Hey folks! This is a demo cart to showcase use of coroutines to create animations and dialogue.
By having a single active 'script' coroutine we can do the following:
- reveal text frame by frame
- do nothing until player presses [x]
- give the player a choice of answers [up/down + x] to select
- do nothing until npc has finished walking
- do several of the above simultaneously, and only continue once all of them are finished.
all this without blocking the _update() function
For more info on coroutines, check out the forum post. Also keep an eye out for Fanzine #5, where Dan Sanderson will be exploring these topics!
For a quick text-skip button, add an IF to REVEAL_TEXT()
[i]function reveal_text(str) text = "" for i=1, #str do text = text..sub(str,i,i)[/i] [b]if (btnp(4)) text=str break[/b] [i]yield() end end[/i]
For a text speed option, add a variable and use it as the for loop increment / sub() length value.
Heck, just adding opening and closing exposition you could turn this into any number of jokes/epics/deep thoughts. This makes me want to declare a one-screen RPG jam using this cart as a base. Anyone interested?
Sometimes I don't have much to add except how to save tokens, but hey, gotta go with what I know. You can eliminate the string concatenation like this:
[i]function reveal_text(str) [s]text = ""[/s] for i=1, #str do text = [s]text..sub(str,i,i)[/s][/i] [b]sub(str,1,i)[/b][i] if (btnp(4)) text=str break yield() end end[/i]
I think the previous code was the sort that's better in C/C++, but worse in Lua. This is worse in C++, but better in Lua, due to the fact that Lua never modifies strings, preferring only to copy parts of old ones into new ones, discarding the old ones afterwards.
(Personally, I have found this to be a tough paradigm shift to accept.)
Aha, thanks for pointing that out! Repeated string concatenation is definitely not a desirable thing as far as performance goes (though I guess it's not a huge issue in this case since the code only runs once per frame), but yeah this way is definitely better for saving tokens and being a more elegant use of the available functions.
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