* Major refactoring of the main loop(s) and control flow (WIP)
run_at_fps() is gone 🦀
Instead of nested blocking event loops, there is now an eventloop API
that manages an explicit stack of scenes. This makes Taisei a lot more
portable to async environments where spinning a loop forever without
yielding control simply is not an option, and that is the entire point
of this change.
A prime example of such an environment is the Web (via emscripten).
Taisei was able to run there through a terrible hack: inserting
emscripten_sleep calls into the loop, which would yield to the browser.
This has several major drawbacks: first of all, every function that
could possibly call emscripten_sleep must be compiled into a special
kind of bytecode, which then has to be interpreted at runtime, *much*
slower than JITed WebAssembly. And that includes *everything* down the
call stack, too! For more information, see
https://emscripten.org/docs/porting/emterpreter.html
Even though that method worked well enough for experimenting, despite
suboptimal performance, there is another obvious drawback:
emscripten_sleep is implemented via setTimeout(), which can be very
imprecise and is generally not reliable for fluid animation. Browsers
actually have an API specifically for that use case:
window.requestAnimationFrame(), but Taisei's original blocking control
flow style is simply not compatible with it. Emscripten exposes this API
with its emscripten_set_main_loop(), which the eventloop backend now
uses on that platform.
Unfortunately, C is still C, with no fancy closures or coroutines.
With blocking calls into menu/scene loops gone, the control flow is
reimplemented via so-called (pun intended) "call chains". That is
basically an euphemism for callback hell. With manual memory management
and zero type-safety. Not that the menu system wasn't shitty enough
already. I'll just keep telling myself that this is all temporary and
will be replaced with scripts in v1.4.
* improve build system for emscripten + various fixes
* squish menu bugs
* improve emscripten event loop; disable EMULATE_FUNCTION_POINTER_CASTS
Note that stock freetype does not work without
EMULATE_FUNCTION_POINTER_CASTS; use a patched version from the
"emscripten" branch here:
https://github.com/taisei-project/freetype2/tree/emscripten
* Enable -Wcast-function-type
Calling functions through incompatible pointers is nasal demons and
doesn't work in WASM.
* webgl: workaround a crash on some browsers
* emscripten improvements:
* Persist state (config, progress, replays, ...) in local IndexDB
* Simpler HTML shell (temporary)
* Enable more optimizations
* fix build if validate_glsl=false
* emscripten: improve asset packaging, with local cache
Note that even though there are rules to build audio bundles, audio
does *not* work yet. It looks like SDL2_mixer can not work without
threads, which is a problem. Yet another reason to write an OpenAL
backend - emscripten supports that natively.
* emscripten: customize the html shell
* emscripten: force "show log" checkbox unchecked initially
* emscripten: remove quit shortcut from main menu (since there's no quit)
* emscripten: log area fixes
* emscripten/webgl: workaround for fullscreen viewport issue
* emscripten: implement frameskip
* emscripter: improve framerate limiter
* align List to at least 8 bytes (shut up warnings)
* fix non-emscripten builds
* improve fullscreen handling, mainly for emscripten
* Workaround to make audio work in chromium
emscripten-core/emscripten#6511
* emscripten: better vsync handling; enable vsync & disable fxaa by default
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