Kraken fixes

Changes:
- Fixed an issue where touching 2 krakens at the same time would spawn 3 krakens.
- Fixed an issue where sometimes 2 krakens would be placed under same tile in overworld (which made it look as if there was only single kraken).

maps/pirates/balance.lua

@@ -569,7 +569,7 @@ function Public.krakens_per_free_slot(overworldx)
 	if rng < 0.0025 * multiplier then
 		return 3
 	elseif rng < 0.075 * multiplier then
-		return 1
+		return 2
 	elseif rng < 0.5 * multiplier then
 		return 1
 	else

maps/pirates/math.lua

@@ -100,7 +100,7 @@ function Public.random_float_in_range(from, to)
 end
 
 -- Returns vector in random direction.
--- scalar: sets returned vector length. If nil, 1 will be chosen
+-- scalar: returned vector length. If nil, 1 will be chosen.
 function Public.random_vec(scalar)
 	scalar = scalar or 1
 	local random_angle = Public.random_float_in_range(0, 2 * Public.pi)
@@ -110,6 +110,41 @@ function Public.random_vec(scalar)
 	}
 end
 
+-- Returns unique contiguous array indices.
+-- array_size: size of contiguous array.
+-- count: amount of unique indices to take from the array (elements are taken in range [1, array_size]).
+--
+-- Example with {array_size = 5, count = 3}:
+-- - Possible return value: {4, 1, 5}
+--
+-- Idea taken from this big brained stranger https://stackoverflow.com/a/2380705
+function Public.random_unique_array_indices(array_size, count)
+	if count > array_size then
+		return nil
+	end
+
+	local modified_indices = {}
+	local result_indices = {}
+	for i = 0, count - 1 do
+		local curr_array_size = array_size - i
+		local num = Public.random(curr_array_size)
+
+		if modified_indices[num] == nil then
+			result_indices[#result_indices + 1] = num
+		else
+			result_indices[#result_indices + 1] = modified_indices[num]
+		end
+
+		if modified_indices[curr_array_size] == nil then
+			modified_indices[num] = curr_array_size
+		else
+			modified_indices[num] = modified_indices[curr_array_size]
+		end
+	end
+
+	return result_indices
+end
+
 function Public.snap_to_grid(point)
 	return {x = Public.ceil(point.x), y = Public.ceil(point.x)}
 end

maps/pirates/overworld.lua

@@ -495,22 +495,15 @@ function Public.generate_overworld_destination(p)
 	-- end
 
 	if position_candidates then
-		local positions_placed = {}
-		local whilesafety = 0
-		while whilesafety < 10 and (#positions_placed < Math.min(kraken_count, 10)) do
-			local p_chosen, p_kraken
-			local whilesafety2 = 0
-			while whilesafety2 < 50 and ((not p_kraken) or Utils.contains(positions_placed, p_chosen)) do
-				p_chosen = position_candidates[Math.random(#position_candidates)]
-				p_kraken = Utils.psum{p_chosen, p}
-				whilesafety2 = whilesafety2 + 1
+		local random_indices = Math.random_unique_array_indices(#position_candidates, Math.min(kraken_count, 10))
+		if random_indices then
+			for _, idx in ipairs(random_indices) do
+				local p_chosen = position_candidates[idx]
+				local p_kraken = Utils.psum{p_chosen, p}
+				Crowsnest.draw_kraken(p_kraken)
+				memory.overworld_krakens[#memory.overworld_krakens + 1] = p_kraken
 			end
-			Crowsnest.draw_kraken(p_kraken)
-			positions_placed[#positions_placed + 1] = p_kraken
-			memory.overworld_krakens[#memory.overworld_krakens + 1] = p_kraken
-			whilesafety = whilesafety + 1
 		end
-		-- game.print(#positions_placed .. ' krakens placed for' .. macro_p.x .. ', ' .. macro_p.y)
 	end
 end
 
@@ -577,16 +570,15 @@ end
 
 function Public.check_for_kraken_collisions()
 	local memory = Memory.get_crew_memory()
-	local krakens = memory.overworld_krakens
-
-	for i, k in ipairs(krakens) do
 
+	for i = #memory.overworld_krakens, 1, -1 do
+		local k = memory.overworld_krakens[i]
 		local relativex = Crowsnest.platformrightmostedge + k.x - memory.overworldx
 		local relativey = k.y - memory.overworldy
 
 		if (relativex <= 3.5 and relativex >= -3.5 and relativey >= -4 and relativey <= 4) then
 			Kraken.try_spawn_kraken()
-			memory.overworld_krakens = Utils.ordered_table_with_index_removed(krakens, i)
+			memory.overworld_krakens = Utils.ordered_table_with_index_removed(memory.overworld_krakens, i)
 		end
 	end
 end