This applet is a demonstration of the A* search algorithm. The Pythagorean distance from the avatar to the goal point is used as the heuristic value.
Left-click individual cells to increase cost. Full black cells are impassable (4 clicks). Holding down the shift key while clicking lowers cell cost.
Right-click a cell at any time to set or move the goal (red circle).
The current closed set of cells has a green border, and the current open set of cells has a purple border.