Bootstrapping the Quintus Engine: Part II - HTML5 Mobile Game Development - page 174

controls: DEFAULT_TOUCH_CONTROLS,
width: Q.el.attr('width') || Q.width,
bottom: Q.el.attr('height') || Q.height
}).extend(opts||{});
opts.unit = (opts.width / opts.controls.length);
opts.size = opts.unit - 2 * opts.gutter;
function getKey(touch) {
var pos = Q.input.touchLocation(touch);
for(var i=0,len=opts.controls.length;i<len;i++) {
if(pos.x < opts.unit * (i+1)) {
return opts.controls[i][0];
}
}
}
function touchDispatch(event) {
var elemPos = Q.el.position(),
wasOn = {},
i, len, tch, key, actionName;
// Reset all the actions bound to controls
// but keep track of all the actions that were on
for(i=0,len = opts.controls.length;i<len;i++) {
actionName = opts.controls[i][0];
if(Q.inputs[actionName]) { wasOn[actionName] = true; }
Q.inputs[actionName] = false;
}
for(i=0,len=event.touches.length;i<len;i++) {
tch = event.touches[i];
key = getKey(tch);
if(key) {
// Mark this input as on
Q.inputs[key] = true;
// Either trigger a new action
// or remove from wasOn list
if(!wasOn[key]) {
Q.input.trigger(key);
} else {
delete wasOn[key];
}
}