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lib8: interpolate: optimize some edge cases for blending

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This commit is contained in:
Torrie Fischer 2024-12-15 17:48:20 +01:00
parent 3329ad7b89
commit b21cdef8b0
1 changed files with 23 additions and 10 deletions
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17
src/lib8/interpolate.rs
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@ -12,12 +12,21 @@ pub trait Fract8Ops {
impl Fract8Ops for u8 {
fn scale8(self, scale: Fract8) -> Self {
match scale {
0 => 0,
255 => self,
_ =>
// borrowed from FastLED
(self as u16 * (1 + scale as u16)).unsigned_shr(8) as u8
}
}
fn blend8(self, other: Self, scale: Fract8) -> Self {
((((self as u16).unsigned_shl(8).bitor(other as u16)) as u16).wrapping_add(other as u16 * scale as u16).wrapping_sub(self as u16 * scale as u16)).unsigned_shr(8) as u8
match scale {
0 => self,
255 => other,
_ => ((((self as u16).unsigned_shl(8).bitor(other as u16)) as u16).wrapping_add(other as u16 * scale as u16).wrapping_sub(self as u16 * scale as u16)).unsigned_shr(8) as u8
}
}
}
@ -31,7 +40,10 @@ impl Fract8Ops for Rgb<u8> {
}
fn blend8(self, other: Self, scale: Fract8) -> Self {
match (other.r, other.g, other.b) {
match scale {
0 => self,
255 => other,
_ => match (other.r, other.g, other.b) {
(0, 0, 0) => self,
_ => Rgb::new(
self.r.blend8(other.r, scale),
@ -41,6 +53,7 @@ impl Fract8Ops for Rgb<u8> {
}
}
}
}
pub fn scale8<T: Fract8Ops>(i: T, scale: Fract8) -> T {
i.scale8(scale)