我有一个程序在按键上播放正弦波音符。这个想法是模拟一种乐器。我添加了一些用于调整音量的代码，但每次播放新音符时，音量的这个值似乎都会刷新。如何调整，以便当按下一个键调整音量时，音量保持此值直到再次改变？
import pygame
from pygame.locals import *
import math
import numpy
pygame.init()
bits = 16
pygame.mixer.pre_init(44100, -bits, 2)
def generate_sound(freq):
volume = 0.5
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(volume)
for s in range(n_samples):
t = float(s)/sample_rate # time in seconds
buf[s][0] = int(round(max_sample*math.sin(2*math.pi*freq*t))) # left
buf[s][1] = int(round(max_sample*math.sin(2*math.pi*freq*t))) # right
return pygame.sndarray.make_sound(buf)
size = (1200, 720)
screen = pygame.display.set_mode(size, pygame.HWSURFACE | pygame.DOUBLEBUF)
duration = 2.0 # in seconds
sample_rate = 44100
n_samples = int(round(duration*sample_rate))
#lower
sound_130_81 = generate_sound(130.81) #C
_running = True
while _running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
_running = False
if event.type == KEYDOWN:
#Volume control
if event.key == K_1:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.1)
elif event.key == K_2:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.2)
elif event.key == K_3:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.3)
elif event.key == K_4:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.4)
elif event.key == K_5:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.5)
elif event.key == K_6:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.6)
elif event.key == K_7:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.7)
elif event.key == K_8:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.8)
elif event.key == K_9:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.9)
elif event.key == K_0:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(1.0)
elif event.key == K_BACKSPACE:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.0)
volume = c.get_volume()
if event.key == K_ESCAPE:
_running = False
#lower notes DOWN
elif event.key == K_z:
sound_130_81.play(-1)
if event.type == KEYUP:
#lower notes UP
if event.key == K_z:
sound_130_81.fadeout(350) #fade sound by .35 seconds
pygame.quit()
答案 0 :(得分：0)
您正在generate_sound方法的开头设置音量。您需要使用现有值，而不是每次都将其设置为固定值。将其作为可在调用者中调整的参数（最好）传入，或者如果您的语言支持，则将其设置为全局值。
我并不特别了解python，但它可能会像以下内容一样工作：
import pygame
from pygame.locals import *
import math
import numpy
pygame.init()
bits = 16
volume = 0.5
pygame.mixer.pre_init(44100, -bits, 2)
def generate_sound(freq, volume):
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(volume)
#setup our numpy array to handle 16 bit ints, which is what we set our mixer to expect with "bits" up above
buf = numpy.zeros((n_samples, 2), dtype = numpy.int16)
max_sample = 2**(bits - 1) - 1
for s in range(n_samples):
t = float(s)/sample_rate # time in seconds
buf[s][0] = int(round(max_sample*math.sin(2*math.pi*freq*t))) # left
buf[s][1] = int(round(max_sample*math.sin(2*math.pi*freq*t))) # right
return pygame.sndarray.make_sound(buf)
size = (1200, 720)
screen = pygame.display.set_mode(size, pygame.HWSURFACE | pygame.DOUBLEBUF)
duration = 2.0 # in seconds
sample_rate = 44100
n_samples = int(round(duration*sample_rate))
#lower
sound_130_81 = generate_sound(130.81, volume) #C
sound_146_83 = generate_sound(146.83, volume) #D
sound_164_81 = generate_sound(164.81, volume) #E
sound_174_61 = generate_sound(174.61, volume) #F
sound_196_00 = generate_sound(196.00, volume) #G
sound_220_00 = generate_sound(220.00, volume) #A
sound_246_94 = generate_sound(246.94, volume) #B
#middle
sound_261_63 = generate_sound(261.63, volume) #C
sound_293_66 = generate_sound(293.66, volume) #D
sound_329_63 = generate_sound(329.63, volume) #E
sound_349_23 = generate_sound(349.23, volume) #F
sound_392_00 = generate_sound(392.00, volume) #G
sound_440_00 = generate_sound(440.00, volume) #A
sound_493_88 = generate_sound(493.88, volume) #B
#higher
sound_523_25 = generate_sound(523.25, volume) #C
sound_587_33 = generate_sound(587.33, volume) #D
sound_659_25 = generate_sound(659.25, volume) #E
sound_698_46 = generate_sound(698.46, volume) #F
sound_783_99 = generate_sound(783.99, volume) #G
sound_880_00 = generate_sound(880.00, volume) #A
sound_987_77 = generate_sound(987.77, volume) #B
sound_1046_50 = generate_sound(1046.50, volume) #C
#This will keep the sound playing forever, the quit event handling allows the pygame window to close without crashing
_running = True
while _running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
_running = False
if event.type == KEYDOWN:
#Volume control
if event.key == K_1:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.1)
elif event.key == K_2:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.2)
elif event.key == K_3:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.3)
elif event.key == K_4:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.4)
elif event.key == K_5:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.5)
elif event.key == K_6:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.6)
elif event.key == K_7:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.7)
elif event.key == K_8:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.8)
elif event.key == K_9:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.9)
elif event.key == K_0:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(1.0)
elif event.key == K_BACKSPACE:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.0)
volume = c.get_volume()
if event.key == K_ESCAPE:
_running = False
#lower notes DOWN
elif event.key == K_z:
sound_130_81.play(-1)
elif event.key == K_x:
sound_146_83.play(-1)
elif event.key == K_c:
sound_164_81.play(-1)
elif event.key == K_v:
sound_174_61.play(-1)
elif event.key == K_b:
sound_196_00.play(-1)
elif event.key == K_n:
sound_220_00.play(-1)
elif event.key == K_m:
sound_246_94.play(-1)
elif event.key == K_COMMA:
sound_261_63.play(-1)
#middle notes DOWN
elif event.key == K_a:
sound_261_63.play(-1)
elif event.key == K_s:
sound_293_66.play(-1)
elif event.key == K_d:
sound_329_63.play(-1)
elif event.key == K_f:
sound_349_23.play(-1)
elif event.key == K_g:
sound_392_00.play(-1)
elif event.key == K_h:
sound_440_00.play(-1)
elif event.key == K_j:
sound_493_88.play(-1)
elif event.key == K_k:
sound_523_25.play(-1)
#higher notes DOWN
elif event.key == K_q:
sound_523_25.play(-1)
elif event.key == K_w:
sound_587_33.play(-1)
elif event.key == K_e:
sound_659_25.play(-1)
elif event.key == K_r:
sound_698_46.play(-1)
elif event.key == K_t:
sound_783_99.play(-1)
elif event.key == K_y:
sound_880_00.play(-1)
elif event.key == K_u:
sound_987_77.play(-1)
elif event.key == K_i:
sound_1046_50.play(-1)
if event.type == KEYUP:
#lower notes UP
if event.key == K_z:
sound_130_81.fadeout(350) #fade sound by .35 seconds
elif event.key == K_x:
sound_146_83.fadeout(1000)
elif event.key == K_c:
sound_164_81.fadeout(350)
elif event.key == K_v:
sound_174_61.fadeout(350)
elif event.key == K_b:
sound_196_00.fadeout(350)
elif event.key == K_n:
sound_220_00.fadeout(350)
elif event.key == K_m:
sound_246_94.fadeout(350)
elif event.key == K_COMMA:
sound_261_63.fadeout(350)
#middle notes UP
elif event.key == K_a:
sound_261_63.fadeout(350)
elif event.key == K_s:
sound_293_66.fadeout(350)
elif event.key == K_d:
sound_329_63.fadeout(350)
elif event.key == K_f:
sound_349_23.fadeout(350)
elif event.key == K_g:
sound_392_00.fadeout(350)
elif event.key == K_h:
sound_440_00.fadeout(350)
elif event.key == K_j:
sound_493_88.fadeout(350)
elif event.key == K_k:
sound_523_25.fadeout(350)
#higher notes UP
elif event.key == K_q:
sound_523_25.fadeout(350)
elif event.key == K_w:
sound_587_33.fadeout(350)
elif event.key == K_e:
sound_659_25.fadeout(350)
elif event.key == K_r:
sound_698_46.fadeout(350)
elif event.key == K_t:
sound_783_99.fadeout(350)
elif event.key == K_y:
sound_880_00.fadeout(350)
elif event.key == K_u:
sound_987_77.fadeout(350)
elif event.key == K_i:
sound_1046_50.fadeout(350)
pygame.quit()