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))
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Answer
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