简单的 Pygame 动画口吃答案

【问题标题】：Simple Pygame animation stuttering简单的 Pygame 动画口吃
【发布时间】：2016-10-03 16:38:54
【问题描述】：

我有一个用“Pygame”绘制的简单弹跳框窗口。一切似乎都正常，除了一点点烦恼。它经常口吃！我不知道是什么导致了口吃。我认为这可能是延迟，所以我实现了一个固定的时间步长以允许循环赶上，但这没有效果。

#--- initialize pygame window ---#
import pygame
import time
pygame.init()
size = (1200,500)
screen = pygame.display.set_mode(size, pygame.RESIZABLE)
fps = 60

#--- define color palette ---#
black = (0,0,0)
white = (255,255,255)

#--- define the player ---#
class player:
    def __init__(self,screen,surface, color):
        self.speed = 3
        self.direction_x = 1
        self.direction_y = 1
        self.screen = screen
        self.surface = surface
        self.rect = self.surface.get_rect()
        self.color = color
    def set_pos(self, x,y):
        self.rect.x = x
        self.rect.y = y
    def advance_pos(self):
        screen_width, screen_height = screen.get_size()
        if self.rect.x + self.rect.width > screen_width or player1.rect.x < 0:
            player1.direction_x *= -1
            player1.speed = 3
        elif player1.rect.y + player1.rect.height > screen_height or player1.rect.y < 0:
            player1.direction_y *= -1
            player1.speed = 3
        else:
            player1.speed -= 0.001
        self.rect.x += self.speed * self.direction_x
        self.rect.y += self.speed * self.direction_y
    def draw(self):
        pygame.draw.rect(self.surface, self.color, [0,0,self.rect.width,self.rect.height])
    def blit(self):
        screen.blit(self.surface, self.rect)
player1 = player(screen, pygame.Surface((50,50)), white)
player1.set_pos(50,50)
player1.draw()

#--- define game variables ---#
previous = time.time() * 1000
lag = 0.0
background = black
done = False

#--- game ---#
while not done:

    #--- update time step ---#
    current = time.time() * 1000
    elapsed = current - previous
    lag += elapsed
    previous = current

    #--- process events ---#
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True
            break
        if event.type == pygame.VIDEORESIZE:
            screen = pygame.display.set_mode((event.w, event.h), pygame.RESIZABLE)

    #--- update logic ---#

    while True:
        player1.advance_pos()
        lag -= fps
        if lag <= fps:
            break

    #--- draw to screen ---#
    screen.fill(background)
    player1.blit()
    pygame.display.update()
    pygame.time.Clock().tick(fps)

【问题讨论】：

你看过this链接吗？那里提供的答案有一些有用的建议。如果您需要 60 fps，则需要 vsync，我不确定 pygame 是否提供，除非您使用 pyopengl 之类的东西进行 pygame 渲染。
我不知道 PyOpenGL。谢谢！
如果您以前没有使用过 OpenGL，从头开始学习 OpenGL 可能会非常具有挑战性。如果有帮助，我可以发布一个演示，复制您已经使用 pygame 和 pyopengl 编写的内容。
那太棒了
我运行了您的代码，但没有遇到任何明显的卡顿。你得到什么FPS？如果它以 60 fps 运行，则不应该有任何明显的卡顿。我还建议创建一个时钟变量，例如 clock = pygame.time.Clock() 然后调用 clock.tick(fps) 而不是你的最后一行，这样每帧都会创建一个新的时钟对象。

标签： python pygame

【解决方案1】：

这是对您的代码的重写，它使用 opengl 代替渲染。主要变化如下：

我使用了 opengl 即时模式，该模式已过时且已弃用，但起初更容易理解。大多数 gl 调用要么在 player.draw() 方法中，要么在主循环中。

我修正了计时器的完成方式。我不是只做clock.tick(fps)，而是手动跟踪对帧进行所有处理所需的时间，并添加适当的毫秒延迟以达到60 fps。您可以在迁移到 opengl 之前尝试使用现有的 pygame 代码进行修改，因为这可能足以消除大部分卡顿。

import pygame
import time
from OpenGL.GL import *

class Player:
    def __init__(self, screen, width, height, color):
        self.x = 0
        self.y = 0
        self.speed = 3
        self.direction_x = 1
        self.direction_y = 1
        self.screen = screen
        self.width = width
        self.height = height
        self.color = color

    def set_pos(self, x, y):
        self.x = x
        self.y = y

    def advance_pos(self):
        screen_width, screen_height = screen.get_size()
        if self.x + self.width > screen_width or self.x < 0:
            self.direction_x *= -1
            self.speed = 3
        elif self.y + self.height > screen_height or self.y < 0:
            self.direction_y *= -1
            self.speed = 3
        else:
            self.speed -= 0.001
        self.x += self.speed * self.direction_x
        self.y += self.speed * self.direction_y

    def draw(self):
        glMatrixMode(GL_MODELVIEW)
        glLoadIdentity()
        glTranslate(self.x, self.y, 0)
        glBegin(GL_QUADS)
        glColor(*self.color)
        glVertex(0, 0, 0)
        glVertex(self.width, 0, 0)
        glVertex(self.width, self.height, 0)
        glVertex(0, self.height, 0)
        glEnd()

if __name__ == "__main__":
    pygame.init()
    size = width, height = (550, 400)
    screen = pygame.display.set_mode(size, pygame.RESIZABLE | pygame.DOUBLEBUF | pygame.OPENGL)
    fps = 60
    black = (0,0,0,255)
    white = (255,255,255,255)

    player1 = Player(screen, 50, 50, white)
    player1.set_pos(50,50)

    done = False
    previous = time.time() * 1000
    glClearColor(*black)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    glOrtho(0, width, height, 0, -1, 1)
    clock = pygame.time.Clock()

    while not done:
        current = time.time() * 1000
        elapsed = current - previous
        previous = current
        delay = 1000.0/fps - elapsed
        delay = max(int(delay), 0)

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                done = True
                break
            if event.type == pygame.VIDEORESIZE:
                size = width, height = event.w, event.h
                screen = pygame.display.set_mode(size, pygame.RESIZABLE | pygame.DOUBLEBUF | pygame.OPENGL)
                glMatrixMode(GL_PROJECTION)
                glLoadIdentity()
                glOrtho(0, width, height, 0, -1, 1)
                glViewport(0, 0, width, height)

                #reset player movement and position to avoid glitches where player is trapped outside new window borders
                player1.set_pos(50, 50)
                player1.direction_x = 1
                player1.direction_y = 1

        player1.advance_pos()
        glClear(GL_COLOR_BUFFER_BIT)
        glClear(GL_DEPTH_BUFFER_BIT)
        player1.draw()
        pygame.display.flip()
        pygame.time.delay(delay)

【讨论】：

太棒了！谢谢你的帮助。 OpenGL 会很有趣。

【解决方案2】：

我在进入“未完成”循环之前创建了一个时钟对象，并且没有更多的滞后

#--- initialize pygame window ---#
import pygame
import time
pygame.init()
size = (1200,500)
screen = pygame.display.set_mode(size, pygame.RESIZABLE)
fps = 60

#--- define color palette ---#
black = (0,0,0)
white = (255,255,255)

#--- define the player ---#
class player:
    def __init__(self,screen,surface, color):
        self.speed = 3
        self.direction_x = 1
        self.direction_y = 1
        self.screen = screen
        self.surface = surface
        self.rect = self.surface.get_rect()
        self.color = color
    def set_pos(self, x,y):
        self.rect.x = x
        self.rect.y = y
    def advance_pos(self):
        screen_width, screen_height = screen.get_size()
        if self.rect.x + self.rect.width > screen_width or player1.rect.x < 0:
            player1.direction_x *= -1
            player1.speed = 3
        elif player1.rect.y + player1.rect.height > screen_height or player1.rect.y < 0:
            player1.direction_y *= -1
            player1.speed = 3
        else:
            player1.speed -= 0.001
        self.rect.x += self.speed * self.direction_x
        self.rect.y += self.speed * self.direction_y
    def draw(self):
        pygame.draw.rect(self.surface, self.color, [0,0,self.rect.width,self.rect.height])
    def blit(self):
        screen.blit(self.surface, self.rect)
player1 = player(screen, pygame.Surface((50,50)), white)
player1.set_pos(50,50)
player1.draw()

#--- define game variables ---#
previous = time.time() * 1000
lag = 0.0
background = black
done = False
clock=pygame.time.Clock()

#--- game ---#
while not done:

    #--- update time step ---#
    current = time.time() * 1000
    elapsed = current - previous
    lag += elapsed
    previous = current

    #--- process events ---#
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True
            break
        if event.type == pygame.VIDEORESIZE:
            screen = pygame.display.set_mode((event.w, event.h), pygame.RESIZABLE)

    #--- update logic ---#

    while True:
        player1.advance_pos()
        lag -= fps
        if lag <= fps:
            break

    #--- draw to screen ---#
    screen.fill(background)
    player1.blit()
    pygame.display.update()
    clock.tick(fps)

pygame.quit()

【讨论】：