Update on CEMU 1.6.2 (Patreon)

CEMU 1.6.2 will release next Saturday (29th October). As usual the update will first be available to $5+ Patrons and a week later for everyone else.

Here is a list of changes that you can expect in 1.6.2:

Accelerated Streamout

One of Wii U's more advanced GPU hardware capabilities is called 'Streamout'. Essentially this feature allows games to offload work from CPU and execute it on the GPU. There are some limitiations but if used correctly by game developers it can lead to tremendous speedups in a game. That said, not that many Wii U games actually make use of this hardware feature.

Starting with CEMU 1.6.2 we will now use something called Transform Feedback which is the modern equivalent of Streamout in OpenGL. So rather than emulating Streamout in software we will use GPU hardware acceleration just like a real Wii U. As a result, Streamout emulation is much faster in 1.6.2.

Here is a list of games that use Streamout heavily and will likely see a FPS boost from this change:

• Xenoblade Chronicles X
  
• Super Smash Bros
• Donkey Kong Country Tropical Freeze

As a side effect the new Streamout implemention also fixed some bugs. For example the grass in XCX is now visible.

More CPU optimizations, bugfixes and various changes

Additionally to what I mentioned above, the next CEMU release will have a bunch of miscellanous changes. Better Amiibo support, optimizations to the emulation core and maybe compatibility and audio improvements if time allows. Some of the issues that were introduced in 1.6.1 will also be fixed.

A look into the future

With the completion of hardware accelerated Streamout, it's worth to mention that the list of missing features for the graphic backend is getting really short. Making the graphic backend feature-complete is within reach! The missing features are:

• MSAA/Antialiasing
  
• Tessellation
• Conditional Render Queries
  
• Shader Storage Buffer Objects (SSBO)
  
• Compute Shaders

There is a good chance that the first three features on this list will be implemented within the next two months. The remaining two, SSBO and Compute Shaders, are a bit trickier but we might be able to have them implemented in early 2017.

Due the complexity of Wii U's GPU I don't expect that we will ever run out of graphic bugs. But having a feature-complete backend means that we will have more time that we can invest into other parts of the emulator. To put things into perspective, this year 90% of development time went into the graphic backend alone.