Create a pool object for player missile

In this article we will create a pool object inside the player missile manager class which will then be used to recycle those player missile objects. Creating pool object for the player missile is a lot more complicated than creating pool object for the enemy missile because in order to use the player missile pool object we will need to amend a few classes such as the game manager class in the pygame project.

Before we create a player missile pool object we will need to do this first,

1) Put the player missile manager directly under the player object so that player object can control the player missile manager which will then control the player missiles.

Here is the edit version of the player class.

from pygame.locals import *
from GameSprite import GameSprite
from pygame import math as mt
from MissileManager import MissileManager
import pygame

class Player(object):

    def __init__(self, scene):

        self.image = 'Asset/player.png'
        self.scene = scene
        self.width = 40
        self.height = 40
        self.missile_count = 10
        self.direction_x = 0
        self.direction_y = 0
        self.rect = Rect(0, 0, self.width, self.height)
        self.sprite = GameSprite(self.image, self.rect)
        self.sprite_surface = self.sprite.getImage()  # get the player sprite surface
        self.bwidth, self.bheight = 660, 660
        self.pos = mt.Vector2(self.bwidth / 2, self.bheight / 2)  # initialize the position of the player sprite
        self.draw_pos = mt.Vector2(self.pos.x, self.pos.y)
        self.missile_manager = MissileManager(scene)

        pygame.display.set_icon(self.sprite_surface) # use the same player surface object as the icon for the game window

    def setX(self, _x):

        # set new x position and detect the boundary on the game scene
        self.direction_x = _x

    def setY(self, _y):

        # set new y position and detect the boundary on the game scene
        self.direction_y = _y

    def setStrike(self, strike):

        self.missile_manager.setStrike(strike)

    def update(self):

        if(self.direction_x == -0.1):
            if(self.pos.x > 0):
                self.pos.x += self.direction_x
        elif(self.direction_x == 0.1):
            if(self.pos.x + self.width <= self.bwidth):
                self.pos.x += self.direction_x
        if(self.direction_y == -0.1):
            if (self.pos.y > 0):
                self.pos.y += self.direction_y
        elif (self.direction_y == 0.1):
            if (self.pos.y + self.height <= self.bheight):
                self.pos.y += self.direction_y

        self.draw_pos = mt.Vector2(self.pos.x, self.pos.y)
        self.missile_manager.update(self.pos.x, self.pos.y)

    def get(self):
        return (self.pos.x, self.pos.y)


    def draw(self):
        self.scene.blit(self.sprite_surface,  self.draw_pos)
        self.missile_manager.draw()

    def getMissileManager(self):

        return self.missile_manager

Next we will need to edit the player missile manager class which will now include a new pool object to recycle the missile.

from Missile import Missile
from GameSprite import GameSprite
from pygame.locals import *
from Objectpool import Objectpool

class MissileManager(object):

    def __init__(self, scene):
        self.scene = scene
        self.missile_count = 10
        self.missile_list = []
        self.image = 'Asset/missile.png'
        self.width = 20
        self.height = 20
        self.rect = Rect(0, 0, self.width, self.height)
        self.strike = False
        self.strike_again = 0
        self.missile_object_pool = Objectpool(self.missile_count)
        # initialize game sprite object
        self.sprite = GameSprite(self.image, self.rect)

    def setStrike(self, strike):

        # set the missile strike flag
        self.strike = strike
        self.strike_again += 1

    def create_missile(self, x, y):
        if(self.missile_count >= 0):

            if (self.missile_object_pool.getSize() > 0):
                self.missile_list.append(self.missile_object_pool.obtain_missile(x, y))
            else:
                self.missile_surface = self.sprite.getImage()
                self.missile_list.append(Missile(self.missile_surface, x, y))
            self.missile_count -= 1

    def update(self,x,y):
        if (self.strike == True and self.strike_again > 1):
            self.strike_again = 0
            self.create_missile(x + 5, y - 8)  # create more missile
        self.missile_update()
        self.check_boundary()

    def missile_update(self):

        for item in list(self.missile_list):
            if(item.on == False):
                self.missile_list.remove(item)
                self.missile_count += 1
                self.missile_object_pool.recycle(item)
            else:
                item.update()

    def check_boundary(self):

        for i in range(len(self.missile_list)):
            if (self.missile_list[i].y < 0):
                self.missile_list[i].on = False

    def draw(self):

        # blit the missile on  the scene
        for i in range(len(self.missile_list)):
            self.scene.blit(self.missile_list[i].missile_surface, self.missile_list[i].missile_pos)

Finally we will edit the Game Manager class so it will directly call the player object to update as well as to set the strike’s Boolean variable to the True or False condition.

from Player import Player
from Background import Background
from MissileManager import MissileManager
from EnemyManager import EnemyManager
from Overlap import Overlap
import pygame

class GameManager(object):

    def __init__(self, scene):

        self.scene = scene
        self.player = Player(self.scene)
        self.background = Background(self.scene)
        self.enemy_manager = EnemyManager(self.scene, self.player)
        self.overlap_manager = Overlap()
        self.load_music()
        self.play_music()

    def load_music(self):
        pygame.mixer_music.load('Music/winternight.ogg')

    def play_music(self):
        pygame.mixer_music.play(-1) #play the music infinite time

    def set_player_x(self, _x):
        self.player.setX(_x)

    def set_player_y(self, _y):
        self.player.setY(_y)

    def set_missile_strike(self, strike):
        self.player.setStrike(strike)

    def update(self):
        self.player.update()
        self.enemy_manager.update()
        self.isOverlap()

    # check for player, enemy, missiles overlap
    def isOverlap(self):
        self.overlap_manager.iseOverlap(self.player, self.enemy_manager)

    def draw(self):
        self.background.draw()
        self.player.draw()
        self.enemy_manager.draw()
        pygame.display.flip()

OK, with that we are now ready to create the exploration manager which will be used to create explosion on the game scene in the next chapter.