Question

Information in map is :

     <objectgroup name="Waypoint" width="32" height="24">
  <object name="waypointsline" x="843" y="3">
   <polyline points="0,0 -13,130 -39,202 -69,237 -125,262 -162,295 -189,340 -184,376 -166,411 -124,453 -98,484 -78,529 -78,598 -80,659 -101,689 -200,695 -317,700 -453,696 -534,693 -566,656 -582,622 -585,563 -586,488 -577,428 -550,335 -547,284 -565,225 -599,190 -675,171 -751,164 -799,133 -829,93 -842,17"/>
  </object>
 </objectgroup>

How can I extract them in objective-C?

I tried:

    NSMutableDictionary *waypoints = [objects objectNamed:@"waypointsline"];
if(waypoints) {
    NSString* v = [waypoints valueForKey:@"waypointsline"];
}

And it returned nil.

Answer 1

Polyline and polygon in TMX were introduced to cocos2d-iphone in version 2.0-rc0:

[NEW] TileMap: polygon, polilines and gid are parsed from the objects (issue #1311)

If you are using newer version than 2.0-rc0, I guess you can access the points by something similar to:

CCTMXObjectGroup *objectGroup = [tileMapLayer objectGroupNamed:@"someGroup"];
NSMutableDictionary *waypoints = [[objectGroup objectNamed:@"waypointsline"];
NSString *v = [waypoints objectForKey:@"polylinePoints"];

For more details please refer to:

• HOW TO: convert TMX polygon objects into box2d shapes for collision detection (look like the category implementations in this post can help with prior-2.0-rc0 versions)
• cocos2d-iphone issue #1311
• cocos2d-iphone issue #1311 change on GitHub