ref: 094fc8b15f98807833143e29f1f7d36a1ca4b28c
dir: /sys/src/games/sokoban/README/
If you click with mouse button 1 on a (destination) square then the following may happen. If - the destination square is on the same row or column as glenda, and - there is a ball next to glenda (in the direction of the destination square), and - all squares between the ball and the destination square (where glenda will move) are empty, and - the square next to the destination square where glenda will push the ball is empty too, then glenda will move to the destination square, pushing the ball while moving. Otherwise, if glenda can go to the destination square without touching anything, it will do so. Otherwise, nothing will happen. The breadth-first search algorithm should find a fast route. it can be seen in action by toggling the 'animate' entry in the button 3 menu.