Quadtree Demo 02

Description and Instructions:

• This demo features 2 different Quadtree Modes: Point-Region [PR] and Destructible [Dest]
• Press 'r' to reset Quadtree to initialization state (empty if [PR], undamaged if [Dest])
• Press 'm' to change current Quadtree mode between [PR] and [Dest] (note: resets Quadtree)
• In [PR] mode: pressing 'a' will toggle automatic placement of random points into Quadtree
• In [PR] mode: left mouse click adds xor removes point at mouse coordinates from Quadtree
• In [Dest] mode: left mouse click 'punches hole' into Quadtree via disk position/radius
• In [Dest] mode: mousewheel changes radius of disk used to 'punch holes' into Quadtree