redbot/cogs/audio/equalizer.py
# The equalizer class and some audio eq functions are derived from
# 180093157554388993's work, with his permission
from pathlib import Path
from typing import Final
from redbot.core.i18n import Translator
_ = Translator("Audio", Path(__file__))
class Equalizer:
def __init__(self):
self.band_count: Final[int] = 15
self.bands = [0.0 for _loop_counter in range(self.band_count)]
def set_gain(self, band: int, gain: float):
if band < 0 or band >= self.band_count:
raise IndexError(f"Band {band} does not exist!")
gain = min(max(gain, -0.25), 1.0)
self.bands[band] = gain
def get_gain(self, band: int):
if band < 0 or band >= self.band_count:
raise IndexError(f"Band {band} does not exist!")
return self.bands[band]
def visualise(self):
block = ""
bands = [str(band + 1).zfill(2) for band in range(self.band_count)]
bottom = (" " * 8) + " ".join(bands)
gains = [1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.0, -0.1, -0.2, -0.25]
for gain in gains:
prefix = ""
if gain > 0:
prefix = "+"
elif gain == 0:
prefix = " "
block += f"{prefix}{gain:.2f} | "
for value in self.bands:
if value >= gain:
block += "[] "
else:
block += " "
block += "\n"
block += bottom
return block