Calculating Map Seams

I have been spending time working on how to merge the seams of adjacent tiles. Most of the tiles in the game are a 9 x 9 matrix and the corners in the game join to form a single area.

I have a html file that allows me to draw a rectangle over each area. This gives me an array of the area on each card. If I rotate the card to make a different map, I rotate the corrordinate of each tile using the tiles center.

Once the map is ready, the seams (edges of each card) are calculated so the adjacent tiles are merged. This forms a new grid – after the seams are calculated the tiles can no longer be swapped or rotated. The tiles are calculated and a merged into a single PNG file which is then used by zombizied_gui.