controller.js

"use strict"    
/* Copyright (c) 2014, Robert Buchholz <rbuch703@gmail.com> 
   The contents of this file are licensed under the GNU General Public License version 3
   (see the LICENSE file in the project root for details)
*/

function getSign(pos, neg)
{
    if (pos && (!neg)) return  1;
    if (neg && (!pos)) return -1;
    return 0;
}


var Controller = {

    position: {lat: 0, lng: 0},
    localPosition : { x:0, y:0, z: 1.5 }, //camera position in the local coordinate system ('z' is height)
    viewAngleYaw : 0,
    viewAnglePitch : 0,

    getPosition : function()
    {
        return { "lat": Controller.position.lat, "lng": Controller.position.lng };
    },

    getEffectivePosition : function()
    {
        var metersPerDegreeLat = Helpers.getEarthCircumference() / 360;
        var metersPerDegreeLng = metersPerDegreeLat * Math.cos( Controller.position.lat / 180 * Math.PI);

        return {lat: Controller.position.lat + Controller.localPosition.y / metersPerDegreeLat,
                lng: Controller.position.lng + Controller.localPosition.x / metersPerDegreeLng,
                height: Controller.localPosition.z};
    },
    
    getLocalPosition: function()
    {
        return [Controller.localPosition.x, Controller.localPosition.y, Controller.localPosition.z];
    },

    buildQueryString: function()
    {
        var effPos = Controller.getEffectivePosition();
        
        return "?lat=" + effPos.lat.toFixed(8) +
               "&lng=" + effPos.lng.toFixed(8) +
               "&yaw="+Controller.viewAngleYaw.toFixed(1)+
               "&pitch="+Controller.viewAnglePitch.toFixed(1)+
               "&height="+Controller.localPosition.z;
    },

    initFromQueryString: function(queryString)
    {
        var query = toDictionary(queryString);
        if ("lat" in query && "lng" in query)
        {
            Controller.position = {lat:query["lat"], lng: query["lng"]};
            
            if ("yaw" in query)
                Controller.viewAngleYaw = query["yaw"];

            if ("pitch" in query )
                Controller.viewAnglePitch=query["pitch"];

            if ("height" in query)
                Controller.localPosition.z = query["height"];
            
        }
    },

	onMouseDown: function(e)
	{
	    if (e.button != 0) 
	        return;

	    Controller.x = e.clientX;
	    Controller.y = e.clientY;
	    Controller.down = "mouse";
	},
	
	onMouseUp: function(e)
	{
	    if (e.button != 0) 
	        return;
	    Controller.down = null;
	},
	
	keysDown: {},
	
	lastKeyEventProcessed: null,

    turn: function(yaw, pitch)
    {
        Controller.viewAngleYaw = Controller.viewAngleYaw % 360;
        
        Controller.viewAngleYaw += yaw;
        Controller.viewAnglePitch += pitch;
        
        if (Controller.viewAnglePitch > 60)
            Controller.viewAnglePitch = 60;
        if (Controller.viewAnglePitch < -60)
            Controller.viewAnglePitch = -60;
    },
    
    move: function(dRight, dForward)
    {
        var arc = Controller.viewAngleYaw / 180 * Math.PI;
        var forwardX = Math.sin(arc);
        var forwardY = Math.cos(arc);

        var rightX = Math.sin(arc + Math.PI/2.0);
        var rightY = Math.cos(arc + Math.PI/2.0);
        
        var dx = dRight*rightX + dForward*forwardX;
        var dy = dRight*rightY + dForward*forwardY;

        Controller.localPosition.x += dx;
        Controller.localPosition.y += dy;
    },
    
	updateKeyInteraction: function()
	{
        var now = new Date().getTime();

        //nothing to track anymore --> reset state
        if (!Controller.keysStillPressed())
        {
            Controller.lastKeyEventProcessed = null;
            return;
        }

        // Nothing tracked yet --> initialize state, but do nothing else.
        // (there is not yet a 'dt' that we could base computations on)
        if (Controller.lastKeyEventProcessed === null)
        {
            Controller.lastKeyEventProcessed = now;
            return;
        }

        var dt = now - Controller.lastKeyEventProcessed;

        Controller.lastKeyEventProcessed = now;

        if (dt > 1000)
        {
            console.log("[WARN] extensive time step (%s ms)", dt);
            dt = 1000;
        }

        var dy = dt/400 * getSign(("W" in Controller.keysDown) || ("up" in Controller.keysDown), 
                                  ("S" in Controller.keysDown) || ("down" in Controller.keysDown));
                                  
        var dx = dt/400 * getSign( "D" in Controller.keysDown, "A" in Controller.keysDown);

        Controller.move(dx, dy);

        var turnX = dt/10 * getSign( "right" in Controller.keysDown, "left" in Controller.keysDown );

        var turnY = 0;
        if (Controller.keysStillPressed() && Controller.down != "mouse" && Math.abs(Controller.viewAnglePitch) > 1)
            turnY = (Controller.viewAnglePitch < 0 ? 1 : -1) * dt/40;

        Controller.turn(turnX, turnY);

        Controller.updateHistoryState();
	},
	
	x:null,
	y:null,
	//id of the touch event that is currently tracked as 'down'; "mouse" if the mouse is tracked, null if none
    down: null,
    
	onKeyDown: function(evt) 
	{
        var key = null;
        switch (evt.keyCode)
        {
            
            case 65: key = "A"; break;
            case 68: key = "D"; break;
            case 83: key = "S"; break;
            case 87: key = "W"; break;
            case 37: key = "left"; break;
            case 38: key = "up"; break;
            case 39: key = "right";break;
            case 40: key = "down"; break;

        }
        
        if (key in Controller.keysDown) //is just a reoccuring event for a key that is still pressed
            return;

        if (key != null)
        {            
            Controller.updateKeyInteraction();
            Controller.keysDown[key] = key;
        }
        
        if (Controller.onRequestFrameRender)
            Controller.onRequestFrameRender();

    },

	onKeyUp: function(evt)
	{
        switch (evt.keyCode)
        {
            
            case 65: delete Controller.keysDown["A"];     break;
            case 68: delete Controller.keysDown["D"];     break;
            case 83: delete Controller.keysDown["S"];     break;
            case 87: delete Controller.keysDown["W"];     break;
            case 37: delete Controller.keysDown["left"];  break;
            case 38: delete Controller.keysDown["up"];    break;
            case 39: delete Controller.keysDown["right"]; break;
            case 40: delete Controller.keysDown["down"];  break;
        }
        Controller.updateKeyInteraction();
    },
    
    keysStillPressed: function()
    {
        return Object.keys(Controller.keysDown).length > 0;
    },
	
    onMouseMove: function(e)
	{
	    //e.preventDefault();
        if (Controller.down != "mouse" ) return;
        var dx = e.clientX - Controller.x;
        var dy = e.clientY - Controller.y;

        Controller.x = e.clientX;
        Controller.y = e.clientY;

        Controller.turn(dx / 5.0, - dy / 5.0);
        
        Controller.updateHistoryState();
        if (Controller.onRequestFrameRender)
            Controller.onRequestFrameRender();

	},

    getTouchData: function(touches, identifier)
    {
        if (identifier === null)
            return null;
            
        for (var i in touches)
        {
            if (touches[i].identifier == identifier)
            {
                return touches[i];
            }
        }
        return null;
    },
    
    onTouchDown: function(ev)
    {
        ev.preventDefault();
        var touch = ev.changedTouches[0];
        Controller.down = touch.identifier;
        Controller.x = touch.clientX;
        Controller.y = touch.clientY;
        //errorLog.textContent = "Touched down at (" + touch.identifier + ", " + touch.clientX + ", " + touch.clientY + ") - " + Controller.down;
    },
    
    onTouchEnd: function(ev)
    {
        ev.preventDefault();
        Controller.down = null;
    },

    onTouchMove: function(ev)
    {
    
        ev.preventDefault();
        //errorLog.textContent = "Touch move";
        
        
        var touch = Controller.getTouchData(ev.changedTouches, Controller.down);
        if (touch === null)
            return;

            
        var dx = touch.clientX - Controller.x;
        var dy = touch.clientY - Controller.y;

        Controller.x = touch.clientX;
        Controller.y = touch.clientY;

        //errorLog.textContent = "Touch move with down=" + Controller.down + ", delta =(" + dx + ", " + dy + ")";

        //Controller.move(0,        -dy / 100.0);
        //Controller.turn(dx / 5.0, 0       );
        Controller.turn(dx / 5.0, -dy/5.0 );

        Controller.updateHistoryState();
        if (Controller.onRequestFrameRender)
            Controller.onRequestFrameRender();
    },
    
   
    updateTimeoutId: null,
    // schedules a history state update so that the update is performed once no
    // update request has been made for a second (1000ms). This keeps the history state
    // reasonably up-to-date while preventing excessive history state updates (which incur
    // a performance penalty at least in Firefox).
    updateHistoryState : function()
    {
        if (Controller.updateTimeoutId)
            window.clearTimeout(Controller.updateTimeoutId);
        
        Controller.updateTimeoutId = window.setTimeout( function() 
            {
                
                var url = document.URL;
                if (url.indexOf("?") >= 0) // already contains a query string --> remove it
                    url = url.substring(0, url.indexOf("?"));
                
                var metersPerDegreeLat = Helpers.getEarthCircumference() / 360;
                var metersPerDegreeLng = metersPerDegreeLat * Math.cos( Controller.position.lat / 180 * Math.PI);
                //console.log("Resolution x: %s m/°, y: %s m/°", metersPerDegreeLng, metersPerDegreeLat);

                url += Controller.buildQueryString();

                history.replaceState(null, document.title, url);
            },1000);
    }
}