Question

当用户按下 q 发射子弹时，就没有平稳的运动。他们需要在屏幕上移动鼠标才能使子弹移动。

我尝试在youtube上环顾StackOverflow，重新组织代码。

def tank(x,y,turretpos):
        x = int(x)
        y = int(y)
        possibleturrets = [(x-25, y-2), (x-25, y-4), (x-25, y-6), (x-25, y-8), (x-24, y-10),
                  (x-24, y-12), (x-23, y-14), (x-20, y-16), (x-18, y-18), (x-16, y-20)]

        pygame.draw.circle(screen,black,(x,y),10)
        pygame.draw.rect(screen,black,(x-tankheight,y,tankwidth,tankheight))
        pygame.draw.line(screen,black,(x,y),possibleturrets[turretpos], turretwidth)
        pygame.draw.line(screen,black,(x,y),possibleturrets[turretpos], turretwidth)

        startx = 15
        for i in range(7):
            pygame.draw.circle(screen,black,(x-startx,y+20),wheelwidth)
            startx -= 5

        return possibleturrets

def fire(gun,tankx,tanky,turretpos):
    fire = True
    startingshellx = gun[0][0]
    startingshelly = gun[0][1]
    while fire: 
        for event in pygame.event.get():
            startingshellx -= (12-turretpos)*2
            startingshelly += int((((startingshellx - (gun[0][0]))*0.015)**2) - (turretpos+turretpos/(12-turretpos)))
            pygame.draw.circle(screen,red,(startingshellx, startingshelly-turretpos),5)
            if startingshelly > height-100:
                fire = False
            pygame.display.update()

我希望用户敲击 q ，子弹应以抛物线形状顺利发射。

Answer 1

您必须更新主循环而不是事件循环中的位置。注意，仅当事件发生时才执行事件循环。这意味着在按下按钮时执行一次，在释放按钮时执行第二次。鼠标的移动也是一个事件，并导致事件循环被执行。

以下可能有效。内部事件处理由pygame.event.pump()完成，而不是事件循环：

Sub Trial_RUN()
    For t = 0 To 5
        TestValueMethod (True)
        TestValueMethod (False)
    Next t

End Sub




Sub TestValueMethod(useValue2 As Boolean)
Dim beginTime As Date, aCell As Range, rngAddress As String, ResultsColumn As Long
ResultsColumn = 5

'have some values in your RngAddress. in my case i put =Rand() in the cells, and then set to values
rngAddress = "A2:A399999" 'I changed this around on my sets.



With ThisWorkbook.Sheets(1)
.Range(rngAddress).Offset(0, 1).ClearContents


beginTime = Now

For Each aCell In .Range(rngAddress).Cells
    If useValue2 Then
        aCell.Offset(0, 1).Value2 = aCell.Value2 + aCell.Offset(-1, 1).Value2
    Else
        aCell.Offset(0, 1).Value = aCell.Value + aCell.Offset(-1, 1).Value
    End If

Next aCell

Dim Answer As String
 If useValue2 Then Answer = " using Value2"

.Cells(Rows.Count, ResultsColumn).End(xlUp).Offset(1, 0) = DateDiff("S", beginTime, Now) & _
            " seconds. For " & .Range(rngAddress).Cells.Count & " cells, at " & Now & Answer


End With


End Sub

但是我建议更改设计。避免使用相同名称的函数和变量。不要在主循环内进行额外的循环显示更新：

def fire(gun,tankx,tanky,turretpos):
    firebullet = True
    startingshellx = gun[0][0]
    startingshelly = gun[0][1]
    while firebullet: 

        pygame.event.pump()

        startingshellx -= (12-turretpos)*2
        startingshelly += int((((startingshellx - (gun[0][0]))*0.015)**2) - (turretpos+turretpos/(12-turretpos)))
        pygame.draw.circle(screen,red,(startingshellx, startingshelly-turretpos),5)
        if startingshelly > height-100:
            firebullet = False
        pygame.display.update()

如果要生成平滑运动，则必须使用浮动点值进行计算：

def fire(shellpos, tankx, tanky, turretpos):
    shellpos[0] -= (12-turretpos)*2
    shellpos[1] += (((shellpos[0] - (gun[0][0]))*0.015)**2) - (turretpos+turretpos/(12-turretpos))
    pygame.draw.circle(screen,red,(round(shellpos[0]), round(shellpos[1]-turretpos)),5)
    return (shellpos[1] <= height-100), shellpos

run = True
firebullet = False
while run:

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_q:
                firebullet, shellpos = True, gun[0]

    # [...]

    if firebullet:
        firebullet, shellpos = fire(shellpos, tankx, tanky, turretpos)

    # [...]    

    pygame.display.update()

在绘制对象（圆形）时，将坐标坐标{int()或round转换为整数值：

startingshellx -= (12-turretpos)*2
startingshelly += (((startingshellx - (gun[0][0]))*0.015)**2) - (turretpos+turretpos/(12-turretpos))

请注意，如果将值截断为整数值，则在添加之前，将丢失小数位：

pygame.draw.circle(screen,red,(round(startingshellx), round(startingshelly-turretpos)),5)

如果稍后执行转换操作，则结果的唯一小数位将丢失：

>>> int(0.3) + int(0.4) + int(0.5) + int(0.6)
0

round()如果小数位数> = 0.5，则给出下一个刨丝器的整数值：

>>> int(0.3 + 0.4 + 0.5 + 0.6)
1

用户需要移动鼠标才能发射子弹

1 个答案: