mirror of
https://github.com/transistorfet/moa.git
synced 2024-11-17 07:08:41 +00:00
708e7706f3
Now it's up to 99% tests passing, 15362 are still failing, but many of those are the unimplemented IN/OUT instructions, which the Genesis doesn't seem to use
109 lines
4.8 KiB
Plaintext
109 lines
4.8 KiB
Plaintext
|
|
2021/10/21:
|
|
|
|
Frontend/Backend Interface
|
|
--------------------------
|
|
|
|
- need a way for the frontend window to be updated with graphics data from a backend device
|
|
- also need access to input key and joystick presses; other interfaces can be used for audio, etc
|
|
- it would be nice if it was possible to have multiple video output devices in a system
|
|
outputting to different windows (ie. one window per video device)
|
|
|
|
|
|
- either the frontend calls a function in the backend to update the window, or the backend
|
|
calls an indirect function on the frontend to update the window
|
|
|
|
- Frontend calling backend:
|
|
- Opt 1 - supply a callback and object separately, pass object to callback (no closure)
|
|
- older way but should work
|
|
- object needs to be Arc in order to share, but doesn't need to be wrapped in a tuple struct
|
|
- con: if object is device itself, would still need to use tuple struct wrapper for Addressable
|
|
- Opt 2 - supply a trait object with an update method
|
|
- frontend would store a Box<dyn Window>
|
|
- device would have to make a wrapper: `struct WindowWrapper(Arc<ActualDevice>)` and
|
|
impl Window on WindowWrapper, and `struct DeviceWrapper(Arc<ActualDevice>)` and impl
|
|
Addressable/Steppable on DeviceWrapper
|
|
- pro: in-sync on-demand rendering
|
|
- con: lots of complications and indirection
|
|
- Opt 3 - supply a common object that devices can update, and that then updates the window
|
|
- backend would define a Frame type object which would contain a rendered frame
|
|
- system thread would render to the Frame, ui thread would then copy the Frame to window
|
|
- con: lots of copying of pixel data
|
|
- con: out of sync rendering
|
|
- pro: ui can handle any scaling
|
|
|
|
- Backend calling frontend:
|
|
- Opt 4 - host can produce a generic window object that satisfies Window trait
|
|
- the device struct which needs the window would have a type parameter for the window
|
|
object, and the system thread (step) would call an update function on the generic
|
|
window to copy the rendered frame to a ui buffer, which then copies again on ui thread
|
|
- window object can only have a buffer, but it can use a native format rather than internal format
|
|
- con: out of sync rendering
|
|
- Opt 5 - host can produce a Window trait object
|
|
- the device would just store the trait object so no need for a type param
|
|
- the frontend can't put the native window in the window object so it would need to be a buffer
|
|
- con: would need a wrapper if the frontend needs internal access to the common device
|
|
- this is
|
|
|
|
- Opt 3, 4, and 5 would all involve an intermediate buffer, but with Opt 4 or 5, that buffer can be native-compatible
|
|
- Opt 3, 4, and 5 are out of sync updating
|
|
|
|
- Opt 1 and 2 can be in-sync updating if the device object is supplied, but not if it uses an intermediate buffer
|
|
|
|
- it seems like Opt 4 isn't working because you can't make an existential generic (can't return MiniWindow as W: Window)
|
|
- it seems Opt 5 works, but is trying to update the screen waaay too much, and causing the sim to almost never move.
|
|
Even with a simple count limit, it seems to pause when it tries updating the screen, probably due to lock contention
|
|
- Opt 1 is misleading because you still need a shared object, and it can't be a generic, so it's either a backend-specific
|
|
struct or a dyn trait object, so really it's the same as Opt 2, or Opt 3
|
|
- it might be possible to have a common data struct that contains 2 frames, one that can only be updated by the sim, and one
|
|
that can only be read by in-sync update function, and they are swapped on update (if the writable one isn't locked), so
|
|
that the updating is still in sync in the ui thread, but the rendering is happening in another thread
|
|
|
|
|
|
2021/12/07:
|
|
|
|
Signals, Etc.
|
|
-------------
|
|
|
|
* think more about what kinds of signals are used:
|
|
- one setter with one or more passive listeners (bank_register, updated by writing to and used whenever a value is read)
|
|
- one or more setters and one listeners (reset, bus_request for the CPUs)
|
|
- one one-shot setter (no reset) with one active listener that resets the signal (certain interrupts, including a vsync interrupt)
|
|
- what about interrupt controller?
|
|
|
|
|
|
2023/05/22:
|
|
|
|
Refactoring Execution of m68k
|
|
-----------------------------
|
|
|
|
* would it be possible to construct something that behaves more like the microcode executor using steps in chained form,
|
|
with side effects and quirks and flags (and exceptions) handled as such
|
|
|
|
```
|
|
// ADD
|
|
executor.start()
|
|
.fetch_src(src)
|
|
.fetch_dest(dest)
|
|
.add()
|
|
.write_dest(dest)
|
|
.set_flags("XCNVS")
|
|
.finish()?;
|
|
|
|
|
|
// BRA
|
|
executor.start()
|
|
.branch_offset(offset)
|
|
.finish()?;
|
|
|
|
// JMP
|
|
executor.start()
|
|
.fetch_src(target)
|
|
.branch_absolute()
|
|
.finish()?;
|
|
|
|
```
|
|
|
|
|
|
|