為映像背景添加一個圓圈

// Only draw this debugging information in , well , debug builds.

#if DEBUG

- (void) draw

{

    // Iterate through all nodes of the layer.

    for ( CCNode* node
in [ self children ] )

    {

        // Make sure the node is a CCSprite and has the right tags.

        if ( [ node isKindOfClass: [
CCSprite class ] ] && ( node.tag ==
1 || node.tag ==
2 ) )

        {

            // The sprite's collision radius is a percentage of its image width. Use that to draw a circle

            // which represents the sprite's collision radius.

            CCSprite* sprite = (CCSprite*) node;

            float radius = [ sprite
texture ].contentSize.width * 0.4f;

            float angle =
0;

            int numSegments =
10;

            bool drawLineToCenter =
NO;

            ccDrawCircle( sprite.position , radius , angle , numSegments , drawLineToCenter );

        }

    }

}

#endif