We Keep Coding

Get any objects (Rect, Surfaces...) at position / coordinates X, Y

So the question is simple:
Given a Surface, let's call it screen and x,y coordinates, can I get anything that lays at that coordinates on that Surface?
For example, let's say we have typical, Player attack, and if the attack reach the Enemy position x,y then enemy dies.
So given this simple app (is an example only not a real app)
import pygame as pg
from pygame.math import Vector2
# pygame constants
CLOCK = pg.time.Clock()
WIN_SIZE = (1280, 640)
# pygame setup
pg.init()
# screen
window = pg.display.set_mode(WIN_SIZE, 0, 32)
background = pg.Surface(WIN_SIZE)
player = pg.Surface(Vector2(12, 64))
player_rect = player.get_rect(topleft=Vector2(150, 150))
player_attack = False
player.fill((102, 255, 178))
player_attack_range = 20 # player can hit at min 20 pixel from target
enemy = pg.Surface(Vector2(12, 64))
enemy_rect = player.get_rect(topleft=Vector2(175, 150))
enemy.fill(pg.Color("green"))
while True:
background.fill((0, 0, 0)) # screen clear
# Render enemy
attacked = False
if player_attack:
# !!!!! HERE !!!!!
# Now we check if the playuer is close enough to the enemy, so we MUST know the enemy pos
distance_x = abs(player_rect.x - enemy_rect.x)
if distance_x > player_attack_range:
attacked = True
enemy.fill(pg.Color("red"))
if not attacked:
enemy.fill(pg.Color("green"))
background.blit(enemy, enemy_rect.topleft)
# Render player
background.blit(player, player_rect.topleft)
# Events
for event in pg.event.get():
if event.type == pg.QUIT or (
event.type == pg.KEYDOWN and event.key == pg.K_ESCAPE): # x button and esc terminates the game!
exit(1)
# ............. Mouse ............. #
if event.type == pg.MOUSEBUTTONDOWN:
if event.button == 1:
player_attack = True
if event.type == pg.MOUSEBUTTONUP:
if event.button == 1:
player_attack = False
pg.display.update() # 2) Update the game
window.blit(background, (0, 0)) # 3) Repaint the screen
CLOCK.tick(60) # 4) Wait 60 Frames
When is attacked
Now I always seen it done this way more or less:
distance_x = abs(player_rect.x - enemy_rect.x)
if distance_x > player_attack_range:
attacked = True
enemy.fill(pg.Color("red"))
With this example, I'm not pointing out the code implementation but the fact that, the player must know the target position and then check whether or not the target is hit
But what I want to know, let's say I don't know the enemy position, and the player just attacks, is there a way that we can get what's currently on the surface at the attack range?
So do something like
attacked_area_x = abs(player_rect.x + player_attack_range) # only care of x coords
rects_or_surfaces_in_area = background.what_have_we_got_here(Vector(attacked_area, 0))
for r in rects_or_surfaces_in_area:
print("Hit!")

Update
So By checking MDN documentation of Game Development MDN I actually find a game algorithm / Technique that is similar (but concept is the same) of my solution.
Is called the Broad Phase
From the documentation:
road phase should give you a list of entities that could be colliding. This can be implemented with a spacial data structure that will give you a rough idea of where the entity exists and what exist around it. Some examples of spacial data structures are Quad Trees, R-Trees or a Spacial Hashmap.
So yes, it seems one of many good approach to solve this problem.
So, after some research and thanks to Rabbid76 and his answer here How do I detect collision in pygame? which covers in details the most common collisions in Pygame, it seems that what I was looking for natively is just not possible.
Maybe is normal, I'm also new to game development and maybe what I want to do just doesn't make any sense, but I bet it does.
The scenario I'm facing is, just one player with a sword hitting, so I asked my self, why should I need to know prior what objects lie on the sword path and check if is hit, instead, do the hit and request to the parent screen "what object are in the sword path"? , which, is for sure faster because we don't need to know what object that have collision are (and avoid a for loop and check for each react/surface).
So, let's say there are many many object that have collision and a player may hit it, it would be way faster do don't know what' there but request it instead to the surface, so basically the surface should be aware of its children / objects.
I tried a bit the Surface.subsurface() and the Surface.get_parent() but couldn't make it work, anyway still, in a surface area we may have many thinks like:
draws, Rect, Surfaces, Sprites, Imgs etc...
I have only 2 solutions in my mind:
Map the objects coordinates
This only really works if, the entities are static, if so, then we could create a dict with key x:y coordinates and then check if the sword is in within a certain x:y and exist in the dict, then the entity is hit.
But with entity then moves by themself, is a nigtmare and will have a worst problem than before, you would need to update the keys at each frame and so on..
Make it 'distance' sensible
So, this could apply to each entity that is moving and may or may not hit something that has a collision. But staying on the example context, let's say we are iterating thourgh entities / object that at each frame are updating their position.
We could check how distant are from the player, let's say 2 chunks away (or the sword lenght) and collect them in a list
Then we that list, we check if, once the sword is updated, is hitting anything close by.
Still, pretty sure there are better ways (without changing or extending pygame its self).
And maybe, by extending pygame, there may be a way to implement a 'surface aware' class that when we request a specific Rect area, it tells us what's there.

Python3: Deleting enemy from dynamic array when colliding with the player

I am creating a sidescroller shooter game in which the enemies(drones)spawn contantly on the right side of the screen. The recently created enemies are appended to a list drones Each enemy goes towards the left of the screen. Once they are out of the screen, they get removed from the list.
I also want to remove the drones when they collide with the player. The following code works properly as long as there are multiple objects in the drones list, but when the list has only one item (so one drone is on the screen) that drone does not get deleted upon collision.
I have no idea why the first list item cannot be destroyed.
drones = []
class Drone
#other call methods
def hit(self):
del drones[drones.index(self)]
def generate_enemy():
global drones
if len(drones) < 20:
if (random.randint(1,100) == 1):
drones.append(Drone(screenWidth, random.randint(300,500))
def main():
global drones
while True:
#main loop stuff happening
if condition == True:
generate_enemy():
#main loop stuff happening
if player and (len(drones) > 0):
for i in range(len(drones)-1):
if drones[i].hitbox.colliderect(player.hitbox):
drones[i].hit()
main()

The "correct" way to do this in pygame is to let your classes inherit from Sprite, then use a Group instead of a simple list to store your enemies, and using pygame.sprite.spritecollide for collision detection with the dokill argument set to True.

Python: Keyboard input without repeat delay

For those who don't know, repeat delay is the slight pause between, when holding down a key, the letter first appearing and it repeating. This might be a useful feature when typing, however when you start to write games, it becomes very annoying. An example is when you need to move a character; it will move a tiny bit, pause, and then start to move again. Tkinter code:
ball = canvas.create_rectangle(50, 50, 100, 100)
def move():
canvas.move(ball, 0, 3)
canvas.bind_all("<space>", move)
If space is pressed, the ball will move down 3 pixels, pause, and then start moving normally. I was wondering if there is any way to avoid that pause, for example a module that reads directly from the keyboard, and not the windows-processed keyboard. I know that it is possible to "cheat" by, for example, automatically running the function when you expect the delay to occur; sadly that is inaccurate and can result in choppy movement. Thanks in advance

Make a recursion loop for while it is pressed. Or that's how I do it, at least.
moving = False
def move():
global moving
moving = True
def stop_moving():
global moving
moving = False
def myloop():
global moving
if moving == True:
canvas.move(ball, 0, 3)
root.after(1, myloop)
root.bind('<space>', lambda e: move())
root.bind('<KeyRelease-space>', lambda e: stop_moving())
just make sure you call your loop once before root.mainloop()
#like this
root.after(1, myloop)
root.mainloop()

How to make an object have temporary invincibility?

I'm making a game in pygame and I need my ship to be immune for, about, 3 seconds after a collision with an asteroid. I tried every function I found, but it didn't work.
Here's the collision part of my code:
if collision == True:
ship_game = ship_destroyed
lifes -= 1;
And then i have this part:
if collision:
pi = True
collision = False
pygame.time.delay(1000)
This variable called pi I use in case of collision to put the ship in the middle of screen:
if pi == True:
ship_game = ship
pos_ship={'x': WScreen/2, 'y': HScreen/2}
pi = False
I think that's enough for you to understand my problem. Thank you :)

This could be accomplished by introducing a variable collision_immune that you set to True when a collision is detected. At the same time you record the time of the last collision in a variable collision_time. You can get the time from pygame.time.get_ticks(). Then in an appropriate part of your main loop, that is not shown above, you can check if the time since the last collision is more than, say, 3 seconds and reset collision_immune to False. This could look something like this
if collision == True:
ship_game = ship_destroyed
lifes -= 1;
collision_immune = True
collision_time = pygame.time.get_ticks()
Then somewhere, maybe at the beginning of the main loop, you put
if pygame.time.get_ticks() - collision_time > 3000: # The time is in ms.
collision_immune = False
Now you can use the variable collision_immune in your game logic to determine if the ship is immune from a recent collision.
Happy pygaming! :)

You need to keep track of the time when the last collision took place (last_collision_time = time.time()) and then when a collision happens you check if that value is less than 3 seconds ago (if time.time() - last_collision_time < 3.:) and handle it as you see fit. In this case clearly by not having the collision destroy the ship.

OOP style:
class Ship:
def immune(self):
return self.last_collide_time > current_time() - 3000
def collide(self):
if self.immune(): return
self.lifes -= 1
self.last_collide_time = current_time()
# ....

How would I create random locations for many groups of sprites?

I have tried a for loop with the blit and draw methods and using different variables for " PlayerSprite " and " Treegroup "
for PlayerSprite in Treegroup:
surface.blit(PlayerSprite,(random.randrange(100,500),random.randrange(100,600)))
also tried
SPRITES=[]
for Sprites in range(10):
Sprites= PlayerSprite
SPRITES.append(Sprites)
all I get are errors
screen=pygame.display.set_mode((640,480))
background1=pygame.image.load("C:\Pygame-Docs\examples\data\Random Map.bmp")
class Tree1(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.image=pygame.image.load('C:\Pygame-Docs\examples\data\Tree 1.bmp')
self.image=self.image.convert()
self.rect=self.image.get_rect()
self.rect.centerx=random.randrange(10,100)
self.rect.centery=random.randrange(10,100)
# Makes a group of trees
Howmanytrees=random.randrange(5,10)
Trees=[]
for tree in range(Howmanytrees):
trees=Tree1()
Trees.append(trees)
# Howmany groups
for Treegroup in range(10):
Treegroup=Trees
# Places groups
PlayerSprite=pygame.sprite.Group(Treegroup)
# keeps loop ( game ) going until canceled
keepgoing=True
while keepgoing:
for event in pygame.event.get():
if event.type==pygame.QUIT:
keepgoing=False
# actually draws screen
screen.blit(background1,(0,0))
PlayerSprite.draw(screen)
pygame.display.flip()
This code only displays 5 to 10 trees " Trees=[] "
and nothing else. I have worked on this problem for over a week , read many tutorials, looked on many websites, nothing seems to work. I must be overlooking or missing somethig. I thought this would be easy!
Thanks so much!

As far as I understand what you want to achieve, the below code should help you. I kept it very very simple regarding python syntax, as you seems to be a newbie (for experienced programmers: yes, what I wrote below is horrible python code, but I believe the OP can understand it and it may help).
The key is that if you want to get several groups of trees, you must have a loop within a loop. The inner loop put the trees inside the group, and the outer loop put several groups. Of course you can (and should) certainly hide the inner loop behind some function or class.
# Howmany groups ? say 3
trees_groups = []
number_of_groups = 3
for _ in range(number_of_groups):
# Choose a base position for my group of trees
base_x = random.randrange(0,530)
base_y = random.randrange(0,370)
# Makes a group of trees
trees=[]
number_of_trees = random.randrange(5,10)
for _ in range(number_of_trees):
one_tree = Tree1()
trees.append(one_tree)
for tree in trees:
tree.rect.centerx += base_x
tree.rect.centery += base_y
trees_groups.append(tree)
# Places groups
PlayerSprite=pygame.sprite.Group(trees_groups)
Some after notes:
And as other posters said, you should not use capitalized variables as you do. The python usage is to keep them for classes
Also looping using range when the base variant is not used is bad practice. I emphasized this by using underline as a variable name for the loop variant when it is not used.

I would use randint and move_ip to get what you want. Here is a code snippet from my own game that works just as well:
self.rect.move_ip(random.randint(minX, maxX), random.randint(minY, maxY))
the four variables minX, maxX, minY, maxY form a rectangle where the sprite can be placed. In your case, the trees would be placed along the entire screen, but with a reduced max X and Y range so trees won't clip through the bottom of the screen.
Also, use a Group class to store your trees rather than a list. A list stops the spawning of multiple trees, while a Group does. Here is how to call it:
Treegroup = pygame.sprite.Group
and to add a sprite to the group:
Treegroup.add(Tree1(screen))
Make sure the class itself has screen in its init, like so:
def __init__(self, screen)
Once that's done, your code should look something like this:
for Treegroup in range(10):
Treegroup.add(Tree(screen))
[...]
class Tree(pygame.sprite.Sprite):
def __init__(self, screen):
pygame.sprite.Sprite.__init__(self)
self.image, self.rect = load_image('tree.png', -1)
self.rect.move_ip(random.randint(0, 800), random.randint(0, 600))
self.area = screen.get_rect()

It doesn't really make much sense to me.
for tree in range(Howmanytrees):
trees=Tree1()
Trees.append(trees)
Your loop here is doing nothing at all. tree should be a number between 0 and Howmanytrees. Again, the following block isn't indented so it's not part of the loop. Even so, the block still wouldn't work. Also, you're confusing yourself and us with variable names. Trees is the object? trees is the list? Don't do this. Seriously.
No idea what the following code is up to.
# Howmany groups
for Treegroup in range(10):
Treegroup=Trees
Create your SpriteGroup passing in the aforementioned trees list? Or am I missing something :) TreeGroup = Trees 10 times is just going to do that 10 times. You are not using the loop variant. The only thing that modifies during the loop. Even so, this entire block of code is useless.
while keepgoing:
for event in pygame.event.get():
if event.type==pygame.QUIT:
keepgoing=False
This is going to cause a nice infinite loop. It is evaluating the keepgoing variable constantly. This will never get set to false unless the user quits, but also it will never display anything on the screen. Lose this. Use this instead:
for event in pygame.event.get():
if event.type == QUIT:
return
This will not cause an infinite loop as there are only so many events to be processed per tick. Then the program will loop around and do the process or updating, rendering and getting input again.