问题
I'm making a constellation that starts from (0,0). The previous line has to disappear after a two second delay and when the left is clicked within the two second delay, white circles should appear. I don't know why my timer isn't working and I'm not sure how to make the line disappear. Also the circles don't appear. This is my code
from pygame import *
import random
init()
size = width, height = 700, 700
screen = display.set_mode(size)
button = 0
BLACK = (0, 0, 0)
GREEN = (0, 255, 0)
RED = (255, 0, 0)
BLUE = (0,0,255)
WHITE = (255,255,255)
colors = (RED,GREEN,BLUE)
time.set_timer(USEREVENT, 2000)
mx = 0
my = 0
def drawScene(screen, button):
if button == 1:
draw.circle(screen,RED,(mx,my), 5)
draw.line(screen,RED,(mx,my),(lx,ly),2)
draw.circle(screen,RED,(lx,ly), 5)
display.flip()
if button == 3:
draw.line(screen,random.choice(colors),(mx,my),(lx,ly),2)
draw.circle(screen,random.choice(colors),(lx,ly), 5)
display.flip()
running = True
myClock = time.Clock()
start = time.get_ticks()
# Game Loop
while running:
lx = mx
ly = my
for evnt in event.get(): # checks all events that happen
if evnt.type == QUIT:
running = False
if evnt.type == MOUSEBUTTONDOWN:
mx,my = evnt.pos
button = evnt.button
cx,cy = mouse.get_pos()
draw.circle(screen,WHITE,(cx,cy),5)
if evnt.type == USEREVENT:
my_event = event.Event(USEREVENT)
time.set_timer(my_event , 2000)
drawScene(screen, button)
myClock.tick(60) # waits long enough to have 60 fps
quit()
回答1:
I hope this is what you were wanting and the comments are clear.
from pygame import *
import random
init()
size = width, height = 700, 700
screen = display.set_mode(size)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
WHITE = (255, 255, 255)
colors = (RED, GREEN, BLUE)
time.set_timer(USEREVENT, 2000)
mx = 0
my = 0
def drawScene(screen, button, prev_point, new_point):
if button == 1:
draw.circle(screen, RED, prev_point, 5)
draw.circle(screen, WHITE, new_point, 5)
draw.line (screen, RED, prev_point, new_point, 2)
display.flip()
if button == 3:
draw.line (screen, random.choice(colors), prev_point, new_point,2)
draw.circle(screen, random.choice(colors), new_point, 5)
display.flip()
running = True
myClock = time.Clock()
prev_render = time.get_ticks() #time in ticks that last render occured
prev_point = (mx, my) #where previous line ended
#function for when to re draw the scene
#ternary if. if override == True, then return true. Else return if time since last update > 2secs
rerender = lambda time_since_update, override: (time_since_update>2000, True)[override]
# Game Loop
while running:
override = False
for evnt in event.get(): # checks all events that happen
if evnt.type == QUIT:
running = False
if evnt.type == MOUSEBUTTONDOWN:
override = True #force window to rerender
new_point = evnt.pos #(mx, my)
button = evnt.button
#rerender window only if necessary. (personal preference)
updated_at = time.get_ticks()
dt = updated_at-prev_render #time difference
if(rerender(dt, override)):
screen.fill(BLACK)
drawScene(screen, button, prev_point, new_point)
prev_point = new_point
prev_render = updated_at
display.update()
myClock.tick(60) # waits long enough to have 60 fps
quit()
回答2:
This is not a complete solution, but I'll give you a general idea how how to start
Create a list of times and a list of lines:
lines = []
Get the current time in the main application loop:
current_time = pygame.time.get_ticks()
When the mouse is clicked then compute the time when the line has to disappear (current_time + 2000) and compute a random color.
Add a Dictionary with the start point, the end point, the time when the line has to disappear and the color to the list of lines.
If the list of lines is empty, then the start point of the line is (0, 0) else the start point is the end point of the last line in the list:
if event.type == pygame.MOUSEBUTTONDOWN:
disappear_time = current_time + 2000
line_color = random.choice(colors)
prev_pt = (0, 0) if len(lines) == 0 else lines[-1]['end']
lines.append({'start': prev_pt, 'end': event.pos, 'time': disappear_time, 'color': line_color})
When the current time exceeds the time which is stored in time, then remove a point and a time form the lists of lines:
if len(times) > 0 and current_time > times[0]:
del lines[0]
Draw the lines by and circles in a loop:
screen.fill(BLACK)
for li in lines:
pygame.draw.line(screen, li['color'], li['start'], li['end'], 2)
pygame.draw.circle(screen, li['color'], li['start'], 5)
pygame.draw.circle(screen, li['color'], li['end'], 5)
See the example:
import pygame
import random
pygame.init()
size = width, height = 700, 700
screen = pygame.display.set_mode(size)
BLACK = (0, 0, 0)
GREEN = (0, 255, 0)
RED = (255, 0, 0)
BLUE = (0,0,255)
WHITE = (255,255,255)
colors = (RED,GREEN,BLUE)
lines = []
running = True
myClock = pygame.time.Clock()
while running:
current_time = pygame.time.get_ticks()
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
if event.type == pygame.MOUSEBUTTONDOWN:
disappear_time = current_time + 2000
line_color = random.choice(colors)
prev_pt = (0, 0) if len(lines) == 0 else lines[-1]['end']
lines.append({'start': prev_pt, 'end': event.pos, 'time': disappear_time, 'color': line_color})
if len(lines) > 0 and current_time > lines[0]['time']:
del lines[0]
screen.fill(BLACK)
for li in lines:
pygame.draw.line(screen, li['color'], li['start'], li['end'], 2)
pygame.draw.circle(screen, li['color'], li['start'], 5)
pygame.draw.circle(screen, li['color'], li['end'], 5)
pygame.display.flip()
myClock.tick(60)
quit()
来源：https://stackoverflow.com/questions/61682742/how-can-you-make-the-previous-line-disappear-in-python