What is the fastest dependable key input method?

[Pete]

I've almost exclusively used INKEY$ over the past 30 years. INP is faster, but it is hard to control. Other methods would be PEEK/POKE and _KEYHIT. One obvious problem with INKEY$ is that _LIMIT is required in the loop to prevent your computer from going Fukushima. I would imagine INP has the same problem with high CPU usage if _LIMIT is not used. I don't know if _KEYHIT has the same CPU usage issues. If not, that is a benefit because a mouse routine in a _LIMIT loop is a bit tricky. Limiting the frames can cause mouse input to be missed but I've found a way around that. So mostly it's just about if other calls are being processed while a key routine is being polled, which routine is the fastest (less likely to result in a lagging type response, while being dependable, INKEY$, INP, PEEK/POKE, or _KEYHIT?

Pete

[FellippeHeitor]

INKEY$, INP, PEEK and POKE are all emulated, which makes the assumption that one is faster than the other just not true as in the days of yore. That also means they wrap the raw data provided by the OS in a way that mimics DOS days. The data you get by reading _KEYHIT (and _KEYDOWN by analogy) are the direct representation of what the OS is passing to the framework QB64 uses, so I'd recommend going with those.

The requirement for _LIMIT doesn't directly relate to any of these functions but to the fact that you'll want to read input in a loop. You'd better use _LIMIT in a loop even if it's just DO: _LIMIT 30: LOOP, with nothing else in it, for the sake of preserving CPU cycles.

[Pete]

But none of what you touched based on has anything to do with why the grass seed I planted in my front yard failed to germinate. This is why I was hoping Steve would reply, too.

Actually, that tells me a lot. Oh, not about my lawn situation, about how QB64 works. That's very interesting about _KEYHIT working directly with the OS, while the other methods are now all emulated.

I think I'll make a small converter function so I can still use all my SELECT CASE statements that use INKEY$ character designation. While I'm not too old to remember those, I think I'm a bit past the age of learning to associate the _KEYHIT scancode numbers.

Thanks for the great explanation. It's amazing you have the time for this... although I suspect you're typing with one hand and changing diapers with the other. Just remember not to powder the keyboard! (Actually I shouldn't joke about baby powder. Talc is a health risk if inhaled. Powders made with cornstarch, instead of talc, are less problematic but still of a concern. Pediatrician organizations do not endorse cornstarch powders, either.)

Pete

[Clippy]

Biggest problem with key input is with key combinations or pressing 2 arrow keys at once to go diagonally.

INP works better in QB64 with an array and it no longer gets messed up with the Number Lock setting.

Use a Windows function to read keys when not in focus. See you on Tapatalk in 2 years...

[Pete]

OK, I'll bite... Why in 2 years???

Pete

[bplus]

OK, I'll bite... Why in 2 years???

Pete

I think Ted is making a radically conservative bet on the time it will take to get net54 back up or the least time before he will break down and try Tapatalk again. Just an impression I am getting, of course he might object to my use of adjective (or is it adverb, -ly usually indicates adverbs) "radically".  :D

Well this is how threads get derailed, but since we are this far and "inquiring minds need to know":
https://www.google.com/search?client=opera&q=adverbs+and+adjectives&sourceid=opera&ie=UTF-8&oe=UTF-8

Some adverbs end in -ly, but not all. ... Instead, the key to telling the difference between adjectives and adverbs is understanding how they work: Adjectives describe a noun or pronoun. Adverbs describe a verb, adjective, or other adverb.

(The bold is missing in quote, I added back in twice where it applies to my question above.)



Update / Edit:
I have picked up the subject of the mystery of decoding a combination key press here:
https://www.qb64.org/forum/index.php?topic=238.15
Reply #23 as it applies to InForm key presses

BTW is this still accurate / relevant to current QB64 version:

Code: QB64: [Select]

1.   x = _KEYHIT
2.   IF x THEN
3.     IF x < 0 THEN  'negative value means key released
4.       COLOR 2
5.       PRINT "Released ";
6.       x = -x
7.     ELSE
8.       COLOR 10
9.       PRINT "Pressed ";   'positive value means key pressed
10.     END IF
11.     IF x < 256 THEN    'ASCII code values
12.       PRINT "ASCII "; x;
13.       IF x >= 32 AND x <= 255 THEN PRINT "[" + CHR$(x) + "]" ELSE PRINT
14.     END IF
15.     IF x >= 256 AND x < 65536 THEN '2 byte key codes
16.       PRINT "2-BYTE-COMBO "; x AND 255; x \ 256;
17.       x2 = x \ 256
18.       IF x2 >= 32 AND x2 <= 255 THEN PRINT "[" + CHR$(x2) + "]" ELSE PRINT
19.     END IF
20.     IF x >= 100000 AND x < 200000 THEN      'QB84 Virtual Key codes
21.       PRINT "SDL VK"; x - 100000
22.       END IF
23.       IF x >= 200000 AND x < &H40000000 THEN
24.             PRINT "QB64 VK"; x - 200000
25.     END IF
26.     IF x >= &H40000000 THEN              'Unicode values (IME Input mode)
27.       PRINT "UNICODE "; x - &H40000000; "0x" + HEX$(x - &H40000000) + " ...";
28.       cx = POS(1): cy = CSRLIN
29.       _FONT unifont
30.       LOCATE cy, cx
31.       COLOR 15
32.       z$ = MKL$(x - &H40000000) + MKL$(0)
33.       PRINT z$ + z$ + z$;
34.       _FONT font
35.       LOCATE cy, 1: PRINT
36.     END IF
37.   END IF
38.  

It is from:
http://qb64.org/wiki/KEYHIT
that I used to try and make sense of __UI_KeyHit values.  I ask because WTH? is SDL VK?