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use crate::{
pixel::Pixel,
ser::{Ser, Sink, Source},
};
#[derive(Clone, Debug)]
pub struct Block {
size: (usize, usize),
inner: BlockInner,
}
#[derive(Clone, Debug)]
pub enum BlockInner {
Literal(Vec<Pixel>),
Split(Box<[Block; 2]>),
Reference { translation: (usize, usize) },
}
impl Block {
pub fn write(&self, sink: &mut impl std::io::Write) -> std::io::Result<()> {
match &self.inner {
BlockInner::Literal(pixels) => {
sink.put(0u8)?;
pixels.write(sink)?;
}
BlockInner::Split(box [a, b]) => {
sink.put(1u8)?;
a.write(sink)?;
b.write(sink)?;
}
BlockInner::Reference { translation: _ } => {
sink.put(2u8)?;
}
}
Ok(())
}
pub fn read(source: &mut impl std::io::Read, size: (usize, usize)) -> std::io::Result<Self> {
let inner = match source.get::<u8>()? {
0 => BlockInner::Literal(source.get()?),
1 => BlockInner::Split(Box::new({
let subsize = if size.0 > size.1 {
(size.0 / 2, size.1)
} else {
(size.0, size.1 / 2)
};
[Block::read(source, subsize)?, Block::read(source, subsize)?]
})),
2 => todo!(),
_ => panic!("file corrupt"),
};
Ok(Self { size, inner })
}
}
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