Spice must flow!

And flow it will! I spent the weekend implementing harvesters and refineries. Right now, a harvester is capable to driving to a spice field, happily seperate the spice from the sand, find a refinery, drive back and enter the refinery. Once in, the refinery will empty the harvester, provide credits to the player and when the harvester is empty, it will deploy it.

Our initial state: Idle harvester and refinery

Most of the harvesting code is still the same as it was before, but I also changed quite a lot. Most of the changes are in the refinery, which now has a 'landing zone', the area where the harvester has to land in order for the spice to flow. Initially it used the building coordinates to find it's way into the refinery, but this meant the harvester would drive to the center of the building. Also, I updated the images concering the harvester and the animation, so they use up less VRAM(Altho it came with a dirty hack: I have to figure out in which directions to displace the animation, otherwise it looks dislocated)

The harvester is collecting spice

When a harvester is full, it will request a list of all known refineries. It will traverse this list and attempt to find the most suitable refinery. That is, with the shortest queue or no queue at all. When it comes by an idle refinery, it will stop searching. When it has found a refinery, it will inform the refinery that it's enroute, lay out a path and start it's dangerous journey back home(Esp. when no carry-alls are around). The refinery will now start 'blinking' it's landing zone(when idle), or otherwise just queue up the harvester.

Harvester returning to the refinery, which has a blinking landing pad

When the harvester has reached the refinery, it will wait for clearance. The clearance means the refinery is ready to receive the harvester and refine whatever goodness it brings. When the harvester receives it's clearance, it will roll onto the landing zone and remove itself from the scene. This is important, because it will otherwise keep rendering itself, which will look weird: A harvester ontop of a refinery with a harvester in it. The refinery stores the harvester internally, so when the refinery is destroyed, it will automatically destroy the harvester aswell.

Refinery processing a harvester

It takes 35 seconds for a fully loaded harvester to unload(20 credits per second). When done, a harvester will ALWAYS be deployed, even when a carry-all is signaled to pick it up. This is done because it might take a while before the carry-all arrives, and when deployed, it gives other harvesters the chance to enter the refinery. This was something that annoyed me in the original game: When a harvester was waiting for a carry-all to arrive, it took a while, so other harvesters had to wait, while I was already low on cash.

To do:
- Have harvesters return back to the spice field
- Limit the number of tiles searched for new spice
- Harvester spice dunes first, then normal spice
- Fix bug related to tiles not being free'd
- Have a carry-all unload the harvester into the refinery
- Have carry-alls bring a harvester to a newly placed refinery