android - 如何在谷歌地图android中以给定角度旋转多边形

Question

我

我正在开发我必须在点击时绘制多个固定大小的多边形的应用程序让我们考虑例如 10 x 25。这样我现在已经成功存档我需要以给定的角度旋转选定的多边形(让我们考虑 0 到360 )当我点击 + 按钮时，多边形应该向右旋转并增加 1 度角，类似地点击 - 按钮应该向左旋转多边形任何人都知道如何实现这个？

添加一些代码以供考虑。

public void drawPolygonWithGivenDimention(LatLng latLng,float width,float  height,float innerDistance,boolean forUpdate,int id)
{
    model = new ModelMarker();

    model.setId(id);

    // Paras Outer Polygon
    Location clickedPoint = new Location("clicked");
    clickedPoint.setLatitude(latLng.latitude);
    clickedPoint.setLongitude(latLng.longitude);

    LatLng latLng0 = new LatLng(clickedPoint.getLatitude(), clickedPoint.getLongitude());
    pointList.add(latLng0);

    Location loc1 = locationForAngle(0.0f, clickedPoint, width);
    LatLng latLng1 = new LatLng(loc1.getLatitude(), loc1.getLongitude());
    pointList.add(latLng1);

    Location loc2 = locationForAngle(90.0f, loc1, height);
    LatLng latLng2 = new LatLng(loc2.getLatitude(), loc2.getLongitude());
    pointList.add(latLng2);

    Location loc3 = locationForAngle(180.0f, loc2, width);
    LatLng latLng3 = new LatLng(loc3.getLatitude(), loc3.getLongitude());
    pointList.add(latLng3);

    model.setPointList(pointList);


    // Paras Inner Polygon
    Location locPeri = locationForAngle(0.0f,clickedPoint,innerDistance);//Change\
    locPeri = locationForAngle(90.0f ,locPeri,innerDistance);

    LatLng latLng10 = new LatLng(locPeri.getLatitude(), locPeri.getLongitude());
    pointListInner.add(latLng10);

    Location loc11 = locationForAngle(0.0f, locPeri, width-innerDistance*2);
    LatLng latLng11 = new LatLng(loc11.getLatitude(), loc11.getLongitude());
    pointListInner.add(latLng11);

    Location loc12 = locationForAngle(90.0f, loc11, height-innerDistance*2);
    LatLng latLng12 = new LatLng(loc12.getLatitude(), loc12.getLongitude());
    pointListInner.add(latLng12);

    Location loc13 = locationForAngle(180.0f, loc12, width-innerDistance*2);
    LatLng latLng13 = new LatLng(loc13.getLatitude(), loc13.getLongitude());
    pointListInner.add(latLng13);
    model.setPointListInner(pointListInner);

    drawOuterPolygon(forUpdate);
}


private void drawOuterPolygon(boolean forUpdate)
{
    try
    {
        pointList = model.getPointList();
        Polygon poligone;
        PolygonOptions polygoneOptions = new PolygonOptions();
        polygoneOptions.addAll(pointList);
        polygoneOptions.strokeWidth(2);
        polygoneOptions.strokeColor(Color.BLACK);

        polygoneOptions.fillColor(drawColor);

        poligone = googleMap.addPolygon(polygoneOptions);
        poligone.setClickable(true);
        if(forUpdate)
            polygons.set(selectedMarkerPosition,poligone);
        else
            polygons.add(poligone);


        model.setPolygon(poligone);
        model.setPolygons(polygons);

        drawInnerPolygon(forUpdate);
        //getCenterPoint();

    }
    catch (Exception e)
    {
        e.printStackTrace();
    }
 }

 public Location locationForAngle(float angle,Location center,float distances)
{
    //in Yard 6975174.98 radius of earth
    double distanceRadians = distances / 6967410.0; // Yards
    //6,371 = Earth's radius in km
    double bearingRadians = deg2rad(angle);
    double fromLatRadians = deg2rad(center.getLatitude());
    double fromLonRadians = deg2rad(center.getLongitude());
    double toLatRadians = Math.asin( Math.sin(fromLatRadians) * Math.cos(distanceRadians)+ Math.cos(fromLatRadians) *  Math.sin(distanceRadians) * Math.cos(bearingRadians) );
    double toLonRadians = fromLonRadians + Math.atan2(Math.sin(bearingRadians) * Math.sin(distanceRadians) * Math.cos(fromLatRadians), Math.cos(distanceRadians)- Math.sin(fromLatRadians) * Math.sin(toLatRadians));
    // adjust toLonRadians to be in the range -180 to +180...
    toLonRadians = Math.IEEEremainder((toLonRadians + 3*M_PI), ((2*M_PI)) - M_PI);
    Location result = new Location("");
    result.setLatitude(rad2deg(toLatRadians));
    result.setLongitude(rad2deg(toLonRadians));
    return result;
}

double M_PI  = 3.14159265358979323846264338327950288;

public double deg2rad(double degrees)
{
    return  (degrees * (M_PI/180));
}
public double rad2deg(double radians)
{
    return  (radians * (180/M_PI));
}

Answer 1

如果所有标记具有相同的大小和颜色(或者没有那么多不同的标记)似乎最简单的方法是使用 Marker.setRotation() 方法:

public class MainActivity extends AppCompatActivity implements OnMapReadyCallback {

    private static final LatLng MAP_CENTER = new LatLng(22.3038715,70.8009047);

    private GoogleMap mGoogleMap;
    private MapFragment mMapFragment;

    private Button mButtonMinus;
    private Button mButtonPlus;

    private Marker mMarker;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mButtonMinus = (Button) findViewById(R.id.button_minus);
        mButtonMinus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mMarker.setRotation(mMarker.getRotation() - 1);
            }
        });

        mButtonPlus = (Button) findViewById(R.id.button_plus);
        mButtonPlus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mMarker.setRotation(mMarker.getRotation() + 1);
            }
        });

        mMapFragment = (MapFragment) getFragmentManager()
                .findFragmentById(R.id.map_fragment);
        mMapFragment.getMapAsync(this);
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mGoogleMap = googleMap;

        mGoogleMap.animateCamera(CameraUpdateFactory.newLatLngZoom(MAP_CENTER, 16));

        mMarker = mGoogleMap.addMarker(new MarkerOptions()
                .icon(BitmapDescriptorFactory.fromResource(R.drawable.ic_marker_rot))
                .position(MAP_CENTER)
                .alpha(0.75f)
                .anchor(0.5f, 0.5f)
                .rotation(0));
    }

}

其中 R.drawable.ic_marker_rot 是北向标记图标:

和activity_main.xml是:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="<your_package>.MainActivity">

    <fragment
        android:id="@+id/map_fragment"
        android:name="com.google.android.gms.maps.MapFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <LinearLayout
        android:id="@+id/buttons_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:orientation="horizontal">

        <Button
            android:id="@+id/button_minus"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="-"/>

        <Button
            android:id="@+id/button_plus"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="+"/>

    </LinearLayout>

</RelativeLayout>

结果你有类似的东西:

如果您有多个标记，则需要对其进行管理(在创建时添加到列表、确定选定的标记等)

在其他情况下(您确实需要绘制每个标记)最简单的方法是将 LatLng 坐标转换为屏幕坐标:

Projection projection = mGoogleMap.getProjection();
Point screenPosition = projection.toScreenLocation(mMarker.getPosition());

比在 Point 上应用旋转(例如 this 中 Entreco 的答案)，而不是将旋转的屏幕坐标(矩形的每个点)转换回 LatLng:

mGoogleMap.getProjection().fromScreenLocation(screenPosition);

并像您已经绘制的那样绘制矩形。