希望我没有弄错 - 我不太记得了.

I hope I didn't make mistake - I don't remeber it too well.

atan2(dy, dx) 有错误 - 必须是 atan2(dx, dy)

there was mistake in atan2(dy, dx) - has to be atan2(dx, dy)

如果你有子弹的位置和速度，以及目标的位置，它会计算新的位置(一帧/移动后)位置.

It calculate new position (after one frame/move) if you have bullet's position and speed, and target's position.

你必须重复一遍

import math

speed = 10

# bullet current position
x1 = 0
y1 = 0

# taget possition
x2 = 100
y2 = 100

dx = x2 - x1
dy = y2 - y1

angle = math.atan2(dx, dy)
#print(math.degrees(angle))

cx = speed * math.sin(angle)
cy = speed * math.cos(angle)
#print(cx, cy)

# bullet new current position
x1 += cx
y1 += cy

print(x1, y1)

循环示例

它需要 abs() 在 if abs(cx)

顺便说一句:如果 target 没有改变位置或者 bullet 没有改变 angle 那么你可以只计算一次 cx,cy.

BTW: if target doesn't change place or bullet doesn't change angle then you can calculate cx,cy only once.

import math

def move(x1, y1, x2, y2, speed):

    # distance
    dx = x2 - x1
    dy = y2 - y1

    # angle
    angle = math.atan2(dx, dy)
    #print(math.degrees(angle))

    # 
    cx = speed * math.sin(angle)
    cy = speed * math.cos(angle)
    #print(cx, cy)

    # if distance is smaller then `cx/cy`
    # then you have to stop in target.
    if abs(cx) < abs(dx) or abs(cy) < abs(dy):
        # move bullet to new position
        x1 += cx
        y1 += cy
        in_target = False
    else:
        # move bullet to target
        x1 = x2
        y1 = y2
        in_target = True

    return x1, y1, in_target

#--- 

speed = 10

# bullet position
x1 = 10
y1 = 0

# taget possition
x2 = 120
y2 = 10

print('x: {:6.02f} | y: {:6.02f}'.format(x1, y1))

in_target = False

while not in_target:
    x1, y1, in_target = move(x1, y1, x2, y2, speed)
    print('x: {:6.02f} | y: {:6.02f}'.format(x1, y1))

结果

x:  10.00 | y:   0.00
x:  19.96 | y:   0.91
x:  29.92 | y:   1.81
x:  39.88 | y:   2.72
x:  49.84 | y:   3.62
x:  59.79 | y:   4.53
x:  69.75 | y:   5.43
x:  79.71 | y:   6.34
x:  89.67 | y:   7.24
x:  99.63 | y:   8.15
x: 109.59 | y:   9.05
x: 119.55 | y:   9.96
x: 120.00 | y:  10.00

顺便说一句:如果 target 没有改变位置或者 bullet 没有改变 angle 那么你可以只计算一次 cx,cy.

BTW: if target doesn't change place or bullet doesn't change angle then you can calculate cx,cy only once.