sge-pygame 旋转 parent 和 child 精灵
sge-pygame rotating parent and child sprites
我已经研究并试图解决这个问题很长一段时间了。我正在尝试创建一个 parent/child 附加系统，以便当 parent 移动时，children 附加到它 move/rotate/scales 相同。我遇到的主要问题是旋转。
这是我目前用于 children:
的代码
def _rotate(self, origin, point, angle):
ox, oy = origin
px, py = point
qx = ox + math.cos(angle) * (px - ox) - math.sin(angle) * (py - oy)
qy = oy + math.sin(angle) * (px - ox) + math.cos(angle) * (py - oy)
return qx, qy
_rotate 代码将 2D 点旋转我在搜索问题答案时找到的原点周围的角度。我使用的点是每个 boxes/sprites.
的中心
旋转parent时，我使用sge-pygameimage_rotation，然后移动到children定位。之后我需要根据新位置和新角度计算出 children 的旋转，以旋转 child.
发生的事情的图像：
初始
和
旋转 10 度
Parent是大矩形，方框是child。
我遇到的第二个问题是弄清楚 child 的旋转角度是多少，以使其与 parent 保持一致。我通过 stackflow 发现 math.atan2 的使用应该用于此但是我似乎无法弄清楚如何使用它。
如有任何帮助，我们将不胜感激。
谢谢
您可以在实例化期间将枢轴和所需的偏移量传递给 child（我在下面的示例中使用 pygame.math.Vector2s）。如果 parent 移动，更新其所有 children（我将它们存储在列表中）并将 parent 的速度传递给它们，它们也可以用来更新它们的位置。
旋转的原理类似，你只需要将角度传递给children，然后旋转它们的偏移向量和图像，并将新矩形的中心设置为旧中心加上偏移。
import sys
import pygame as pg
from pygame.math import Vector2
class Player(pg.sprite.Sprite):
def __init__(self, pos, *groups):
super().__init__(groups)
self.image = pg.Surface((90, 40), pg.SRCALPHA)
self.image.fill(pg.Color('steelblue2'))
self.orig_image = self.image
self.rect = self.image.get_rect(center=pos)
self.vel = Vector2(0, 0)
self.pos = Vector2(pos)
self.angle = 0
# A list that holds all children instances.
self.children = [Child(self.pos, Vector2(90, 30), *groups)]
def update(self):
self.pos += self.vel
self.rect.center = self.pos
for child in self.children:
child.move(self.vel)
def rotate(self, angle):
self.angle += angle
# Rotate the image and generate a new rect to keep it centered.
self.image = pg.transform.rotate(self.orig_image, self.angle)
self.rect = self.image.get_rect(center=self.rect.center)
# Rotate the children.
for child in self.children:
child.rotate(angle)
class Child(pg.sprite.Sprite):
def __init__(self, pos, offset, *groups):
super().__init__(groups)
self.image = pg.Surface((50, 30), pg.SRCALPHA)
self.image.fill(pg.Color('mediumaquamarine'))
self.orig_image = self.image
self.rect = self.image.get_rect(center=pos)
self.pos = Vector2(pos) # Parent center.
# Offset from parent center.
self.offset = Vector2(offset)
self.angle = 0
def move(self, vel):
self.pos += vel
self.rect.center = self.pos + self.offset
def rotate(self, angle):
# Rotate the offset vector (negative angle otherwise it would
# rotate in the wrong direction).
self.offset.rotate_ip(-angle)
self.angle += angle
# Rotate the image.
self.image = pg.transform.rotate(self.orig_image, self.angle)
# Add the new offset to the center.
self.rect = self.image.get_rect(center=self.rect.center + self.offset)
def main():
screen = pg.display.set_mode((640, 480))
clock = pg.time.Clock()
sprite_group = pg.sprite.Group()
player = Player((100, 250), sprite_group)
done = False
while not done:
for event in pg.event.get():
if event.type == pg.QUIT:
done = True
elif event.type == pg.KEYDOWN:
if event.key == pg.K_d:
player.vel.x = 5
elif event.key == pg.K_r:
player.rotate(15)
elif event.key == pg.K_c:
player.children.append(Child(
player.pos, Vector2(-90, -30), sprite_group))
elif event.type == pg.KEYUP:
if event.key == pg.K_d:
player.vel.x = 0
sprite_group.update()
screen.fill((30, 30, 30))
sprite_group.draw(screen)
pg.display.flip()
clock.tick(30)
if __name__ == '__main__':
pg.init()
main()
pg.quit()
sys.exit()
按'd'向右移动，'r'旋转，按'c'添加更多children。
您首先将 parent 和 child 旋转相同的量（在本例中，假设 parent 应该被控制而 child 不应该被控制）。然后你只需将 child 移动到 parent 的枢轴点（在本例中为它的中心），并在 parent 所面对的方向上进行额外的偏移（偏移当然是选修的）。
from math import cos, sin, radians
import pygame
pygame.init()
SIZE = WIDTH, HEIGHT = 720, 480
BACKGROUND_COLOR = pygame.Color('black')
FPS = 60
screen = pygame.display.set_mode(SIZE)
clock = pygame.time.Clock()
def update_child_rotation(parent, child, degrees, offset):
# Rotate the parent and child with the same angle.
parent.rotate(degrees)
child.rotate(degrees)
# Calculate the direction the parent is pointing. If you remember the unit circle then you'll
# know that cos(angle) represent the x value and sin(angle) the y value. At angle = 0 the direction
# is to the right (which is what your sprite should be pointing, otherwise you'll have to add an angle
# offset), and it rotates counterclockwise. The minus in '-sin' is because pygame uses positive y as downwards.
angle_in_radians = radians(parent.angle)
direction = pygame.math.Vector2(cos(angle_in_radians), -sin(angle_in_radians))
# Update the child's position to the parent's position but with an added offset in the direction the parent
# is pointing.
child.position = parent.position + direction * offset
class Entity(pygame.sprite.Sprite):
def __init__(self, position, size):
super().__init__()
self.original_image = pygame.Surface(size)
self.original_image.fill((255, 0, 0))
self.original_image.set_colorkey(BACKGROUND_COLOR)
self.image = self.original_image
self.rect = self.image.get_rect(center=position)
self.angle = 0
self.position = pygame.math.Vector2(position)
self.velocity = pygame.math.Vector2(0, 0)
def rotate(self, degrees):
self.angle = (self.angle + degrees) % 360
self.image = pygame.transform.rotate(self.original_image, self.angle)
self.rect = self.image.get_rect(center=self.position)
def update(self, dt):
self.position += self.velocity
self.rect.center = self.position
def main():
parent = Entity(position=(200, 200), size=(128, 32))
child = Entity(position=(356, 200), size=(32, 32))
all_sprites = pygame.sprite.Group(parent, child)
running = True
while running:
dt = clock.tick(FPS) / 1000
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
elif event.type == pygame.KEYDOWN:
if event.key == pygame.K_q:
update_child_rotation(parent, child, 10, 156)
elif event.key == pygame.K_e:
update_child_rotation(parent, child, -10, 156)
elif event.type == pygame.KEYUP:
if event.key == pygame.K_RIGHT or event.key == pygame.K_LEFT:
parent.velocity.x = 0
elif event.key == pygame.K_DOWN or event.key == pygame.K_UP:
parent.velocity.y = 0
all_sprites.update(dt)
screen.fill(BACKGROUND_COLOR)
all_sprites.draw(screen)
pygame.display.update()
if __name__ == '__main__':
main()
我已经研究并试图解决这个问题很长一段时间了。我正在尝试创建一个 parent/child 附加系统，以便当 parent 移动时，children 附加到它 move/rotate/scales 相同。我遇到的主要问题是旋转。
这是我目前用于 children:
的代码def _rotate(self, origin, point, angle):
ox, oy = origin
px, py = point
qx = ox + math.cos(angle) * (px - ox) - math.sin(angle) * (py - oy)
qy = oy + math.sin(angle) * (px - ox) + math.cos(angle) * (py - oy)
return qx, qy
_rotate 代码将 2D 点旋转我在搜索问题答案时找到的原点周围的角度。我使用的点是每个 boxes/sprites.
的中心旋转parent时，我使用sge-pygameimage_rotation，然后移动到children定位。之后我需要根据新位置和新角度计算出 children 的旋转，以旋转 child.
发生的事情的图像：
初始
和
旋转 10 度
Parent是大矩形，方框是child。
我遇到的第二个问题是弄清楚 child 的旋转角度是多少，以使其与 parent 保持一致。我通过 stackflow 发现 math.atan2 的使用应该用于此但是我似乎无法弄清楚如何使用它。
如有任何帮助，我们将不胜感激。
谢谢
您可以在实例化期间将枢轴和所需的偏移量传递给 child（我在下面的示例中使用 pygame.math.Vector2s）。如果 parent 移动，更新其所有 children（我将它们存储在列表中）并将 parent 的速度传递给它们，它们也可以用来更新它们的位置。
旋转的原理类似，你只需要将角度传递给children，然后旋转它们的偏移向量和图像，并将新矩形的中心设置为旧中心加上偏移。
import sys
import pygame as pg
from pygame.math import Vector2
class Player(pg.sprite.Sprite):
def __init__(self, pos, *groups):
super().__init__(groups)
self.image = pg.Surface((90, 40), pg.SRCALPHA)
self.image.fill(pg.Color('steelblue2'))
self.orig_image = self.image
self.rect = self.image.get_rect(center=pos)
self.vel = Vector2(0, 0)
self.pos = Vector2(pos)
self.angle = 0
# A list that holds all children instances.
self.children = [Child(self.pos, Vector2(90, 30), *groups)]
def update(self):
self.pos += self.vel
self.rect.center = self.pos
for child in self.children:
child.move(self.vel)
def rotate(self, angle):
self.angle += angle
# Rotate the image and generate a new rect to keep it centered.
self.image = pg.transform.rotate(self.orig_image, self.angle)
self.rect = self.image.get_rect(center=self.rect.center)
# Rotate the children.
for child in self.children:
child.rotate(angle)
class Child(pg.sprite.Sprite):
def __init__(self, pos, offset, *groups):
super().__init__(groups)
self.image = pg.Surface((50, 30), pg.SRCALPHA)
self.image.fill(pg.Color('mediumaquamarine'))
self.orig_image = self.image
self.rect = self.image.get_rect(center=pos)
self.pos = Vector2(pos) # Parent center.
# Offset from parent center.
self.offset = Vector2(offset)
self.angle = 0
def move(self, vel):
self.pos += vel
self.rect.center = self.pos + self.offset
def rotate(self, angle):
# Rotate the offset vector (negative angle otherwise it would
# rotate in the wrong direction).
self.offset.rotate_ip(-angle)
self.angle += angle
# Rotate the image.
self.image = pg.transform.rotate(self.orig_image, self.angle)
# Add the new offset to the center.
self.rect = self.image.get_rect(center=self.rect.center + self.offset)
def main():
screen = pg.display.set_mode((640, 480))
clock = pg.time.Clock()
sprite_group = pg.sprite.Group()
player = Player((100, 250), sprite_group)
done = False
while not done:
for event in pg.event.get():
if event.type == pg.QUIT:
done = True
elif event.type == pg.KEYDOWN:
if event.key == pg.K_d:
player.vel.x = 5
elif event.key == pg.K_r:
player.rotate(15)
elif event.key == pg.K_c:
player.children.append(Child(
player.pos, Vector2(-90, -30), sprite_group))
elif event.type == pg.KEYUP:
if event.key == pg.K_d:
player.vel.x = 0
sprite_group.update()
screen.fill((30, 30, 30))
sprite_group.draw(screen)
pg.display.flip()
clock.tick(30)
if __name__ == '__main__':
pg.init()
main()
pg.quit()
sys.exit()
按'd'向右移动，'r'旋转，按'c'添加更多children。
您首先将 parent 和 child 旋转相同的量（在本例中，假设 parent 应该被控制而 child 不应该被控制）。然后你只需将 child 移动到 parent 的枢轴点（在本例中为它的中心），并在 parent 所面对的方向上进行额外的偏移（偏移当然是选修的）。
from math import cos, sin, radians
import pygame
pygame.init()
SIZE = WIDTH, HEIGHT = 720, 480
BACKGROUND_COLOR = pygame.Color('black')
FPS = 60
screen = pygame.display.set_mode(SIZE)
clock = pygame.time.Clock()
def update_child_rotation(parent, child, degrees, offset):
# Rotate the parent and child with the same angle.
parent.rotate(degrees)
child.rotate(degrees)
# Calculate the direction the parent is pointing. If you remember the unit circle then you'll
# know that cos(angle) represent the x value and sin(angle) the y value. At angle = 0 the direction
# is to the right (which is what your sprite should be pointing, otherwise you'll have to add an angle
# offset), and it rotates counterclockwise. The minus in '-sin' is because pygame uses positive y as downwards.
angle_in_radians = radians(parent.angle)
direction = pygame.math.Vector2(cos(angle_in_radians), -sin(angle_in_radians))
# Update the child's position to the parent's position but with an added offset in the direction the parent
# is pointing.
child.position = parent.position + direction * offset
class Entity(pygame.sprite.Sprite):
def __init__(self, position, size):
super().__init__()
self.original_image = pygame.Surface(size)
self.original_image.fill((255, 0, 0))
self.original_image.set_colorkey(BACKGROUND_COLOR)
self.image = self.original_image
self.rect = self.image.get_rect(center=position)
self.angle = 0
self.position = pygame.math.Vector2(position)
self.velocity = pygame.math.Vector2(0, 0)
def rotate(self, degrees):
self.angle = (self.angle + degrees) % 360
self.image = pygame.transform.rotate(self.original_image, self.angle)
self.rect = self.image.get_rect(center=self.position)
def update(self, dt):
self.position += self.velocity
self.rect.center = self.position
def main():
parent = Entity(position=(200, 200), size=(128, 32))
child = Entity(position=(356, 200), size=(32, 32))
all_sprites = pygame.sprite.Group(parent, child)
running = True
while running:
dt = clock.tick(FPS) / 1000
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
elif event.type == pygame.KEYDOWN:
if event.key == pygame.K_q:
update_child_rotation(parent, child, 10, 156)
elif event.key == pygame.K_e:
update_child_rotation(parent, child, -10, 156)
elif event.type == pygame.KEYUP:
if event.key == pygame.K_RIGHT or event.key == pygame.K_LEFT:
parent.velocity.x = 0
elif event.key == pygame.K_DOWN or event.key == pygame.K_UP:
parent.velocity.y = 0
all_sprites.update(dt)
screen.fill(BACKGROUND_COLOR)
all_sprites.draw(screen)
pygame.display.update()
if __name__ == '__main__':
main()