# See: http://wiki.flightgear.org/MapStructure
# Class things:
var name = 'TERRAIN';
var parents = [DotSym];
var __self__ = caller(0)[0];
DotSym.makeinstance( name, __self__ );

var element_type = "group";

var tile_list = ["tile_00.png","tile_04.png","tile_06.png"];

var updateTerrain = func(size){
	if(me.fetching) return;
	var pos = geo.aircraft_position();
	var lat = pos.lat();
	var lon = pos.lon();
	me.fetching = 1;

	for (var a=0; a < me.tileradius; a+=1) {

		var len = size(me.terrlayer["L" ~ a]);

		for (var r=0; r < len; r+=1) {

			var imgx = math.mod(r*a,3);
			
			me.terrlayer["L" ~ a].setFile(me.imgpath ~ me.tile_list[imgx]).show();
			me.terrlayer["R" ~ a].setFile(me.imgpath ~ me.tile_list[2-imgx]).show();

		}

	}

	me.last_request = getprop("sim/time/elapsed-sec");
	me.fetching = 0;
};

var init = func {
	print('TERRAIN init');
	me.tile = 20;
	me.fetching = 0;
	me.timeStamp = nil;
	me.fetchRad = me.model.fetchRad; # Radius of radar layer to fetch
	me.range = me.model.rangeNm; # Range of Navigation Display
	me.viewport_radius = me.getOption('viewport_radius', 670);
	me.imgpath = get_local_path('res/');

	var tile = me.tile;

	var gx = int(me.viewport_radius / tile);

	me.tileradius = gx;

	me.terrlayer = {}; #me.element.createChild("image").set("z-index", -100).hide();

	var centx = me.viewport_radius;

	for (var c=0; c<gx; c+=1) {
		var hh = c * tile;
		var mx = (c == 0) ? gx : int(math.sqrt(gx*gx-c*c));
		var py = (gx-1) * tile;
		var pxr = centx+(c*tile);
		var pxl = centx-(c*tile)-tile;
		var grplx = [];
		var grprx = [];
		for (var r=0; r<mx; r+=1) {
			append(grplx , me.element.createChild("image").set("z-index", -100).setSize(tile,tile).setTranslation(pxl,py));
			append(grprx , me.element.createChild("image").set("z-index", -100).setSize(tile,tile).setTranslation(pxr,py));
			py-=tile;
		}
		me.terrlayer["L" ~ c] = grplx;
		me.terrlayer["R" ~ c] = grprx;
	}
	
	me.last_request = -600;
	me.update_interval = 600;
	
	#var r_scaled = (me.fetchRad*me.viewport_radius)/me.range;
	#me.fetchWXRMap(r_scaled);
	
	#me.timeStamp = nil;
	#http.load("https://api.rainviewer.com/public/maps.json").done(func(r) me.timeStamp = processRequest(r));
};

var draw = func {
	var range = me.layer.map.getRange(); # Range of Navigation Display
	var update_size = (range != me.range);
	me.range = range;
	me.fetchRad = me.model.fetchRad; # Radius of radar layer to fetch
	var r_scaled = (me.fetchRad*me.viewport_radius)/me.range;
	var hdg = me.layer.map.getHdg();
	var rot = 0 - hdg;
	if(rot < 0) rot = 360 + rot + -getprop("/environment/magnetic-variation-deg"); 
	me.element.setRotation(rot*D2R);
	if(update_size){
		#me.terrlayer.hide();
		#me.terrlayer.setSize(2*r_scaled, 2*r_scaled)
		#		  .setTranslation(-r_scaled, -r_scaled);
		#me.terrlayer.show();
	}

	if(getprop("sim/time/elapsed-sec") - me.last_request > me.update_interval) {
		me.updateTerrain(r_scaled);
	}
};