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Index › Programming Questions & Help › Syntax Questions › Keyboard-Input 101
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Keyboard-Input 101 (Read 1549 times)
:lukas
Keyboard-Input 101
Dec 5th, 2009, 4:29am  
Hi!

Well, I guess there should be a tutorial for what I want to know somewhere out there in the internets but I didn't find any that briefly explain exactly what I want to know:


When using the keyboard as a means of input in Processing, I always come across some difficulties. My questions according to those:

1.: How can I make my program react to input from multiple different keys simultaneously and independently? (so it doesn't ignore one pressed key once I press another etc.)
2.: How can I make the program only react once for every keypress of a certain key until it's released and pressed again? So... if I made a platformer and wanted the character to jump only once whenever a keypress on the "jump"-key is detected opposed to having him jump up and down if the key is held down.

What are the simplest ways of accomplishing those things?
Are there finished standard-functions for keyboard-input already that I could somehow implement into my code? (with which I mean: functions that handle things like multiple simultaneous keypresses and key-tapping)

Thanks in advance,
Lukas
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blindfish
Re: Keyboard-Input 101
Reply #1 - Dec 5th, 2009, 5:17am  
As you might imagine the first part of this question gets asked a lot - so a search might have been a good idea Wink

I think the last time I answered it with one possible approach was here...

The second part shouldn't be too difficult - just add another boolean.  Here's some pseudo-code:

Code:
// onPress:
  if(space) {
    // note that '!jumped' is equivalent to 'jumped == false' 
    if(!jumped) { // if jump hasn't already happened this keypress
      jump(); // jump! 
      jump = true; // Make sure jump won't happen again until key is released
    }
  }

// onKeyRelease:
if(space) {
  jump = false;  // jump is false so the next key press will allow a jump
}
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Where is the what if the what is in why?
 
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