A few years ago we introduced Javascript coding in Construct . It's consistently the most popular programming language in the world according to StackOverflow's...
There are two approaches to using scripting: one is full scripting, and the other is through the event sheet context. The latter is what I recommend.
"there is still some limitations and missing API, so you have to mess with events from time to time"
You actually answered your own question, try collision performance test with only the JS Scripting API.
So for me, fully switching to scripting means you could lose like 0-10% of engine features, depending on the game you are making (in most cases i really doubt you will lose anything, and even if you do, you can still use event sheet to avoid those limitations without much pain). At the same time, scripting gives you 300% more features and flexibility, so those 10% are easily compensated :)
Btw, do you mean there is no "on collision" event and testOverlap doesn't use collision cells for optimization? If so, yes, it is a limitation. One of my unfinished games was based around a lot of collisions, and even though i didn't really optimized it, it worked okay, so it depends on the game you are making.
I never really saw any feature requests of such optimization, so i don't think much people really needed it. Recently there was a discussion on collision cells and Ashley introduced condition cell size editing. I guess, we are not far from having those optimizations in code too.
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"You actually answered your own question"
I mean, having limitations is far from "making a game without an engine" as you stated in the original comment, in my opinion. Yes, i don't have convenient access to some features, but I still use most of the engine features without any problem.
And again, scripting gives you inumerous ways of more advanced and flexible usage of built-in engine features, which will never be possible in even sheet, so scripting gives you much more than event sheet in may cases.
Scripting also gives you ways to use 3rd party solutions much more easily, which again gives you great power, increasing your abilities compared to even sheets yet again.
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