If player comes within a radius of enemy,change state - python

So I've been teaching myself some pygame for the past few months, doing a spaceship game.
I have multiple enemy spaceships that guard a certain area. If the player comes within a certain radius of them, I want to change the enemy's state. What's the best way to do this for a beginner, without using vectors?

You can create a method in your program called is_close and then call it for each player and enemy comparison. It would look something like this:
def is_close(object1, object2, distance):
return math.hypot(object2.x-object1.x, object2.y-object1.y) < float(distance)
... #rest of your code
while True: #This is your main while loop
... #rest of your code
for enemy in enemies:
if is_close(player, enemy, 25):
enemy.state = new_state #change state, this may simply be a color change

Related

why does this code only register certain collisions and not all?

Hi i have a code for a game where there are multiple fruits falling from the sky and the frog at the bottom has to try and catch them. When he catches one the score goes up. This only happens when the frog collides with some of the fruit and not all of them. And the score randomly starts increasing unstoppably for no reason after a certain point. Here is most of the code as im not sure where the error would be :
import pygame, sys, time, random
from pygame.locals import *
from math import fabs
######### constants ##########
jumpvel=20
fallingspeed=1
running= True
blue= [129,183 ,253]
pink=[255,174,201]
textcolour= [255,255,255]
x=700//2
y=1000//2
score=0
thingylist= ['fruit1.bmp','fruit2.bmp','fruit3.bmp','fruit4.bmp','fruit5.bmp','fruit1.bmp','fruit2.bmp','fruit3.bmp','fruit4.bmp','fruit5.bmp','naughty1.bmp','naughty2.bmp','naughty3.bmp',]
all_things=[]
for i in range (12):
new_thing_image=pygame.image.load(thingylist[(random.randrange(0,12))])
new_thing_image.set_colorkey(pink)
new_thing_rect=new_thing_image.get_rect()
new_thing_rect.x=random.randrange(0,950)
new_thing_rect.y=-random.randrange(50,500)
all_things.append([new_thing_image,new_thing_rect])
def checkCollision (frog_rect,all_things,score):
collides_with=None
for thing_image, thing_rect in all_things:
if frog_rect.colliderect(thing_rect):
collides_with=True
if collides_with == True:
score= score+100
return collides_with,score
######## initialising screen#########
pygame.init()
gamedisplay=pygame.display.set_mode((1000,600)) #making the screen
pygame.display.set_caption('frog')
clock=pygame.time.Clock()# frames per second
bg=pygame.image.load('actual clouds.bmp').convert()
############ initialising sprites##############
frog= pygame.image.load('actual frog.bmp')
frog.set_colorkey(blue)
frog_rect=frog.get_rect()
frog_rect.centerx=(x)
frog_rect.centery=(y)
##########drawing things#############
def drawThings (all_things):
for item in all_things:
new_thing_image, new_thing_rect= item
gamedisplay.blit(new_thing_image, (new_thing_rect.x, new_thing_rect.y))
#########update display function###########
def update(x,y,all_things,score):
gamedisplay.blit(bg,[0,0])
gamedisplay.blit(frog,(x,y))
for thing in range (len(all_things)):
new_thing_rect=all_things[i][1]
#thing_rect.y=thing_rect.y+fallingspeed
new_thing_rect.y+= fallingspeed
drawThings(all_things)
label=font.render("score "+ str(score) ,1,textcolour)
gamedisplay.blit(label,(750,10))
gamedisplay.blit(heart1,(750,50))
gamedisplay.blit(heart2,(850,50))
gamedisplay.blit(heart2,(800,50))
pygame.display.update()
pygame.time.delay(50)
while running == True:
gamedisplay.blit(bg,[0,0])
gamedisplay.blit(frog,(x,y))
drawThings(all_things)
label=font.render("score "+ str(score) ,1,textcolour)
gamedisplay.blit(label,(750,10))
pygame.display.flip()
pygame.event.pump()
key=pygame.key.get_pressed()
for item in all_things:
new_thing_image, new_thing_rect= item
new_thing_rect.y+= fallingspeed
if new_thing_rect.y >450:
new_thing_rect.x=random.randrange(0,950)
new_thing_rect.y=-random.randrange(50,500)
############collision detection##########
detect,score =checkCollision (frog_rect, all_things,score)
update(x,y,all_things,score)
The score should increase every time it collides with any of the falling friuts not just certain ones and not just start increasing randomly non-stop. Any help would be appreciated thankyou !
Based on the code snippet - which does not include the frog-position updating code, I would guess that the problems of:
Score randomly increasing
Collisions not always working
Are caused by the collision rectangle being defined once for the frog's starting position, but then never being updated with changes in the frog's position.
############ initialising sprites##############
frog= pygame.image.load('actual frog.bmp')
frog.set_colorkey(blue)
frog_rect=frog.get_rect()
frog_rect.centerx=(x) # <-- rect only ever updated here!
frog_rect.centery=(y)
This would lead to the described symptoms, since scoring-objects (fruit?) falling through the collision rectangle would add to the score (seemingly randomly), and when the frog was still over it's original position, collision would work perfectly. If the frog was partially over the rect it would somewhat work, and not at all once the frog moved away that start-position rect.
The solution to the problem is to update the co-ordinates of the rectangle frog_rect whenever the x & y of the frog's position is updated. This can be achieved by setting the frog_rect.centerx and frog_rect.centery inside the update() function:
def update(x, y, all_things, score ):
frog_rect.x = x
frog_rect.y = y
The frog's rect is initialised with .centerx, .centery co-ordinates, but the frog is draw at x,y, so the collision rect begins a little off-centre too. Thus it would be best to update the initialisation function as well:
frog_rect=frog.get_rect()
frog_rect.x = x
frog_rect.y = y

In Python, how can I execute two Turtle commands simultaneously?

As in having two Turtles moving at once. For example, I import two turtles, then try to have both of them move forward alongside each other. How can I do this?
bob = turtle.Turtle()
john = turtle.Turtle()
def move_turtles(ammount):
for i in range(ammount // 10):
bob.forward(10)
john.forward(10)
move_turtles(100)
There's no way to move them at the same time, although you can use something like that. It moves the turtles by 10 points each, so it gives the impression that they are moving together, but they are actually moving separately by little ammounts. It repeats the operation (ammount //10) times, and moves 10 in each iteration, so if you were to give 50 as an input, it would move 5 times 10 points, resulting in 50. You can then customize the function to move by a little a turtle so they don't overlap and so on.
You can move multiple turtles independently at the same time using timer events -- you can even have them move at different rates, both in time and space:
import turtle
turtle.setworldcoordinates(0, -100, 100, 100)
bob = turtle.Turtle(shape="turtle")
bob.penup()
bob.sety(20)
john = turtle.Turtle(shape="turtle")
john.penup()
john.sety(-20)
def move_bob():
bob.forward(1)
if bob.xcor() < 90:
turtle.ontimer(move_bob, 75)
def move_john():
john.forward(2)
if john.xcor() < 90:
turtle.ontimer(move_john, 100)
move_bob()
move_john()
turtle.exitonclick()
Other folks also use threads to achieve this but timer events are built into the turtle module.
There is a way to control frames using the Turtle module - you need to change the screen attributes.
screen = turtle.Screen()
screen.tracer(0)
This method makes all turtle movement invisible until you run screen.update(), and then every turtle will be visually updated at the same time on the screen. In your case, you can write screen.update() after the movement of both turtles, and they will appear to move at the same time.

objects in a sprite.Group() not behaving as unique objects as they should

Below is the troubling code with a quick breakdown.
if player.attacked == True and delay >= 60: #if it's monster's turn plus a built in delay so everything isn't instant
for enemy in enemies_list: #iterating the all the enemies in the sprite group
if enemy.attack_rdy == True and enemy.health >0 and delay ==60: #if THAT particular monster hasn't attacked, isn't dead, and the delay has been long enough.
player.hit.play() #play the player's damaged sound
damage = random.randrange(each.attack[0],each.attack[1]+1)-player.armor #random attack roll of a tuple assigned to the enemy class
player.health -= damage
enemy.attack_rdy = False #Sets THIS particular enemy so that he may not attack until it's his turn again
player.damaged = True #Just triggers an animation on the player
each.attack_anim = 1 #triggers an animation on the enemy
break #stops the for loop so that everything doesn't happen at once and relies on the delay int.
Problem:
This iteration works properly in that the player is accurately attacked the correct number of times in accordance to the number of enemies attacking him. For some weird reason the same enemy will be attacking all those times however. When the attacking enemy dies, another one simply takes over his task of being the one who attacks. I can make no sense of it.
In true bonehead fashion, after staring at and editing my code for hours I find my blunder mere moments after posting. It's really just a stupid error.
each.attack_anim = 1
SHOULD read
enemy.attack_anim = 1
With blunder corrected, code runs as designed.

Pygame deleting an object in a list

I just started programming in OOP style last week when deciding to make a small game. But now I seem to be stuck. I'll explain what I have so far:
When the player hits a button, a bullet object is created next to the player and the bullet object is added to the bullets[] list. The bullet then travels horizontally across the screen in the designated direction. If the bullet collides with a player or a wall, it is removed from the bullets[] list. So far, so good.
Now I just cant seem to figure out how to remove the bullet from the bullets[] list when it leaves the screen (screen is defined between 0 and xmax). Also, after I remove the bullet from the list, should I also remove the object itsself, or is this done automatically?
Code so far:
class BULLET(object):
#Constructor for the bullet, bullets are stored into array 'bullets'
# The direction is stored to keep track of which player fired the bullet
def __init__(self,location,direction,color):
self.rect = pg.Rect(location[0],location[1],xmax/160,xmax/160)
self.bullet_type="normal"
self.direction=direction
self.color=color
bullets.append(self)
#Moves the bullet horizontally across the screen, in the specified direction
# The move function also checks for collision with any walls or players
# The move function removes the bullet object from the list and destroys it
# when it leaves the left or right side of the screen
def move(self,bullet_speed):
self.rect.x += bullet_speed
for wall in walls:
if self.rect.colliderect(wall.rect):
index=wall.rect.collidelist(bullets)
del bullets[index]
#Do I need to delete the object too? or just the list item?
for player in players:
if self.rect.colliderect(player.rect):
index=player.rect.collidelist(bullets)
if player.immune_timer <= 0:
del bullets[index]
player.immunity(500)
player.life -= 1
if self.rect.centerx > xmax or self.rect.centerx <0:
#This is where I would like this instance of the bullet object to be deleted
# and to have the object removed from the bullets[] list
What I suggest you do is in your main loop:
bullets = [bullet for bullet in bullets if 0 < bullet.rect.centerx < xmax]
This will only keep the items that should be in the list.

Game ai Line of Sight Python

How would I check to see whether the player is within range of a mob? (I am making a top down game in pyglet) I am making it so that the mobs follow and attack the player if he is within a certain distance of them but I am unsure how to efficiently do this. Would I need to do an "if" statement to see if x > mob.x - 50 and x < mob.x + 50 etc?
I have a class for the mobs
class zombie(pyglet.sprite.Sprite):
def __init__(self, image, x, y, batch,trees):
pyglet.sprite.Sprite.__init__(self, image, x, y, batch=None)
I then used several functions as the different actions they could be doing
def move(self):
...
def idle(self):
...
The player's position is "player.x" and "player.y" (the same for the mobs but with "zombie instead of player)
As Joran said, I think finding the distance betweens the mob and the player's coordinates is the best approach and I will make another function to check the distance.
Sorry if this was unclear
you would probably need to calculate the distance between the monster and the player
sqrt((mob.x-player.x)**2 + (mob.y-player.y)**2)
you could probably simplify it and get rid of the sqrt ...

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