1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
|
mod color;
mod gif;
mod lzw;
pub mod block;
pub mod reader;
pub mod writer;
use core::fmt;
use std::error::Error;
pub use color::Color;
pub use gif::Gif;
pub use lzw::LZW;
/// Perform the algorithm to get the length of a color table from
/// the value of the packed field. The max value here is 256
pub(crate) fn packed_to_color_table_length(packed: u8) -> usize {
2usize.pow(packed as u32 + 1)
}
//TODO: Be sure to check that fields in LSD and Img. Desc. that were reserved
//in 87a aren't set if version is 87a, or that we return a warning, etc. Just
//remember about this.
//bottom of page 24 in 89a
#[derive(Clone, Copy, Debug)]
pub enum EncodingError {
TooManyColors,
NoColorTable,
IndicieSizeMismatch { expected: usize, got: usize },
}
impl fmt::Display for EncodingError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Self::TooManyColors => write!(f, "A palette is limited to 256 colors"),
Self::NoColorTable => write!(
f,
"Refusing to set the background color index when no color table is set!"
),
Self::IndicieSizeMismatch { expected, got } => {
write!(f, "Expected to have {} indicies but got {}", expected, got)
}
}
}
}
impl Error for EncodingError {}
|
