danvics/oxipng
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Fewer pushes

Browse source
This commit is contained in:
Kornel 2021-02-04 13:36:22 +00:00
parent aaee0a6a2e
commit c318ac78e1
1 changed files with 20 additions and 36 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

56
src/filters.rs
View file

@ -71,15 +71,13 @@ pub fn unfilter_line(filter: u8, bpp: usize, data: &[u8], last_line: &[u8], buf:
}
1 => {
for (i, byte) in data.iter().enumerate() {
match i.checked_sub(bpp) {
buf.push(match i.checked_sub(bpp) {
Some(x) => {
let b = buf[x];
buf.push(byte.wrapping_add(b));
byte.wrapping_add(b)
}
None => {
buf.push(*byte);
}
};
None => *byte,
});
}
}
2 => {
@ -95,58 +93,44 @@ pub fn unfilter_line(filter: u8, bpp: usize, data: &[u8], last_line: &[u8], buf:
}
3 => {
for (i, byte) in data.iter().enumerate() {
if last_line.is_empty() {
buf.push(if last_line.is_empty() {
match i.checked_sub(bpp) {
Some(x) => {
let b = buf[x];
buf.push(byte.wrapping_add(b >> 1));
byte.wrapping_add(b >> 1)
}
None => {
buf.push(*byte);
}
};
None => *byte,
}
} else {
match i.checked_sub(bpp) {
Some(x) => {
let b = buf[x];
buf.push(byte.wrapping_add(
((u16::from(b) + u16::from(last_line[i])) >> 1) as u8,
));
byte.wrapping_add(((u16::from(b) + u16::from(last_line[i])) >> 1) as u8)
}
None => {
buf.push(byte.wrapping_add(last_line[i] >> 1));
}
};
};
None => byte.wrapping_add(last_line[i] >> 1),
}
});
}
}
4 => {
for (i, byte) in data.iter().enumerate() {
if last_line.is_empty() {
buf.push(if last_line.is_empty() {
match i.checked_sub(bpp) {
Some(x) => {
let b = buf[x];
buf.push(byte.wrapping_add(b));
byte.wrapping_add(b)
}
None => {
buf.push(*byte);
}
};
None => *byte,
}
} else {
match i.checked_sub(bpp) {
Some(x) => {
let b = buf[x];
buf.push(byte.wrapping_add(paeth_predictor(
b,
last_line[i],
last_line[x],
)));
byte.wrapping_add(paeth_predictor(b, last_line[i], last_line[x]))
}
None => {
buf.push(byte.wrapping_add(last_line[i]));
}
};
};
None => byte.wrapping_add(last_line[i]),
}
});
}
}
_ => unreachable!(),