signs_bot-cd2025/move_func.lua

--[[

	Signs Bot
	=========

	Copyright (C) 2019 Joachim Stolberg

	LGPLv2.1+
	See LICENSE.txt for more information
	
	Signs Bot: Move functions

]]--

-- for lazy programmers
local S = function(pos) if pos then return minetest.pos_to_string(pos) end end
local P = minetest.string_to_pos
local M = minetest.get_meta

local lib = signs_bot.lib


-- Positions to check:
--     3
--  [R]1  
--   4 2
--   5 
function signs_bot.move_robot(pos, param2)
	local pos1 = lib.next_pos(pos, param2)
	local pos2 = {x=pos1.x, y=pos1.y-1, z=pos1.z}
	local pos3 = {x=pos1.x, y=pos1.y+1, z=pos1.z}
	local pos4 = {x=pos.x, y=pos.y-1, z=pos.z}
	local pos5 = {x=pos.x, y=pos.y-2, z=pos.z}
	local new_pos = nil
	
	if lib.check_pos(pos1, pos2) then  -- one step forward
		new_pos = pos1
	elseif lib.check_pos(pos3, pos1) then  -- one step up
		local node = lib.get_node_lvm(pos4)
		if node.name == "signs_bot:robot_leg" then 
			return nil
		end
		new_pos = {x=pos.x, y=pos.y+1, z=pos.z}
		minetest.swap_node(pos, {name="signs_bot:robot_foot"})
		minetest.set_node(new_pos, {name="signs_bot:robot", param2=param2})
		minetest.sound_play('signs_bot_step', {pos = new_pos})
		return new_pos
	elseif lib.check_pos(pos1, pos4) then  -- one step forward
		new_pos = pos1		
	elseif lib.check_pos(pos4, pos5) then  -- one step down
		new_pos = pos4		
	else
		return nil -- blocked
	end
	local node4 = lib.get_node_lvm(pos4)
	if node4.name == "signs_bot:robot_foot" or node4.name == "signs_bot:robot_leg" then
		minetest.remove_node(pos4)
		local node5 = lib.get_node_lvm(pos5)
		if node5.name == "signs_bot:robot_foot" then
			minetest.remove_node(pos5)
		end
	end
	minetest.remove_node(pos)
	minetest.set_node(new_pos, {name="signs_bot:robot", param2=param2})
	minetest.sound_play('signs_bot_step', {pos = new_pos})
	return new_pos
end	
	
function signs_bot.backward_robot(pos, param2)
	local pos1 = lib.next_pos(pos, (param2 + 2) % 4)
	local pos2 = {x=pos1.x, y=pos1.y-1, z=pos1.z}
	local pos4 = {x=pos.x, y=pos.y-1, z=pos.z}
	local pos5 = {x=pos.x, y=pos.y-2, z=pos.z}
	local new_pos = nil
	
	if lib.check_pos(pos1, pos2) then  -- one step forward
		new_pos = pos1
	else
		return nil -- blocked
	end
	local node4 = lib.get_node_lvm(pos4)
	if node4.name == "signs_bot:robot_foot" or node4.name == "signs_bot:robot_leg" then
		minetest.remove_node(pos4)
		local node5 = lib.get_node_lvm(pos5)
		if node5.name == "signs_bot:robot_foot" then
			minetest.remove_node(pos5)
		end
	end
	minetest.remove_node(pos)
	minetest.set_node(new_pos, {name="signs_bot:robot", param2=param2})
	minetest.sound_play('signs_bot_step', {pos = new_pos})
	return new_pos
end	

function signs_bot.turn_robot(pos, param2, dir)
	if dir == "R" then
		param2 = (param2 + 1) % 4
	else
		param2 = (param2 + 3) % 4
	end
	minetest.swap_node(pos, {name="signs_bot:robot", param2=param2})
	minetest.sound_play('signs_bot_step', {pos = pos, gain = 0.6})
	return param2
end	

-- Positions to check:
--   1
--  [R]  
--   2
function signs_bot.robot_up(pos, param2)
	local pos1 = {x=pos.x, y=pos.y+1, z=pos.z}
	local pos2 = {x=pos.x, y=pos.y-1, z=pos.z}
	if lib.check_pos(pos1, pos2) then
		local node = lib.get_node_lvm(pos2)
		if node.name == "signs_bot:robot_leg" then 
			return nil
		elseif node.name == "signs_bot:robot_foot" then 
			minetest.swap_node(pos, {name="signs_bot:robot_leg"})
		else
			minetest.swap_node(pos, {name="signs_bot:robot_foot"})
		end
		minetest.set_node(pos1, {name="signs_bot:robot", param2=param2})
		minetest.sound_play('signs_bot_step', {pos = pos1})
		return pos1
	end
	return nil
end	

-- Positions to check:
--  [R]  
--   1
--   2
--   3
function signs_bot.robot_down(pos, param2)
	local pos1 = {x=pos.x, y=pos.y-1, z=pos.z}
	local pos2 = {x=pos.x, y=pos.y-2, z=pos.z}
	local pos3 = {x=pos.x, y=pos.y-3, z=pos.z}
	local node1 = lib.get_node_lvm(pos1)
	if lib.check_pos(pos1, pos2) 
	or (node1.name == "air" and lib.check_pos(pos2, pos3))
	or (node1.name == "signs_bot:robot_leg" or node1.name == "signs_bot:robot_foot") then
		minetest.remove_node(pos)
		minetest.set_node(pos1, {name="signs_bot:robot", param2=param2})
		minetest.sound_play('signs_bot_step', {pos = pos1})
		return pos1
	end
	return nil
end