Hi,

Sorry if this is the wrong place; I couldn't find a forum on hacks.  This is regarding the multi-key press hack: http://www.processing.org/hacks/hacks:multiplekeys

I used the first example and it works MOST of the time.  The problem comes when holding down many keys.  It seems like if you hold down about 4 or 5 keys, it stops reading in the new presses until other keys are released.  Here is an example I made to illustrate that:

Code:

PFont font;

void setup() {
  size(200,200);
  font = loadFont("ArialMT-12.vlw");
  textFont(font,12);
  stroke(255);
}

void draw(){
  background(0);
  checkKeys();
}

boolean[] keys = new boolean[526];
void checkKeys()
{
  for(int i = 0; i < keys.length; i++)
    if (keys[i] == true){
	text(KeyEvent.getKeyText(i),(i*8)%width,int(i*8/width)*8 + 20);
    }
}

void keyPressed()
{ 
  keys[keyCode] = true;
  println(KeyEvent.getKeyText(keyCode));
}

void keyReleased()
{ 
  keys[keyCode] = false; 
}
 

Try holding down many keys, 1 at a time and watch what happens.


I tried to fix this by using the second example which is supposedly "snappier".  When I first ran the example I got "Cannot parse error text: C:\.....\HelloWorld.java is missing"  I then converted this code into Processing code like this:

Code:

import bak.pcj.set.IntSet;
import bak.pcj.set.IntOpenHashSet;

IntSet keysheld;

void setup() {
  IntSet = new IntOpenHashSet();
  /**
   * @param keycode key integer code, the value are constants defined in KeyEvent Class
   *		    http://java.sun.com/j2se/1.4.2/docs/api/java/awt/event/KeyEvent.html
   *		    e.g. KeyEvent.VK_A for letter A
   *			   KeyEvent.VK_0 for number 0
   *			   KeyEvent.VK_SHIFT for shift button
   * @return true if the key is currently held down, false otherwise
   */


}

boolean checkKeysHeld(int keycode){
  keysheld.contains(keycode);
}

void keyPressed(){
  // add key to the list of keys held down
  // with processing, the KeyEvent object is always available as "keyEvent",
  // the getKeyChar() is already in the variable 'key', and getKeyCode() is in the variable 'keyCode'.
  keysheld.add(keyEvent.getKeyCode());
  println("key pressed: "+KeyEvent.getKeyText(keyEvent.getKeyCode()));
  println("keys in current held list: "+keysheld.toString());
}
void keyReleased(){
  // remove key from the list of keys held down
  keysheld.remove(keyEvent.getKeyCode());
}
 

I now get the error "The package "bak" does not exist. You might be missing a library.

So I guess I have a few questions:
1. Why doesn't the first example work all the time?
2. The 2nd example seems to be Java code, I think. Should this compile in Processing? If (yes) {why doesn't it?} else {why did someone post it in the Processing hacks section?}
3.Where can I obtain the "bak" library to compile this code?

Sorry this was loooong, but more information is better than less right?

fjen wrote on Dec 16^th, 2008, 9:35am:


thanks for your help. follow up question on #1.

are these grids the same on all keyboards? i'm making a 2 player, 1 keyboard game which involves holding down a lot of keys.  i think my only hope is to find sets of keys that do not interfere which each other. but this will only work if the connections are standard. thanks!