如何在图形中实现渐变效果？(Python)

Question

# imports
import pygame
import sys
import random

def randomcolor():

    blue = (0, 0, 255)
    red = (255, 0, 0)
    green = (0, 255, 0)
    white = (255, 255, 255)

    selection = random.randrange(1, 5)
    if selection == 1:
        return blue
    elif selection == 2:
        return red
    elif selection == 3:
        return green
    elif selection == 4:
        return white

def start(dx, dy):

    #initialize
    pygame.init()
    size = width, height = 640, 480
    x = width / 2
    y = height / 2
    randc = (0, 0, 255)

    #call window as ROOT
    root = pygame.display.set_mode(size)
    pygame.display.set_caption("Moving Object")

    #main loop
    while 1:
        root.fill(0)

        if x > 640:
            randc = randomcolor()
            dx = -dx
            x += dx
        elif x < 0:
            randc = randomcolor()
            dx = -dx
            x += dx
        else:
            x += dx

        if y > 480:
            randc = randomcolor()
            dy = -dy
            y += dy
        elif y < 0:
            randc = randomcolor()
            dy = -dy
            y += dy
        else:
            y += dy

        pygame.draw.circle(root, randc, (x, y), 20, 0)
        pygame.time.wait(10)
        pygame.display.flip()
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                sys.exit(0)


velx = input("Enter velocity in x: ")
vely = input("Enter velocity in y: ")
start(velx, vely)

简单来说，我想让我的程序在两个“关键帧”之间生成更多的画面，这样在快速播放时，动画看起来会更流畅。现在我使用pygame.time的原因是，即使速度设为1，动画还是非常快，所以这是我能想到的让动画速度变得合理的方法。

Answer 1

这里有几个小建议：

1) 使用时钟来控制帧率

 clock = pygame.time.Clock()

然后在循环中调用

clock.tick(fps)

2) 考虑根据更新之间经过的时间来调整移动，这样可以消除帧率变化带来的影响

time = pygame.time.get_ticks() # time in ms
timepassed = lastTime - time

## do distance traveled calculations with speed x timepassed

lastTime = time # set the time of this update so it can be used next loop

你想要的流畅感会来自于一个高且稳定的帧率