moa VS pixels

The code is here if you're interested: https://github.com/transistorfet/moa System is the top level component and devices.rs has the traits that System uses to interact with the components. The machines directory has the system definitions that build a specific machine to emulate.

A few months ago, I wrote a 68000 emulator in Rust named Moa. My original goal was to emulate a simple computer I had previously built. After only a few weeks, I had that software up and running in the emulator, and my attention turned to what other platforms with 68000s I could try emulating. My thoughts quickly turned to the Sega Genesis and without thinking about it too much, I dove right in. What started as an unserious half-thought of "wouldn't that be cool" turned into a few months of fighting documentation, game programming hacks, and my sanity with some side quests along the way, all in the name of finding and squashing bugs in the 68k emulator I had already written.

There's not much to it. Only one window can be created at the moment, and input is not yet supported. The threaded option is also not shown here. Before long, the code grew more complicated, and now includes parsing of command line arguments with the clap crate. To see the latest version, check out the Genesis machine-specific binary and the MiniFB host impl and main loop

Since the 68000 has a reasonably orthogonal instruction set, we can break down the opcode word into sub-components, and build up instructions by separately interpreting those sub-components, rather than having a match arm for each of the 65536 combinations. There is a really helpful chart by GoldenCrystal which shows the full breakdown of opcodes for the 68000. We can look at the first 4 bits of the instruction word to separate it into 16 broad categories of instruction, and then further break it down from there. The full code can be seen here

https://github.com/parasyte/pixels

That gives you a simple software framebuffer, and it builds as a native app or for the web.

On a more recent machine, that same (well, more primitive) app with pixels or softbuffer struggled beyond acceptable. But was definitely poorly written.

I’ve ported the application from being based on pixels crate to the powerful bevy game engine

Well, it depends on how you use it; writing to an image buffer isn't much less efficient than writing to any normal buffer (in fact, although displaying your scene to a window efficiently is important, your main bottleneck will be the actual ray tracing loop). You may want to read this article for a practical example of using an ImageBuffer to create and draw a texture with Piston. Other window backends you could use, apart from pixels which was already mentioned in another comment, include minifb and Mini GL, though I haven't personally used them.

You can use wgpu instead of opengl as in the pixels example: https://github.com/parasyte/pixels/tree/main/examples/minimal-fltk

It might be possible but with a raycaster you probably want to be able to easily set all pixels and create your own small engine. Something like the pixels crate should fit your purpose: https://github.com/parasyte/pixels

The reality is that I have used unsafe that is also unsound out of convenience because fixing it is a papercut too many. And this tends to be common! I know enough to spot unsoundness in other projects (sometimes even early). But not enough to be confident in my own abilities to write sound unsafe code. Why? Because it's really flipping hard, that's why!

Also, if you just want to get-things-done, then https://github.com/parasyte/pixels might be a bit better, to avoid reinventing the wheel.

However, I recently got a new M2 Macbook Air and started noticing some super weird behavior. While playing Pokemon Silver with an unlocked framerate, I'd notice that the game would slow down to below 60FPS, even on a release build. After printing a little debugging info I found the culprit in the rendering logic which was handled by the MiniFB crate. At first I thought switching to a GPU renderer (such as https://github.com/parasyte/pixels) would help, and it... kinda did?

pixels uses wgpu and runs fine.