advanced_npc/actions/pathfinder.lua
Hector Franqui fb549e7f93 Pathfinder: Drop jumper.lua's pathfinder in favor of MarkBu's pathfinder with slight modifications, as the later one supports 3D paths.
Clean up old pathfinder code.
Add path decoration to MarkBu pathfinder's generated paths.
Change actions.lua and places.lua to use the new pathfinder.
Properly modify README.md.
2017-06-17 11:47:51 -04:00

391 lines
11 KiB
Lua

-- Pathfinding code by MarkBu, original can be found here:
-- https://github.com/MarkuBu/pathfinder
--
-- Modifications by Zorman2000
-- This version is slightly modified to use another "walkable" function,
-- plus add a "decorating" path function which allows to know the type
-- of nodes in the path.
---------------------------------------------------------------------------------------
-- Pathfinding functionality
---------------------------------------------------------------------------------------
npc.pathfinder = {}
local pathfinder = {}
npc.pathfinder.node_types = {
start = 0,
goal = 1,
walkable = 2,
openable = 3,
non_walkable = 4
}
npc.pathfinder.nodes = {
openable_prefix = {
"doors:",
"cottages:gate",
"cottages:half_door"
}
}
-- This function is used to determine if a node is walkable
-- or openable, in which case is good to use when finding a path
function pathfinder.is_good_node(node, exceptions)
--local function is_good_node(node, exceptions)
-- Is openable is to support doors, fence gates and other
-- doors from other mods. Currently, default doors, gates
-- and cottages doors are supported.
local is_openable = false
for _,node_prefix in pairs(npc.pathfinder.nodes.openable_prefix) do
local start_i,end_i = string.find(node.name, node_prefix)
if start_i ~= nil then
is_openable = true
break
end
end
if node ~= nil and node.name ~= nil and not minetest.registered_nodes[node.name].walkable then
return npc.pathfinder.node_types.walkable
elseif is_openable then
return npc.pathfinder.node_types.openable
else
for i = 1, #exceptions do
if node.name == exceptions[i] then
return npc.pathfinder.node_types.walkable
end
end
return npc.pathfinder.node_types.non_walkable
end
end
function pathfinder.get_decorated_path(path)
-- Get details from path nodes
local path_detail = {}
for i = 1, #path do
local node = minetest.get_node(path[i])
table.insert(path_detail, {pos=path[i], type=pathfinder.is_good_node(node, {})})
end
npc.log("DEBUG", "Detailed path: "..dump(path_detail))
return path_detail
end
function npc.pathfinder.find_path(start_pos, end_pos, entity, decorate_path)
local path = pathfinder.find_path(start_pos, end_pos, entity)
if path then
if decorate_path then
path = pathfinder.get_decorated_path(path)
end
else
npc.log("ERROR", "Couldn't find path from "..minetest.pos_to_string(start_pos)
.." to "..minetest.pos_to_string(end_pos))
end
return path
end
-- From this point onwards is MarkBu's original pathfinder code,
-- except for the "walkable" function, which is modified by Zorman2000
-- to include doors and other "walkable" nodes.
-- The version here is exactly this:
-- https://github.com/MarkuBu/pathfinder/commit/ca0b433bf5efde5da545b11b2691fa7f7e53dc30
--[[
minetest.get_content_id(name)
minetest.registered_nodes
minetest.get_name_from_content_id(id)
local ivm = a:index(pos.x, pos.y, pos.z)
local ivm = a:indexp(pos)
minetest.hash_node_position({x=,y=,z=})
minetest.get_position_from_hash(hash)
start_index, target_index, current_index
^ Hash of position
current_value
^ {int:hCost, int:gCost, int:fCost, hash:parent, vect:pos}
]]--
local openSet = {}
local closedSet = {}
local function get_distance(start_pos, end_pos)
local distX = math.abs(start_pos.x - end_pos.x)
local distZ = math.abs(start_pos.z - end_pos.z)
if distX > distZ then
return 14 * distZ + 10 * (distX - distZ)
else
return 14 * distX + 10 * (distZ - distX)
end
end
local function get_distance_to_neighbor(start_pos, end_pos)
local distX = math.abs(start_pos.x - end_pos.x)
local distY = math.abs(start_pos.y - end_pos.y)
local distZ = math.abs(start_pos.z - end_pos.z)
if distX > distZ then
return (14 * distZ + 10 * (distX - distZ)) * (distY + 1)
else
return (14 * distX + 10 * (distZ - distX)) * (distY + 1)
end
end
-- This function is used to determine if a node is walkable
-- or openable, in which case is good to use when finding a path
local function walkable(node, exceptions)
local exceptions = exceptions or {}
-- Is openable is to support doors, fence gates and other
-- doors from other mods. Currently, default doors, gates
-- and cottages doors are supported.
--minetest.log("Is good node: "..dump(node))
local is_openable = false
for _,node_prefix in pairs(npc.pathfinder.nodes.openable_prefix) do
local start_i,end_i = string.find(node.name, node_prefix)
if start_i ~= nil then
is_openable = true
break
end
end
-- Detect mg_villages ceilings usage of thin wood nodeboxes
-- TODO: Improve
local is_mg_villages_ceiling = false
if node.name == "cottages:wood_flat" then
is_mg_villages_ceiling = true
end
if node ~= nil and node.name ~= nil and not minetest.registered_nodes[node.name].walkable then
return false
elseif is_openable then
return false
elseif is_mg_villages_ceiling then
return false
else
for i = 1, #exceptions do
if node.name == exceptions[i] then
return false
end
end
return true
end
end
local function check_clearance(cpos, x, z, height)
for i = 1, height do
local n_name = minetest.get_node({x = cpos.x + x, y = cpos.y + i, z = cpos.z + z}).name
local c_name = minetest.get_node({x = cpos.x, y = cpos.y + i, z = cpos.z}).name
--~ print(i, n_name, c_name)
if walkable(n_name) or walkable(c_name) then
return false
end
end
return true
end
local function get_neighbor_ground_level(pos, jump_height, fall_height)
local node = minetest.get_node(pos)
local height = 0
if walkable(node) then
repeat
height = height + 1
if height > jump_height then
return nil
end
pos.y = pos.y + 1
node = minetest.get_node(pos)
until not walkable(node)
return pos
else
repeat
height = height + 1
if height > fall_height then
return nil
end
pos.y = pos.y - 1
node = minetest.get_node(pos)
until walkable(node)
return {x = pos.x, y = pos.y + 1, z = pos.z}
end
end
function pathfinder.find_path(pos, endpos, entity)
local start_index = minetest.hash_node_position(pos)
local target_index = minetest.hash_node_position(endpos)
local count = 1
openSet = {}
closedSet = {}
local h_start = get_distance(pos, endpos)
openSet[start_index] = {hCost = h_start, gCost = 0, fCost = h_start, parent = nil, pos = pos}
-- Entity values
local entity_height = math.ceil(entity.collisionbox[5] - entity.collisionbox[2])
local entity_fear_height = entity.fear_height or 2
local entity_jump_height = entity.jump_height or 1
repeat
local current_index
local current_values
-- Get one index as reference from openSet
for i, v in pairs(openSet) do
current_index = i
current_values = v
break
end
-- Search for lowest fCost
for i, v in pairs(openSet) do
if v.fCost < openSet[current_index].fCost or v.fCost == current_values.fCost and v.hCost < current_values.hCost then
current_index = i
current_values = v
end
end
openSet[current_index] = nil
closedSet[current_index] = current_values
count = count - 1
if current_index == target_index then
-- print("Success")
local path = {}
local reverse_path = {}
repeat
if not closedSet[current_index] then
return
end
table.insert(path, closedSet[current_index].pos)
current_index = closedSet[current_index].parent
if #path > 100 then
-- print("path to long")
return
end
until start_index == current_index
repeat
table.insert(reverse_path, table.remove(path))
until #path == 0
-- print("path lenght: "..#reverse_path)
return reverse_path
end
local current_pos = current_values.pos
local neighbors = {}
local neighbors_index = 1
for z = -1, 1 do
for x = -1, 1 do
local neighbor_pos = {x = current_pos.x + x, y = current_pos.y, z = current_pos.z + z}
local neighbor = minetest.get_node(neighbor_pos)
local neighbor_ground_level = get_neighbor_ground_level(neighbor_pos, entity_jump_height, entity_fear_height)
local neighbor_clearance = false
if neighbor_ground_level then
-- print(neighbor_ground_level.y - current_pos.y)
--minetest.set_node(neighbor_ground_level, {name = "default:dry_shrub"})
local node_above_head = minetest.get_node(
{x = current_pos.x, y = current_pos.y + entity_height, z = current_pos.z})
if neighbor_ground_level.y - current_pos.y > 0 and not walkable(node_above_head) then
local height = -1
repeat
height = height + 1
local node = minetest.get_node(
{x = neighbor_ground_level.x,
y = neighbor_ground_level.y + height,
z = neighbor_ground_level.z})
until walkable(node) or height > entity_height
if height >= entity_height then
neighbor_clearance = true
end
elseif neighbor_ground_level.y - current_pos.y > 0 and walkable(node_above_head) then
neighbors[neighbors_index] = {
hash = nil,
pos = nil,
clear = nil,
walkable = nil,
}
else
local height = -1
repeat
height = height + 1
local node = minetest.get_node(
{x = neighbor_ground_level.x,
y = current_pos.y + height,
z = neighbor_ground_level.z})
until walkable(node) or height > entity_height
if height >= entity_height then
neighbor_clearance = true
end
end
neighbors[neighbors_index] = {
hash = minetest.hash_node_position(neighbor_ground_level),
pos = neighbor_ground_level,
clear = neighbor_clearance,
walkable = walkable(neighbor),
}
else
neighbors[neighbors_index] = {
hash = nil,
pos = nil,
clear = nil,
walkable = nil,
}
end
neighbors_index = neighbors_index + 1
end
end
for id, neighbor in pairs(neighbors) do
-- don't cut corners
local cut_corner = false
if id == 1 then
if not neighbors[id + 1].clear or not neighbors[id + 3].clear
or neighbors[id + 1].walkable or neighbors[id + 3].walkable then
cut_corner = true
end
elseif id == 3 then
if not neighbors[id - 1].clear or not neighbors[id + 3].clear
or neighbors[id - 1].walkable or neighbors[id + 3].walkable then
cut_corner = true
end
elseif id == 7 then
if not neighbors[id + 1].clear or not neighbors[id - 3].clear
or neighbors[id + 1].walkable or neighbors[id - 3].walkable then
cut_corner = true
end
elseif id == 9 then
if not neighbors[id - 1].clear or not neighbors[id - 3].clear
or neighbors[id - 1].walkable or neighbors[id - 3].walkable then
cut_corner = true
end
end
if neighbor.hash ~= current_index and not closedSet[neighbor.hash] and neighbor.clear and not cut_corner then
local move_cost_to_neighbor = current_values.gCost + get_distance_to_neighbor(current_values.pos, neighbor.pos)
local gCost = 0
if openSet[neighbor.hash] then
gCost = openSet[neighbor.hash].gCost
end
if move_cost_to_neighbor < gCost or not openSet[neighbor.hash] then
if not openSet[neighbor.hash] then
count = count + 1
end
local hCost = get_distance(neighbor.pos, endpos)
openSet[neighbor.hash] = {
gCost = move_cost_to_neighbor,
hCost = hCost,
fCost = move_cost_to_neighbor + hCost,
parent = current_index,
pos = neighbor.pos
}
end
end
end
if count > 100 then
-- print("fail")
return
end
until count < 1
-- print("count < 1")
return {pos}
end