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The GamePad (DRC), Pro Controller & Classic Controller can be emulated, which can be mapped to either your keyboard or any USB controller. Cemu currently supports DirectInput and XInput.
The GamePad (DRC) screen is rendered into the main window of Cemu while holding the TAB key on your keyboard or by mapping it to a controller button. You can also toggle between the screens by pressing CTRL + TAB. Additionally, the GamePad view can be displayed in a second window.
Yes, mostly. But be warned, some sound effects and filters are not yet supported and there can be sudden loud noises in certain games.
Online support is almost non-existant and will work only in applications that rely only on very basic network functionality and require no server authentication. This currently only includes the Wii U web browser and possibly some homebrew applications.
Multi-platform support is planned and so far many development decisions have been in favor of supporting multiple platforms (e.g. choosing OpenGL over DirectX for rendering). But currently there are thousands of other little things that need to be done before work on ports can be started.
At this point Cemu can already be considered highly optimized and possible future optimizations will only arrive in small and incremental steps. Keep in mind that emulation always requires a high performance system compared to the emulated system. For Cemu, the single core performance of your CPU (and by extension RAM speed) is the most important factor for fullspeed emulation.
Despite what you may have heard, DX12 or Vulkan will not magically increase speed. Those APIs do perform better in some situations but none of those apply to Cemu. The architecture of the Wii U GPU adds some additional constraints that almost nullify any optimization potential given by DX12/Vulkan. Nevertheless, a Vulkan backend is planned for the far future.
Cemu currently does not provide the best experience out of the box and some tweaking is almost necessary. For best performance: Set GPU buffer cache accuracy to low (but turn it higher if you get graphic flickering), CPU timer to 'host based' and CPU mode to 'recompiler'. Game specific tweaks might be necessary so it's advised to check google or the wiki for recommended options.
Game profiles are text files that can be used to setup game specific configurations in Cemu. You can find game profiles in the 'gameProfiles' folder of Cemu. There is also an example.ini explaining the available options and how to configure them. Note that some 'expert options' are only available via game profiles but not via Cemu's GUI.
We dropped the idea of a detailed roadmap early on after realizing that planning ahead doesn't go well together with the unpredictability of emulator development. We still have long term goals but generally the roadmap can be simplified to one sentence: Improve the emulator in every regard. What exactly to work on is decided from version to version or sometimes even on a day by day basis.
No, Cemu frequently exceeds the usage of more than 4GB of RAM and therefore cannot run on 32bit systems.
Yes, debugging tools are planned and in fact are already being worked on. However, since they are rather low priority they won't be ready for a while.