/////////////////////////////////////////////
// Variables
cercleBase = 1;             			// S : cercle de base
latTympan = 44.01805;             			// L : Lattitude de la projection stéréographique du tympan
// 44.01805	: Montauban
// 48.85667 : Paris
// 43.91056 : Saint Michel l'Observatoire

decliEcliptique = 23.44 ;          	// D : Déclinaison de l'écliptique
resAz=10;									// Resolution en degre des cercle d'azimut. ie un cercle tous les resAz degres

/////////////////////////////////////////////
// COMMON FUNCTIONS FOR PRJ ASTROLABE
/////////////////////////////////////////////

//Projection d'un point M (latitude lat)
function proj_M (lat) {
	proj = 2*cercleBase*tan((90-lat)/2);
	return proj;	
	}

//Converttion degrée vers radian
function radians(degrees)	{
  var pi = Math.PI;
  return degrees * (pi/180);
}

// Diamètre des almucantarats
function diamAlmucantarat(z) {					// z: distance zenitale de l'almucantarat
	b= 2*cercleBase*tan((90-latTympan+z)/2);	// point le plus eloigne du pole
	c= 2*cercleBase*tan((90-latTympan-z)/2);	// point le plus près du pole
	u=b-c;												// u: diametre de l'almucantarat	
	return u;
	}

// Offset vertical du centre de l'almucantarat	
function distAlmucantarat(z) {					// z: distance zenitale de l'almucantarat
	b= 2*cercleBase*tan((90-latTympan+z)/2);	// point le plus eloigne du pole
	c= 2*cercleBase*tan((90-latTympan-z)/2);	// point le plus près du pole
	u=b-c;												// u: diametre de l'almucantarat
	p=b-(u/2);											// p: distance du pole au centre de l'almucantarat
	return p;
	}
	
// Ajoute du texte à la position XY
function AddTextXY(X,Y,Str) {
	 var pos = new RVector(X,Y)

    // create an operation for adding objects:
    var op = new RAddObjectsOperation();
    // create a text entity and add it to the operation:
    var text = new RTextEntity(
        this.getDocument(),
        new RTextData(
              pos,                 // position
              pos,                 // alignment point
              0.1,                 // height
              2.0,                 // text width (ignored for now)
              RS.VAlignBottom,        // alignments
              RS.HAlignCenter,
              RS.LeftToRight,
              RS.Exact,
              1.0,                 // line spacing factor
              Str,              // the text
              "Arial",      // font
              false,        // bold
              false,        // italic
              0.0,          // angle
              false         // simple text without formatting
        )
    );
    op.addObject(text);

    // apply the operation to the current drawing:
    this.getDocumentInterface().applyOperation(op);
	}

//Ajout de texte en mode polaire (+Offset XY)	
function AddTextPolar(X,Y,Ro,Teta,Str) {
	 var pos = new RVector(X+Ro*Math.cos(Teta),Y+Ro*Math.sin(Teta));

    // create an operation for adding objects:
    var op = new RAddObjectsOperation();
    // create a text entity and add it to the operation:
    var text = new RTextEntity(
        this.getDocument(),
        new RTextData(
              pos,                 // position
              pos,                 // alignment point
              0.05,                 // height
              0.1,                 // text width (ignored for now)
              RS.VAlignTop,        // alignments
              RS.HAlignCenter,
              RS.LeftToRight,
              RS.Exact,
              1.0,                 // line spacing factor
              Str,          // the text
              "Arial",      // font
              false,        // bold
              false,        // italic
              Teta,          // angle
              false         // simple text without formatting
        )
    );
    op.addObject(text);

    // apply the operation to the current drawing:
    this.getDocumentInterface().applyOperation(op);
	}
	
function anglesArcAlmucantarat(R0, R1, Y1) {	
	var N=(Math.pow(R0,2)-Math.pow(R1,2)+Math.pow(Y1,2))/(2*Y1);	
	return Math.asin((Y1-N)/R1);
}	

function anglesArc(R0, Y0, R1, X1, Y1) {	
	var N=(Math.pow(R1,2)-Math.pow(R0,2)-Math.pow(X1,2)-Math.pow(Y1,2)+Math.pow(Y0,2))/(2*(Y0-Y1));
	var A=Math.pow(X1/(Y0-Y1),2)+1;
	var B=-2*Y0*X1/(Y0-Y1)+2*N*X1/(Y0-Y1);
	var C=Math.pow(Y0,2)+Math.pow(N,2)-Math.pow(R0,2)-2*Y0*N;
	var D=Math.sqrt(Math.pow(B,2)-4*A*C);
	//var X=(-B+D)/(2*A);
	//var Y=N+X*X1/(Y0-Y1);
	return [(-B+D)/(2*A),(-B-D)/(2*A)];
	//return X;
}

//	anglesArc(2.883, 2.077, 3.624, 2.329, -1.925)
//	anglesArcAlmucantarat(3.047026341389337,2.883778178285558,2.0775409939531815)

/////////////////////////////////////////////
// Variables calculées
diamEcliptique = 2*cercleBase*(tan((90+decliEcliptique)/2)+tan((90-decliEcliptique)/2));  // E : diamètre de l'écliptique
distEcliptique = (diamEcliptique/2)-(2*cercleBase*tan((90-decliEcliptique)/2));      		// F : Distance du pole au centre du cercle de l'écliptique
distZenit=proj_M(latTympan);

/////////////////////////////////////////////
//RObject 

var pos = new RVector(0,0);	
var colR = new RColor(255,0,0);
var colV = new RColor(0,255,0);
var colB = new RColor(0,0,255);
var di = this.getDocumentInterface();
var document = this.getDocument();
var op = new RAddObjectsOperation();

/////////////////////////////////////////////
// autre variable

var X=0;
var Y=0;


projTropCan=proj_M(23.44);
projTropCapr=proj_M(-23.44);
projEqu=proj_M(0);

var circTropCapr = new RCircle(new RVector(X,Y), projTropCapr);
var circTropCan = new RCircle(new RVector(X,Y), projTropCan);
var circEqu = new RCircle(new RVector(X,Y), projEqu);
var circTropCaprEntity = new RCircleEntity(document, new RCircleData(circTropCapr));
var circTropCanEntity = new RCircleEntity(document, new RCircleData(circTropCan));
var circEquEntity = new RCircleEntity(document, new RCircleData(circEqu));

op.addObject(circTropCaprEntity, false);
op.addObject(circTropCanEntity, false);
op.addObject(circEquEntity, false);

circTropCaprEntity.setColor(colR);
circTropCanEntity.setColor(colR);
circEquEntity.setColor(colR);

circTropCaprEntity.setLineweight(0);
circTropCanEntity.setLineweight(0);
circEquEntity.setLineweight(0);

/////////////////////////////////////////////
// dessine les Almucantarats
var colV = new RColor(0,255,0);
for (var i=5; i<=90;i=i+5) {
	r = diamAlmucantarat(i)/2;
	dist = distAlmucantarat(i);
	AddTextXY(0,dist-r,String(i));	
	if ((r+dist) <= projTropCapr) {
		var circ = new RCircle(new RVector(0,dist), r);
		var circEntity = new RCircleEntity(document, new RCircleData(circ));
		op.addObject(circEntity, false);
		circEntity.setColor(colV);
		circEntity.setLineweight(0);
	}
	else {
		angle = anglesArcAlmucantarat(projTropCapr, r, dist);
		var arc = new RArc(new RVector(0,dist), r, -angle, Math.PI+angle, true);
		var arcEntity = new RArcEntity (document, new RArcData(arc));
		op.addObject(arcEntity, false);
		arcEntity.setColor(colV);
		arcEntity.setLineweight(0);
	}	
	
}

/////////////////////////////////////////////
// dessine les courbes d'égal azimut

posCentreAzY=(distZenit-2*cercleBase/cos(latTympan));
rAlmu90=diamAlmucantarat(90)/2;
distAlmu90=distAlmucantarat(90);

for (var az=0; az<=90;az=az+5) {
	posCentreAzX=2*cercleBase/(cos(latTympan)*tan(az));
	rayonAz=2*cercleBase/(cos(latTympan)*sin(az));
	X1=anglesArc(projTropCapr,0,rayonAz,posCentreAzX,posCentreAzY);
	X2=anglesArc(rAlmu90,distAlmu90,rayonAz,posCentreAzX,posCentreAzY);
	angle1=Math.acos((posCentreAzX-X1[0])/rayonAz);
	angle2=Math.acos((posCentreAzX-X2[1])/rayonAz);
	angle3=Math.acos((posCentreAzX-X2[0])/rayonAz);
	if(X1>X2) {
		var arc1 = new RArc(new RVector(posCentreAzX,posCentreAzY),rayonAz,Math.PI-angle2,Math.PI-angle3,true);
		var arc2 = new RArc(new RVector(-posCentreAzX,posCentreAzY),rayonAz,angle2,angle3,false);
		var arcEntity1 = new RArcEntity (document, new RArcData(arc1));
		var arcEntity2 = new RArcEntity (document, new RArcData(arc2));
		arcEntity1.setLineweight(0);
		arcEntity2.setLineweight(0);
		arcEntity.setColor(colB);
		op.addObject(arcEntity1, false);
		op.addObject(arcEntity2, false);
		AddTextPolar(posCentreAzX,posCentreAzY,rayonAz,Math.PI-angle3,String(az));
		AddTextPolar(-posCentreAzX,posCentreAzY,rayonAz,angle3,String(360-az));
		AddTextPolar(posCentreAzX,posCentreAzY,rayonAz,Math.PI-angle2,String(180+az));
		AddTextPolar(-posCentreAzX,posCentreAzY,rayonAz,angle2,String(180-az));

	}
	else {
		var arc1 = new RArc(new RVector(posCentreAzX,posCentreAzY),rayonAz,Math.PI-angle2,Math.PI-angle1,true);
		var arc2 = new RArc(new RVector(-posCentreAzX,posCentreAzY),rayonAz,angle2,angle1,false);
		var arcEntity1 = new RArcEntity (document, new RArcData(arc1));
		var arcEntity2 = new RArcEntity (document, new RArcData(arc2));
		arcEntity1.setLineweight(0);
		arcEntity2.setLineweight(0);
		//arcEntity.setColor(colB);
		op.addObject(arcEntity1, false);
		op.addObject(arcEntity2, false);
		AddTextPolar(posCentreAzX,posCentreAzY,rayonAz,Math.PI-angle1,String(az));
		AddTextPolar(-posCentreAzX,posCentreAzY,rayonAz,angle1,String(360-az));
		AddTextPolar(posCentreAzX,posCentreAzY,rayonAz,Math.PI-angle2,String(180+az));
		AddTextPolar(-posCentreAzX,posCentreAzY,rayonAz,angle2,String(180-az));
	}	
}
		
//	addCircle(posCentreAzX,posCentreAzY,rayonAz);
//	addCircle(-posCentreAzX,posCentreAzY,rayonAz);



/////////////////////////////////////////////
// dessine horizon E/W et meridien N/S
//addLine(-projTropCapr,0,projTropCapr,0);
//addLine(0,-projTropCapr,0,projTropCapr);
var lineNS = new RLine(0,-projTropCapr,0,projTropCapr);
var lineEW = new RLine(-projTropCapr,0,projTropCapr,0);
var lineNSEntity = new RLineEntity (document, new RLineData(lineNS));
var lineEWEntity = new RLineEntity (document, new RLineData(lineEW));
lineNSEntity.setLineweight(0);
lineEWEntity.setLineweight(0);
lineNSEntity.setColor(colR);
lineEWEntity.setColor(colR);
op.addObject(lineNSEntity, false);
op.addObject(lineEWEntity, false);
	
	//var circ = new RCircle(new RVector(0,dist), r);
	//var circEntity = new RCircleEntity(document, new RCircleData(circ));
	//op.addObject(circEntity, false);
	//circEntity.setColor(colV);
	//circEntity.setLineweight(0);
	//addCircle(0,dist,r);

di.applyOperation(op);
autoZoom();