Difference between revisions of "Complete Roguelike Tutorial, using python+libtcod, extras scrolling code"

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<center><h1>'''Map Scrolling & Advanced Map Generation'''</h1></center>
<center><h1>'''Extras'''</h1></center>





Revision as of 07:59, 13 November 2011

This is part of the code for a series of tutorials; the main page can be found here.



Extras


Map Scrolling

Note to reader: I found this post buried deep in side a tutorial writing thread, that never made it's way here. I apologize for the brevity, but hopefully others will find this sample code as useful as I have! - Hadlock

http://doryen.eptalys.net/forum/index.php?topic=328.300

« Reply #304 on: September 14, 2011, 05:24:01 am » Thanks for the kind words Nikolai, it's really appreciated And thank you Isher, for sharing those changes; it's great to know how to move to the latest versions without breaking stuff (I'll do that at some point). Stitch, I'll be using a VCS soon, and will probably upload a clean version to an online repository when it's finished

It seems a popular change to the code is to introduce scrolling, but it's also the hardest. I know, I coded and re-coded the "ultimate" scrolling code many times now... the first attempts were really difficult and I wasn't even sure why it was working Anyway, I'm preparing an extra on that.

So, without further ado... here's the map scrolling code for you to download. I'll try to write the explanation soon. If you find any bugs please tell me, it's not 100% tested

Tip: run a diff against the latest tutorial code if you want to highlight just the changes.

(edit: corrected bug! didn't take long to find one...)


#!/usr/bin/python
#
# libtcod python tutorial
#

import libtcodpy as libtcod
import math
import textwrap
import shelve

#actual size of the window
SCREEN_WIDTH = 80
SCREEN_HEIGHT = 50

#size of the map portion shown on-screen
CAMERA_WIDTH = 80
CAMERA_HEIGHT = 43

#size of the map
MAP_WIDTH = 100
MAP_HEIGHT = 100

#sizes and coordinates relevant for the GUI
BAR_WIDTH = 20
PANEL_HEIGHT = 7
PANEL_Y = SCREEN_HEIGHT - PANEL_HEIGHT
MSG_X = BAR_WIDTH + 2
MSG_WIDTH = SCREEN_WIDTH - BAR_WIDTH - 2
MSG_HEIGHT = PANEL_HEIGHT - 1
INVENTORY_WIDTH = 50

#parameters for dungeon generator
ROOM_MAX_SIZE = 10
ROOM_MIN_SIZE = 6
MAX_ROOMS = 50
MAX_ROOM_MONSTERS = 3
MAX_ROOM_ITEMS = 2

#spell values
HEAL_AMOUNT = 4
LIGHTNING_DAMAGE = 20
LIGHTNING_RANGE = 5
CONFUSE_RANGE = 8
CONFUSE_NUM_TURNS = 10
FIREBALL_RADIUS = 3
FIREBALL_DAMAGE = 12


FOV_ALGO = 0  #default FOV algorithm
FOV_LIGHT_WALLS = True  #light walls or not
TORCH_RADIUS = 10

LIMIT_FPS = 20  #20 frames-per-second maximum


color_dark_wall = libtcod.Color(0, 0, 100)
color_light_wall = libtcod.Color(130, 110, 50)
color_dark_ground = libtcod.Color(50, 50, 150)
color_light_ground = libtcod.Color(200, 180, 50)


class Tile:
	#a tile of the map and its properties
	def __init__(self, blocked, block_sight = None):
		self.blocked = blocked
		
		#all tiles start unexplored
		self.explored = False
		
		#by default, if a tile is blocked, it also blocks sight
		if block_sight is None: block_sight = blocked
		self.block_sight = block_sight

class Rect:
	#a rectangle on the map. used to characterize a room.
	def __init__(self, x, y, w, h):
		self.x1 = x
		self.y1 = y
		self.x2 = x + w
		self.y2 = y + h
	
	def center(self):
		center_x = (self.x1 + self.x2) / 2
		center_y = (self.y1 + self.y2) / 2
		return (center_x, center_y)
	
	def intersect(self, other):
		#returns true if this rectangle intersects with another one
		return (self.x1 <= other.x2 and self.x2 >= other.x1 and
				self.y1 <= other.y2 and self.y2 >= other.y1)

class Object:
	#this is a generic object: the player, a monster, an item, the stairs...
	#it's always represented by a character on screen.
	def __init__(self, x, y, char, name, color, blocks=False, fighter=None, ai=None, item=None):
		self.x = x
		self.y = y
		self.char = char
		self.name = name
		self.color = color
		self.blocks = blocks
		self.fighter = fighter
		if self.fighter:  #let the fighter component know who owns it
			self.fighter.owner = self
		
		self.ai = ai
		if self.ai:  #let the AI component know who owns it
			self.ai.owner = self
		
		self.item = item
		if self.item:  #let the Item component know who owns it
			self.item.owner = self
	
	def move(self, dx, dy):
		#move by the given amount, if the destination is not blocked
		if not is_blocked(self.x + dx, self.y + dy):
			self.x += dx
			self.y += dy
	
	def move_towards(self, target_x, target_y):
		#vector from this object to the target, and distance
		dx = target_x - self.x
		dy = target_y - self.y
		distance = math.sqrt(dx ** 2 + dy ** 2)
		
		#normalize it to length 1 (preserving direction), then round it and
		#convert to integer so the movement is restricted to the map grid
		dx = int(round(dx / distance))
		dy = int(round(dy / distance))
		self.move(dx, dy)
	
	def distance_to(self, other):
		#return the distance to another object
		dx = other.x - self.x
		dy = other.y - self.y
		return math.sqrt(dx ** 2 + dy ** 2)
	
	def distance(self, x, y):
		#return the distance to some coordinates
		return math.sqrt((x - self.x) ** 2 + (y - self.y) ** 2)
	
	def send_to_back(self):
		#make this object be drawn first, so all others appear above it if they're in the same tile.
		global objects
		objects.remove(self)
		objects.insert(0, self)
	
	def draw(self):
		#only show if it's visible to the player
		if libtcod.map_is_in_fov(fov_map, self.x, self.y):
			(x, y) = to_camera_coordinates(self.x, self.y)
			
			if x is not None:
				#set the color and then draw the character that represents this object at its position
				libtcod.console_set_foreground_color(con, self.color)
				libtcod.console_put_char(con, x, y, self.char, libtcod.BKGND_NONE)
	
	def clear(self):
		#erase the character that represents this object
		(x, y) = to_camera_coordinates(self.x, self.y)
		if x is not None:
			libtcod.console_put_char(con, x, y, ' ', libtcod.BKGND_NONE)


class Fighter:
	#combat-related properties and methods (monster, player, NPC).
	def __init__(self, hp, defense, power, death_function=None):
		self.max_hp = hp
		self.hp = hp
		self.defense = defense
		self.power = power
		self.death_function = death_function
	
	def attack(self, target):
		#a simple formula for attack damage
		damage = self.power - target.fighter.defense
		
		if damage > 0:
			#make the target take some damage
			message(self.owner.name.capitalize() + ' attacks ' + target.name + ' for ' + str(damage) + ' hit points.')
			target.fighter.take_damage(damage)
		else:
			message(self.owner.name.capitalize() + ' attacks ' + target.name + ' but it has no effect!')
	
	def take_damage(self, damage):
		#apply damage if possible
		if damage > 0:
			self.hp -= damage
			
			#check for death. if there's a death function, call it
			if self.hp <= 0:
				function = self.death_function
				if function is not None:
					function(self.owner)
	
	def heal(self, amount):
		#heal by the given amount, without going over the maximum
		self.hp += amount
		if self.hp > self.max_hp:
			self.hp = self.max_hp

class BasicMonster:
	#AI for a basic monster.
	def take_turn(self):
		#a basic monster takes its turn. if you can see it, it can see you
		monster = self.owner
		if libtcod.map_is_in_fov(fov_map, monster.x, monster.y):
			
			#move towards player if far away
			if monster.distance_to(player) >= 2:
				monster.move_towards(player.x, player.y)
				
			#close enough, attack! (if the player is still alive.)
			elif player.fighter.hp > 0:
				monster.fighter.attack(player)

class ConfusedMonster:
	#AI for a temporarily confused monster (reverts to previous AI after a while).
	def __init__(self, old_ai, num_turns=CONFUSE_NUM_TURNS):
		self.old_ai = old_ai
		self.num_turns = num_turns
	
	def take_turn(self):
		if self.num_turns > 0:  #still confused...
			#move in a random direction, and decrease the number of turns confused
			self.owner.move(libtcod.random_get_int(0, -1, 1), libtcod.random_get_int(0, -1, 1))
			self.num_turns -= 1
			
		else:  #restore the previous AI (this one will be deleted because it's not referenced anymore)
			self.owner.ai = self.old_ai
			message('The ' + self.owner.name + ' is no longer confused!', libtcod.red)


class Item:
	#an item that can be picked up and used.
	def __init__(self, use_function=None):
		self.use_function = use_function
	
	def pick_up(self):
		#add to the player's inventory and remove from the map
		if len(inventory) >= 26:
			message('Your inventory is full, cannot pick up ' + self.owner.name + '.', libtcod.red)
		else:
			inventory.append(self.owner)
			objects.remove(self.owner)
			message('You picked up a ' + self.owner.name + '!', libtcod.green)
		
	def drop(self):
		#add to the map and remove from the player's inventory. also, place it at the player's coordinates
		objects.append(self.owner)
		inventory.remove(self.owner)
		self.owner.x = player.x
		self.owner.y = player.y
		message('You dropped a ' + self.owner.name + '.', libtcod.yellow)
	
	def use(self):
		#just call the "use_function" if it is defined
		if self.use_function is None:
			message('The ' + self.owner.name + ' cannot be used.')
		else:
			if self.use_function() != 'cancelled':
				inventory.remove(self.owner)  #destroy after use, unless it was cancelled for some reason

def is_blocked(x, y):
	#first test the map tile
	if map[x][y].blocked:
		return True
	
	#now check for any blocking objects
	for object in objects:
		if object.blocks and object.x == x and object.y == y:
			return True
	
	return False

def create_room(room):
	global map
	#go through the tiles in the rectangle and make them passable
	for x in range(room.x1 + 1, room.x2):
		for y in range(room.y1 + 1, room.y2):
			map[x][y].blocked = False
			map[x][y].block_sight = False

def create_h_tunnel(x1, x2, y):
	global map
	#horizontal tunnel. min() and max() are used in case x1>x2
	for x in range(min(x1, x2), max(x1, x2) + 1):
		map[x][y].blocked = False
		map[x][y].block_sight = False

def create_v_tunnel(y1, y2, x):
	global map
	#vertical tunnel
	for y in range(min(y1, y2), max(y1, y2) + 1):
		map[x][y].blocked = False
		map[x][y].block_sight = False

def make_map():
	global map, objects
	
	#the list of objects with just the player
	objects = [player]
	
	#fill map with "blocked" tiles
	map = [[ Tile(True)
		for y in range(MAP_HEIGHT) ]
			for x in range(MAP_WIDTH) ]

	rooms = []
	num_rooms = 0
	
	for r in range(MAX_ROOMS):
		#random width and height
		w = libtcod.random_get_int(0, ROOM_MIN_SIZE, ROOM_MAX_SIZE)
		h = libtcod.random_get_int(0, ROOM_MIN_SIZE, ROOM_MAX_SIZE)
		#random position without going out of the boundaries of the map
		x = libtcod.random_get_int(0, 0, MAP_WIDTH - w - 1)
		y = libtcod.random_get_int(0, 0, MAP_HEIGHT - h - 1)
		
		#"Rect" class makes rectangles easier to work with
		new_room = Rect(x, y, w, h)
		
		#run through the other rooms and see if they intersect with this one
		failed = False
		for other_room in rooms:
			if new_room.intersect(other_room):
				failed = True
				break
		
		if not failed:
			#this means there are no intersections, so this room is valid
			
			#"paint" it to the map's tiles
			create_room(new_room)
			
			#add some contents to this room, such as monsters
			place_objects(new_room)
			
			#center coordinates of new room, will be useful later
			(new_x, new_y) = new_room.center()
			
			if num_rooms == 0:
				#this is the first room, where the player starts at
				player.x = new_x
				player.y = new_y
			else:
				#all rooms after the first:
				#connect it to the previous room with a tunnel
				
				#center coordinates of previous room
				(prev_x, prev_y) = rooms[num_rooms-1].center()
				
				#draw a coin (random number that is either 0 or 1)
				if libtcod.random_get_int(0, 0, 1) == 1:
					#first move horizontally, then vertically
					create_h_tunnel(prev_x, new_x, prev_y)
					create_v_tunnel(prev_y, new_y, new_x)
				else:
					#first move vertically, then horizontally
					create_v_tunnel(prev_y, new_y, prev_x)
					create_h_tunnel(prev_x, new_x, new_y)
			
			#finally, append the new room to the list
			rooms.append(new_room)
			num_rooms += 1

			
def place_objects(room):
	#choose random number of monsters
	num_monsters = libtcod.random_get_int(0, 0, MAX_ROOM_MONSTERS)
	
	for i in range(num_monsters):
		#choose random spot for this monster
		x = libtcod.random_get_int(0, room.x1+1, room.x2-1)
		y = libtcod.random_get_int(0, room.y1+1, room.y2-1)
		
		#only place it if the tile is not blocked
		if not is_blocked(x, y):
			if libtcod.random_get_int(0, 0, 100) < 80:  #80% chance of getting an orc
				#create an orc
				fighter_component = Fighter(hp=10, defense=0, power=3, death_function=monster_death)
				ai_component = BasicMonster()
				
				monster = Object(x, y, 'o', 'orc', libtcod.desaturated_green,
					blocks=True, fighter=fighter_component, ai=ai_component)
			else:
				#create a troll
				fighter_component = Fighter(hp=16, defense=1, power=4, death_function=monster_death)
				ai_component = BasicMonster()
				
				monster = Object(x, y, 'T', 'troll', libtcod.darker_green,
					blocks=True, fighter=fighter_component, ai=ai_component)
			
			objects.append(monster)
	
	#choose random number of items
	num_items = libtcod.random_get_int(0, 0, MAX_ROOM_ITEMS)
	
	for i in range(num_items):
		#choose random spot for this item
		x = libtcod.random_get_int(0, room.x1+1, room.x2-1)
		y = libtcod.random_get_int(0, room.y1+1, room.y2-1)
		
		#only place it if the tile is not blocked
		if not is_blocked(x, y):
			dice = libtcod.random_get_int(0, 0, 100)
			if dice < 70:
				#create a healing potion (70% chance)
				item_component = Item(use_function=cast_heal)
				
				item = Object(x, y, '!', 'healing potion', libtcod.violet, item=item_component)
			elif dice < 70+10:
				#create a lightning bolt scroll (10% chance)
				item_component = Item(use_function=cast_lightning)
				
				item = Object(x, y, '#', 'scroll of lightning bolt', libtcod.light_yellow, item=item_component)
			elif dice < 70+10+10:
				#create a fireball scroll (10% chance)
				item_component = Item(use_function=cast_fireball)
				
				item = Object(x, y, '#', 'scroll of fireball', libtcod.light_yellow, item=item_component)
			else:
				#create a confuse scroll (10% chance)
				item_component = Item(use_function=cast_confuse)
				
				item = Object(x, y, '#', 'scroll of confusion', libtcod.light_yellow, item=item_component)
			
			objects.append(item)
			item.send_to_back()  #items appear below other objects


def render_bar(x, y, total_width, name, value, maximum, bar_color, back_color):
	#render a bar (HP, experience, etc). first calculate the width of the bar
	bar_width = int(float(value) / maximum * total_width)
	
	#render the background first
	libtcod.console_set_background_color(panel, back_color)
	libtcod.console_rect(panel, x, y, total_width, 1, False)
	
	#now render the bar on top
	libtcod.console_set_background_color(panel, bar_color)
	if bar_width > 0:
		libtcod.console_rect(panel, x, y, bar_width, 1, False)
	
	#finally, some centered text with the values
	libtcod.console_set_foreground_color(panel, libtcod.white)
	libtcod.console_print_center(panel, x + total_width / 2, y, libtcod.BKGND_NONE,
		name + ': ' + str(value) + '/' + str(maximum))

def get_names_under_mouse():
	#return a string with the names of all objects under the mouse
	mouse = libtcod.mouse_get_status()
	(x, y) = (mouse.cx, mouse.cy)
	(x, y) = (camera_x + x, camera_y + y)  #from screen to map coordinates
	
	#create a list with the names of all objects at the mouse's coordinates and in FOV
	names = [obj.name for obj in objects
		if obj.x == x and obj.y == y and libtcod.map_is_in_fov(fov_map, obj.x, obj.y)]
	
	names = ', '.join(names)  #join the names, separated by commas
	return names.capitalize()

def move_camera(target_x, target_y):
	global camera_x, camera_y, fov_recompute
	
	#new camera coordinates (top-left corner of the screen relative to the map)
	x = target_x - CAMERA_WIDTH / 2  #coordinates so that the target is at the center of the screen
	y = target_y - CAMERA_HEIGHT / 2
	
	#make sure the camera doesn't see outside the map
	if x < 0: x = 0
	if y < 0: y = 0
	if x > MAP_WIDTH - CAMERA_WIDTH - 1: x = MAP_WIDTH - CAMERA_WIDTH - 1
	if y > MAP_HEIGHT - CAMERA_HEIGHT - 1: y = MAP_HEIGHT - CAMERA_HEIGHT - 1
	
	if x != camera_x or y != camera_y: fov_recompute = True
	
	(camera_x, camera_y) = (x, y)

def to_camera_coordinates(x, y):
	#convert coordinates on the map to coordinates on the screen
	(x, y) = (x - camera_x, y - camera_y)
	
	if (x < 0 or y < 0 or x >= CAMERA_WIDTH or y >= CAMERA_HEIGHT):
		return (None, None)  #if it's outside the view, return nothing
	
	return (x, y)

def render_all():
	global fov_map, color_dark_wall, color_light_wall
	global color_dark_ground, color_light_ground
	global fov_recompute
	
	move_camera(player.x, player.y)
	
	if fov_recompute:
		#recompute FOV if needed (the player moved or something)
		fov_recompute = False
		libtcod.map_compute_fov(fov_map, player.x, player.y, TORCH_RADIUS, FOV_LIGHT_WALLS, FOV_ALGO)
		libtcod.console_clear(con)

		#go through all tiles, and set their background color according to the FOV
		for y in range(CAMERA_HEIGHT):
			for x in range(CAMERA_WIDTH):
				(map_x, map_y) = (camera_x + x, camera_y + y)
				visible = libtcod.map_is_in_fov(fov_map, map_x, map_y)
				
				wall = map[map_x][map_y].block_sight
				if not visible:
					#if it's not visible right now, the player can only see it if it's explored
					if map[map_x][map_y].explored:
						if wall:
							libtcod.console_set_back(con, x, y, color_dark_wall, libtcod.BKGND_SET)
						else:
							libtcod.console_set_back(con, x, y, color_dark_ground, libtcod.BKGND_SET)
				else:
					#it's visible
					if wall:
						libtcod.console_set_back(con, x, y, color_light_wall, libtcod.BKGND_SET )
					else:
						libtcod.console_set_back(con, x, y, color_light_ground, libtcod.BKGND_SET )
					#since it's visible, explore it
					map[map_x][map_y].explored = True

	#draw all objects in the list, except the player. we want it to
	#always appear over all other objects! so it's drawn later.
	for object in objects:
		if object != player:
			object.draw()
	player.draw()
	
	#blit the contents of "con" to the root console
	libtcod.console_blit(con, 0, 0, MAP_WIDTH, MAP_HEIGHT, 0, 0, 0)
	
	
	#prepare to render the GUI panel
	libtcod.console_set_background_color(panel, libtcod.black)
	libtcod.console_clear(panel)
	
	#print the game messages, one line at a time
	y = 1
	for (line, color) in game_msgs:
		libtcod.console_set_foreground_color(panel, color)
		libtcod.console_print_left(panel, MSG_X, y, libtcod.BKGND_NONE, line)
		y += 1
	
	#show the player's stats
	render_bar(1, 1, BAR_WIDTH, 'HP', player.fighter.hp, player.fighter.max_hp,
		libtcod.light_red, libtcod.darker_red)
	
	#display names of objects under the mouse
	libtcod.console_set_foreground_color(panel, libtcod.light_gray)
	libtcod.console_print_left(panel, 1, 0, libtcod.BKGND_NONE, get_names_under_mouse())
	
	#blit the contents of "panel" to the root console
	libtcod.console_blit(panel, 0, 0, SCREEN_WIDTH, PANEL_HEIGHT, 0, 0, PANEL_Y)
	

def message(new_msg, color = libtcod.white):
	#split the message if necessary, among multiple lines
	new_msg_lines = textwrap.wrap(new_msg, MSG_WIDTH)
	
	for line in new_msg_lines:
		#if the buffer is full, remove the first line to make room for the new one
		if len(game_msgs) == MSG_HEIGHT:
			del game_msgs[0]
		
		#add the new line as a tuple, with the text and the color
		game_msgs.append( (line, color) )


def player_move_or_attack(dx, dy):
	global fov_recompute
	
	#the coordinates the player is moving to/attacking
	x = player.x + dx
	y = player.y + dy
	
	#try to find an attackable object there
	target = None
	for object in objects:
		if object.fighter and object.x == x and object.y == y:
			target = object
			break
	
	#attack if target found, move otherwise
	if target is not None:
		player.fighter.attack(target)
	else:
		player.move(dx, dy)
		fov_recompute = True


def menu(header, options, width):
	if len(options) > 26: raise ValueError('Cannot have a menu with more than 26 options.')
	
	#calculate total height for the header (after auto-wrap) and one line per option
	header_height = libtcod.console_height_left_rect(con, 0, 0, width, SCREEN_HEIGHT, header)
	if header == '':
		header_height = 0
	height = len(options) + header_height
	
	#create an off-screen console that represents the menu's window
	window = libtcod.console_new(width, height)
	
	#print the header, with auto-wrap
	libtcod.console_set_foreground_color(window, libtcod.white)
	libtcod.console_print_left_rect(window, 0, 0, width, height, libtcod.BKGND_NONE, header)
	
	#print all the options
	y = header_height
	letter_index = ord('a')
	for option_text in options:
		text = '(' + chr(letter_index) + ') ' + option_text
		libtcod.console_print_left(window, 0, y, libtcod.BKGND_NONE, text)
		y += 1
		letter_index += 1
	
	#blit the contents of "window" to the root console
	x = SCREEN_WIDTH/2 - width/2
	y = SCREEN_HEIGHT/2 - height/2
	libtcod.console_blit(window, 0, 0, width, height, 0, x, y, 1.0, 0.7)
	
	#present the root console to the player and wait for a key-press
	libtcod.console_flush()
	key = libtcod.console_wait_for_keypress(True)
	
	if key.vk == libtcod.KEY_ENTER and key.lalt:  #(special case) Alt+Enter: toggle fullscreen
		libtcod.console_set_fullscreen(not libtcod.console_is_fullscreen())
	
	#convert the ASCII code to an index; if it corresponds to an option, return it
	index = key.c - ord('a')
	if index >= 0 and index < len(options): return index
	return None

def inventory_menu(header):
	#show a menu with each item of the inventory as an option
	if len(inventory) == 0:
		options = ['Inventory is empty.']
	else:
		options = [item.name for item in inventory]
	
	index = menu(header, options, INVENTORY_WIDTH)
	
	#if an item was chosen, return it
	if index is None or len(inventory) == 0: return None
	return inventory[index].item

def msgbox(text, width=50):
	menu(text, [], width)  #use menu() as a sort of "message box"

def handle_keys():
	key = libtcod.console_check_for_keypress(libtcod.KEY_PRESSED)
	
	if key.vk == libtcod.KEY_ENTER and key.lalt:
		#Alt+Enter: toggle fullscreen
		libtcod.console_set_fullscreen(not libtcod.console_is_fullscreen())
		
	elif key.vk == libtcod.KEY_ESCAPE:
		return 'exit'  #exit game
	
	if game_state == 'playing':
		#movement keys
		if key.vk == libtcod.KEY_UP:
			player_move_or_attack(0, -1)
			
		elif key.vk == libtcod.KEY_DOWN:
			player_move_or_attack(0, 1)
			
		elif key.vk == libtcod.KEY_LEFT:
			player_move_or_attack(-1, 0)
			
		elif key.vk == libtcod.KEY_RIGHT:
			player_move_or_attack(1, 0)
		else:
			#test for other keys
			key_char = chr(key.c)
			
			if key_char == 'g':
				#pick up an item
				for object in objects:  #look for an item in the player's tile
					if object.x == player.x and object.y == player.y and object.item:
						object.item.pick_up()
						break
			
			if key_char == 'i':
				#show the inventory; if an item is selected, use it
				chosen_item = inventory_menu('Press the key next to an item to use it, or any other to cancel.\n')
				if chosen_item is not None:
					chosen_item.use()
			
			if key_char == 'd':
				#show the inventory; if an item is selected, drop it
				chosen_item = inventory_menu('Press the key next to an item to drop it, or any other to cancel.\n')
				if chosen_item is not None:
					chosen_item.drop()
			
			return 'didnt-take-turn'

def player_death(player):
	#the game ended!
	global game_state
	message('You died!', libtcod.red)
	game_state = 'dead'
	
	#for added effect, transform the player into a corpse!
	player.char = '%'
	player.color = libtcod.dark_red

def monster_death(monster):
	#transform it into a nasty corpse! it doesn't block, can't be
	#attacked and doesn't move
	message(monster.name.capitalize() + ' is dead!', libtcod.orange)
	monster.char = '%'
	monster.color = libtcod.dark_red
	monster.blocks = False
	monster.fighter = None
	monster.ai = None
	monster.name = 'remains of ' + monster.name
	monster.send_to_back()

def target_tile(max_range=None):
	#return the position of a tile left-clicked in player's FOV (optionally in a range), or (None,None) if right-clicked.
	while True:
		#render the screen. this erases the inventory and shows the names of objects under the mouse.
		render_all()
		libtcod.console_flush()
		
		key = libtcod.console_check_for_keypress()
		mouse = libtcod.mouse_get_status()  #get mouse position and click status
		(x, y) = (mouse.cx, mouse.cy)
		(x, y) = (camera_x + x, camera_y + y)  #from screen to map coordinates
		
		if mouse.rbutton_pressed or key.vk == libtcod.KEY_ESCAPE:
			return (None, None)  #cancel if the player right-clicked or pressed Escape
		
		#accept the target if the player clicked in FOV, and in case a range is specified, if it's in that range
		if (mouse.lbutton_pressed and libtcod.map_is_in_fov(fov_map, x, y) and
			(max_range is None or player.distance(x, y) <= max_range)):
			return (x, y)

def target_monster(max_range=None):
	#returns a clicked monster inside FOV up to a range, or None if right-clicked
	while True:
		(x, y) = target_tile(max_range)
		if x is None:  #player cancelled
			return None
		
		#return the first clicked monster, otherwise continue looping
		for obj in objects:
			if obj.x == x and obj.y == y and obj.fighter and obj != player:
				return obj

def closest_monster(max_range):
	#find closest enemy, up to a maximum range, and in the player's FOV
	closest_enemy = None
	closest_dist = max_range + 1  #start with (slightly more than) maximum range
	
	for object in objects:
		if object.fighter and not object == player and libtcod.map_is_in_fov(fov_map, object.x, object.y):
			#calculate distance between this object and the player
			dist = player.distance_to(object)
			if dist < closest_dist:  #it's closer, so remember it
				closest_enemy = object
				closest_dist = dist
	return closest_enemy

def cast_heal():
	#heal the player
	if player.fighter.hp == player.fighter.max_hp:
		message('You are already at full health.', libtcod.red)
		return 'cancelled'
	
	message('Your wounds start to feel better!', libtcod.light_violet)
	player.fighter.heal(HEAL_AMOUNT)

def cast_lightning():
	#find closest enemy (inside a maximum range) and damage it
	monster = closest_monster(LIGHTNING_RANGE)
	if monster is None:  #no enemy found within maximum range
		message('No enemy is close enough to strike.', libtcod.red)
		return 'cancelled'
	
	#zap it!
	message('A lighting bolt strikes the ' + monster.name + ' with a loud thunder! The damage is '
		+ str(LIGHTNING_DAMAGE) + ' hit points.', libtcod.light_blue)
	monster.fighter.take_damage(LIGHTNING_DAMAGE)

def cast_fireball():
	#ask the player for a target tile to throw a fireball at
	message('Left-click a target tile for the fireball, or right-click to cancel.', libtcod.light_cyan)
	(x, y) = target_tile()
	if x is None: return 'cancelled'
	message('The fireball explodes, burning everything within ' + str(FIREBALL_RADIUS) + ' tiles!', libtcod.orange)
	
	for obj in objects:  #damage every fighter in range, including the player
		if obj.distance(x, y) <= FIREBALL_RADIUS and obj.fighter:
			message('The ' + obj.name + ' gets burned for ' + str(FIREBALL_DAMAGE) + ' hit points.', libtcod.orange)
			obj.fighter.take_damage(FIREBALL_DAMAGE)
	
def cast_confuse():
	#ask the player for a target to confuse
	message('Left-click an enemy to confuse it, or right-click to cancel.', libtcod.light_cyan)
	monster = target_monster(CONFUSE_RANGE)
	if monster is None: return 'cancelled'
	
	#replace the monster's AI with a "confused" one; after some turns it will restore the old AI
	old_ai = monster.ai
	monster.ai = ConfusedMonster(old_ai)
	monster.ai.owner = monster  #tell the new component who owns it
	message('The eyes of the ' + monster.name + ' look vacant, as he starts to stumble around!', libtcod.light_green)


def save_game():
	#open a new empty shelve (possibly overwriting an old one) to write the game data
	file = shelve.open('savegame', 'n')
	file['map'] = map
	file['objects'] = objects
	file['player_index'] = objects.index(player)  #index of player in objects list
	file['inventory'] = inventory
	file['game_msgs'] = game_msgs
	file['game_state'] = game_state
	file.close()

def load_game():
	#open the previously saved shelve and load the game data
	global map, objects, player, stairs, inventory, game_msgs, game_state
	
	file = shelve.open('savegame', 'r')
	map = file['map']
	objects = file['objects']
	player = objects[file['player_index']]  #get index of player in objects list and access it
	inventory = file['inventory']
	game_msgs = file['game_msgs']
	game_state = file['game_state']
	file.close()
	
	initialize_fov()

def new_game():
	global player, inventory, game_msgs, game_state
	
	#create object representing the player
	fighter_component = Fighter(hp=30, defense=2, power=5, death_function=player_death)
	player = Object(0, 0, '@', 'player', libtcod.white, blocks=True, fighter=fighter_component)

	#generate map (at this point it's not drawn to the screen)
	make_map()
	initialize_fov()

	game_state = 'playing'
	inventory = []

	#create the list of game messages and their colors, starts empty
	game_msgs = []

	#a warm welcoming message!
	message('Welcome stranger! Prepare to perish in the Tombs of the Ancient Kings.', libtcod.red)

def initialize_fov():
	global fov_recompute, fov_map
	fov_recompute = True
	
	#create the FOV map, according to the generated map
	fov_map = libtcod.map_new(MAP_WIDTH, MAP_HEIGHT)
	for y in range(MAP_HEIGHT):
		for x in range(MAP_WIDTH):
			libtcod.map_set_properties(fov_map, x, y, not map[x][y].blocked, not map[x][y].block_sight)
	
	libtcod.console_clear(con)  #unexplored areas start black (which is the default background color)
	
def play_game():
	global camera_x, camera_y
	
	player_action = None
	(camera_x, camera_y) = (0, 0)
	
	while not libtcod.console_is_window_closed():
		#render the screen
		render_all()
		
		libtcod.console_flush()

		#erase all objects at their old locations, before they move
		for object in objects:
			object.clear()
		
		#handle keys and exit game if needed
		player_action = handle_keys()
		if player_action == 'exit':
			save_game()
			break
		
		#let monsters take their turn
		if game_state == 'playing' and player_action != 'didnt-take-turn':
			for object in objects:
				if object.ai:
					object.ai.take_turn()

def main_menu():
	img = libtcod.image_load('menu_background.png')
	
	while not libtcod.console_is_window_closed():
		#show the background image, at twice the regular console resolution
		libtcod.image_blit_2x(img, 0, 0, 0)
		
		#show the game's title, and some credits!
		libtcod.console_set_foreground_color(0, libtcod.light_yellow)
		libtcod.console_print_center(0, SCREEN_WIDTH/2, SCREEN_HEIGHT/2-4, libtcod.BKGND_NONE, 'TOMBS OF THE ANCIENT KINGS')
		libtcod.console_print_center(0, SCREEN_WIDTH/2, SCREEN_HEIGHT-2, libtcod.BKGND_NONE, 'By Jotaf')
		
		#show options and wait for the player's choice
		choice = menu('', ['Play a new game', 'Continue last game', 'Quit'], 24)
		
		if choice == 0:  #new game
			new_game()
			play_game()
		if choice == 1:  #load last game
			try:
				load_game()
			except:
				msgbox('\n No saved game to load.\n', 24)
				continue
			play_game()
		elif choice == 2:  #quit
			break

libtcod.console_set_custom_font('arial10x10.png', libtcod.FONT_TYPE_GREYSCALE | libtcod.FONT_LAYOUT_TCOD)
libtcod.console_init_root(SCREEN_WIDTH, SCREEN_HEIGHT, 'python/libtcod tutorial', False)
libtcod.sys_set_fps(LIMIT_FPS)
con = libtcod.console_new(MAP_WIDTH, MAP_HEIGHT)
panel = libtcod.console_new(SCREEN_WIDTH, PANEL_HEIGHT)

main_menu()