We will call
two trapezoids adjacent if they share a vertical boundary:6.838, Computational Geometry; Fall 2001
Point Location
Sergi Elizalde & David Pritchard
We will call
two trapezoids adjacent if they share a vertical boundary:
The diagram illustrates
that a trapezoid can have many neighbours
However, our
assumption that no two points share the same x-coordinate makes this impossible
How many neighbours
can a given triangle D have on the left side?
- it will have no neighbours if top and bottom meet at leftp or D is on the edge of the bounding box
- it will have one neighbour if leftp is an endpoint of top or bottom
- it will have two neighbours if leftp splits the left side in half
So on the left
and right sides together it may have up to four neighbours; we will call these
the upper left, lower left, upper right, lower right
neighbours of D