elements.
https://github.com/IntelRealSense/librealsense/issues/2450
If you open the Viewer script with the link below and do a 'find' search in the browser for the word "imgui" on the page to highlight all references to it, you can see how the Viewer script handles Imgui interface element setup.
https://github.com/IntelRealSense/librealsense/blob/master/tools/realsense-viewer/realsense-viewer.cpp
I am guessing by the image you provided that you want to simplify the display by not showing the rows above, such as the icon toolbar and the Add Source panel?
I do not have experience of programming the SDK's GUI. An analysis of the Viewer script though suggests how the panels may be being generated.
- My speculation would be that the Add Source panel at the top is generated on line 309 with this instruction:
ImGui::Begin("Add Device Panel", nullptr, flags);
You could try deleting or commenting out that line and see how it affects the options panel layout.
https://github.com/IntelRealSense/librealsense/blob/master/tools/realsense-viewer/realsense-viewer.cpp#L309
- I am guessing that the section that you want to show at the top has its initialization instruction on line 422,
ImGui::Begin("Control Panel", nullptr, flags | ImGuiWindowFlags_AlwaysVerticalScrollbar);
https://github.com/IntelRealSense/librealsense/blob/master/tools/realsense-viewer/realsense-viewer.cpp#L422
I apologize that I could not provide a clearer answer. I see that you have also posted this question on the GitHub, which is an excellent idea as the RealSense developers are located there. Good luck!
