Question

Say I have a grid with 9 points:

1       2     3


4       5     6



7        8    9

Each point / node can be connected to other nodes to form segments:

1       2     3
|
|
4       5     6
|       |
|       |
|       |
7-------8-----9

In this illustration, 1 is connected to 4, 4 is connected to 1 and 7, 7 is connected to 4 8, 8 is connected to 5 and 9, 5 is connected to 8, and 9 is connected to 8.

If I simply rendered this like this:

for each node n1
for each node n2 in n1
create segment from n1 to n2.

This would generate a lot of duplicate segments.

Would there be a way to do it so that I only create the necessary number of segments?

My goal is to be able to say, break the link between 1 and 4 and connect 1 and 5 together and regenerate the grid.

I’m trying to generate a simple city.

Thanks

Answer 1

The structure illustrated in your ASCII drawings is called a graph. In particular, you are trying to generate a planar graph. There are several common ways to represent a graph data structure in a computer program.

These Wikipedia links are very heavy on the mathematical theory, but I hope you find them helpful.