createInitialGrid method
Initializes the queue with a cell covering the extent of the area.
@param env the area extent to cover @param cellQueue the queue to initialize
Implementation
void createInitialGrid(Envelope env, PriorityQueue cellQueue) {
double cellSize = math.max(env.getWidth(), env.getHeight());
double hSide = cellSize / 2.0;
// Check for flat collapsed input and if so short-circuit
// Result will just be centroid
if (cellSize == 0) return;
Coordinate? centre = env.centre();
if(centre != null) {
cellQueue.add(createCell(centre.x, centre.y, hSide));
}
}