Which graphical toolkits are not API wrappers?

Question

API

1. As I understand it, most graphical toolkits are a wrapper over the main OS API. For example Tk, WinForms, wxWidgets and so on. But the question is, does everyone do it this way? Let's say, due to which Qt looks very native on different platforms? Is it a wrapper or draws everything on its own?
2. Are combined options possible? When half is drawn on its own, and wrappers are used for some of the functions (buttons are different, menus, etc.)?
3. Are there any toolkits that use DirectX/OpenGL depending on the platform? Or DirectX/OpenGL has nothing to do with it at all?

Answer 1

1. Any UI library ends up drawing everything using the API provided by the OS. The only question is how low-level or high-level this API is. Also, do not forget that in addition to rendering, there is the behavior of controls, event handling. Here, too, default handlers can be used, or they can be overridden.
Some operating systems have a standard control library (Windows, OSX) and some don't (Linux).
2. Possible. For example, VCL.
3. There are also different backends. For example DlangUI. There are also using DirectX / OpenGL. For example Firemonkey

Answer 2

1.Qt draws widgets with what the system allows.
For Embedded Qt (at least the fourth branch) can draw everything itself directly to the framebuffer.
2. ХЗ
3. And what is the point of implementing the same functionality, in fact, twice? A framework must behave the same way everywhere, and using both OpenGL and DirectX makes this difficult.