我怎样才能让我的子弹看起来像是从我的枪尖中出来？

Question

我有在我的子弹不看问题喜欢他们来了我的枪出来，他们看起来像他们来的球员身体出视频，你可以在视频中看到它拍摄别的地方或者它的枪了同样的事情左侧它向上射击很好，但向下射击很糟糕VIDEO

我试着把我的枪调到 120，但结果是一切都对右侧有效，而不对左侧VIDEO 有效，因为你可以看到它只是小故障

我的弹丸课

class projectile(object):
   def __init__(self, x, y, dirx, diry, color):
       self.x = x
       self.y = y
       self.dirx = dirx
       self.diry = diry
       self.slash = pygame.image.load("round.png")
       self.slash = pygame.transform.scale(self.slash,(self.slash.get_width()//2,self.slash.get_height()//2))
       self.rect  = self.slash.get_rect()
       self.rect.topleft = ( self.x, self.y )
       self.speed = 18
       self.color = color
       self.hitbox = (self.x + -18, self.y, 46,60)

我的射弹是如何附加的

        if event.type == pygame.MOUSEBUTTONDOWN:           
                    
                    # this is for the bullets
            if len(bullets) < 3:
                if box1.health > 25:
                    mousex, mousey = pygame.mouse.get_pos()

                    playerman.isJump = True
                    start_x, start_y = playerman.x - 30, playerman.y  - 65
                    mouse_x, mouse_y = event.pos

                    dir_x, dir_y = mouse_x - start_x, mouse_y - start_y
                    distance = math.sqrt(dir_x**2 + dir_y**2)
                    if distance > 0:
                        new_bullet = projectile(start_x, start_y, dir_x/distance, dir_y/distance, (0,0,0))
                        bullets.append(new_bullet)
                

                # this is displaying the bullets for the player            
    for bullet in bullets[:]:
        bullet.move()
        if bullet.x < 0 or bullet.x > 900 or bullet.y < 0 or bullet.y > 900:
            bullets.pop(bullets.index(bullet))

    def draw(self,drawX,drawY):
 
        self.rect.topleft =  (drawX,drawY)
 
            # the guns hitbox
 
            # rotatiing the gun
        dx = self.look_at_pos[0] - self.rect.centerx
        dy = self.look_at_pos[1] - self.rect.centery 
            
        angle = (190/math.pi) * math.atan2(-dy, dx)
      
        gun_size = self.image.get_size()
        pivot = (8, gun_size[1]//2)
            
 
        blitRotate(window, self.image, self.rect.center, pivot, angle)

        if((angle > 90 or angle < -90) and self.gunDirection != "left"):
            self.gunDirection = "left"
            self.image = pygame.transform.flip(self.image, False, True)
        if((angle < 90 and angle > -90) and self.gunDirection != "right"):
            self.gunDirection = "right"
            self.image = pygame.transform.flip(self.image, False, True)

我的全枪班

 
class handgun():
    def __init__(self,x,y,height,width,color):
        self.x = x
        self.y = y
        self.height = height
        self.width = width
        self.color = color
        self.rect = pygame.Rect(x,y,height,width)
 
 
        # LOL THESE IS THE HAND
        self.shootsright = pygame.image.load("hands.png")
        self.image = self.shootsright
        self.rect  = self.image.get_rect(center = (self.x, self.y))
        self.look_at_pos = (self.x, self.y)
 
        self.isLookingAtPlayer = False
        self.look_at_pos = (x,y)
            
 
 
 
        self.hitbox = (self.x + -18, self.y, 46,60)

 
        self.gunDirection = "right"
    def draw(self,drawX,drawY):
 
        self.rect.topleft =  (drawX,drawY)
 
            # the guns hitbox
 
            # rotatiing the gun
        dx = self.look_at_pos[0] - self.rect.centerx
        dy = self.look_at_pos[1] - self.rect.centery 
            
        angle = (120/math.pi) * math.atan2(-dy, dx)
      
        gun_size = self.image.get_size()
        pivot = (8, gun_size[1]//2)
            
 
        blitRotate(window, self.image, self.rect.center, pivot, angle)

        if((angle > 90 or angle < -90) and self.gunDirection != "left"):
            self.gunDirection = "left"
            self.image = pygame.transform.flip(self.image, False, True)
        if((angle < 90 and angle > -90) and self.gunDirection != "right"):
            self.gunDirection = "right"
            self.image = pygame.transform.flip(self.image, False, True)




    def lookAt( self, coordinate ):
            
        self.look_at_pos = coordinate
 
 
 
white = (255,255,255)
handgun1 = handgun(300,300,10,10,white)




how my images are blitted

```def blitRotate(surf, image, pos, originPos, angle):
 
        # calcaulate the axis aligned bounding box of the rotated image
    w, h = image.get_size()
    sin_a, cos_a = math.sin(math.radians(angle)), math.cos(math.radians(angle)) 
    min_x, min_y = min([0, sin_a*h, cos_a*w, sin_a*h + cos_a*w]), max([0, sin_a*w, -cos_a*h, sin_a*w - cos_a*h])
 
        # calculate the translation of the pivot 
    pivot        = pygame.math.Vector2(originPos[0], -originPos[1])
    pivot_rotate = pivot.rotate(angle)
    pivot_move   = pivot_rotate - pivot
 
        # calculate the upper left origin of the rotated image
    origin = (pos[0] - originPos[0] + min_x - pivot_move[0], pos[1] - originPos[1] - min_y + pivot_move[1])
 
        # get a rotated image
    rotated_image = pygame.transform.rotate(image, angle)
 
        # rotate and blit the image
    surf.blit(rotated_image, origin)
 

我想我想说的是我怎样才能让我的枪完全在我的鼠标位置旋转而没有任何问题

我的完整代码脚本

Answer 1

在我看来，你的子弹好像来自玩家坐标而不是枪的边缘。您可能需要将用于枪的相同偏移应用于射弹原点。或者只是在旋转后提取枪的右上角和右下角坐标并将射弹原点设置为等于平均位置。

至于为什么枪好像没有指向指针的方向，坐标原点在物体的左上角而不是中心。将光标对象的位置偏移一半宽度和高度可能会更容易。否则，您需要做一些额外的三角函数来根据到光标的距离调整偏移量。

例子

这是找到 2 个点的一个很好的示例，但请注意，其他 2 个点是镜像的。（这可以解决，但我没有打扰）

改编自 -如何在 Pygame 中围绕偏离中心的支点旋转图像

和 From -以度数为单位旋转另一个点 python

在线 IDE - https://repl.it/@ikoursh/tracking

import pygame
import math
import time


def rotate(origin, point, angle):
    """
    Rotate a point counterclockwise by a given angle around a given origin.
    """
    angle = math.radians(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]


def blitRotate(surf, image, pos, originPos, angle):
    # calculate the axis aligned bounding box of the rotated image
    w, h = image.get_size()
    sin_a, cos_a = math.sin(math.radians(angle)), math.cos(math.radians(angle))
    min_x, min_y = min([0, sin_a * h, cos_a * w, sin_a * h + cos_a * w]), max(
        [0, sin_a * w, -cos_a * h, sin_a * w - cos_a * h])

    # calculate the translation of the pivot
    pivot = pygame.math.Vector2(originPos[0], -originPos[1])
    pivot_rotate = pivot.rotate(angle)
    pivot_move = pivot_rotate - pivot

    # calculate the upper left origin of the rotated image
    origin = (
        round(pos[0] - originPos[0] + min_x - pivot_move[0]), round(pos[1] - originPos[1] - min_y + pivot_move[1]))

    box_rel = [[0, 0], [w, 0], [w, -h], [0, -h]]
    box_n_rotate = [rotate(originPos, p, -angle) for p in box_rel]  # crete a box with negative rotation
    for i in range(len(box_n_rotate)):
        box_n_rotate[i][0] += pos[0] - originPos[0]
        box_n_rotate[i][1] += pos[1] - originPos[1]

    for c in box_n_rotate[:2]:
        pygame.draw.circle(screen, (0, 255, 0), [round(c[i]) for i in range(len(c))], 5)

    # get a rotated image
    rotated_image = pygame.transform.rotate(image, angle)

    # rotate and blit the image
    surf.blit(rotated_image, origin)


pygame.init()
size = (400, 400)
screen = pygame.display.set_mode(size)
clock = pygame.time.Clock()

image = pygame.image.load('boomerang64.png')
pivot = (48, 21)

angle, frame = 0, 0
done = False
while not done:
    clock.tick(60)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True
    screen.fill(0)

    pos = (200 + math.cos(frame * 0.05) * 100, 200 + math.sin(frame * 0.05) * 50)
    blitRotate(screen, image, pos, pivot, angle)

    pygame.draw.line(screen, (0, 255, 0), (pos[0] - 20, pos[1]), (pos[0] + 20, pos[1]), 3)
    pygame.draw.line(screen, (0, 255, 0), (pos[0], pos[1] - 20), (pos[0], pos[1] + 20), 3)
    pygame.display.flip()
    frame += 1
    angle += 1
    # time.sleep(0.2)

pygame.quit()