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use crate::{Ch16, Ch32, Ch8, Channel};
use std::fmt::Debug;
use std::marker::PhantomData;
use std::ops::Mul;
pub trait Alpha:
Copy + Debug + Default + PartialEq + Mul<Output = Self>
{
type Chan: Channel;
fn value(&self) -> Self::Chan;
}
#[derive(Clone, Copy, Debug, Default, PartialEq)]
pub struct Opaque<C> {
value: PhantomData<C>,
}
impl<C, H> From<H> for Opaque<C>
where
C: Channel + From<H>,
H: Channel,
{
fn from(_value: H) -> Self {
Opaque::default()
}
}
impl<C: Channel> From<Opaque<C>> for Ch8 {
fn from(_value: Opaque<C>) -> Self {
Ch8::MAX
}
}
impl<C: Channel> From<Opaque<C>> for Ch16 {
fn from(_value: Opaque<C>) -> Self {
Ch16::MAX
}
}
impl<C: Channel> From<Opaque<C>> for Ch32 {
fn from(_value: Opaque<C>) -> Self {
Ch32::MAX
}
}
impl<C, A> From<Translucent<A>> for Opaque<C>
where
C: Channel,
A: Channel,
{
fn from(_: Translucent<A>) -> Self {
Opaque::default()
}
}
impl<C: Channel> Mul<Self> for Opaque<C> {
type Output = Self;
fn mul(self, _rhs: Self) -> Self {
self
}
}
impl<C: Channel> Alpha for Opaque<C> {
type Chan = C;
fn value(&self) -> C {
C::MAX
}
}
#[derive(Clone, Copy, Debug, Default, PartialEq)]
pub struct Translucent<C: Channel> {
value: C,
}
impl<C, H> From<H> for Translucent<C>
where
C: Channel + From<H>,
H: Channel,
{
fn from(value: H) -> Self {
let value = value.into();
Translucent { value }
}
}
impl From<u8> for Translucent<Ch8> {
fn from(value: u8) -> Self {
Ch8::new(value).into()
}
}
impl From<u16> for Translucent<Ch16> {
fn from(value: u16) -> Self {
Ch16::new(value).into()
}
}
impl From<f32> for Translucent<Ch32> {
fn from(value: f32) -> Self {
Ch32::new(value).into()
}
}
impl<C: Channel> Mul<Self> for Translucent<C> {
type Output = Self;
fn mul(self, rhs: Self) -> Self {
let value = self.value * rhs.value;
Translucent { value }
}
}
impl<C: Channel> Translucent<C> {
pub fn new(value: C) -> Self {
Translucent { value }
}
}
impl<C, A> From<Opaque<A>> for Translucent<C>
where
C: Channel,
A: Channel,
{
fn from(_: Opaque<A>) -> Self {
Self::new(C::MAX)
}
}
impl<C: Channel> Alpha for Translucent<C> {
type Chan = C;
fn value(&self) -> C {
self.value
}
}
#[derive(Copy, Clone, Debug, PartialEq, Default)]
pub struct AssociatedAlpha;
#[derive(Copy, Clone, Debug, PartialEq, Default)]
pub struct SeparatedAlpha;
pub trait AlphaMode: Copy + Clone + Debug + PartialEq + Default {
const ID: AlphaModeID;
fn encode<C: Channel, A: Alpha<Chan = C>>(c: C, a: A) -> C;
fn decode<C: Channel, A: Alpha<Chan = C>>(c: C, a: A) -> C;
}
impl AlphaMode for AssociatedAlpha {
const ID: AlphaModeID = AlphaModeID::Associated;
fn encode<C: Channel, A: Alpha<Chan = C>>(c: C, a: A) -> C {
c * a.value()
}
fn decode<C: Channel, A: Alpha<Chan = C>>(c: C, a: A) -> C {
c / a.value()
}
}
impl AlphaMode for SeparatedAlpha {
const ID: AlphaModeID = AlphaModeID::Separated;
fn encode<C: Channel, A: Alpha<Chan = C>>(c: C, _a: A) -> C {
c
}
fn decode<C: Channel, A: Alpha<Chan = C>>(c: C, _a: A) -> C {
c
}
}
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum AlphaModeID {
Associated,
Separated,
UnknownAlpha,
}