1
0
Fork 0
fgdata/Phi/examples/horizon.js
2015-11-19 15:33:46 +01:00

66 lines
2.8 KiB
JavaScript

// Configure require.js and tell it where to find our modules
require.config({
baseUrl : '.', // use this base if we don't give absolute paths
paths : {
knockout : '/3rdparty/knockout/knockout-3.2.0',
knockprops : '/lib/knockprops',
},
});
require([
// we depend on those modules
'knockout', // lookup 'knockout' in the 'paths' attribute above,
// load the script and pass the resulting object as the
// first parameter below
'knockprops' // load 'knockprops' in the 'paths' attribute above etc.
], function(ko) {
// ko is now the locally available knockout extension
// the second arg would be knockprops but that is not needed as it registers itself with knockout.utils
// this creates the websocket to FG and registers listeners for the named properites
ko.utils.knockprops.setAliases({
pitch: "/orientation/pitch-deg",
roll: "/orientation/roll-deg"
});
// knockout stuff - create a ViewModel representing the data of the page
function ViewModel() {
var self = this;
// magic function,
// create observables for all defined properties
ko.utils.knockprops.makeObservablesForAllProperties( self );
// we now have observables as if we typed
// self.pitch = ko.observable();
// self.roll = ko.observable();
// but our knockprops observables always reflect the value of the FG property
// updated at frame rate through the websocket
// build the transform-string for the css transform property
// we want something "rotate(45deg) translate(30%)"
// see http://knockoutjs.com/documentation/computed-pure.html
self.groundTransform = ko.pureComputed(function() {
return "rotate(" + (-self.roll()) + "deg) " + self.groundTranslateTransform();
});
// this little helper just scales and clamps the y-translation
self.groundTranslateTransform = ko.pureComputed(function() {
var t = 100 * (self.pitch() / 45);
if( t > 100 ) t = 100;
if( t < -100 ) t = -100;
return "translateY(" + ( t ) + "%)";
});
}
// Create the ViewModel instance and tell knockout to process the data-bind
// attributes of all elements within our wrapper-div.
ko.applyBindings(new ViewModel(), document.getElementById('wrapper'));
// now, every update of a registered property in flightgear gets to our browser
// through the websocket. Knockprops delivers each change to the associated ko.observable
// and fires the listeners of the observable. Those listeners trigger the change of the HTML DOM
// which results in a redraw of the browser window.
});