osmdroid API解读（十）

osmdroid-android org.osmdroid.util.constants包

1. GeoConstants

地理常数

public interface GeoConstants {    public static final int RADIUS_EARTH_METERS = 6378137; // 赤道半径    public static final double METERS_PER_STATUTE_MILE = 1609.344; //每法定英里米数    public static final double METERS_PER_NAUTICAL_MILE = 1852; // 每海里米数    public static final double FEET_PER_METER = 3.2808399; // 每米英尺数    public static final int EQUATORCIRCUMFENCE = (int) (2 * Math.PI * RADIUS_EARTH_METERS);//赤道周长}

osmdroid-android org.osmdroid.util包

二维距离计算工具

public class Distance {    //计算两点间距离    public static double getSquaredDistanceToPoint(            final double pFromX, final double pFromY, final double pToX, final double pToY) {        final double dX = pFromX - pToX;        final double dY = pFromY - pToY;        return dX * dX + dY * dY;    }    //计算点到线的距离    public static double getSquaredDistanceToLine(            final double pFromX, final double pFromY,            final double pAX, final double pAY, final double pBX, final double pBY    ) {        if (pAX == pBX && pAY == pBY) {            return getSquaredDistanceToPoint(pAX, pAY, pFromX, pFromY);        }        final double cross = crossProduct(pAX, pAY, pBX, pBY, pFromX, pFromY);        return cross * cross / getSquaredDistanceToPoint(pAX, pAY, pBX, pBY);    }    //计算点到线段的距离    public static double getSquaredDistanceToSegment(            final double pFromX, final double pFromY,            final double pAX, final double pAY, final double pBX, final double pBY    ) {        if (pAX == pBX && pAY == pBY) {            return getSquaredDistanceToPoint(pAX, pAY, pFromX, pFromY);        }        double dot = dotProduct(pAX, pAY, pBX, pBY, pFromX, pFromY);        if (dot > 0) {            return getSquaredDistanceToPoint(pFromX, pFromY, pBX, pBY);        }        dot = dotProduct(pBX, pBY, pAX, pAY, pFromX, pFromY);        if (dot > 0) {            return getSquaredDistanceToPoint(pFromX, pFromY, pAX, pAY);        }        final double cross = crossProduct(pAX, pAY, pBX, pBY, pFromX, pFromY);        return cross * cross / getSquaredDistanceToPoint(pAX, pAY, pBX, pBY);    }    //计算叉乘AB x AC    private static double crossProduct(            final double pAX, final double pAY, final double pBX, final double pBY,            final double pCX, final double pCY) {        return (pBX - pAX) * (pCY - pAY) - (pBY - pAY) * (pCX - pAX);    }    //计算点乘AB . AC    private static double dotProduct(            final double pAX, final double pAY, final double pBX, final double pBY,            final double pCX, final double pCY) {        return (pBX - pAX) * (pCX - pBX) + (pBY - pAY) * (pCY - pBY);    }}

2. MyMath

public class MyMath implements MathConstants {    private MyMath() {    }    //Gudermann逆转换    public static double gudermannInverse(final double aLatitude) {        return Math.log(Math.tan(PI_4 + (DEG2RAD * aLatitude / 2)));    }    //Gudermann转换    public static double gudermann(final double y) {        return RAD2DEG * Math.atan(Math.sinh(y));    }    //取余    public static int mod(int number, final int modulus) {        if (number > 0)            return number % modulus;        while (number < 0)            number += modulus;        return number;    }    //转换为比pValue小的最大整数    public static long floorToLong(final double pValue) {        final long result = (long) pValue;        if (result <= pValue) {            return result;        }        return result - 1;    }    //转换为比pValue小的最大整数    public static int floorToInt(final double pValue) {        final int result = (int) pValue;        if (result <= pValue) {            return result;        }        return result - 1;    }}

3. PointL

长整型点

public class PointL {    public long x;    public long y;        ...}

4. RectL

长整型矩形

public class RectL {    public long left;    public long top;    public long right;    public long bottom;        ...}

5. GeoPoint

由经度、纬度、高程描述的地理点

public class GeoPoint implements IGeoPoint, MathConstants, GeoConstants, Parcelable, Serializable, Cloneable {    static final long serialVersionUID = 1L;    private double mLongitude;//经度    private double mLatitude;//纬度    private double mAltitude;//高程     @Deprecated    public GeoPoint(final int aLatitudeE6, final int aLongitudeE6) {        this.mLatitude = aLatitudeE6 / 1E6;        this.mLongitude = aLongitudeE6 / 1E6;    }     @Deprecated    public GeoPoint(final int aLatitudeE6, final int aLongitudeE6, final int aAltitude) {        this.mLatitude = aLatitudeE6 / 1E6;        this.mLongitude = aLongitudeE6 / 1E6;        this.mAltitude = aAltitude;    }    public GeoPoint(final double aLatitude, final double aLongitude) {        this.mLatitude = aLatitude;        this.mLongitude = aLongitude;    }    public GeoPoint(final double aLatitude, final double aLongitude, final double aAltitude) {        this.mLatitude = aLatitude;        this.mLongitude = aLongitude;        this.mAltitude = aAltitude;    }    public GeoPoint(final Location aLocation) {        this(aLocation.getLatitude(), aLocation.getLongitude(), aLocation.getAltitude());    }    public GeoPoint(final GeoPoint aGeopoint) {        this.mLatitude = aGeopoint.mLatitude;        this.mLongitude = aGeopoint.mLongitude;        this.mAltitude = aGeopoint.mAltitude;    }    //将字符串转化为GeoPoint对象    public static GeoPoint fromDoubleString(final String s, final char spacer) {        ...    }    //将反向的字符串转换为GeoPoint对象    public static GeoPoint fromInvertedDoubleString(final String s, final char spacer) {        ...    }    //将整型的字符串转换为GeoPoint对象    public static GeoPoint fromIntString(final String s) {        ...    }    @Override    public double getLongitude() {        return this.mLongitude;    }    @Override    public double getLatitude() {        return this.mLatitude;    }    public double getAltitude() {        return this.mAltitude;    }    public void setLatitude(final double aLatitude) { this.mLatitude = aLatitude; }    public void setLongitude(final double aLongitude) { this.mLongitude = aLongitude; }    public void setAltitude(final double aAltitude) {        this.mAltitude = aAltitude;    }    public void setCoords(final double aLatitude, final double aLongitude) {        this.mLatitude = aLatitude;        this.mLongitude = aLongitude;    }    //克隆一个GeoPoint对象    @Override    public GeoPoint clone() {        return new GeoPoint(this.mLatitude, this.mLongitude, this.mAltitude);    }    //转换为整数型字符串    public String toIntString() {        return new StringBuilder().               append(((int)(this.mLatitude*1E6))).               append(",").               append(((int)(this.mLongitude*1E6))).               append(",").               append((int)(this.mAltitude))        .toString();    }    //转换为字符串    @Override    public String toString() {        return new StringBuilder().append(this.mLatitude).append(",").append(this.mLongitude).append(",").append(this.mAltitude)        .toString();    }    @Override    public boolean equals(final Object obj) {        if (obj == null) {            return false;        }        if (obj == this) {            return true;        }        if (obj.getClass() != getClass()) {            return false;        }        final GeoPoint rhs = (GeoPoint) obj;        return rhs.mLatitude == this.mLatitude && rhs.mLongitude == this.mLongitude && rhs.mAltitude == this.mAltitude;    }    @Override    public int hashCode() {        return 37 * (17 * (int)(mLatitude*1E-6) + (int)(mLongitude*1E-6)) + (int)mAltitude;    }    //求两点间距离(整数型)    @Deprecated    public int distanceTo(final IGeoPoint other) {        return (int) (distanceToAsDouble(other));    }    //求两点间double类型距离    public double distanceToAsDouble(final IGeoPoint other) {        final double lat1 = DEG2RAD * getLatitude();        final double lat2 = DEG2RAD * other.getLatitude();        final double lon1 = DEG2RAD * getLongitude();        final double lon2 = DEG2RAD * other.getLongitude();        return RADIUS_EARTH_METERS * 2 * Math.asin(Math.min(1, Math.sqrt(                Math.pow(Math.sin((lat2 - lat1) / 2), 2)                + Math.cos(lat1) * Math.cos(lat2)                * Math.pow(Math.sin((lon2 - lon1) / 2), 2)        )));    }    //角度差    public double bearingTo(final IGeoPoint other) {        final double lat1 = Math.toRadians(this.mLatitude);        final double long1 = Math.toRadians(this.mLongitude);        final double lat2 = Math.toRadians(other.getLatitude());        final double long2 = Math.toRadians(other.getLongitude());        final double delta_long = long2 - long1;        final double a = Math.sin(delta_long) * Math.cos(lat2);        final double b = Math.cos(lat1) * Math.sin(lat2) -                         Math.sin(lat1) * Math.cos(lat2) * Math.cos(delta_long);        final double bearing = Math.toDegrees(Math.atan2(a, b));        final double bearing_normalized = (bearing + 360) % 360;        return bearing_normalized;    }    //求与该点距离为aDistanceInMeters，aBearingInDegrees的点    public GeoPoint destinationPoint(final double aDistanceInMeters, final double aBearingInDegrees) {        // convert distance to angular distance        final double dist = aDistanceInMeters / RADIUS_EARTH_METERS;        // convert bearing to radians        final double brng = DEG2RAD * aBearingInDegrees;        // get current location in radians        final double lat1 = DEG2RAD * getLatitude();        final double lon1 = DEG2RAD * getLongitude();        final double lat2 = Math.asin(Math.sin(lat1) * Math.cos(dist) + Math.cos(lat1)                * Math.sin(dist) * Math.cos(brng));        final double lon2 = lon1        + Math.atan2(Math.sin(brng) * Math.sin(dist) * Math.cos(lat1), Math.cos(dist)                - Math.sin(lat1) * Math.sin(lat2));        final double lat2deg = lat2 / DEG2RAD;        final double lon2deg = lon2 / DEG2RAD;        return new GeoPoint(lat2deg, lon2deg);    }    //两点中心坐标    public static GeoPoint fromCenterBetween(final GeoPoint geoPointA, final GeoPoint geoPointB) {        return new GeoPoint((geoPointA.getLatitude() + geoPointB.getLatitude()) / 2,                (geoPointA.getLongitude() + geoPointB.getLongitude()) / 2);    }    //转换为double字符串    public String toDoubleString() {        return new StringBuilder().append(this.mLatitude).append(",")        .append(this.mLongitude).append(",").append(this.mAltitude).toString();    }    //转换为反向的字符串    public String toInvertedDoubleString() {        return new StringBuilder().append(this.mLongitude).append(",")        .append(this.mLatitude).append(",").append(this.mAltitude).toString();    }     @Deprecated      @Override     public int getLatitudeE6() {          return (int) (this.getLatitude() * 1E6);     }     @Deprecated     @Override     public int getLongitudeE6() {          return (int) (this.getLongitude()* 1E6);     }}

6. LocationUtils

位置计算工具

public class LocationUtils implements UtilConstants {    private LocationUtils() {    }    //从Gps或网络获取最新的位置    public static Location getLastKnownLocation(final LocationManager pLocationManager) {        if (pLocationManager == null) {            return null;        }        final Location gpsLocation = getLastKnownLocation(pLocationManager, LocationManager.GPS_PROVIDER);        final Location networkLocation = getLastKnownLocation(pLocationManager, LocationManager.NETWORK_PROVIDER);        if (gpsLocation == null) {            return networkLocation;        } else if (networkLocation == null) {            return gpsLocation;        } else {            // both are non-null - use the most recent            if (networkLocation.getTime() > gpsLocation.getTime() + Configuration.getInstance().getGpsWaitTime()) {                return networkLocation;            } else {                return gpsLocation;            }        }    }    private static Location getLastKnownLocation(final LocationManager pLocationManager, final String pProvider) {        try {            if (!pLocationManager.isProviderEnabled(pProvider)) {                return null;            }        } catch (final IllegalArgumentException e) {            return null;        }        return pLocationManager.getLastKnownLocation(pProvider);    }}

7. SegmentIntersection

计算二维线段交点的类

public class SegmentIntersection {        ...}

8. SegmentClipper

剪切线段工具

public class SegmentClipper {        ...}

9. TileSystem

瓦片系统代理。用于经纬度坐标与瓦片编号系统坐标的转换。

public final class TileSystem {

        ...}

10. TileLooper

一个用于给定视口所有地图瓦片的循环。

public abstract class TileLooper {

        ...}

11. BoundingBox

有边界的经纬度方框

public class BoundingBox implements Parcelable, Serializable, MapViewConstants {    static final long serialVersionUID = 2L;    protected final double mLatNorth;//框的北边纬度    protected final double mLatSouth;//框的南边纬度    protected final double mLonEast;//框的东边经度    protected final double mLonWest;//框的西边经度    public BoundingBox(final double north, final double east, final double south, final double west) {        this.mLatNorth = north;        this.mLonEast = east;        this.mLatSouth = south;        this.mLonWest = west;        //validate the values        //  30 > 0 OK        // 30 < 0 not ok        if (north > 90.0)            throw new IllegalArgumentException("north must be less than 90");        if (south < -90.0)            throw new IllegalArgumentException("north more than -90");        if (west < -180)            throw new IllegalArgumentException("west must be more than -180");        if (east > 180)            throw new IllegalArgumentException("east must be less than 180");    }    //克隆框    public BoundingBox clone(){        return new BoundingBox(this.mLatNorth, this.mLonEast, this.mLatSouth, this.mLonWest);    }    //获取包含本框以及bb2的经纬度框    public BoundingBox concat(BoundingBox bb2){        return new BoundingBox(                Math.max(this.mLatNorth, bb2.getLatNorth()),                Math.max(this.mLonEast, bb2.getLonEast()),                Math.min(this.mLatSouth, bb2.getLatSouth()),                Math.min(this.mLonWest, bb2.getLonWest()));    }    //获取框的中心经纬度点    @Deprecated    public GeoPoint getCenter() {        return new GeoPoint((this.mLatNorth + this.mLatSouth) / 2.0,                (this.mLonEast + this.mLonWest) / 2.0);    }    public GeoPoint getCenterWithDateLine() {        final double latitude = (mLatNorth + mLatSouth) / 2.0;        double longitude = (mLonEast + mLonWest) / 2.0;        if (mLonEast < mLonWest) {            longitude += TileSystem.MaxLongitude;        }        return new GeoPoint(latitude, longitude);    }    //获取米为单位的对角线距离    public double getDiagonalLengthInMeters() {        return new GeoPoint(this.mLatNorth, this.mLonWest).distanceTo(new GeoPoint(                this.mLatSouth, this.mLonEast));    }    public double getLatNorth() {        return this.mLatNorth;    }    public double getLatSouth() {        return this.mLatSouth;    }    public double getLonEast() {        return this.mLonEast;    }    public double getLonWest() {        return this.mLonWest;    }    //获取纬度差    public double getLatitudeSpan() {        return Math.abs(this.mLatNorth - this.mLatSouth);    }    //获取经度差    public double getLongitudeSpan() {        return Math.abs(this.mLonEast - this.mLonWest);    }    //获取一个经纬度点在框模型中的相对位置，左上点为（0,0），右下角为（1,1）点    public PointF getRelativePositionOfGeoPointInBoundingBoxWithLinearInterpolation(            final double aLatitude, final double aLongitude, final PointF reuse) {        final PointF out = (reuse != null) ? reuse : new PointF();        final float y = (float)((this.mLatNorth - aLatitude) / getLatitudeSpan());        final float x = 1 - (float) ((this.mLonEast - aLongitude) / getLongitudeSpan());        out.set(x, y);        return out;    }    public PointF getRelativePositionOfGeoPointInBoundingBoxWithExactGudermannInterpolation(            final double aLatitude, final double aLongitude, final PointF reuse) {        final PointF out = (reuse != null) ? reuse : new PointF();        final float y = (float) ((gudermannInverse(this.mLatNorth) - gudermannInverse(aLatitude)) / (gudermannInverse(this.mLatNorth) - gudermannInverse(this.mLatSouth)));        final float x = 1 - (float) ((this.mLonEast - aLongitude) / getLongitudeSpan());        out.set(x, y);        return out;    }    //根据相对位置反算经纬度点    public GeoPoint getGeoPointOfRelativePositionWithLinearInterpolation(final float relX,            final float relY) {        double lat = this.mLatNorth - (this.getLatitudeSpan() * relY);        double lon = this.mLonWest + (this.getLongitudeSpan() * relX);        /* Bring into bounds. */        while (lat > 90.5)            lat -= 90.5;        while (lat < -90.5)            lat += 90.5;        /* Bring into bounds. */        while (lon > 180.0)            lon -= 180.0;        while (lon < -180.0)            lon += 180.0;        return new GeoPoint(lat, lon);    }    public GeoPoint getGeoPointOfRelativePositionWithExactGudermannInterpolation(final float relX,            final float relY) {        final double gudNorth = gudermannInverse(this.mLatNorth);        final double gudSouth = gudermannInverse(this.mLatSouth);        double lat = gudermann((gudSouth + (1 - relY) * (gudNorth - gudSouth)));        double lon = this.mLonWest + (this.getLongitudeSpan() * relX);        /* Bring into bounds. */        while (lat > 90.500000)            lat -= 90.500000;        while (lat < -90.500000)            lat += 90.500000;        /* Bring into bounds. */        while (lon > 180.000000)            lon -= 180.000000;        while (lon < -180.000000)            lon += 180.000000;        return new GeoPoint(lat, lon);    }    public BoundingBox increaseByScale(final float pBoundingboxPaddingRelativeScale) {        final GeoPoint pCenter = this.getCenter();        final double mLatSpanPadded_2 = (this.getLatitudeSpan() * pBoundingboxPaddingRelativeScale) / 2.0;        final double mLonSpanPadded_2 = (this.getLongitudeSpan() * pBoundingboxPaddingRelativeScale) / 2.0;        return new BoundingBox(pCenter.getLatitude() + mLatSpanPadded_2,                pCenter.getLongitude() + mLonSpanPadded_2, pCenter.getLatitude()                        - mLatSpanPadded_2, pCenter.getLongitude() - mLonSpanPadded_2);    }    @Override    public String toString() {        return new StringBuffer().append("N:").append(this.mLatNorth).append("; E:")                .append(this.mLonEast).append("; S:").append(this.mLatSouth).append("; W:")                .append(this.mLonWest).toString();    }    //将一个点放入一个框模型中    public GeoPoint bringToBoundingBox(final double aLatitude, final double aLongitude) {        return new GeoPoint(Math.max(this.mLatSouth, Math.min(this.mLatNorth, aLatitude)),                Math.max(this.mLonWest, Math.min(this.mLonEast, aLongitude)));    }    //构造一系列点的框模型    public static BoundingBox fromGeoPoints(final List<? extends IGeoPoint> partialPolyLine) {        double minLat = Double.MAX_VALUE;        double minLon = Double.MAX_VALUE;        double maxLat = -Double.MAX_VALUE;        double maxLon = -Double.MAX_VALUE;        for (final IGeoPoint gp : partialPolyLine) {            final double latitude = gp.getLatitude();            final double longitude = gp.getLongitude();            minLat = Math.min(minLat, latitude);            minLon = Math.min(minLon, longitude);            maxLat = Math.max(maxLat, latitude);            maxLon = Math.max(maxLon, longitude);        }        return new BoundingBox(maxLat, maxLon, minLat, minLon);    }    //查看点是否在框中    public boolean contains(final IGeoPoint pGeoPoint) {        return contains(pGeoPoint.getLatitude(), pGeoPoint.getLongitude());    }    public boolean contains(final double aLatitude, final double aLongitude) {        return ((aLatitude < this.mLatNorth) && (aLatitude > this.mLatSouth))                && ((aLongitude < this.mLonEast) && (aLongitude > this.mLonWest));    }     @Deprecated     public int getLatitudeSpanE6() {          return (int)(getLatitudeSpan() * 1E6);     }     @Deprecated     public int getLongitudeSpanE6() {          return (int)(getLongitudeSpan() * 1E6);     }        ...}