update all battle locations

lib/BattleCam.lua

@@ -431,7 +431,22 @@ function BattleCam.rig(arena, groundY, canonical)
   -- arena's own axis, and the room the player has is all on the far side of
   -- that -- out toward square-on. (orbitRange measures exactly that room.)
   local steer = steered and -BattleCam.orbit * BattleCam.orbitRange(arena) or 0
-  local yaw = steer + (fixed and 0
+  -- ------- and the quarter turn the arena itself is standing at
+  --
+  -- An arena may be laid down any of the four ways (BattleArena's `turn`),
+  -- and the rig is solved for ONE of them: eye off the player's shoulder,
+  -- back down an axis that runs north-south. So the whole offset is turned
+  -- with the ground under it, which leaves the camera in exactly the same
+  -- place RELATIVE to the two mons -- same distance, same height, same
+  -- angle -- and therefore lands them on the same two screen anchors at the
+  -- same size. A turn is a fact about the map, never about the shot.
+  --
+  -- It goes in with the drift and the steer rather than beside them because
+  -- it is the same rotation about the same point; the player's own orbit is
+  -- then measured from wherever the arena starts, so both stops travel with
+  -- it and side-on stays side-on.
+  local base = math.rad(arena.turn or 0)
+  local yaw = base + steer + (fixed and 0
               or BattleCam.PAN_YAW * phase(BattleCam.t, BattleCam.PAN_PERIOD))
   local c, s = math.cos(yaw), math.sin(yaw)
   -- the breath scales the whole offset, height included, so the eye moves
@@ -443,7 +458,11 @@ function BattleCam.rig(arena, groundY, canonical)
   local dz = (R.side * s + R.back * c) * k
 
   local eye = { mx + dx, groundY + R.height * k, mz + dz }
-  local focus = { mx + R.lookX, groundY + R.lookY, mz }
+  -- the aim's own offset turns with the arena too, and with the BASE alone --
+  -- the drift and the steer swing the eye about the focus, so a focus that
+  -- followed them would take the thing being orbited around with it
+  local bc, bs = math.cos(base), math.sin(base)
+  local focus = { mx + R.lookX * bc, groundY + R.lookY, mz + R.lookX * bs }
 
   -- and the climb: the eye swung UP about the focus, at a constant radius.
   -- About the focus so the aim stays nailed to the two mons and only the