Changes

== PM1 Quadtree ==

== PM1 Quadtree ==

[[Image:Pm1_example.png|PM1 Quadtree example]]

[[Image:Pm1_example3.png|PM1 Quadtree example]]

A PM1 Quadtree follows the following rules:

A PM1 Quadtree follows the following rules:

== PM2 Quadtree ==

== PM2 Quadtree ==

[[Image:Pm2_example.png|PM2 Quadtree example]]

[[Image:Pm2_example3.png|PM2 Quadtree example]]

A PM2 Quadtree follows the following rules:

A PM2 Quadtree follows the following rules:

# At most, one vertex can lie in a region represented by a quadtree leaf node.

# At most, one vertex can lie in a region represented by a quadtree leaf node.

# If a quadtree leaf node's region contains a vertex, then it can contain no q-edge that does not include that vertex. (<= im not sure that is correct, see [http://www.cs.virginia.edu/~kld5r/pm_quadtree_evan.ppt&pli=1])

# If a quadtree leaf node's region contains a vertex, then it can contain no q-edge that does not include that vertex.  

# If a quadtree leaf node's region contains no vertices, then it can contain only q-edges that meet at a common vertex exterior to the region.

# If a quadtree leaf node's region contains no vertices, then it can contain only q-edges that meet at a common vertex exterior to the region.

# Each region's quadtree leaf node is maximal.

# Each region's quadtree leaf node is maximal.

== PM3 Quadtree ==

== PM3 Quadtree ==

[[Image:Pm3_example.png|PM3 Quadtree example]]

[[Image:Pm3_example3.png|PM3 Quadtree example]]

A PM3 Quadtree follows the following rules:

A PM3 Quadtree follows the following rules: