View source for Roguelike Tutorial, using python3+tdl, part 8 code

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This is part of a series of tutorials; the main page can be found [[Roguelike Tutorial, using python3+tdl|here]].

The tutorial uses tdl version 3.1.0 and Python 3.5
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== Items and inventory ==

<div style="background-color: #EEEEEE; border-style: dotted"><syntaxhighlight lang="python">
#!/usr/bin/env python3

import tdl
from random import randint
import colors
import math
import textwrap


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

#size of the map
MAP_WIDTH = 80
MAP_HEIGHT = 43

#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 = 30
MAX_ROOM_MONSTERS = 3
MAX_ROOM_ITEMS = 2
 
#spell values
HEAL_AMOUNT = 4


FOV_ALGO = 'BASIC'
FOV_LIGHT_WALLS = True
TORCH_RADIUS = 10

LIMIT_FPS = 20  #20 frames-per-second maximum


color_dark_wall = (0, 0, 100)
color_light_wall = (130, 110, 50)
color_dark_ground = (50, 50, 150)
color_light_ground = (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 GameObject:
    #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.color = color
        self.name = name
        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 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):
        global visible_tiles

        #only show if it's visible to the player
        if (self.x, self.y) in visible_tiles:
            #draw the character that represents this object at its position
            con.draw_char(self.x, self.y, self.char, self.color, bg=None)

    def clear(self):
        #erase the character that represents this object
        con.draw_char(self.x, self.y, ' ', self.color, bg=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 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 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 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 (monster.x, monster.y) in visible_tiles:
    
            #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 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 + '.', colors.red)
        else:
            inventory.append(self.owner)
            objects.remove(self.owner)
            message('You picked up a ' + self.owner.name + '!', colors.green)

    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 my_map[x][y].blocked:
        return True
 
    #now check for any blocking objects
    for obj in objects:
        if obj.blocks and obj.x == x and obj.y == y:
            return True
 
    return False

def create_room(room):
    global my_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):
            my_map[x][y].blocked = False
            my_map[x][y].block_sight = False

def create_h_tunnel(x1, x2, y):
    global my_map
    for x in range(min(x1, x2), max(x1, x2) + 1):
        my_map[x][y].blocked = False
        my_map[x][y].block_sight = False

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


def is_visible_tile(x, y):
    global my_map

    if x >= MAP_WIDTH or x < 0:
        return False
    elif y >= MAP_HEIGHT or y < 0:
        return False
    elif my_map[x][y].blocked == True:
        return False
    elif my_map[x][y].block_sight == True:
        return False
    else:
        return True

def make_map():
    global my_map
 
    #fill map with "blocked" tiles
    my_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 = randint(ROOM_MIN_SIZE, ROOM_MAX_SIZE)
        h = randint(ROOM_MIN_SIZE, ROOM_MAX_SIZE)
        #random position without going out of the boundaries of the map
        x = randint(0, MAP_WIDTH-w-1)
        y = randint(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)
 
            #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 randint(0, 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)
 
            #add some contents to this room, such as monsters
            place_objects(new_room)
 
            #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 = randint(0, MAX_ROOM_MONSTERS)
 
    for i in range(num_monsters):
        #choose random spot for this monster
        x = randint(room.x1+1, room.x2-1)
        y = randint(room.y1+1, room.y2-1)
 
 
        #only place it if the tile is not blocked
        if not is_blocked(x, y):
            if randint(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 = GameObject(x, y, 'o', 'orc', colors.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 = GameObject(x, y, 'T', 'troll', colors.darker_green,
                    blocks=True, fighter=fighter_component, ai=ai_component)

            objects.append(monster)

    #choose random number of items
    num_items = randint(0, MAX_ROOM_ITEMS)
    
    for i in range(num_items):
        #choose random spot for this item
        x = randint(room.x1+1, room.x2-1)
        y = randint(room.y1+1, room.y2-1)
        
        #only place it if the tile is not blocked
        if not is_blocked(x, y):
            #create a healing potion
            item_component = Item(use_function=cast_heal)

            item = GameObject(x, y, '!', 'healing potion', colors.violet, 
                              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
    panel.draw_rect(x, y, total_width, 1, None, bg=back_color)
    
    #now render the bar on top
    if bar_width > 0:
        panel.draw_rect(x, y, bar_width, 1, None, bg=bar_color)

    #finally, some centered text with the values
    text = name + ': ' + str(value) + '/' + str(maximum)
    x_centered = x + (total_width-len(text))//2
    panel.draw_str(x_centered, y, text, fg=colors.white, bg=None)

def get_names_under_mouse():

    #return a string with the names of all objects under the mouse
    (x, y) = mouse_coord

    #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 (obj.x, obj.y) in visible_tiles]

    names = ', '.join(names)  #join the names, separated by commas
    return names.capitalize()

def render_all():
    global fov_recompute
    global visible_tiles

    if fov_recompute:
        fov_recompute = False
        visible_tiles = tdl.map.quickFOV(player.x, player.y,
                                         is_visible_tile,
                                         fov=FOV_ALGO,
                                         radius=TORCH_RADIUS,
                                         lightWalls=FOV_LIGHT_WALLS)

        #go through all tiles, and set their background color according to the FOV
        for y in range(MAP_HEIGHT):
            for x in range(MAP_WIDTH):
                visible = (x, y) in visible_tiles
                wall = my_map[x][y].block_sight
                if not visible:
                    #if it's not visible right now, the player can only see it if it's explored
                    if my_map[x][y].explored:
                        if wall:
                            con.draw_char(x, y, None, fg=None, bg=color_dark_wall)
                        else:
                            con.draw_char(x, y, None, fg=None, bg=color_dark_ground)
                else:
                    if wall:
                        con.draw_char(x, y, None, fg=None, bg=color_light_wall)
                    else:
                        con.draw_char(x, y, None, fg=None, bg=color_light_ground)
                    #since it's visible, explore it
                    my_map[x][y].explored = True


    #draw all objects in the list
    for obj in objects:
        if obj != player:
            obj.draw()
    player.draw()
    #blit the contents of "con" to the root console and present it
    root.blit(con, 0, 0, MAP_WIDTH, MAP_HEIGHT, 0, 0)

    #prepare to render the GUI panel
    panel.clear(fg=colors.white, bg=colors.black)

    #print the game messages, one line at a time
    y = 1
    for (line, color) in game_msgs:
        panel.draw_str(MSG_X, y, line, bg=None, fg=color)
        y += 1

    #show the player's stats
    render_bar(1, 1, BAR_WIDTH, 'HP', player.fighter.hp, player.fighter.max_hp,
        colors.light_red, colors.darker_red)

    #display names of objects under the mouse
    panel.draw_str(1, 0, get_names_under_mouse(), bg=None, fg=colors.light_gray)
    
    #blit the contents of "panel" to the root console
    root.blit(panel, 0, PANEL_Y, SCREEN_WIDTH, PANEL_HEIGHT, 0, 0)

def message(new_msg, color = colors.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 obj in objects:
        if obj.fighter and obj.x == x and obj.y == y:
            target = obj
            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 textwrap) and one line per option
    header_wrapped = []
    for header_line in header.splitlines():
        header_wrapped.extend(textwrap.wrap(header_line, width))
    header_height = len(header_wrapped)
    height = len(options) + header_height

    #create an off-screen console that represents the menu's window
    window = tdl.Console(width, height)
    
    #print the header, with wrapped text
    window.draw_rect(0, 0, width, height, None, fg=colors.white, bg=None)
    for i, line in enumerate(header_wrapped):
        window.draw_str(0, 0+i, header_wrapped[i])

    #print all the options
    y = header_height
    letter_index = ord('a')
    for option_text in options:
        text = '(' + chr(letter_index) + ') ' + option_text
        window.draw_str(0, y, text, bg=None)
        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
    root.blit(window, x, y, width, height, 0, 0)

    #present the root console to the player and wait for a key-press
    tdl.flush()
    key = tdl.event.key_wait()
    key_char = key.char
    if key_char == '':
        key_char = ' ' # placeholder
    
    #convert the ASCII code to an index; if it corresponds to an option, return it
    index = ord(key_char) - 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 handle_keys():
    global playerx, playery
    global fov_recompute
    global mouse_coord

    keypress = False
    for event in tdl.event.get():
        if event.type == 'KEYDOWN':
            user_input = event
            keypress = True
        if event.type == 'MOUSEMOTION':
            mouse_coord = event.cell

    if not keypress:
        return 'didnt-take-turn' #TODO: Add to tutorial

    if user_input.key == 'ENTER' and user_input.alt:
        #Alt+Enter: toggle fullscreen
        tdl.set_fullscreen(not tdl.get_fullscreen())
 
    elif user_input.key == 'ESCAPE':
        return 'exit'  #exit game

    if game_state == 'playing':
        #movement keys
        if user_input.key == 'UP':
            player_move_or_attack(0, -1)

        elif user_input.key == 'DOWN':
            player_move_or_attack(0, 1)

        elif user_input.key == 'LEFT':
            player_move_or_attack(-1, 0)

        elif user_input.key == 'RIGHT':
            player_move_or_attack(1, 0)
        else:
            #test for other keys
            if user_input.text == 'g':
                #pick up an item
                for obj in objects:  #look for an item in the player's tile
                    if obj.x == player.x and obj.y == player.y and obj.item:
                        obj.item.pick_up()
                        break

            if user_input.text == '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()

            return 'didnt-take-turn'

def player_death(player):
    #the game ended!
    global game_state
    message('You died!', colors.red)
    game_state = 'dead'
    
    #for added effect, transform the player into a corpse!
    player.char = '%'
    player.color = colors.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!', colors.orange)
    monster.char = '%'
    monster.color = colors.dark_red
    monster.blocks = False
    monster.fighter = None
    monster.ai = None
    monster.name = 'remains of ' + monster.name
    monster.send_to_back()

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

#############################################
# Initialization & Main Loop                #
#############################################

tdl.set_font('arial10x10.png', greyscale=True, altLayout=True)
root = tdl.init(SCREEN_WIDTH, SCREEN_HEIGHT, title="Roguelike", fullscreen=False)
tdl.setFPS(LIMIT_FPS)
con = tdl.Console(MAP_WIDTH, MAP_HEIGHT)
panel = tdl.Console(SCREEN_WIDTH, PANEL_HEIGHT)

#create object representing the player
fighter_component = Fighter(hp=30, defense=2, power=5, death_function=player_death)
player = GameObject(0, 0, '@', 'player', colors.white, blocks=True, fighter=fighter_component)

#the list of objects with those two
objects = [player]

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

fov_recompute = True
game_state = 'playing'
player_action = None

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.', 
        colors.red)

mouse_coord = (0, 0)

while not tdl.event.is_window_closed():

    #draw all objects in the list
    render_all()

    tdl.flush()

    #erase all objects at their old locations, before they move
    for obj in objects:
        obj.clear()

    #handle keys and exit game if needed
    player_action = handle_keys()
    if player_action == 'exit':
        break
        
    #let monsters take their turn
    if game_state == 'playing' and player_action != 'didnt-take-turn':
        for obj in objects:
            if obj.ai:
                obj.ai.take_turn()
</syntaxhighlight></div>

[[Category:Developing]]