public void process() {
if (in instanceof VSDouble) {
out.setValue(Math.asin(in.getValue()));
out.setChanged(true);
element.notifyPin(0);
}
}
/**
* Converts a point from pixel XY coordinates at a specified level of detail into
* latitude/longitude WGS-84 coordinates (in degrees)
*
* @param pixelX X coordinate in pixels
* @param pixelY Y coordinate in pixels
* @param levelOfDetail Level of detail, from 1 (lowest detail) to 23 (highest detail)
* @return LatLon Geodetic coordinates
*/
public static LatLon PixelXYToLatLong(int pixelX, int pixelY, int levelOfDetail) {
double mapSize = (double) calcMapSize(levelOfDetail);
double x = (pixelX - 0.5) / mapSize;
double y = (pixelY - 0.5) / mapSize;
double lon = 360 * x - 180;
double b = Math.pow(Math.E, -4 * Math.PI * (y - 0.5));
double sinLatitude = (b - 1) / (1 + b);
double lat = Math.asin(sinLatitude) * 180 / Math.PI;
return LatLon.fromDegrees(lat, lon);
}
/**
* Compute the view range footprint on the globe.
*
* @param dc the current <code>DrawContext</code>
* @param steps the number of steps.
* @return an array list of <code>LatLon</code> forming a closed shape.
*/
protected ArrayList<LatLon> computeViewFootPrint(DrawContext dc, int steps) {
ArrayList<LatLon> positions = new ArrayList<LatLon>();
Position eyePos = dc.getView().getEyePosition();
Angle distance =
Angle.fromRadians(
Math.asin(
dc.getView().getFarClipDistance()
/ (dc.getGlobe().getRadius() + eyePos.getElevation())));
if (distance.degrees > 10) {
double headStep = 360d / steps;
Angle heading = Angle.ZERO;
for (int i = 0; i <= steps; i++) {
LatLon p = LatLon.greatCircleEndPosition(eyePos, heading, distance);
positions.add(p);
heading = heading.addDegrees(headStep);
}
return positions;
} else return null;
}
private static LinkedList<Point2D> getCirclePoints(
double centerLat, double centerLong, int numberOfPoints, double radius) {
LinkedList<Point2D> Point2Ds = new LinkedList<Point2D>();
double lat1, long1;
double d_rad;
double delta_pts;
double radial, lat_rad, dlon_rad, lon_rad;
// convert coordinates to radians
lat1 = Math.toRadians(centerLat);
long1 = Math.toRadians(centerLong);
// radius is in meters
d_rad = radius / 6378137;
// loop through the array and write points
for (int i = 0; i <= numberOfPoints; i++) {
delta_pts = 360 / (double) numberOfPoints;
radial = Math.toRadians((double) i * delta_pts);
// This algorithm is limited to distances such that dlon < pi/2
lat_rad =
Math.asin(
Math.sin(lat1) * Math.cos(d_rad)
+ Math.cos(lat1) * Math.sin(d_rad) * Math.cos(radial));
dlon_rad =
Math.atan2(
Math.sin(radial) * Math.sin(d_rad) * Math.cos(lat1),
Math.cos(d_rad) - Math.sin(lat1) * Math.sin(lat_rad));
lon_rad = ((long1 + dlon_rad + Math.PI) % (2 * Math.PI)) - Math.PI;
Point2Ds.add(new Point2D.Double(Math.toDegrees(lat_rad), Math.toDegrees(lon_rad)));
}
return Point2Ds;
}
private int calculate_angle(int rad, int x, int y) {
/*
double angle = 0,
sin_value = Math.asin ((double)y / (double)rad),
tan_value = Math.atan ((double)y / (double)x);
if (x >= 0)
angle = (x != 0) ? tan_value : sin_value +
((y < 0) ? 2*Math.PI : 0);
else
angle = Math.PI + tan_value;
return (int) Math.round (angle * 180.0 / Math.PI);
*/
double angle = 0.0, sin_value = Math.asin((double) Math.abs(y) / (double) rad);
if (x >= 0 && y >= 0) angle = sin_value;
else if (x < 0 && y >= 0) angle = sin_value + Math.PI / 2.0;
else if (x < 0 && y < 0) angle = sin_value + Math.PI;
else if (x >= 0 && y < 0) angle = sin_value + 3.0 * Math.PI / 2.0;
return (int) Math.round(angle * 180.0 / Math.PI);
}