Npc target passing fixes

Hostile NPC's will not randomly agro other NPC's at long ranges. NPC's will alert each other to the player more freely (and at greater range based on game Difficulty), so that they don't ignore the player when their allies are killed right next to them. Player summons will not target Cold Flame Traps when they are damaged.

game/engines/default/engine/interface/ActorAI.lua

@@ -147,12 +147,12 @@ function _M:setTarget(target, last_seen)
if last_seen then
self.ai_state.target_last_seen = last_seen
else
-		local target_pos = target and self.fov and self.fov.actors and self.fov.actors[self.ai_target.actor] or {x=self.x, y=self.y}
+		local target_pos = target and (self.fov and self.fov.actors and self.fov.actors[target] or {x=target.x, y=target.y}) or {x=self.x, y=self.y} --No FOV: aiSeeTargetPos will assume new target position is ~3 turns old by default (AI_LOCATION_GUESS_ERROR)
self.ai_state.target_last_seen=table.merge(self.ai_state.target_last_seen or {}, {x=target_pos.x, y=target_pos.y, turn=game.turn}) -- Merge to keep obfuscation data
end
end
-_M.AI_SEEN_CACHE_DELAY = 10 * 100
+_M.AI_LOCATION_GUESS_ERROR = 3  -- Start position guess errors at ~3 grids
--- Returns the seen coords of the target
-- This will usually return the exact coords, but if the target is only partially visible (or not at all)
@@ -167,12 +167,12 @@ function _M:aiSeeTargetPos(target)
local spread = 0
-- Guess Cache turn to update position guess (so it's consistent during a turn)
-	-- Start at -1000 to make sure ti gets run the first time.
-	LSeen.GCache_turn = LSeen.GCache_turn or game.turn - self.AI_SEEN_CACHE_DELAY
+	-- Set last cache turn before game turn to make sure it gets run the first time.
+	LSeen.GCache_turn = LSeen.GCache_turn or game.turn - self.AI_LOCATION_GUESS_ERROR * game.energy_to_act/game.energy_per_tick
-- Guess Cache known turn for spread calculation (self.ai_state.target_last_seen.turn
-- can't be used because it's needed by FOV code)
-	LSeen.GCknown_turn = LSeen.GCknown_turn or game.turn - self.AI_SEEN_CACHE_DELAY
+	LSeen.GCknown_turn = LSeen.GCknown_turn or game.turn - self.AI_LOCATION_GUESS_ERROR * game.energy_to_act/game.energy_per_tick
-- Check if target is currently seen
local see, chance = self:canSee(target)
@@ -188,6 +188,10 @@ function _M:aiSeeTargetPos(target)
if LSeen.GCache_x then -- update guess with new random position. Could use util.findFreeGrid here at cost of speed
tx = math.floor(LSeen.GCache_x + (tx-LSeen.GCache_x)/2)
ty = math.floor(LSeen.GCache_y + (ty-LSeen.GCache_y)/2)
+				if not target:canMove(tx, ty, true) then -- find a reasonable spot if target can't be at that position
+					local nx, ny = util.findFreeGrid(tx, ty, spread, false)
+					if nx then tx, ty = nx, ny end
+				end
end
LSeen.GCache_x, LSeen.GCache_y = tx, ty
LSeen.GCache_turn = game.turn