Callback: Watched cargo accepted
Watched cargo accepted (148)
Called when a cargo type specified in property 20 is accepted by a house tile, or to be more specific, in a station that has the house tile in its acceptance area. It will be called for each tile of a multi-tile building whenever a tile with property 20 accepts cargo. This means if more than one tile has cargoes specified in property 20, the callback can be called multiple times on the same tile in the same tick. The low word of variable 18 contains the offset of the trigger tile relative to the current tile; the low byte contains the X offset, the high byte the Y offset. (0 means it's the same tile, negative coordinates mean it's northward, positive southward.) With this, you can tell apart the callings within the same tick. The high word of variable 18 contains random bits, the bits are the same for each tile of multi-tile buildings.
The return values can be the same as for callback 1B. Like all animation callbacks, if the high byte of the result is nonzero, it will be interpreted as a sound effect number, and the corresponding sound effect will be played at the tile.
Due to implementation details, up to 250 game ticks can pass between the actual acceptance and triggering this callback.
This callback isn't available if the station2 structure isn't present - see the property 20 entry for more information.