Add mixer.Channel.set_source_location()

[yunline]

def set_source_location(self, angle:float, distance:float) -> None: ...

Example:

import pygame
import time

pygame.init()
pygame.mixer.init()

snd=pygame.mixer.Sound("你吼那么大声干什么嘛.mp3")

ch=snd.play(loops=10)
angle=0
distance=50 # distance from 0 to 255
while ch.get_busy():
    ch.set_source_location(angle,distance)
    angle+=1
    angle%=360
    time.sleep(0.005)

You should hear the sound running around you.

[MyreMylar]

We could perhaps have an interactive test here

[MyreMylar]

LGTM 👍

New test works great!

[Starbuck5]

I assumed from the title of this PR that this was a way to set the playback time of a channel. I.e. rewind or seek forward to a time.

I'm quite excited to see it's actually about setting the direction of a sound effect. That could be a super cool effect!

However I'm wondering if we can get a more clear name than set_position to illustrate the functionality. Maybe set_direction or something like set_playback_angle? Just throwing out ideas, what do you think?

[MyreMylar]

I assumed from the title of this PR that this was a way to set the playback time of a channel. I.e. rewind or seek forward to a time.

I'm quite excited to see it's actually about setting the direction of a sound effect. That could be a super cool effect!

However I'm wondering if we can get a more clear name than set_position to illustrate the functionality. Maybe set_direction or something like set_playback_angle? Just throwing out ideas, what do you think?

I believe this is usually called positional audio. Looking elsewhere OpenAL uses a concept of audio sources for its positional audio implementation - perhaps we could go with something like set_source_location() which may be both somewhat familiar to users of OpenAL, cover both direction and angle, and also unique/intriguing enough that other users read the docs to figure out exactly what it does. @Starbuck5 is correct that we are already using the function name set_pos() in mixer.music to refer to setting the time position in the music file.

[yunline]

This function should support float input

[Starbuck5]

Thanks!