Till Nagel のコードを使用して世界地図を投影し、緯度と経度の座標に基づいてデータをプロットしています。しかし今、マウスの位置の緯度と経度の座標を取得したいと思います。mouseX と mouseY を指定すると、地図上の経度と緯度が返されます。誰か助けてくれませんか?以下は私が使用するコードです:
/**
* Utility class to convert between geo-locations and Cartesian screen coordinates.
* Can be used with a bounding box defining the map section.
*
* (c) 2011 Till Nagel, tillnagel.com
*/
public class MercatorMap {
public static final float DEFAULT_TOP_LATITUDE = 80;
public static final float DEFAULT_BOTTOM_LATITUDE = -80;
public static final float DEFAULT_LEFT_LONGITUDE = -180;
public static final float DEFAULT_RIGHT_LONGITUDE = 180;
/** Horizontal dimension of this map, in pixels. */
protected float mapScreenWidth;
/** Vertical dimension of this map, in pixels. */
protected float mapScreenHeight;
/** Northern border of this map, in degrees. */
protected float topLatitude;
/** Southern border of this map, in degrees. */
protected float bottomLatitude;
/** Western border of this map, in degrees. */
protected float leftLongitude;
/** Eastern border of this map, in degrees. */
protected float rightLongitude;
private float topLatitudeRelative;
private float bottomLatitudeRelative;
private float leftLongitudeRadians;
private float rightLongitudeRadians;
public MercatorMap(float mapScreenWidth, float mapScreenHeight) {
this(mapScreenWidth, mapScreenHeight, DEFAULT_TOP_LATITUDE, DEFAULT_BOTTOM_LATITUDE, DEFAULT_LEFT_LONGITUDE, DEFAULT_RIGHT_LONGITUDE);
}
/**
* Creates a new MercatorMap with dimensions and bounding box to convert between geo-locations and screen coordinates.
*
* @param mapScreenWidth Horizontal dimension of this map, in pixels.
* @param mapScreenHeight Vertical dimension of this map, in pixels.
* @param topLatitude Northern border of this map, in degrees.
* @param bottomLatitude Southern border of this map, in degrees.
* @param leftLongitude Western border of this map, in degrees.
* @param rightLongitude Eastern border of this map, in degrees.
*/
public MercatorMap(float mapScreenWidth, float mapScreenHeight, float topLatitude, float bottomLatitude, float leftLongitude, float rightLongitude) {
this.mapScreenWidth = mapScreenWidth;
this.mapScreenHeight = mapScreenHeight;
this.topLatitude = topLatitude;
this.bottomLatitude = bottomLatitude;
this.leftLongitude = leftLongitude;
this.rightLongitude = rightLongitude;
this.topLatitudeRelative = getScreenYRelative(topLatitude);
this.bottomLatitudeRelative = getScreenYRelative(bottomLatitude);
this.leftLongitudeRadians = getRadians(leftLongitude);
this.rightLongitudeRadians = getRadians(rightLongitude);
}
/**
* Projects the geo location to Cartesian coordinates, using the Mercator projection.
*
* @param geoLocation Geo location with (latitude, longitude) in degrees.
* @returns The screen coordinates with (x, y).
*/
public PVector getScreenLocation(PVector geoLocation) {
float latitudeInDegrees = geoLocation.x;
float longitudeInDegrees = geoLocation.y;
return new PVector(getScreenX(longitudeInDegrees), getScreenY(latitudeInDegrees));
}
private float getScreenYRelative(float latitudeInDegrees) {
return log(tan(latitudeInDegrees / 360f * PI + PI / 4));
}
protected float getScreenY(float latitudeInDegrees) {
return mapScreenHeight * (getScreenYRelative(latitudeInDegrees) - topLatitudeRelative) / (bottomLatitudeRelative - topLatitudeRelative);
}
private float getRadians(float deg) {
return deg * PI / 180;
}
protected float getScreenX(float longitudeInDegrees) {
float longitudeInRadians = getRadians(longitudeInDegrees);
return mapScreenWidth * (longitudeInRadians - leftLongitudeRadians) / (rightLongitudeRadians - leftLongitudeRadians);
}
}