Make bullets fire off in the direction the player is facing
Question:
I was just getting some help to figure out how to get my player fire bullets when I realized that they only go (kinda expected this but however as only had y value for movement). I don’t know how I’ll make the bullets fire off in the direction the player is facing.
I have some idea of what to but I just don’t know how to do it… I thought I could somehow use the cursor and player tracking that’s in this game for the visuals but I don’t know how to make that a one-time thing instead of a constant. For diagonal movement of the bullet, I have no clue.
Code below (split into two parts/file Main.py and PlayerSprite.py):
Main:
py.init()
py.mixer.init()
screen = py.display.set_mode((WIDTH, HEIGHT))
py.display.set_caption("Dimensional Drifter")
clock = py.time.Clock()
all_sprites = py.sprite.Group()
NPCs = py.sprite.Group()
bullets = py.sprite.Group()
player = Player()
all_sprites.add(player)
for i in range(14):
n = NPC(player)
all_sprites.add(n)
NPCs.add(n)
# Game loop
running = True
while running:
# keep loop running at the right speed
clock.tick(FPS)
for event in py.event.get():
# check for closing window
if event.type == py.QUIT:
running = False
elif event.type == py.KEYDOWN:
if event.key == py.K_SPACE:
New_bullet = player.Shoot()
all_sprites.add(New_bullet)
bullets.add(New_bullet)
# Update
all_sprites.update()
# # check if there a collision between the bullet and NPC
hits = py.sprite.groupcollide(NPCs, bullets, True, True)
# check if there a collision between the player and NPC
hits = py.sprite.spritecollide(player, NPCs, True)
if hits:
running = False
# updates the position of of mouse and rotates it towards the mouse position
mouse_x, mouse_y = py.mouse.get_pos()
player.rotate(mouse_x, mouse_y)
# render
screen.fill(BLACK)
all_sprites.draw(screen)
# flip the display
py.display.flip()
py.quit()
PlayerSprite
import pygame as py
import math
import random
WIDTH = 800
HEIGHT = 600
FPS = 60
# define colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
YELLOW = (255, 255, 0)
class Player(py.sprite.Sprite):
def __init__(self):
py.sprite.Sprite.__init__(self)
self.image = py.Surface((40, 40), py.SRCALPHA)
self.image.fill(GREEN)
self.rect = self.image.get_rect()
self.rect.centerx = WIDTH / 2
self.rect.bottom = HEIGHT / 2
self.Yspeed = 0
self.rotatableimage = self.image
def update(self):
self.Xspeed = 0
self.Yspeed = 0
# line below allow for key press to equate to move of sprite
keypreesed = py.key.get_pressed()
if keypreesed[py.K_a]:
self.Xspeed = - 11
if keypreesed[py.K_d]:
self.Xspeed = 11
if keypreesed[py.K_w]:
self.Yspeed = - 11
if keypreesed[py.K_s]:
self.Yspeed = 11
self.rect.x += self.Xspeed
self.rect.y += self.Yspeed
# line below allow the sprite to wrap around the screen
if self.rect.left > WIDTH:
self.rect.right = 0
if self.rect.right < 0:
self.rect.left = WIDTH
if self.rect.top > HEIGHT:
self.rect.top = 0
if self.rect.bottom < 0:
self.rect.bottom = HEIGHT
def rotate(self, mouse_x, mouse_y):
rel_x = mouse_x - self.rect.x
rel_y = mouse_y - self.rect.y
angle = (180 / math.pi) * -math.atan2(rel_y, rel_x)
self.image = py.transform.rotate(self.rotatableimage, int(angle))
self.rect = self.image.get_rect(center=(self.rect.centerx, self.rect.centery))
return
def Shoot(self):
return Bullet(self.rect.centerx, self.rect.top)
class NPC(py.sprite.Sprite):
def __init__(self, player):
py.sprite.Sprite.__init__(self)
self.player = player
self.image = py.Surface((30, 30)).convert_alpha()
self.image.fill(RED)
self.originalimage = self.image
self.rect = self.image.get_rect()
self.spawn()
# allows of spawning from all four side of the screen and set the x, y speed and spawn position
def spawn(self):
self.direction = random.randrange(4)
if self.direction == 0:
self.rect.x = random.randrange(WIDTH - self.rect.width)
self.rect.y = random.randrange(-100, -40)
self.Xspeed = random.randrange(-2, 2)
self.Yspeed = random.randrange(4, 8)
elif self.direction == 1:
self.rect.x = random.randrange(WIDTH - self.rect.width)
self.rect.y = random.randrange(HEIGHT, HEIGHT + 60)
self.Xspeed = random.randrange(-2, 2)
self.Yspeed = -random.randrange(4, 8)
elif self.direction == 2:
self.rect.x = random.randrange(-100, -40)
self.rect.y = random.randrange(HEIGHT - self.rect.height)
self.Xspeed = random.randrange(4, 8)
self.Yspeed = random.randrange(-2, 2)
elif self.direction == 3:
self.rect.x = random.randrange(WIDTH, WIDTH + 60)
self.rect.y = random.randrange(HEIGHT - self.rect.height)
self.Xspeed = -random.randrange(4, 8)
self.Yspeed = random.randrange(-2, 2)
def update(self):
self.rect.x += self.Xspeed
self.rect.y += self.Yspeed
# makes it so that NPC point to wards the player as it passes from side to side
dir_x, dir_y = self.player.rect.x - self.rect.x, self.player.rect.y - self.rect.y
self.rot = (180 / math.pi) * math.atan2(-dir_x, -dir_y)
self.image = py.transform.rotate(self.originalimage, self.rot)
# Respawns the NPC when they hit an side
if self.direction == 0:
if self.rect.top > HEIGHT + 10:
self.spawn()
elif self.direction == 1:
if self.rect.bottom < -10:
self.spawn()
elif self.direction == 2:
if self.rect.left > WIDTH + 10:
self.spawn()
elif self.direction == 3:
if self.rect.right < -10:
self.spawn()
class Bullet(py.sprite.Sprite):
def __init__(self, x, y):
py.sprite.Sprite.__init__(self)
self.image = py.Surface((5, 5))
self.image.fill(YELLOW)
self.rect = self.image.get_rect()
self.rect.bottom = y
self.rect.centerx = x
self.Yspeed = -10
def update(self):
self.rect.y += self.Yspeed
# kill if moved of screen
if self.rect.bottom > HEIGHT or self.rect.top < 0:
self.kill()
if self.rect.right > WIDTH or self.rect.left < 0:
self.kill()
Answers:
Add 2 attributes self.lastX and self.lastY to the class Player and change the attributes when the player changes the direction:
class Player(py.sprite.Sprite):
def __init__(self):
# [...]
self.lastX = 0
self.lastY = -10
def update(self):
# [...]
self.rect.x += self.Xspeed
self.rect.y += self.Yspeed
if self.Xspeed != 0 or self.Yspeed != 0:
self.lastX = self.Xspeed
self.lastY = self.Yspeed
Add an argument Xspeed ans Yspeed to the class Bullet
class Bullet(py.sprite.Sprite):
def __init__(self, x, y, Xspeed, Yspeed):
py.sprite.Sprite.__init__(self)
self.image = py.Surface((5, 5))
self.image.fill(YELLOW)
self.rect = self.image.get_rect()
self.rect.bottom = y
self.rect.centerx = x
self.Xspeed = Xspeed
self.Yspeed = Yspeed
def update(self):
self.rect.x += self.Xspeed
self.rect.y += self.Yspeed
# [...]
Set the attributes when the bullet spawns
class Player(py.sprite.Sprite):
# [...]
def Shoot(self):
return Bullet(self.rect.centerx, self.rect.centery, self.lastX, self.lastY)
Alternatively it is also possible to set the speed dependent on the direction to the mouse cursor.
Get the position of the player and the mouse cursor and compute the x and y distance (Vector ):
pos = self.rect.center
mpos = py.mouse.get_pos()
vx = mpos[0] - pos[0]
vy = mpos[1] - pos[1]
If the mouse position and the bullet position are equal, that does not make any sense, thus the bullet is skipped
if vx == 0 and vy == 0:
return None
Of course this vector is far to long, if you would use it for the direction (Xspeed, Yspeed) directly, then the bullet would step to the mouse cursor in one turn.
In the following I use pygame.math.Vector2, because it provides the handy method scale_to_length, that scales a vector to a specified Euclidean length:
direction = py.math.Vector2(vx, vy)
direction.scale_to_length(10)
Now the x and y component of the vector contain the x and y component of the speed. Since the components are floating point values, they are round to integral values:
return Bullet(pos[0], pos[1], round(direction.x), round(direction.y))
Method Shoot:
class Player(py.sprite.Sprite):
# [...]
def Shoot(self):
pos = self.rect.center
mpos = py.mouse.get_pos()
vx, vy = mpos[0] - pos[0], mpos[1] - pos[1]
if vx == 0 and vy == 0:
return None
direction = py.math.Vector2(vx, vy)
direction.scale_to_length(10)
return Bullet(pos[0], pos[1], round(direction.x), round(direction.y))
Note, if you set the bullet dependent on the direction to the mouse cursor, then it may be useful to spawn the bullet by a mouse click:
while running:
# [...]
for event in py.event.get():
if event.type == py.QUIT:
# [...]
elif event.type == py.MOUSEBUTTONDOWN:
if event.button == 1:
New_bullet = player.Shoot()
if New_bullet:
all_sprites.add(New_bullet)
bullets.add(New_bullet)
You can use pygames Vector2 to move in any direction. You calculate the angle of the player you can use that.
class Player(py.sprite.Sprite):
def __init__(self):
...
self.angle = 0
def rotate(self, mouse_x, mouse_y):
...
self.angle = -angle #make negative otherwise it will be going away from mouse
def Shoot(self):
return Bullet(self.rect.centerx, self.rect.top, py.math.Vector2(1,0).rotate(self.angle))
then in your bullet class, get the direction and add to its position
class Bullet(py.sprite.Sprite):
def __init__(self, x, y, Dir):
...
self.Dir = Dir
def update(self):
self.rect.y += self.Dir[1] * self.speed
self.rect.x += self.Dir[0] * self.speed
...
I was just getting some help to figure out how to get my player fire bullets when I realized that they only go (kinda expected this but however as only had y value for movement). I don’t know how I’ll make the bullets fire off in the direction the player is facing.
I have some idea of what to but I just don’t know how to do it… I thought I could somehow use the cursor and player tracking that’s in this game for the visuals but I don’t know how to make that a one-time thing instead of a constant. For diagonal movement of the bullet, I have no clue.
Code below (split into two parts/file Main.py and PlayerSprite.py):
Main:
py.init()
py.mixer.init()
screen = py.display.set_mode((WIDTH, HEIGHT))
py.display.set_caption("Dimensional Drifter")
clock = py.time.Clock()
all_sprites = py.sprite.Group()
NPCs = py.sprite.Group()
bullets = py.sprite.Group()
player = Player()
all_sprites.add(player)
for i in range(14):
n = NPC(player)
all_sprites.add(n)
NPCs.add(n)
# Game loop
running = True
while running:
# keep loop running at the right speed
clock.tick(FPS)
for event in py.event.get():
# check for closing window
if event.type == py.QUIT:
running = False
elif event.type == py.KEYDOWN:
if event.key == py.K_SPACE:
New_bullet = player.Shoot()
all_sprites.add(New_bullet)
bullets.add(New_bullet)
# Update
all_sprites.update()
# # check if there a collision between the bullet and NPC
hits = py.sprite.groupcollide(NPCs, bullets, True, True)
# check if there a collision between the player and NPC
hits = py.sprite.spritecollide(player, NPCs, True)
if hits:
running = False
# updates the position of of mouse and rotates it towards the mouse position
mouse_x, mouse_y = py.mouse.get_pos()
player.rotate(mouse_x, mouse_y)
# render
screen.fill(BLACK)
all_sprites.draw(screen)
# flip the display
py.display.flip()
py.quit()
PlayerSprite
import pygame as py
import math
import random
WIDTH = 800
HEIGHT = 600
FPS = 60
# define colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
YELLOW = (255, 255, 0)
class Player(py.sprite.Sprite):
def __init__(self):
py.sprite.Sprite.__init__(self)
self.image = py.Surface((40, 40), py.SRCALPHA)
self.image.fill(GREEN)
self.rect = self.image.get_rect()
self.rect.centerx = WIDTH / 2
self.rect.bottom = HEIGHT / 2
self.Yspeed = 0
self.rotatableimage = self.image
def update(self):
self.Xspeed = 0
self.Yspeed = 0
# line below allow for key press to equate to move of sprite
keypreesed = py.key.get_pressed()
if keypreesed[py.K_a]:
self.Xspeed = - 11
if keypreesed[py.K_d]:
self.Xspeed = 11
if keypreesed[py.K_w]:
self.Yspeed = - 11
if keypreesed[py.K_s]:
self.Yspeed = 11
self.rect.x += self.Xspeed
self.rect.y += self.Yspeed
# line below allow the sprite to wrap around the screen
if self.rect.left > WIDTH:
self.rect.right = 0
if self.rect.right < 0:
self.rect.left = WIDTH
if self.rect.top > HEIGHT:
self.rect.top = 0
if self.rect.bottom < 0:
self.rect.bottom = HEIGHT
def rotate(self, mouse_x, mouse_y):
rel_x = mouse_x - self.rect.x
rel_y = mouse_y - self.rect.y
angle = (180 / math.pi) * -math.atan2(rel_y, rel_x)
self.image = py.transform.rotate(self.rotatableimage, int(angle))
self.rect = self.image.get_rect(center=(self.rect.centerx, self.rect.centery))
return
def Shoot(self):
return Bullet(self.rect.centerx, self.rect.top)
class NPC(py.sprite.Sprite):
def __init__(self, player):
py.sprite.Sprite.__init__(self)
self.player = player
self.image = py.Surface((30, 30)).convert_alpha()
self.image.fill(RED)
self.originalimage = self.image
self.rect = self.image.get_rect()
self.spawn()
# allows of spawning from all four side of the screen and set the x, y speed and spawn position
def spawn(self):
self.direction = random.randrange(4)
if self.direction == 0:
self.rect.x = random.randrange(WIDTH - self.rect.width)
self.rect.y = random.randrange(-100, -40)
self.Xspeed = random.randrange(-2, 2)
self.Yspeed = random.randrange(4, 8)
elif self.direction == 1:
self.rect.x = random.randrange(WIDTH - self.rect.width)
self.rect.y = random.randrange(HEIGHT, HEIGHT + 60)
self.Xspeed = random.randrange(-2, 2)
self.Yspeed = -random.randrange(4, 8)
elif self.direction == 2:
self.rect.x = random.randrange(-100, -40)
self.rect.y = random.randrange(HEIGHT - self.rect.height)
self.Xspeed = random.randrange(4, 8)
self.Yspeed = random.randrange(-2, 2)
elif self.direction == 3:
self.rect.x = random.randrange(WIDTH, WIDTH + 60)
self.rect.y = random.randrange(HEIGHT - self.rect.height)
self.Xspeed = -random.randrange(4, 8)
self.Yspeed = random.randrange(-2, 2)
def update(self):
self.rect.x += self.Xspeed
self.rect.y += self.Yspeed
# makes it so that NPC point to wards the player as it passes from side to side
dir_x, dir_y = self.player.rect.x - self.rect.x, self.player.rect.y - self.rect.y
self.rot = (180 / math.pi) * math.atan2(-dir_x, -dir_y)
self.image = py.transform.rotate(self.originalimage, self.rot)
# Respawns the NPC when they hit an side
if self.direction == 0:
if self.rect.top > HEIGHT + 10:
self.spawn()
elif self.direction == 1:
if self.rect.bottom < -10:
self.spawn()
elif self.direction == 2:
if self.rect.left > WIDTH + 10:
self.spawn()
elif self.direction == 3:
if self.rect.right < -10:
self.spawn()
class Bullet(py.sprite.Sprite):
def __init__(self, x, y):
py.sprite.Sprite.__init__(self)
self.image = py.Surface((5, 5))
self.image.fill(YELLOW)
self.rect = self.image.get_rect()
self.rect.bottom = y
self.rect.centerx = x
self.Yspeed = -10
def update(self):
self.rect.y += self.Yspeed
# kill if moved of screen
if self.rect.bottom > HEIGHT or self.rect.top < 0:
self.kill()
if self.rect.right > WIDTH or self.rect.left < 0:
self.kill()
Add 2 attributes self.lastX and self.lastY to the class Player and change the attributes when the player changes the direction:
class Player(py.sprite.Sprite):
def __init__(self):
# [...]
self.lastX = 0
self.lastY = -10
def update(self):
# [...]
self.rect.x += self.Xspeed
self.rect.y += self.Yspeed
if self.Xspeed != 0 or self.Yspeed != 0:
self.lastX = self.Xspeed
self.lastY = self.Yspeed
Add an argument Xspeed ans Yspeed to the class Bullet
class Bullet(py.sprite.Sprite):
def __init__(self, x, y, Xspeed, Yspeed):
py.sprite.Sprite.__init__(self)
self.image = py.Surface((5, 5))
self.image.fill(YELLOW)
self.rect = self.image.get_rect()
self.rect.bottom = y
self.rect.centerx = x
self.Xspeed = Xspeed
self.Yspeed = Yspeed
def update(self):
self.rect.x += self.Xspeed
self.rect.y += self.Yspeed
# [...]
Set the attributes when the bullet spawns
class Player(py.sprite.Sprite):
# [...]
def Shoot(self):
return Bullet(self.rect.centerx, self.rect.centery, self.lastX, self.lastY)
Alternatively it is also possible to set the speed dependent on the direction to the mouse cursor.
Get the position of the player and the mouse cursor and compute the x and y distance (Vector ):
pos = self.rect.center
mpos = py.mouse.get_pos()
vx = mpos[0] - pos[0]
vy = mpos[1] - pos[1]
If the mouse position and the bullet position are equal, that does not make any sense, thus the bullet is skipped
if vx == 0 and vy == 0:
return None
Of course this vector is far to long, if you would use it for the direction (Xspeed, Yspeed) directly, then the bullet would step to the mouse cursor in one turn.
In the following I use pygame.math.Vector2, because it provides the handy method scale_to_length, that scales a vector to a specified Euclidean length:
direction = py.math.Vector2(vx, vy)
direction.scale_to_length(10)
Now the x and y component of the vector contain the x and y component of the speed. Since the components are floating point values, they are round to integral values:
return Bullet(pos[0], pos[1], round(direction.x), round(direction.y))
Method Shoot:
class Player(py.sprite.Sprite):
# [...]
def Shoot(self):
pos = self.rect.center
mpos = py.mouse.get_pos()
vx, vy = mpos[0] - pos[0], mpos[1] - pos[1]
if vx == 0 and vy == 0:
return None
direction = py.math.Vector2(vx, vy)
direction.scale_to_length(10)
return Bullet(pos[0], pos[1], round(direction.x), round(direction.y))
Note, if you set the bullet dependent on the direction to the mouse cursor, then it may be useful to spawn the bullet by a mouse click:
while running:
# [...]
for event in py.event.get():
if event.type == py.QUIT:
# [...]
elif event.type == py.MOUSEBUTTONDOWN:
if event.button == 1:
New_bullet = player.Shoot()
if New_bullet:
all_sprites.add(New_bullet)
bullets.add(New_bullet)
You can use pygames Vector2 to move in any direction. You calculate the angle of the player you can use that.
class Player(py.sprite.Sprite):
def __init__(self):
...
self.angle = 0
def rotate(self, mouse_x, mouse_y):
...
self.angle = -angle #make negative otherwise it will be going away from mouse
def Shoot(self):
return Bullet(self.rect.centerx, self.rect.top, py.math.Vector2(1,0).rotate(self.angle))
then in your bullet class, get the direction and add to its position
class Bullet(py.sprite.Sprite):
def __init__(self, x, y, Dir):
...
self.Dir = Dir
def update(self):
self.rect.y += self.Dir[1] * self.speed
self.rect.x += self.Dir[0] * self.speed
...