More fun facts!
In an isometric tileset, some images are not centered the same way that Terrain is.
The graphics like Bases and Units have their base Y-value shifted upwards by about half a tile. This is reasonable, since you want to have the possibility of going extra-tall. If you need to go lower, you can just draw the graphics lower-down
However, a great annoyance is that the graphics for Tile Yields, have an inherent X-offset which prevents you from displaying them any further left than this:
I wanted to get the blue production-pips aligned with the center of the tile, but this seems physically impossible.
The Food dots are
already at the leftmost edge of the graphic.
Is there any way to control this graphical offset? There are controls for many offsets, but I haven't seen any reference to this one. It might not have come up before, because I'm not sure how many people have tried to make a 48px wide isometric tileset.
If my graphics were 64px wide, the inherent 12-pixel offset wouldn't be much of a problem.
........
Looking further into it...
This appears to have been a deliberate design decision:
https://github.com/freeciv/freeciv/blob ... 4676-L4696
The const ints
ox and
oy are set to 1/3 of the tile-width for isometric tilesets.
A negative value for Y, shifting the graphic upwards (fine, you can always go lower if you want in your graphic)
A positive value for X, shifting the graphic
rightward (which is
impossible to compensate for).
There's a small chance it was a bug (forgot to make X negative too? Maybe was only supposed to apply to iso-hex?), but given that
every single isometric tileset that's ever been made has its tile yield graphics aligned based on these...could be a pain to fix.
All it takes is one trivial error, and the whole system comes crashing down.