SpatialIndex is a quad tree of spherical triangles. The tree is built in the following way: Start out with 8 triangles on the sphere using the 3 main circles to determine them. Then, every triangle can be decomposed into 4 new triangles by drawing main circles between midpoints of its edges:
. / \
. /\ /\
. / \ / \
This is how the quad tree is built up to a certain level by decomposing every triangle again and again.
Definition at line 55 of file SpatialIndex.h.
|char * SpatialIndex::nameById
int32 conversion to a string (name of database).
WARNING: if name is already allocated, a size of at least 17 is required. The conversion is done by directly calculating the name from a number. To calculate the name of a certain level, the mechanism is that the name is given by (# of nodes in that level) + (id of node). So for example, for the first level, there are 8 nodes, and we get the names from numbers 8 through 15 giving S0,S1,S2,S3,N0,N1,N2,N3. The order is always ascending starting from S0000.. to N3333...
Definition at line 398 of file SpatialIndex.cpp.