Expert help on mapView overlays

[rsxchaps]

I have been working on this overlay in iOS for weeks on end now and at this point I am completely stumped. I have utilized all of apples sample code examples as well as WWDC videos and pdf resources on the site. As a last resort I'm posting this questions in hopes for some guidance. I have a mapView that I can drop custom annotations on/zoom in/zoom out/etc. My goal is to create an overlay that will place an arrow on the custom annotation that the user touches/creates. The very tip of the arrow needs to be at the exact lat/lon of the pin dropped. Essentially anchoring that point so when I pass the arrow overlay a wind direction it will rotate accordingly. almost as if you dropped the point of a protractor on the annotation and then rotated around a radius. I ended up getting this cool method to work with MKPolygon and it was perfect but I cant go that route because I have custom arrows/images that are png's that need to be used.

I can post my code but it's pretty self explanatory. Create an Overlay that conforms to the MKOverlay protocol. Create a overlayView that conforms to the MKOverlayView protocol. Lastly within the MKMapView define the respective delegate methods ex - (MKOverlayView *)mapViewMKMapView *)mapView viewForOverlayid )overlay.

If it helps at all I can get the overlay to appear on the map within my mapOverlayView class by creating a UIImage and then putting that in a UIImageView. It appears by default to line up the top left corner of the view with the center of the annotation. This is great but when I try anchor the imageView or rotate the imageView it becomes off center and turns into a mess. I thought I had a hunch when watching a video on mercator projection and MKMapPoint but to no avail I am still stumped.

Thank you in advance for any direction you can provide.

[rsxchaps]

I took a break from the project today. I've posted the relevant code for the overlay classes. Maybe another set of eyes will get me on the right track. The whole anchor point issue really gets to me. I have to be doing something wrong. Thanks!

//***********MKOverlayView class below ************

- (void)drawMapRect:(MKMapRect)mapRect zoomScale:(MKZoomScale)zoomScale inContext:       (CGContextRef)context 

{
UIImage *image = [UIImage imageNamed:@"arrow.png"];

UIImageView *imageView = [ [ UIImageView alloc ] initWithFrame:CGRectMake(0.0, 0.0, image.size.width, image.size.height) ];

[imageView setImage:image];

//imageView.layer.anchorPoint = CGPointMake(1.0f, 0.5f);    

//CGFloat radian = windDirection * M_PI/180;

// CGAffineTransform rotate = CGAffineTransformMakeRotation(-radian);

//  imageView.transform = rotate;    

imageView setCenter:CGPointMake(0.5f, 0.5f)];

//[imageView.layer setPosition:CGPointMake(-60.0f,15.0f)];

// Wind direction = 90.00000 for a test case

CGFloat radian = windDirection * M_PI/180;

 //[self rotateImage:image withAngle:windDirection*M_PI/180];    

imageView.layer.anchorPoint = CGPointMake(0.5, 1.0);

CGAffineTransform rotate = CGAffineTransformMakeRotation(-radian);

imageView.transform = rotate;    

 [self addSubview:imageView];    

  }
//*********//MKOverlay class below ******************

- (id)initWithCoordinate:(CLLocationCoordinate2D)coordinate converted:(CGPoint)convCoord
{

self = [super init];

if (self != nil) {

lat = coordinate.latitude;

lon = coordinate.longitude;

// Values match up with coordinates from mapView. This checks out. 
NSLog(@"Coords getting passed in to initwithcoords are %f %f",lat, lon);

     }

return self;

}


 - (CLLocationCoordinate2D)coordinateForCone

 {

CLLocationCoordinate2D coord1 = { lat, lon };

  return coord1;
  }
- (MKMapRect)boundingMapRect

{
 MKMapPoint upperLeft = MKMapPointForCoordinate([self coordinateForCone]);

  MKMapRect bounds = MKMapRectMake(upperLeft.x,     upperLeft.y,2000,2000);//500*longitudeMultiplier, 910*latitudeMultiplier);

return bounds;
}