Whip's Planetary Compass and Bearing Script v8.2

/*
/// Whip's Compass & Bearing Code v8.2 - 3/30/16 ///

What's Stable?
- Bearing measured off relelative north direction

How do I use this?
    1) Make a program block with this script loaded into it

    2) Make a remote control pointing forward
        - Add the phrase "Reference" somewhere in its name.

    3) Make a text panel or LCD screen: Add the phrase "Bearing" in the name.
        Also make sure the screen is set to show public text.

    4) Make a timer block
        - set to "trigger now" itself
        - set to "start" itself
        - set to "run program with default argument"

    5) Trigger the timer once and you are good to go! :)

    (Optional): Tinker with the text size until the compass stretches
                the width of the screen. Recommended text size for
                small ship screens is 1.7 size font

Be sure to drop by my workshop page and leave a comment :D
http://steamcommunity.com/sharedfiles/filedetails/?id=616627882

Code by Whiplash141
*/


//You can change these names if you'd like
const string strRemoteName = "Reference"; //name of remote to use as reference
const string strScreenName = "Bearing"; //name of screen to display bearing on

 /*
_______________________________________________________________________________________

======================== Don't edit anything beyond this :) =======================
_______________________________________________________________________________________
*/

Vector3D absoluteNorthVec = new Vector3D(0, 0, 1); //by convention +z is north
double bearingAngle; //measured off relative north
const double rad2deg = 180 / Math.PI; //constant to convert radians to degrees
const string strCompass = "-350--355--="
    + "N=--005--010--015--020--025--030--035--040-=N.E=-050--055--060--065--070--075--080--085--=E=--095--100"
    + "--105--110--115--120--125--130-=S.E=-140--145--150--155--160--165--170--175--=S=--185--190--195--200"
    + "--205--210--215--220-=S.W=-230--235--240--245--250--255--260--265--=W=--275--280--285--290--295--300"
    + "--305--310-=N.W=-320--325--330--335--340--345--350--355--="
    + "N=--005--010-";
string strMessage = "null";
string strCardinalDirection = "";
List<IMyTerminalBlock> listRemotes = new List<IMyTerminalBlock>();
List<IMyTerminalBlock> listScreens = new List<IMyTerminalBlock>();

bool isRemote(IMyTerminalBlock block)
{
    var remote = block as IMyRemoteControl;
    return remote != null;
}

bool isTextPanel(IMyTerminalBlock block)
{
    var textPanel = block as IMyTextPanel;
    return textPanel != null;
}

Vector3D VectorProjection( Vector3D a, Vector3D b )
{
    Vector3D projection = a.Dot( b ) / b.Length() / b.Length() * b;
    return projection;
}

void Main(string arg)
{
    Echo( "WMI Planetary Compass Online... " + RunningSymbol() );

    GridTerminalSystem.SearchBlocksOfName( strRemoteName, listRemotes, isRemote );
    if(listRemotes.Count == 0)
    {
        Echo("[CRITICAL] No remote with tag '" + strRemoteName + "' found");
        return;
    }else{
        GetBearing(); //run bearing code
        WriteBearing(strMessage); //write to text screens
        Echo("Bearing: " + Math.Round(bearingAngle, 2).ToString()); //for debugging
    }
}

void GetBearing()
{
//get forward and right vectors of the ship
    var reference = listRemotes[0] as IMyRemoteControl;
    MatrixD orientation = reference.WorldMatrix;
    Vector3D forwardVec = orientation.Forward;

//get grav vector
    Vector3D gravityVec = reference.GetNaturalGravity();

//check if grav vector exists
    double gravMag = gravityVec.Length();
        if(double.IsNaN( gravMag ) || gravMag == 0)
        {
            Echo("[CRITICAL] No gravity detected!");
            strMessage = "Error: No natural gravity";
            return;
        }

//get east vector
    Vector3D relativeEastVec = gravityVec.Cross(absoluteNorthVec);

//get relative north vector
    Vector3D relativeNorthVec = relativeEastVec.Cross(gravityVec);

//project forward vector onto a plane comprised of the north and east vectors
    Vector3D forwardProjNorthVec = VectorProjection(forwardVec, relativeNorthVec);
    Vector3D forwardProjEastVec = VectorProjection(forwardVec, relativeEastVec);
    Vector3D forwardProjPlaneVec = forwardProjEastVec + forwardProjNorthVec;

//find angle from abs north to projected forward vector measured clockwise
    bearingAngle = Math.Acos(forwardProjPlaneVec.Dot(relativeNorthVec) / forwardProjPlaneVec.Length() / relativeNorthVec.Length()) * rad2deg;                                                                                                                                                   //w.h.i.P l a.s h 1. 4 1

//check direction of angle
    double dotForwardOnEast = forwardVec.Dot(relativeEastVec);

    if(dotForwardOnEast < 0)
    {
        bearingAngle = 360 - bearingAngle; //because of how the angle is measured
    }

//get cardinal direction
    if(bearingAngle < 22.5 || bearingAngle >= 337.5)
    {
        strCardinalDirection = "N";
    }
    else if(bearingAngle < 67.5)
    {
        strCardinalDirection = "NE";
    }
    else if(bearingAngle < 112.5)
    {
        strCardinalDirection = "E";
    }
    else if(bearingAngle < 157.5)
    {
        strCardinalDirection = "SE";
    }
    else if(bearingAngle < 202.5)
    {
        strCardinalDirection = "S";
    }
    else if(bearingAngle < 247.5)
    {
        strCardinalDirection = "SW";
    }
    else if(bearingAngle < 292.5)
    {
        strCardinalDirection = "W";
    }
    else if(bearingAngle < 337.5)
    {
        strCardinalDirection = "NW";
    }

//create string of our data
    strMessage = "Bearing: " + string.Format("{0:000}", Math.Round(bearingAngle))
        + " " + strCardinalDirection
        + "\n[" + strCompass.Substring((int)Math.Floor(bearingAngle), 25)
        + "]\n" + "------------------^------------------";
}

void WriteBearing(string textToWrite)
{

    GridTerminalSystem.SearchBlocksOfName(strScreenName, listScreens, isTextPanel);
    if(listScreens.Count == 0)
    {
        Echo("[ALERT]: No text panel with name tag '" + strScreenName + "' was found");
        return;
    }else{
        for(int i = 0; i < listScreens.Count; i++)
        {
            var thisScreen = listScreens[i] as IMyTextPanel;
            if(thisScreen != null)
            {
                thisScreen.WritePublicText(textToWrite);

                //force text update
                thisScreen.ShowTextureOnScreen();
                thisScreen.ShowPublicTextOnScreen();
            }
        }
    }
}

//Whip's Running Symbol Method
int trackSymbol = 0;
string strRunningSymbol = "";

string RunningSymbol()
{
    switch( trackSymbol )
    {
        case 0:
            strRunningSymbol = "|";
            break;

        case 10:
            strRunningSymbol = "/";
            break;

        case 20:
            strRunningSymbol = "--";
            break;

        case 30:
            strRunningSymbol = "\\";
            break;

        default:
            break;
    }

    trackSymbol++;
    if( trackSymbol > 40 )
        trackSymbol = 0;

    return strRunningSymbol;
}