Custom MKOverlayView Drawing - objective-c

Question

I am trying to create a custom MKOverlayView class that draws the overlay since the normal MKOverlay and MKOverlayView does not suit my needs for the application I am building.
I am having a problem with the drawing of the polygon overlay, when I draw it; it looks no where near as good as if I let MKOverlayView draw it and by that i mean the edges are not sharp and are all pixelated when you zoom in on the map. Also the lines from point to point dont get drawn either for some reason.
Also when zooming in some of the polygons drawing gets clipped out until I zoom back out again.
here is my draw code
- (void)drawMapRect:(MKMapRect)mapRect zoomScale:(MKZoomScale)zoomScale inContext:(CGContextRef)context{
MapOverlay *newOverlay = (MapOverlay *)self.overlay;
CGColorRef ref2 = [newOverlay.strokeColor CGColor];
CGContextSetLineWidth(context, newOverlay.lineWidth);
CGColorRef ref = [newOverlay.fillColor CGColor];
int _countComponents = CGColorGetNumberOfComponents(ref);
if (_countComponents == 4) {
const CGFloat *_components2 = CGColorGetComponents(ref);
CGFloat red = _components2[0];
CGFloat green = _components2[1];
CGFloat blue = _components2[2];
CGFloat alpha = _components2[3];
CGContextSetRGBFillColor(context, red, green, blue, alpha);
}
for (int i=0; i<newOverlay.coordinates.count; i++){
if(i % 2 == 0) {
CLLocationCoordinate2D p;
p.latitude = (CLLocationDegrees)[(NSString *)[newOverlay.coordinates objectAtIndex:i+1]floatValue];
p.longitude = (CLLocationDegrees)[(NSString *)[newOverlay.coordinates objectAtIndex:i] floatValue];
//CLLocation *p = [[CLLocation alloc] initWithLatitude:(CLLocationDegrees)[(NSString *)[newOverlay.coordinates objectAtIndex:i+1] floatValue] longitude:(CLLocationDegrees)[(NSString *)[newOverlay.coordinates objectAtIndex:i] floatValue]];
MKMapPoint point = MKMapPointForCoordinate(p);
CGPoint point2 = [self pointForMapPoint:point];
if (i==0){
CGContextMoveToPoint(context, point2.x, point2.y);
}else{
CGContextAddLineToPoint(context, point2.x, point2.y);
}
}
}
CGContextDrawPath(context, kCGPathFillStroke);
//CGContextStrokePath(context);
}
I have found very little information on custom MKOverlayView classes and how to draw on the map but these were the 2 tutorials that i was using to do this
http://spitzkoff.com/craig/?p=65
http://i.ndigo.com.br/2012/05/ios-maps-with-image-overlays/
UPDATE
I have a feeling it might have something to do with the bounding box of the overlay because if I return the bounding box of the world it displays fine but thats obviously not efficient to have every possible overlay drawn.
here is how I found the bounding box of my overlay in my custom MKOverlay class
- (MKMapRect)boundingMapRect{
double maxY = 0;
double minY = 0;
double maxX = 0;
double minX = 0;
for(NSUInteger i = 0;i < coordinates.count; i++) {
if(i % 2 == 0) {
CLLocationCoordinate2D tempLoc;
tempLoc.latitude =(CLLocationDegrees)[(NSString *)[coordinates objectAtIndex:(NSUInteger)i + 1] floatValue];
tempLoc.longitude = (CLLocationDegrees)[(NSString *)[coordinates objectAtIndex:(NSUInteger)i] floatValue];
MKMapPoint tempPoint = MKMapPointForCoordinate(tempLoc);
if(i == 0){
minX = tempPoint.x;
minY = tempPoint.y;
if(tempPoint.x > maxX){
maxX = tempPoint.x;
}
if (tempPoint.y > maxY){
maxY = tempPoint.y;
}
}else{
if(tempPoint.x > maxX){
maxX = tempPoint.x;
}
if(tempPoint.x < minX){
minX = tempPoint.x;
}
if (tempPoint.y > maxY){
maxY = tempPoint.y;
}
if(tempPoint.y < minY){
minY = tempPoint.y;
}
}
}
}
MKMapRect b2 = MKMapRectMake(minX, maxY, minX-maxX, minY-maxY);
return b2;
//return MKMapRectWorld;
}