Full Distribution

data/lib/core/position.lua

@@ -0,0 +1,75 @@
+Position.directionOffset = {
+	[DIRECTION_NORTH] = {x = 0, y = -1},
+	[DIRECTION_EAST] = {x = 1, y = 0},
+	[DIRECTION_SOUTH] = {x = 0, y = 1},
+	[DIRECTION_WEST] = {x = -1, y = 0},
+	[DIRECTION_SOUTHWEST] = {x = -1, y = 1},
+	[DIRECTION_SOUTHEAST] = {x = 1, y = 1},
+	[DIRECTION_NORTHWEST] = {x = -1, y = -1},
+	[DIRECTION_NORTHEAST] = {x = 1, y = -1}
+}
+
+function Position:getNextPosition(direction, steps)
+	local offset = Position.directionOffset[direction]
+	if offset then
+		steps = steps or 1
+		self.x = self.x + offset.x * steps
+		self.y = self.y + offset.y * steps
+	end
+end
+
+function Position:moveUpstairs()
+	local isWalkable = function (position)
+		local tile = Tile(position)
+		if not tile then
+			return false
+		end
+		
+		local ground = tile:getGround()
+		if not ground or ground:hasProperty(CONST_PROP_BLOCKSOLID) then
+			return false
+		end
+		
+		local items = tile:getItems()
+		for i = 1, tile:getItemCount() do
+			local item = items[i]
+			local itemType = item:getType()
+			if itemType:getType() ~= ITEM_TYPE_MAGICFIELD and not itemType:isMovable() and item:hasProperty(CONST_PROP_BLOCKSOLID) then
+				return false
+			end
+		end
+		return true
+	end
+	
+	local swap = function (lhs, rhs)
+		lhs.x, rhs.x = rhs.x, lhs.x
+		lhs.y, rhs.y = rhs.y, lhs.y
+		lhs.z, rhs.z = rhs.z, lhs.z
+	end
+	
+	self.z = self.z - 1
+	
+	local defaultPosition = self + Position.directionOffset[DIRECTION_SOUTH]
+	if not isWalkable(defaultPosition) then
+		for direction = DIRECTION_NORTH, DIRECTION_NORTHEAST do
+			if direction == DIRECTION_SOUTH then
+				direction = DIRECTION_WEST
+			end
+			
+			local position = self + Position.directionOffset[direction]
+			if isWalkable(position) then
+				swap(self, position)
+				return self
+			end
+		end
+	end
+	swap(self, defaultPosition)
+	return self
+end
+
+function Position:moveRel(x, y, z)
+	self.x = self.x + x
+	self.y = self.y + y
+	self.z = self.z + z
+	return self
+end