memory problem with google map and overlays !

Question

Hi all.

I am drawing some overlays on google map. If i move around the map too much, I get this error :

10-15 14:43:43.020: ERROR/dalvikvm-heap(299): 32768-byte external allocation too large for this process. 10-15 14:43:43.020: ERROR/GraphicsJNI(299): VM won't let us allocate 32768 bytes 10-15 14:43:43.260: ERROR/AndroidRuntime(299): FATAL EXCEPTION: main 10-15 14:43:43.260: ERROR/AndroidRuntime(299): java.lang.OutOfMemoryError: bitmap size exceeds VM budget 10-15 14:43:43.260: ERROR/AndroidRuntime(299): at android.graphics.Bitmap.nativeCreate(Native Method) 10-15 14:43:43.260: ERROR/AndroidRuntime(299): at android.graphics.Bitmap.createBitmap(Bitmap.java:468)

In my heap, I can see that less than 30% has been used.

Can anyone help me out ? Is there a way out ? Thanks.

///////////////////////////////////////////////

public void draw(Canvas canvas, MapView mapv, boolean shadow){

    BusLoc.myMapView.destroyDrawingCache ();
    super.draw(canvas, mapv, shadow);

    Paint mPaint = new Paint();
    mPaint.setDither(true);
    mPaint.setColor(Color.RED);
    mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
    mPaint.setStrokeJoin(Paint.Join.ROUND);
    mPaint.setStrokeCap(Paint.Cap.ROUND);
    mPaint.setStrokeWidth(2);

    /////////////////////////////get the lat/long info/////////////////////////////////////

    BusLoc.mapCenter= BusLoc.myMapView.getMapCenter();
    int latCenter = BusLoc.mapCenter.getLatitudeE6();
    int longCenter = BusLoc.mapCenter.getLongitudeE6();
    int latSpan = BusLoc.myMapView.getLatitudeSpan();
    int longSpan = BusLoc.myMapView.getLongitudeSpan();
    int latMax = latCenter + (latSpan / 2);
    int latMin = latCenter - (latSpan / 2);
    int longMax = longCenter + (longSpan / 2);
    int longMin = longCenter - (longSpan / 2);

    ///////////////////////////////////////////////////////////////////////////////////////


    Log.d("MyOverlay","OnDraw");

    int in=0;
    for(in=0;in<ind-1;in++)
    {
        if (ah1[in][0] ==0 ||(ah1[in+1][0]==0)) break;
        if((ah1[in][0] !=0) &&(ah1[in+1][0]!=0))
        {
            GeoPoint gP1 = new GeoPoint((int)(ah1[in][0]*1e6),(int)(ah1[in][1]*1e6)); //lat,lng
            GeoPoint gP2 = new GeoPoint((int)(ah1[in+1][0]*1e6),(int)(ah1[in+1][1]*1e6));



            Point p1 = new Point();
            Point p2 = new Point();

            Path path = new Path();

            Projection projection = BusLoc.myMapView.getProjection();
            projection.toPixels(gP1, p1);
            projection.toPixels(gP2, p2);

            path.moveTo(p2.x, p2.y);
            path.lineTo(p1.x,p1.y);

            if((((ah1[in][0]<=latMax)&&(ah1[in][0]>=latMin))&&((ah1[in][1]<=longMax)&&(ah1[in][1]>=longMin))) || (((ah1[in+1][0]<=latMax)&&(ah1[in+1][0]>=latMin))&&((ah1[in+1][1]<=longMax)&&(ah1[in+1][1]>=longMin))) )
            {
                canvas.drawPath(path, mPaint);
            }

            Log.d("MyOverlay","drawn: "+gP1.toString()+":"+gP2.toString());
        }
    }
   // BusLoc.myMapView.destroyDrawingCache ();
}

Answer 1

You should explicitly only the draw the overlays that are visible on your screen, if not all the overlays are drawn whether you see them or not, this not only cause trouble with memory but makes moving the map very slow on the not so good devices.

MapController mapControl = map.getController();
        GeoPoint mapCenter = map.getMapCenter();
        int latCenter = mapCenter.getLatitudeE6();
        int longCenter = mapCenter.getLongitudeE6();
        int latSpan = map.getLatitudeSpan();
        int longSpan = map.getLongitudeSpan();
        int latMax = latCenter + (latSpan / 2);
        int latMin = latCenter - (latSpan / 2);
        int longMax = longCenter + (longSpan / 2);
        int longMin = longCenter - (longSpan / 2);

Write some code to detect whether your point of interest is within that viewing range, if it is draw it, if not dont.

I also would asume you are using a small overlay indicator, they can be really tiny and low dpi without loosing quality.