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// The number of channels must be unique and start from 0. They will be treated as indice in the
// mixing matrix and used to form unique bitflags in the channel map, which is a bitmap.
#[derive(Copy, Clone, Debug, PartialEq)]
pub enum Channel {
FrontLeft = 0,
FrontRight = 1,
FrontCenter = 2,
LowFrequency = 3,
BackLeft = 4,
BackRight = 5,
FrontLeftOfCenter = 6,
FrontRightOfCenter = 7,
BackCenter = 8,
SideLeft = 9,
SideRight = 10,
TopCenter = 11,
TopFrontLeft = 12,
TopFrontCenter = 13,
TopFrontRight = 14,
TopBackLeft = 15,
TopBackCenter = 16,
TopBackRight = 17,
Silence = 18,
Discrete = 19, // To be used based on its index
}
impl Channel {
pub const fn number(self) -> usize {
self as usize
}
pub const fn count() -> usize {
Channel::Discrete as usize + 1
}
pub const fn bitmask(self) -> u32 {
1 << self as usize
}
}
bitflags! {
pub struct ChannelMap: u32 {
const FRONT_LEFT = Channel::FrontLeft.bitmask();
const FRONT_RIGHT = Channel::FrontRight.bitmask();
const FRONT_CENTER = Channel::FrontCenter.bitmask();
const LOW_FREQUENCY = Channel::LowFrequency.bitmask();
const BACK_LEFT = Channel::BackLeft.bitmask();
const BACK_RIGHT = Channel::BackRight.bitmask();
const FRONT_LEFT_OF_CENTER = Channel::FrontLeftOfCenter.bitmask();
const FRONT_RIGHT_OF_CENTER = Channel::FrontRightOfCenter.bitmask();
const BACK_CENTER = Channel::BackCenter.bitmask();
const SIDE_LEFT = Channel::SideLeft.bitmask();
const SIDE_RIGHT = Channel::SideRight.bitmask();
const TOP_CENTER = Channel::TopCenter.bitmask();
const TOP_FRONT_LEFT = Channel::TopFrontLeft.bitmask();
const TOP_FRONT_CENTER = Channel::TopFrontCenter.bitmask();
const TOP_FRONT_RIGHT = Channel::TopFrontRight.bitmask();
const TOP_BACK_LEFT = Channel::TopBackLeft.bitmask();
const TOP_BACK_CENTER = Channel::TopBackCenter.bitmask();
const TOP_BACK_RIGHT = Channel::TopBackRight.bitmask();
const SILENCE = Channel::Silence.bitmask();
const DISCRETE = Channel::Discrete.bitmask();
}
}
// Avoid printing the following types in debugging context {:?} by declaring them in impl
// rather than bitflags! {} scope.
impl ChannelMap {
pub const FRONT_2: Self = Self::union(Self::FRONT_LEFT, Self::FRONT_RIGHT);
pub const BACK_2: Self = Self::union(Self::BACK_LEFT, Self::BACK_RIGHT);
pub const FRONT_2_OF_CENTER: Self =
Self::union(Self::FRONT_LEFT_OF_CENTER, Self::FRONT_RIGHT_OF_CENTER);
pub const SIDE_2: Self = Self::union(Self::SIDE_LEFT, Self::SIDE_RIGHT);
}
impl From<Channel> for ChannelMap {
fn from(channel: Channel) -> Self {
ChannelMap::from_bits(channel.bitmask()).expect("convert an invalid channel")
}
}