public G_LatLng fromPointToLatLng(G_Point point)
{
G_Point origin = pixelOrigin_;
float lng = (point.x - origin.x) / pixelsPerLonDegree_;
float latRadians = (point.y - origin.y) / pixelsPerLonRadian_;
float lat = radiansToDegrees(2 * Mathf.Atan(Mathf.Exp(latRadians)) - Mathf.PI / 2);
return new G_LatLng(lat, lng);
}
public MercatorProjection()
{
pixelOrigin_ = new G_Point( MERCATOR_RANGE / 2, MERCATOR_RANGE / 2);
pixelsPerLonDegree_ = MERCATOR_RANGE / 360;
pixelsPerLonRadian_ = MERCATOR_RANGE / (2 * Mathf.PI);
}
public G_Point fromLatLngToPoint(G_LatLng latLng)
{
//$me = $this;
//fromLatLngToPoint(G_LatLng latLng, G_Point opt_point=null
//G_Point point = (opt_point!=null) ? opt_point : new G_Point(0,0);
G_Point point = new G_Point(0,0);
G_Point origin = pixelOrigin_;
point.x = origin.x + latLng.lng * pixelsPerLonDegree_;
// NOTE(appleton): Truncating to 0.9999 effectively limits latitude to
// 89.189. This is about a third of a tile past the edge of the world tile.
float siny = bound(Mathf.Sin(degreesToRadians(latLng.lat)), -0.9999f, 0.9999f);
point.y = origin.y + 0.5f * Mathf.Log((1 + siny) / (1 - siny)) * -pixelsPerLonRadian_;
return point;
}
float[] getCorners(G_LatLng center, float zoom, float mapWidth, float mapHeight)
{
float scale = Mathf.Pow(2, zoom);
MercatorProjection proj = new MercatorProjection();
G_Point centerPx = proj.fromLatLngToPoint(center);
//G_LatLng centerPx = new G_LatLng (0, 0);
G_Point SWPoint = new G_Point(centerPx.x-(mapWidth/2)/scale, centerPx.y+(mapHeight/2)/scale);
G_LatLng SWLatLon = proj.fromPointToLatLng(SWPoint);
G_Point NEPoint = new G_Point(centerPx.x+(mapWidth/2)/scale, centerPx.y-(mapHeight/2)/scale);
G_LatLng NELatLon = proj.fromPointToLatLng(NEPoint);
return new float[]{NELatLon.lat,
NELatLon.lng,
-SWLatLon.lat,
SWLatLon.lng}; // north east south west
}
