analemma.ssc

//
// Author: Alexander Wolf
// Version: 2.1
// License: Public Domain
// Name: Analemma
// Description: A demonstration of the analemma - the path of the Sun across the sky during the year on Earth.
//

include("i18n.inc");

core.goHome();
var JD = core.getJDay();
var color = "#aa0000";
core.setGuiVisible(false);
core.setTimeRate(1);
label = LabelMgr.labelScreen(tr("Analemma"), 20, 20, false, 30, color);
LabelMgr.setLabelShow(label, true);
core.wait(1);
core.clear("natural");
core.setObserverLocation(0, 40, 1, 1, "", "Earth");
core.setDate("2019-12-22T12:00:00", "UTC");
core.selectObjectByName("Sun", false);
StelMovementMgr.setFlagTracking(false);
StelMovementMgr.autoZoomIn(3);
core.wait(5);
StelMovementMgr.zoomTo(80, 1);
core.wait(2);
GridLinesMgr.setFlagAzimuthalGrid(true);
GridLinesMgr.setFlagMeridianLine(true);
StelMovementMgr.zoomTo(100, 3);
core.wait(5);

for (i=0; i<53; i++)
{
    var week = i + 1;
    core.setDate("+1 week");
    var info = core.getObjectInfo("Sun");
    var az = info.azimuth;
    var alt = info.altitude;
    MarkerMgr.markerHorizon(az, alt, true, "gear", color, 5);    
    labelWeek = LabelMgr.labelScreen(tr("Week") + " " + week, 20, 60, false, 20, color);
    LabelMgr.setLabelShow(labelWeek, true);
    core.wait(.25);    
    LabelMgr.setLabelShow(labelWeek, false);
    if (week==1)
    {
        labelWinter = LabelMgr.labelHorizon(tr("Near winter solstice"), 180, 25, true, 14, color);        
    }
    if (week==26)
    {
        labelSummer = LabelMgr.labelHorizon(tr("Near summer solstice"), 180, 74, true, 14, color);        
    }
}

labelFinal = LabelMgr.labelScreen(tr("Yearly path of the Sun"), 20, 60, false, 20, color);
LabelMgr.setLabelShow(labelFinal, true);
SolarSystem.setFlagPlanets(false);
core.wait(5);
SolarSystem.setFlagPlanets(true);
LabelMgr.setLabelShow(labelFinal, false);
core.clear("natural");
LabelMgr.deleteAllLabels();
MarkerMgr.deleteAllMarkers();
core.setJDay(JD);
core.goHome();
core.setGuiVisible(true);