Added connected entities helper

Has helper functions for entities that are "connected" visually
Now used by floaty space block to add the placement preview
This solution isn't perfect, will be improved in the future

src/entities/floaty_space_block.lua

@@ -1,4 +1,5 @@
 local fakeTilesHelper = require("fake_tiles_helper")
+local connectedEntities = require("helpers.connected_entities")
 local utils = require("utils")
 local matrixLib = require("matrix")
 
@@ -26,6 +27,9 @@ end
 function floatySpaceBlock.sprite(room, entity)
     local searchPredicate = getSearchPredicate(entity)
     local relevantBlocks = utils.filter(getSearchPredicate(entity), room.entities)
+
+    connectedEntities.appendIfMissing(relevantBlocks, entity)
+
     local firstEntity = relevantBlocks[1] == entity
 
     if firstEntity then

src/helpers/connected_entities.lua

@@ -0,0 +1,52 @@
+local utils = require("utils")
+
+local connectedEntities = {}
+
+-- Useful for adding a placement preview entity into the entities list
+function connectedEntities.appendIfMissing(entities, target)
+    local seen = false
+
+    for _, entity in ipairs(entities) do
+        if entity == target then
+            seen = true
+
+            break
+        end
+    end
+
+    if not seen then
+        table.insert(entities, target)
+    end
+
+    return seen
+end
+
+function connectedEntities.getEntityRectangles(entities)
+    local rectangles = {}
+    local seenExtra = false
+
+    for _, entity in ipairs(entities) do
+        table.insert(rectangles, utils.rectangle(entity.x, entity.y, entity.width, entity.height))
+
+        if entity == extra then
+            seenExtra = true
+        end
+    end
+
+    return rectangles
+end
+
+function connectedEntities.hasAdjacent(entity, offsetX, offsetY, rectangles, checkWidth, checkHeight)
+    local x, y = entity.x or 0, entity.y or 0
+    local checkX, checkY = x + offsetX, y + offsetY
+
+    for _, rect in ipairs(rectangles) do
+        if utils.aabbCheckInline(rect.x, rect.y, rect.width, rect.height, checkX, checkY, checkWidth or 8, checkHeight or 8) then
+            return true
+        end
+    end
+
+    return false
+end
+
+return connectedEntities