我的目标是将OpenGL ES 2.0与Google地图配合使用。我想创建一个跟随用户的应用程序,因为他们从A点行进到B点。我意识到这可以使用Google Maps addPolyline绘制一条线,但我想使用OpenGL代替显示重叠路径我目前收到的错误是由于错误设置了GLSurfaceView。
GoogleMapsTracker类中的代码如下:
private MapView mapView;
private GoogleMap map;
private GLSurfaceView mGLSurfaceView;
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*/
public static GoogleMapsTracker newInstance() {
GoogleMapsTracker fragment = new GoogleMapsTracker();
fragment.setRetainInstance(true);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mapView = (MapView) getActivity().findViewById(R.id.map);
mGLSurfaceView = new GLSurfaceView(getActivity());
// Check if the system supports OpenGL ES 2.0
final ActivityManager am = (ActivityManager) getActivity().getSystemService(Context.ACTIVITY_SERVICE);
final ConfigurationInfo cInfo = am.getDeviceConfigurationInfo();
final boolean supportsEs2 = cInfo.reqGlEsVersion >= 0x20000;
if(supportsEs2){
// Request an OpenGL ES 2.0 compatible context
mGLSurfaceView.setEGLContextClientVersion(2);
// Set the renderer to out demo renderer, defined below
mGLSurfaceView.setRenderer(new GoogleMapsRenderer(getActivity()));
} else {
// This is where you could create an OpenGL ES1.x compatible
// renderer if you wanted to support both ES 1 and ES 2
Log.d("Does Not Support ES 2.0", "Does NOT Support ES 2.0");
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v;
if(SettingsActivity.mUnits){
v = inflater.inflate(R.layout.google_maps_tracker_metric, container, false);
} else {
v = inflater.inflate(R.layout.google_maps_tracker, container, false);
}
// Gets the MapView from the XML layout and creates it
mapView = (MapView) v.findViewById(R.id.map);
mapView.onCreate(savedInstanceState);
// Gets to GoogleMap from the MapView and does initialization stuff
map = mapView.getMap();
map.getUiSettings().setMyLocationButtonEnabled(true);
map.getUiSettings().setZoomControlsEnabled(true);
map.getUiSettings().setRotateGesturesEnabled(true);
map.setMyLocationEnabled(true);
map.setMapType(GoogleMap.MAP_TYPE_SATELLITE);
// Needs to call MapsInitializer before doing any CameraUpdateFactory calls
MapsInitializer.initialize(this.getActivity());
// Updates the location and zoom of the MapView
CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(new LatLng(45.669656, -111.067373), 18);
map.animateCamera(cameraUpdate);
mGLSurfaceView = (GLSurfaceView) v.findViewById(R.id.gl);
mGLSurfaceView.setEGLContextClientVersion(2);
GoogleMapsRenderer renderer = new GoogleMapsRenderer(getActivity());
mGLSurfaceView.setEGLConfigChooser(8, 8, 8, 8, 16, 0);
mGLSurfaceView.setRenderer(renderer);
mGLSurfaceView.getHolder().setFormat(PixelFormat.TRANSLUCENT);
mGLSurfaceView.setRenderMode(GLSurfaceView.RENDERMODE_CONTINUOUSLY);
mGLSurfaceView.setZOrderOnTop(true);
return v;
}
我的XML代码:
<?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="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" >
<!--fragment
android:name="com.google.android.gms.maps.MapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/map"
tools:context=".MainActivity" /-->
<com.google.android.gms.maps.MapView android:id="@+id/map"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
<android.opengl.GLSurfaceView
android:id="@+id/gl"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.example.tracker.GoogleMapsRenderer"/>
</RelativeLayout>
我收到的错误如下:
05-22 11:02:34.854 22996-22996/com.example.tracker E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.tracker, PID: 22996
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.opengl.GLSurfaceView$GLThread.surfaceCreated()' on a null object reference
at android.opengl.GLSurfaceView.surfaceCreated(GLSurfaceView.java:523)
at android.view.SurfaceView.updateWindow(SurfaceView.java:580)
at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:176)
at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:944)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1970)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1061)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5885)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
at android.view.Choreographer.doCallbacks(Choreographer.java:580)
at android.view.Choreographer.doFrame(Choreographer.java:550)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
我很确定我没有正确地将我的观点加在一起。如果有人可以指出我的错误,并且更好地实现这个想法,那将非常感激。
答案 0 :(得分:1)
我找到了解决问题的方法。只是不确定是否有更好的方法。
基本上,我所做的就是将两个视图(MapView和GLSurfaceView)分成两个不同的片段。然后使用Activity类来调用这两个片段。 XML文件的片段覆盖了相同的区域。以下是我更新的代码。
GoogleMapsActivity:
public class GoogleMapsActivity extends FragmentActivity {
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu items for use in the action bar
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_main, menu);
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
final Context context = this;
return super.onOptionsItemSelected(item);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setTheme(R.style.DarkTheme);
if(SettingsActivity.mUnits){
setContentView(R.layout.google_maps_tracker_metric);
} else {
setContentView(R.layout.google_maps_tracker);
}
}
@Override
protected void onResume(){
super.onResume();
// Get both fragments shown on the same screen
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
GoogleMapsTracker fragment;
fragment = GoogleMapsTracker.newInstance();
GoogleMapsOGLES fragmentOGL;
fragmentOGL = GoogleMapsOGLES.newInstance();
fragmentTransaction.add(R.id.map, fragment);
fragmentTransaction.add(R.id.gl, fragmentOGL);
fragmentTransaction.commit();
}
@Override
protected void onPause(){
super.onPause();
}
@Override
protected void onDestroy() {
super.onDestroy();
}
}
GoogleMapsTracker:
public class GoogleMapsTracker extends Fragment implements OnMapReadyCallback {
@Override
public void onMapReady(GoogleMap map){
}
MapView mapView;
GoogleMap map;
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*/
public static GoogleMapsTracker newInstance() {
GoogleMapsTracker fragment = new GoogleMapsTracker();
fragment.setRetainInstance(true);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mapView = (MapView) getActivity().findViewById(R.id.maps);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v;
v = inflater.inflate(R.layout.fragment_google_maps, container, false);
// Gets the MapView from the XML layout and creates it
mapView = (MapView) v.findViewById(R.id.maps);
mapView.onCreate(savedInstanceState);
// Gets to GoogleMap from the MapView and does initialization stuff
map = mapView.getMap();
map.getUiSettings().setMyLocationButtonEnabled(true);
map.getUiSettings().setZoomControlsEnabled(true);
map.getUiSettings().setRotateGesturesEnabled(true);
map.setMyLocationEnabled(true);
map.setMapType(GoogleMap.MAP_TYPE_SATELLITE);
// Needs to call MapsInitializer before doing any CameraUpdateFactory calls
MapsInitializer.initialize(this.getActivity());
// Updates the location and zoom of the MapView
CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(new LatLng(49.025656, -125.035473), 18);
map.animateCamera(cameraUpdate);
return v;
}
GoogleMapsOGLES:
public class GoogleMapsOGLES extends Fragment {
GLSurfaceView mGLSurfaceView;
private boolean rendererSet = false;
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*/
public static GoogleMapsOGLES newInstance() {
GoogleMapsOGLES fragment = new GoogleMapsOGLES();
fragment.setRetainInstance(true);
return fragment;
}
public GoogleMapsOGLES() {
// Do nothing
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mGLSurfaceView = new GLSurfaceView(getActivity());
// Check if the system supports OpenGL ES 2.0
final ActivityManager am = (ActivityManager) getActivity().getSystemService(Context.ACTIVITY_SERVICE);
final ConfigurationInfo cInfo = am.getDeviceConfigurationInfo();
final boolean supportsEs2 = cInfo.reqGlEsVersion >= 0x20000;
if(supportsEs2){
// Request an OpenGL ES 2.0 compatible context
mGLSurfaceView.setEGLContextClientVersion(2);
// Set the renderer to our demo renderer, defined below
mGLSurfaceView.setRenderer(new GoogleMapsRenderer(getActivity()));
rendererSet = true;
} else {
// This is where you could create an OpenGL ES1.x compatible
// renderer if you wanted to support both ES 1 and ES 2
Log.d("Does Not Support ES 2.0", "Does NOT Support ES 2.0");
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v;
v = inflater.inflate(R.layout.fragment_maps_ogl, container, false);
mGLSurfaceView = (GLSurfaceView) v.findViewById(R.id.ogl);
mGLSurfaceView.setEGLContextClientVersion(2);
GoogleMapsRenderer renderer = new GoogleMapsRenderer(getActivity());
mGLSurfaceView.setZOrderOnTop(true);
mGLSurfaceView.setEGLConfigChooser(8, 8, 8, 8, 16, 0);
mGLSurfaceView.getHolder().setFormat(PixelFormat.TRANSLUCENT);
mGLSurfaceView.setRenderer(renderer);
rendererSet = true;
mGLSurfaceView.setRenderMode(GLSurfaceView.RENDERMODE_CONTINUOUSLY);
return v;
}
google_maps_tracker.xml
<?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="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" >
<fragment
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.example.tracker.GoogleMapsTracker"
class="com.example.tracker.GoogleMapsTracker"/>
<fragment
android:id="@+id/gl"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.example.tracker.GoogleMapsOGLES"
class="com.example.tracker.GoogleMapsOGLES"/>
</RelativeLayout>
xml文件中的片段有自己的xml文件,只是初始化了MapView和GLSurfaceView。