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I need to keep an object moving forward relative to itself while being rotated in pygame [duplicate]

This question already has answers here:
How to make ball bounce off wall with PyGame?
(1 answer)
How do I rotate an image around its center using Pygame?
(6 answers)
Closed 1 year ago.
I'm making a "pong" style game, where the ball rotates 15 degrees every time it hits either the top or the bottom of the screen.
My problem is that when rotating, it still moves in either x or y direction, and being new to pygame, I am unsure of how to keep the ball moving "forward" relative to itself, in the direction of the rotation, and was not sure of how to phrase the question in Google.
The rough code:
class Ball():
def __init__(self) -> None:
self.x, self.y = display_width / 2, display_height / 2
self.raw_sprite = pygame.image.load("assets/ball.png")
self.raw_size = self.raw_sprite.get_size()
self.sprite = pygame.transform.scale(self.raw_sprite, (int(self.raw_size[0]/2), int(self.raw_size[1]/2)))
self.rect = self.sprite.get_rect()
self.width, self.height = self.sprite.get_width(), self.sprite.get_height()
self.rect.x = self.x
self.rect.y = self.y
def render(self) -> None:
screen.blit(self.sprite, (self.x,self.y))
def is_collided_with(self, sprite) -> bool:
return self.rect.colliderect(sprite.rect)
def move(self, direction) -> None:
speed = 5
if direction == "left":
self.x -= speed
else:
self.x += speed
def rotate(self) -> None:
angle = 15
self.sprite = pygame.transform.rotate(self.sprite, (angle))
self.rect = self.sprite.get_rect()
ball = Ball()
ball_direction = "left"
running = True
while running:
if (ball.y == (0 + ball.height)) or (ball.y == (display_height - ball.height)):
ball.rotate()
screen.fill(BLACK)
ball.render()
ball.move(ball_direction)
pygame.quit()
quit()
I've omitted a lot of the code and only left the necessary parts to show the issue.
Thanks for your time.

Move Character with Vector

I am teaching myself pygame and am looking at making my character able to rotate and then move in the direction they are facing.
I can do the rotation but cannot get the character to move in the direction the image is then facing.
The code is on Trinket HERE
class Bob(pygame.sprite.Sprite):
def __init__(self, color , height , width):
super().__init__()
self.image = pygame.Surface([width , height])
self.image.fill(BLACK)
self.image.set_colorkey(BLACK)
#Loading the image for the character
self.img = pygame.image.load("char.jfif")
#creating a copy of the image
self.img_orig = self.img.copy()
#defining the starting angle of the character image
self.angle = 0
self.velocity = 5
self.rect = self.img_orig.get_rect()
def moveLeft(self):
self.angle += 1
self.img = pygame.transform.rotate(self.img_orig, self.angle)
def moveRight(self):
self.rect.x += self.velocity
if self.rect.x > 485:
self.rect.x = 485
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
keys = pygame.key.get_pressed()
if keys[pygame.K_UP]:
pSprite.moveForward()
if keys[pygame.K_DOWN]:
pSprite.moveDown()
if keys[pygame.K_LEFT]:
pSprite.moveLeft()
if keys[pygame.K_RIGHT]:
pSprite.moveRight()
#---- Game Logic Here
#--- Drawing Code Here
#Reset the screen to blank
screen.fill(BLUE)
#Draw Play Area
#Draw Sprites
screen.blit(pSprite.img,(pSprite.rect.x, pSprite.rect.y))

You can use pygame's Vector2 class instead of calculating the position of your sprite yourself.
I also suggest to let the sprite itself handle its movement instead of doing so in the main loop and using a clock for constant framerates and easy control of the speed of your sprites.
You also probably want to use an image format with alpha channel (like PNG).
Here's a simple example:
import pygame
class Actor(pygame.sprite.Sprite):
def __init__(self, pos, *grps):
super().__init__(*grps)
self.image = pygame.image.load('char.png').convert_alpha()
self.image_org = self.image.copy()
self.rect = self.image.get_rect(center=pos)
self.pos = pygame.Vector2(pos)
self.direction = pygame.Vector2((0, -1))
def update(self, events, dt):
pressed = pygame.key.get_pressed()
# if a is pressed, rotate left with 360 degress per second
if pressed[pygame.K_a]: self.direction.rotate_ip(dt * -360)
# if d is pressed, rotate right with 360 degress per second
if pressed[pygame.K_d]: self.direction.rotate_ip(dt * 360)
# check if should move forward or backward
movement = 0
if pressed[pygame.K_w]: movement = 1
if pressed[pygame.K_s]: movement = -1
movement_v = self.direction * movement
if movement_v.length() > 0:
movement_v.normalize_ip()
# move 100px per second in the direction we're facing
self.pos += movement_v * dt * 100
# rotate the image
self.image = pygame.transform.rotate(self.image_org, self.direction.angle_to((0, -1)))
self.rect = self.image.get_rect(center=self.pos)
def main():
pygame.init()
screen = pygame.display.set_mode((600, 480))
sprites = pygame.sprite.Group()
Actor((100, 100), sprites)
clock, dt = pygame.time.Clock(), 0
while True:
events = pygame.event.get()
for e in events:
if e.type == pygame.QUIT:
return
screen.fill('grey')
sprites.draw(screen)
sprites.update(events, dt)
pygame.display.flip()
dt = clock.tick(60) / 1000
main()
char.png

Rotate the player around its center (see How do I rotate an image around its center using PyGame?):
self.angle += 1
self.img = pygame.transform.rotate(self.img_orig, self.angle)
self.rect = self.img.get_rect(center = self.rect.center)
Use an attribute x and y to store the position of the player with floating point accuracy.
class Bob(pygame.sprite.Sprite):
def __init__(self, color , height , width):
# [...]
self.x, self.y = self.rect.center
Compute the direction of the player dependent on the angle with the trgonometric function math.sin and math.cos. Change the position attributes and update the rect attribute:
self.x += self.velocity * math.cos(math.radians(self.angle + 90))
self.y -= self.velocity * math.sin(math.radians(self.angle + 90))
self.rect.center = round(self.x), round(self.y)
The y-axis needs to be reversed (-dy) as the y-axis is generally pointing up, but in the PyGame coordinate system the y-axis is pointing down. In addition, a correction angle must be deducted (+ 90). Since the "angle" is 0 ° when the sprite is looking up, you need to add 90 ° to the angle for the calculation of the direction vector.
See also te in pygame while moving with the keys](How to turn the sprite in pygame while moving with the keys.
Class Bob:
import pygame
import math
BLACK = (0,0,0)
class Bob(pygame.sprite.Sprite):
def __init__(self, color , height , width):
super().__init__()
self.image = pygame.Surface([width , height])
self.image.fill(BLACK)
self.image.set_colorkey(BLACK)
#Loading the image for the character
self.img = pygame.image.load("char.jfif")
#creating a copy of the image
self.img_orig = self.img.copy()
#defining the starting angle of the character image
self.angle = 0
self.velocity = 5
self.rect = self.img_orig.get_rect()
self.x, self.y = self.rect.center
def rotate(self, change_angle):
self.angle += change_angle
self.img = pygame.transform.rotate(self.img_orig, self.angle)
self.rect = self.img.get_rect(center = self.rect.center)
def move(self, distance):
self.x += distance * math.cos(math.radians(self.angle + 90))
self.y -= distance * math.sin(math.radians(self.angle + 90))
self.rect.center = round(self.x), round(self.y)
def moveLeft(self):
self.rotate(1)
def moveRight(self):
self.rotate(-1)
def moveForward(self):
self.move(self.velocity)
def moveDown(self):
self.move(-self.velocity)
When setting the starting position of the player, you need to set the x, y and rect attribute:
pSprite = Bob(WHITE , 25,25)
pSprite.rect.x = 50
pSprite.rect.y = 50
pSprite.x, pSprite.y = pSprite.rect.center

pygame sprite collision with background elements [duplicate]

This question already has answers here:
Pygame mask collision
(1 answer)
How can I made a collision mask?
(1 answer)
Closed 2 years ago.
I've been looking for days to find a solution but any of the other threads could help me.
I've been trying to make the sprite move over the background image. The background have transparent streets that should be the possible paths for the sprite.
I need to detect when the sprite collide with the other part of the background image that is not transparent. i tried perfect collision method but i don't think it's the right solution for my case because the background.rect doesn't make any sense.
I also tried the overlap method but it always return true.
The pictures are 32 bit depth and i'm calling convert_alpha()
class sprites(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.x = 200
self.y = 300
self.img= player_sprite
self.rect = player_sprite.get_rect()
self.mask = pygame.mask.from_surface(player_sprite)
def position(self):
dx = mouse_x-self.x
dy = self.y-mouse_y
d = float((dx**2+dy**2)**0.5)
displ_x = dx/d
displ_y = dy/d
self.x += displ_x
self.y += displ_y
if type(self.mask.overlap(object_background.mask,(0,0))):
self.x -= displ_x
self.y -= displ_y
class object_background_class(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.img = object_background_img
self.rect = object_background_img.get_rect()
self.mask = pygame.mask.from_surface(object_background_img.convert_alpha())
object_background = object_background_class()
player = sprites()
player.position() changes each time the coordinates of the sprite accordind to the mouse(x,y) and check if with the new x,y of the player make it collides with the background
game_state = False
while not game_state:
for e in pygame.event.get():
if e == pygame.QUIT:
game_state = True
if e.type == pygame.KEYDOWN and e.type == pygame.K_ESCAPE:
game_state = True
if e.type == pygame.KEYDOWN:
if e.key == 27:
game_state = True
mouse_x, mouse_y = pygame.mouse.get_pos()
player.position()
DISPLAYSURFACE.blit(color_background, (0, 0))
DISPLAYSURFACE.blit(player.img, (player.x, player.y))
DISPLAYSURFACE.blit(object_background.img, (0, 0))
pygame.display.flip()

The game screen is one big coordinate plane, just say if x, y coords of player go over or under whatever x,y coord threshold than do something

I also tried the overlap method but it always return true.
Of course. pygame.sprite.collide_mask() use the .rect and .mask attribute of the sprite object for the collision detection.
You have to update self.rect after moving the player and changing the self.x and self.y attribute of the player:
class sprites(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.x = 200
self.y = 300
self.img= player_sprite
self.rect = player_sprite.get_rect()
self.mask = pygame.mask.from_surface(player_sprite)
def position(self):
dx = mouse_x-self.x
dy = self.y-mouse_y
d = float((dx**2+dy**2)**0.5)
displ_x = dx/d
displ_y = dy/d
self.x += displ_x
self.y += displ_y
if type(self.mask.overlap(object_background.mask,(0,0))):
self.x -= displ_x
self.y -= displ_y
self.rect.topleft = (round(self.x), round(self.y)) # <--- THIS IS MISSING
Now you can use collide_mask:
if pygame.sprite.collide_mask(player, object_background):
# [...]

pygame/python wont detect collision between sprites

im trying to detect a collision between pacman and the boxes, but its not detecting any collision, any help or advice? at the moment ive tried creating a list of instances but that hasnt worked, i dont know what else to do. also its telling me to add more detail but i dont really know what i can add to be honest, sorry
import pygame
import os
import sys
#intialise the game
pygame.init()
screen = pygame.display.set_mode((448, 576))
done = False
y = 320
x = 216
#sets up clock and loads pacman image
clock = pygame.time.Clock()
PACMANSPRITE = pygame.image.load("pacman.png").convert_alpha()
#gets pacman intro music, sets music to lower volume then plays it
pygame.mixer.music.load('pacman_beginning.WAV')
pygame.mixer.music.set_volume(0.01)
pygame.mixer.music.play(0)
#box class, used for boxes to border pacmans map
class boxcollisions(pygame.sprite.Sprite):
def __init__(self, x, y):
self.y = y
self.x = x
self.rect = pygame.Rect(self.x, self.y, 15, 15)
self.color = (0, 128, 255)
def draw(self, screen):
pygame.draw.rect(screen, self.color, self.rect)
#pacmans class
class pacman(pygame.sprite.Sprite):
def __init__(self, image, x, y):
self.image = image
self.y=y
self.x=x
self.rect = self.image.get_rect()
self.rect.left = self.x
self.rect.top = self.y
self.rect.width=16
self.rect.height=16
# move pacman
def movement(self):
pressed= pygame.key.get_pressed()
if pressed[pygame.K_UP]:
self.y -= 2
if pressed[pygame.K_DOWN]:
self.y += 2
if pressed[pygame.K_LEFT]:
self.x -= 2
if pressed[pygame.K_RIGHT]:
self.x += 2
def draw(self, surface):
""" Draw on surface """
# blit yourself at your current position
surface.blit(self.image, (self.x, self.y))
#instances the pacman class
sprite = pacman(PACMANSPRITE, x ,y)
#main game loop
while not done:
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
pygame.quit()
sys.exit()
screen.fill((100,0,0))
#co-ordinates for boxes to set up map boundaries
boundaries=[
[],
[],
[],
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28],
[1,14,15,28], #5
[1,3,4,5,6,8,9,10,11,12,14,15,17,18,19,20,21,23,24,25,26,28],
[1,3,4,5,6,8,9,10,11,12,14,15,17,18,19,20,21,23,24,25,26,28],
[1,3,4,5,6,8,9,10,11,12,14,15,17,18,19,20,21,23,24,25,26,28],
[1,28],
[1,3,4,5,6,8,9,11,12,13,14,15,16,17,18,20,21,23,24,25,26,28], #10
[1,3,4,5,6,8,9,11,12,13,14,15,16,17,18,20,21,23,24,25,26,28],
[1,8,9,14,15,20,21,28],
[1,2,3,4,5,6,8,9,10,11,12,14,15,17,18,19,20,21,23,24,25,26,27,28],
[1,2,3,4,5,6,8,9,10,11,12,14,15,17,18,19,20,21,23,24,25,26,27,28],
[6,8,9,20,21,23], #15
[6,8,9,11,12,13,14,15,16,17,18,20,21,23],
[1,2,3,4,5,6,8,9,11,12,13,14,15,16,17,18,20,21,23,24,25,26,27,28],
[1,11,12,13,14,15,16,17,18,28],
[1,2,3,4,5,6,8,9,11,12,13,14,15,16,17,18,20,21,23,24,25,26,27,28],
[6,8,9,11,12,13,14,15,16,17,18,20,21,23,24,25,26,27,28], #20
[6,8,9,20,21,23],
[6,8,9,11,12,13,14,15,16,17,18,20,21,23],
[1,2,3,4,5,6,8,9,11,12,13,14,15,16,17,18,20,21,23,24,25,26,27,28],
[1,14,15,28],
[1,3,4,5,6,8,9,10,11,12,14,15,17,18,19,20,21,23,24,25,26,28], #25
[1,3,4,5,6,8,9,10,11,12,14,15,17,18,19,20,21,23,24,25,26,28],
[1,5,6,23,24,28],
[1,2,3,5,6,8,9,11,12,13,14,15,16,17,18,20,21,23,24,26,27,28],
[1,2,3,5,6,8,9,11,12,13,14,15,16,17,18,20,21,23,24,26,27,28],
[1,8,9,14,15,20,21,28], # 30
[1,3,4,5,6,7,8,9,10,11,12,14,15,17,18,19,20,21,22,23,24,25,26,28],
[1,3,4,5,6,7,8,9,10,11,12,14,15,17,18,19,20,21,22,23,24,25,26,28],
[1,28],
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28],
]
#builds the boxes
bx=0
by=-16
for row in boundaries:
#y co ordinate
by=by+16
for n in row:
#x co ordinate
n=n-1
bx=n*16
box = boxcollisions(bx, by)
box.draw(screen)
#moves pacman
sprite.movement()
sprite.draw(screen)
#tests for collision
print(pygame.sprite.collide_rect(sprite, box))
pygame.display.flip()
clock.tick(60)

1 - You need update the top and left position at moviment method. look:
# move pacman
def movement(self):
pressed= pygame.key.get_pressed()
if pressed[pygame.K_UP]:
self.y -= 2
if pressed[pygame.K_DOWN]:
self.y += 2
if pressed[pygame.K_LEFT]:
self.x -= 2
if pressed[pygame.K_RIGHT]:
self.x += 2
self.rect.left = self.x
self.rect.top = self.y
2 - You have to verificate the collision into loop, for verification with all boxes
for row in boundaries:
#y co ordinate
by=by+16
for n in row:
#x co ordinate
n=n-1
bx=n*16
box = boxcollisions(bx, by)
box_list.append(box)
box.draw(screen)
if pygame.sprite.collide_rect(sprite, box):
print("collided")

Use rect.collidelist to test if pacman is colliding with a wall sprites in your wall sprites list. It will return -1 as long as no collision is detected

Make a sprite move to the mouse click position step by step

I'm writing a little pirate game in Pygame. If you played sea battles in Empires Total War, you have an idea of what I would like to achieve:
The ship's sprite is at position (x1|y1). The player now clicks at position (x2|y2) on the screen. The sprite is now supposed to take (x2|y2) as its new position - by going there step by step, not by beaming there instantly.
I figured out that it has something to do with the diagonal of the rectangle (x1|y1),(x1|y2),(x2|y2),(x2|y1) but I just can't figure it out, especially not with keeping the speed the same no matter what angle that diagonal has and considering that the x and y values of either (ship or click) might be bigger or smaller than the respective other.
This little snippet is my last try to write a working function:
def update(self, new_x, new_y, speed, screen, clicked):
if clicked:
self.xshift = (self.x - new_x)
self.yshift = ((self.y - new_y) / (self.x - new_x))
if self.x > (new_x + 10):
self.x -= 1
self.y -= self.yshift
elif self.x > new_x and self.x < (new_x + 10):
self.x -= 1
self.y -= self.yshift
elif self.x < (new_x - 10):
self.x += 1
self.y += self.yshift
elif self.x < new_x and self.x < (new_x - 10):
self.x += 1
self.y += self.yshift
else:
self.x += 0
self.y += 0
screen.set_at((self.x, self.y), (255, 0, 255))
The "ship" is just a pink pixel here. The reaction it shows upon my clicks onto the screen is to move roughly towards my click but to stop at a seemingly random distance of the point I clicked.
The variables are:
new_x, new_y = position of mouseclick
speed = constant speed depending on ship types
clicked = set true by the MOUSEBUTTONDOWN event, to ensure that the xshift and yshift of self are only defined when the player clicked and not each frame again.
How can I make the ship move smoothly from its current position to the point the player clicked?

Say the current position is pos, and the point the player clicked is target_pos, then take the vector between pos and target_pos.
Now you know how to get from pos to target_pos, but to move in constant speed (and not the entire distance at once), you have to normalize the vector, and apply a speed constant by scalar multiplication.
That's it.
Complete example: (the relevant code is in the Ship.update method)
import pygame
class Ship(pygame.sprite.Sprite):
def __init__(self, speed, color):
super().__init__()
self.image = pygame.Surface((10, 10))
self.image.set_colorkey((12,34,56))
self.image.fill((12,34,56))
pygame.draw.circle(self.image, color, (5, 5), 3)
self.rect = self.image.get_rect()
self.pos = pygame.Vector2(0, 0)
self.set_target((0, 0))
self.speed = speed
def set_target(self, pos):
self.target = pygame.Vector2(pos)
def update(self):
move = self.target - self.pos
move_length = move.length()
if move_length < self.speed:
self.pos = self.target
elif move_length != 0:
move.normalize_ip()
move = move * self.speed
self.pos += move
self.rect.topleft = list(int(v) for v in self.pos)
def main():
pygame.init()
quit = False
screen = pygame.display.set_mode((300, 300))
clock = pygame.time.Clock()
group = pygame.sprite.Group(
Ship(1.5, pygame.Color('white')),
Ship(3.0, pygame.Color('orange')),
Ship(4.5, pygame.Color('dodgerblue')))
while not quit:
for event in pygame.event.get():
if event.type == pygame.QUIT:
return
if event.type == pygame.MOUSEBUTTONDOWN:
for ship in group.sprites():
ship.set_target(pygame.mouse.get_pos())
group.update()
screen.fill((20, 20, 20))
group.draw(screen)
pygame.display.flip()
clock.tick(60)
if __name__ == '__main__':
main()