I am drawing a bunch of Markers on my Map View.
The information about the position of all objects (latitude and longitude) is stored in an Array.
To optimize performance i don't want to draw ALL Markers. I only want to alloc Markers in the area i am seeing at the moment. But the only information i get from the Route Me API about position/screen is:
center.latitude;
center.longitude;
But this value is only returning the center of my whole map and i want to see the center position (lat and long) of the actual view. I am also able to get the GPS position, but not the center position of the screen. Do you think there is an easy way to get this information?
This is a part of my implementation:
UIImage* object = [UIImage imageNamed:#"object.png"];
CLLocationCoordinate2D buoyLocation;
NSString* templatString;
NSString* templongString;
for (int i =0; i<(myArray.count); i=i+2)
{
templongString = [myArray objectAtIndex:i];
templatString = [myarray objectAtIndex:i+1];
objectLocation.latitude = [templatString floatValue];
objectLocation.longitude = [templongString floatValue];
myMarker = [[RMMarker alloc] initWithUIImage:object anchorPoint:CGPointMake(xspec, yspec)]; //0.5 1.0
[markerManager1 addMarker:myMarker AtLatLong:objectLocation];
}
Take a look at latitudeLongitudeBoundingBoxForScreen in RMMapContents.
Ciao!
-- Randy
Related
I am working with MKMapView's, annotations, overlays, etc, but I'm having a pain in the butt issue with MKMapPointForCoordinate() returning an invalid coordinate.
Code:
MKMapPoint* pointArr;
for (Category* route in validRoutes){
NSString* routeID = [route routeid];
NSArray* pointData = [routes objectForKey:routeID];
pointArr = malloc(sizeof(MKMapPoint) * [pointData count]);
int i = 0;
for (NSDictionary* routeData in pointData) {
NSString* latitude = [routeData objectForKey:#"latitude"];
NSString* longitude = [routeData objectForKey:#"longitude"];
NSLog(#"L: %# L: %#",latitude, longitude);
CLLocationCoordinate2D coord = CLLocationCoordinate2DMake([[f numberFromString:latitude] doubleValue], [[f numberFromString:longitude] doubleValue]);
NSLog(#"Coord: %f %f",coord.latitude,coord.longitude);
MKMapPoint point = MKMapPointForCoordinate(coord);
NSLog(#"Point: %f %f",point.x,point.y);
pointArr[i] = point;
i++;
}
MKPolyline *polyline = [MKPolyline polylineWithPoints:pointArr count: i];
polyline.title = [route name];
[routeOverlays setObject:polyline forKey: [route routeid]];
[map addOverlay:polyline];
free(pointArr);
}
Output Example:
L: 41.380840 L: -83.641319
Coord: 41.380840 -83.641319
Point: 71850240.204982 100266073.824832
I don't understand why the conversion to a MKMapPoint is destroying the values of my CLLocationCoordinate2D. The overlay doesn't show up on the map because the values are invalid...
EDIT: I got the point working by using MKMapPointMake instead, BUT, my overlay still isn't showing. This is the mapView: viewForOverlay: code:
-(MKOverlayView*)mapView:(MKMapView *)mapView viewForOverlay:(id<MKOverlay>)overlay {
MKOverlayView *overlayView = nil;
//Checks if the overlay is of type MKPolyline
if([overlay isKindOfClass:[MKPolyline class]]){
MKPolylineView *routeLineView = [[MKPolylineView alloc] initWithPolyline:overlay];
routeLineView.strokeColor = [UIColor orangeColor];
routeLineView.lineWidth = 10;
return overlayView;
}
return nil;
}
The method gets called (Used a breakpoint to confirm), and I have annotations working (So the delegate has to be setup correctly, I assume)
Double edit: :facepalm: I was returning nil every time in the delegate code. That's what I get for copying and pasting the previous versions code ;P
An MKMapPoint is not a latitude/longitude in degrees (like CLLocationCoordinate2D).
They are not interchangeable and so you should not expect the MKMapPoint x,y values to show any obvious relation to the corresponding latitude and longitude.
An MKMapPoint is the conversion of latitude and longitude onto a flat projection using x,y values which are not in the same scale or range as latitude and longitude. Please see the Map Coordinate Systems section in the Location Awareness Programming Guide for a more detailed explanation.
By the way, if you have CLLocationCoordinate2D values, it's much easier to create a polyline using polylineWithCoordinates instead of polylineWithPoints. That way, you don't need to bother with any conversion.
See iOS SDK: MapKit MKPolyLine not showing for some more details and an example.
EDIT: This is now a confirmed bug with this SDK
I'm using version 1.1.1.2311 of the Google Maps for iOS SDK, and I'm looking to find the bounding latitude and longitude coordinates for the visible map on screen.
I'm using the following code to tell me what the current projection is:
NSLog(#"\n%#,%#\n%#,%#\n%#,%#\n%#,%#\n",
[NSNumber numberWithDouble:mapView.projection.visibleRegion.farLeft.latitude],
[NSNumber numberWithDouble:mapView.projection.visibleRegion.farLeft.longitude],
[NSNumber numberWithDouble:mapView.projection.visibleRegion.farRight.latitude],
[NSNumber numberWithDouble:mapView.projection.visibleRegion.farRight.longitude],
[NSNumber numberWithDouble:mapView.projection.visibleRegion.nearLeft.latitude],
[NSNumber numberWithDouble:mapView.projection.visibleRegion.nearLeft.longitude],
[NSNumber numberWithDouble:mapView.projection.visibleRegion.nearRight.latitude],
[NSNumber numberWithDouble:mapView.projection.visibleRegion.nearRight.longitude]);
From reading the headers, it seems that it may not be updated when the camera moves. Fair enough...
/**
* The GMSProjection currently used by this GMSMapView. This is a snapshot of
* the current projection, and will not automatically update when the camera
* moves. The projection may be nil while the render is not running (if the map
* is not yet part of your UI, or is part of a hidden UIViewController, or you
* have called stopRendering).
*/
But, it appears to update each time the delegate method is called, so I attempted to plot the coordinates to test them...
For the following on my phone:
The output of the NSLog from above gives me the following:
37.34209003645947,-122.0382353290915
37.34209003645947,-122.010769508779
37.30332095984257,-122.0382353290915
37.30332095984257,-122.010769508779
When plotting those coordinates using this I get a projection that seems off:
These coordinates are consistent across app launches which leads me to believe that I'm either consistently doing something wrong, I'm misunderstanding what visibleRegion is, or I've discovered a bug. Anyone care to help me figure out which one it is?
To get the bounding latitude and longitude you have to do the following steps:
GMSCoordinateBounds *bounds = [[GMSCoordinateBounds alloc] initWithRegion:self.googleMapsView.projection.visibleRegion];
CLLocationCoordinate2D northEast = bounds.northEast;
CLLocationCoordinate2D northWest = CLLocationCoordinate2DMake(bounds.northEast.latitude, bounds.southWest.longitude);
CLLocationCoordinate2D southEast = CLLocationCoordinate2DMake(bounds.southWest.latitude, bounds.northEast.longitude);
CLLocationCoordinate2D southWest = bounds.southWest;
Best regards
Robert
I saw your issue here. Hope that they fix this issue in next update.
But now we can take the real visible region like this:
CGPoint topLeftPoint = CGPointMake(0, 0);
CLLocationCoordinate2D topLeftLocation =
[_mapView.projection coordinateForPoint: topLeftPoint];
CGPoint bottomRightPoint =
CGPointMake(_mapView.frame.size.width, _mapView.frame.size.height);
CLLocationCoordinate2D bottomRightLocation =
[_mapView.projection coordinateForPoint: bottomRightPoint];
CGPoint topRightPoint = CGPointMake(_mapView.frame.size.width, 0);
CLLocationCoordinate2D topRightLocation =
[_mapView.projection coordinateForPoint: topRightPoint];
CGPoint bottomLeftPoint =
CGPointMake(0, _mapView.frame.size.height);
CLLocationCoordinate2D bottomLeftLocation =
[_mapView.projection coordinateForPoint: bottomLeftPoint];
GMSVisibleRegion realVisibleRegion;
realVisibleRegion.farLeft = topLeftLocation;
realVisibleRegion.farRight = topRightLocation;
realVisibleRegion.nearLeft = bottomLeftLocation;
realVisibleRegion.nearRight = bottomRightLocation;
[self drawPolylineWithGMSVisibleRegion:realVisibleRegion color:[UIColor redColor] width:10.0f forMap:mapView];
Drawing polyline method:
- (void)drawPolylineWithGMSVisibleRegion:(GMSVisibleRegion)visibleRegion
color:(UIColor*)color
width:(double)width
forMap:(GMSMapView*)mapView{
GMSPolylineOptions *rectangle = [GMSPolylineOptions options];
rectangle.color = color;
rectangle.width = width;
GMSMutablePath *path = [GMSMutablePath path];
[path addCoordinate:visibleRegion.nearRight];
[path addCoordinate:visibleRegion.nearLeft];
[path addCoordinate:visibleRegion.farLeft];
[path addCoordinate:visibleRegion.farRight];
[path addCoordinate:visibleRegion.nearRight];
rectangle.path = path;
[mapView addPolylineWithOptions:rectangle];
}
It works even for map with non-default bearing and angle.
The solution is to download the latest version of the SDK (1.2 at the time of this writing) as the issue has been fixed.
From the 1.2 release notes:
Resolved Issues:
- visibleRegion now reports correctly sized region on Retina devices
Download here.
Looks like the latitude and longitude coordinates you are printing out and manually plotting are possibly off a bit / being truncated. %f defaults to only print out to 6 decimal places.
Here's a related question that might help:
How to print a double with full precision on iOS?
Maybe you give the location Manager the wrong accuracy..
Try to increase it:
locationMgr.desiredAccuracy = kCLLocationAccuracyBest;
The battery is draining moreyy
I am implementing an iOS application, and I want to draw a polyline between several given coordinates on the map.
I wrote the code and got the polylines being drawn from my point reaching an infinite point. In other words the beginning point of the line starts from the my given lat and long point, but the end of the line is infinite and not the other point.
This is my code...
I filled the coordinates in a NSMutableArray called routeLatitudes. The array cells are being filled one for latitude and one for longitude.
MKMapPoint* pointArr = malloc(sizeof(CLLocationCoordinate2D) * [routeLatitudes count]);
for(int idx = 0; idx < [routeLatitudes count]; idx=idx+2)
{
CLLocationCoordinate2D workingCoordinate;
workingCoordinate.latitude=[[routeLatitudes objectAtIndex:idx] doubleValue];
workingCoordinate.longitude=[[routeLatitudes objectAtIndex:idx+1] doubleValue];
MKMapPoint point = MKMapPointForCoordinate(workingCoordinate);
pointArr[idx] = point;
}
// create the polyline based on the array of points.
routeLine = [MKPolyline polylineWithPoints:pointArr count:[routeLatitudes count]];
[mapView addOverlay:self.routeLine];
free(pointArr);
and overlay delegate
- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay
{
MKOverlayView* overlayView = nil;
if(overlay == routeLine)
{
self.routeLineView = [[[MKPolylineView alloc] initWithPolyline:self.routeLine] autorelease];
self.routeLineView.fillColor = [UIColor colorWithRed:51 green:51 blue:255 alpha:1];
self.routeLineView.strokeColor = [UIColor colorWithRed:204 green:0 blue:0 alpha:1];
self.routeLineView.lineWidth = 3;
overlayView = routeLineView;
}
return overlayView;
}
So I need the lines to be drawn between the points over the map. The beginning of the line is the first dropped pin, and the end is on the last dropped pin.
According to the code, the routeLatitudes array has objects listed like this:
index 0: latitude for point 1
index 1: longitude for point 1
index 2: latitude for point 2
index 3: longitude for point 2
index 4: latitude for point 3
index 5: longitude for point 3
...
So if routeLatitudes.count is 6, it actually has only 3 points.
This means the malloc is allocating the wrong number of points and the polylineWithPoints call is also specifying the wrong number of points for the overlay.
The other problem is that since pointArr will contain only half the objects that routeLatitudes has, you can't use the same index value for both arrays.
The for loop index counter idx is being incremented by 2 at each iteration because that's how the routeLatitudes points are layed out but then the same idx value is used to set pointArr.
So for idx=0, pointArr[0] is set but then for idx=2, pointArr[2] is set (instead of pointArr[1]), and so on. This means every other position in pointArr is left uninitialized resulting in the lines "going to infinity".
So the corrected code might look like this:
int pointCount = [routeLatitudes count] / 2;
MKMapPoint* pointArr = malloc(sizeof(MKMapPoint) * pointCount);
int pointArrIndex = 0; //it's simpler to keep a separate index for pointArr
for (int idx = 0; idx < [routeLatitudes count]; idx=idx+2)
{
CLLocationCoordinate2D workingCoordinate;
workingCoordinate.latitude=[[routeLatitudes objectAtIndex:idx] doubleValue];
workingCoordinate.longitude=[[routeLatitudes objectAtIndex:idx+1] doubleValue];
MKMapPoint point = MKMapPointForCoordinate(workingCoordinate);
pointArr[pointArrIndex] = point;
pointArrIndex++;
}
// create the polyline based on the array of points.
routeLine = [MKPolyline polylineWithPoints:pointArr count:pointCount];
[mapView addOverlay:routeLine];
free(pointArr);
Also note in the malloc line, I corrected sizeof(CLLocationCoordinate2D) to sizeof(MKMapPoint). This technically wasn't causing a problem because those two structs happen to be the same length but it's correct to use sizeof(MKMapPoint) since that's what the array is going to contain.
I have a MKMapView (obviously), that shows housing locations around the user.
I have a Radius tool that when a selection is made, the annotations should add/remove based on distance around the user.
I have it add/removing fine but for some reason the annotations won't show up until I zoom in or out.
This is the method that adds/removes the annotations based on distance. I have tried two different variations of the method.
Adds the new annotations to an array, then adds to the map by [mapView addAnnotations:NSArray].
Add the annotations as it finds them using [mapView addAnnotation:MKMapAnnotation];
1.
- (void)updateBasedDistance:(NSNumber *)distance {
//Setup increment for HUD animation loading
float hudIncrement = ( 1.0f / [[[[self appDelegate] rssParser]rssItems] count]);
//Remove all the current annotations from the map
[self._mapView removeAnnotations:self._mapView.annotations];
//Hold all the new annotations to add to map
NSMutableArray *tempAnnotations;
/*
I have an array that holds all the annotations on the map becuase
a lot of filtering/searching happens. So for memory reasons it is
more efficient to load annoations once then add/remove as needed.
*/
for (int i = 0; i < [annotations count]; i++) {
//Current annotations location
CLLocation *tempLoc = [[CLLocation alloc] initWithLatitude:[[annotations objectAtIndex:i] coordinate].latitude longitude:[[annotations objectAtIndex:i] coordinate].longitude];
//Distance of current annotaiton from user location converted to miles
CLLocationDistance miles = [self._mapView.userLocation.location distanceFromLocation:tempLoc] * 0.000621371192;
//If distance is less than user selection, add it to the map.
if (miles <= [distance floatValue]){
if (tempAnnotations == nil)
tempAnnotations = [[NSMutableArray alloc] init];
[tempAnnotations addObject:[annotations objectAtIndex:i]];
}
//For some reason, even with ARC, helps a little with memory consumption
tempLoc = nil;
//Update a progress HUD I use.
HUD.progress += hudIncrement;
}
//Add the new annotaitons to the map
if (tempAnnotations != nil)
[self._mapView addAnnotations:tempAnnotations];
}
2.
- (void)updateBasedDistance:(NSNumber *)distance {
//Setup increment for HUD animation loading
float hudIncrement = ( 1.0f / [[[[self appDelegate] rssParser]rssItems] count]);
//Remove all the current annotations from the map
[self._mapView removeAnnotations:self._mapView.annotations];
/*
I have an array that holds all the annotations on the map becuase
a lot of filtering/searching happens. So for memory reasons it is
more efficient to load annoations once then add/remove as needed.
*/
for (int i = 0; i < [annotations count]; i++) {
//Current annotations location
CLLocation *tempLoc = [[CLLocation alloc] initWithLatitude:[[annotations objectAtIndex:i] coordinate].latitude longitude:[[annotations objectAtIndex:i] coordinate].longitude];
//Distance of current annotaiton from user location converted to miles
CLLocationDistance miles = [self._mapView.userLocation.location distanceFromLocation:tempLoc] * 0.000621371192;
//If distance is less than user selection, add it to the map.
if (miles <= [distance floatValue])
[self._mapView addAnnotation:[annotations objectAtIndex:i]];
//For some reason, even with ARC, helps a little with memory consumption
tempLoc = nil;
//Update a progress HUD I use.
HUD.progress += hudIncrement;
}
}
I have also attempted at the end of the above method:
[self._mapView setNeedsDisplay];
[self._mapView setNeedsLayout];
Also, to force a refresh (saw somewhere it might work):
self._mapView.showsUserLocation = NO;
self._mapView.showsUserLocation = YES;
Any help would be very much appreciated and as always, thank you for taking the time to read.
I'm going to guess that updateBasedDistance: gets called from a background thread. Check with NSLog(#"Am I in the UI thread? %d", [NSThread isMainThread]);. If it's 0, then you should move the removeAnnotations: and addAnnotation: to a performSelectorOnMainThread: invocation, or with GCD blocks on the main thread.
How can i draw polygon with points read from NSMutableArray object in cocos2D framework?
I am able to draw polygon using this function: filled antialiased poly cocos2d
The problem is becouse points argument *(CGPoint poli) must be static object.
Any ideas or suggestions?
What is type of NSMutableArray objects?
You need to extract raw data of points and set it as poli argument.
If it's NSValue with CGPoint then:
NSMutableArray* yourPointsArray;
...
CGPoint* poli = malloc (sizeof (CGPoint) * [yourPointsArray count]);
for (uint i=0; i<[yourPointsArray count]; i++)
{
poli[i] = [[yourPointsArray objectAtIndex: i] CGPointValue];
}
ccFillPoly (poli, [yourPointsArray count], YES);
free (poly);