98 lines
2.7 KiB
Rust
98 lines
2.7 KiB
Rust
use crate::colorspace::ColorSpace;
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use crate::consts::{QOI_HEADER_SIZE, QOI_MAGIC};
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use crate::error::{Error, Result};
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use crate::utils::unlikely;
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#[derive(Copy, Clone, Debug, PartialEq, Eq)]
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pub struct Header {
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pub magic: u32,
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pub width: u32,
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pub height: u32,
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pub channels: u8,
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pub colorspace: ColorSpace,
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}
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impl Default for Header {
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#[inline]
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fn default() -> Self {
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Self {
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magic: QOI_MAGIC,
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width: 1,
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height: 1,
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channels: 3,
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colorspace: ColorSpace::default(),
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}
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}
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}
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#[inline(always)]
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const fn u32_to_be(v: u32) -> [u8; 4] {
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[
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((0xff00_0000 & v) >> 24) as u8,
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((0x00ff_0000 & v) >> 16) as u8,
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((0xff00 & v) >> 8) as u8,
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(0x00ff & v) as u8,
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]
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}
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#[inline(always)]
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const fn u32_from_be(v: &[u8]) -> u32 {
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((v[0] as u32) << 24) | ((v[1] as u32) << 16) | ((v[2] as u32) << 8) | (v[3] as u32)
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}
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impl Header {
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#[inline]
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pub const fn new(width: u32, height: u32, channels: u8) -> Self {
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Self { magic: QOI_MAGIC, width, height, channels, colorspace: ColorSpace::from_u8(0) }
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}
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#[inline]
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pub fn with_colorspace(mut self, colorspace: impl Into<ColorSpace>) -> Self {
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self.colorspace = colorspace.into();
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self
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}
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#[inline]
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pub const fn encoded_size() -> usize {
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QOI_HEADER_SIZE
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}
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#[inline]
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pub(crate) fn to_bytes(&self) -> [u8; QOI_HEADER_SIZE] {
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let mut out = [0; QOI_HEADER_SIZE];
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out[..4].copy_from_slice(&u32_to_be(self.magic));
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out[4..8].copy_from_slice(&u32_to_be(self.width));
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out[8..12].copy_from_slice(&u32_to_be(self.height));
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out[12] = self.channels;
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out[13] = self.colorspace.into();
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out
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}
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#[inline]
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pub(crate) fn from_bytes(v: [u8; QOI_HEADER_SIZE]) -> Self {
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Self {
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magic: u32_from_be(&v[..4]),
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width: u32_from_be(&v[4..8]),
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height: u32_from_be(&v[8..12]),
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channels: v[12],
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colorspace: v[13].into(),
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}
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}
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#[inline]
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pub const fn n_pixels(&self) -> usize {
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(self.width as usize).saturating_mul(self.height as usize)
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}
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#[inline]
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pub const fn validate(&self) -> Result<()> {
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if unlikely(self.magic != QOI_MAGIC) {
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return Err(Error::InvalidMagic { magic: self.magic });
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} else if unlikely(self.height == 0 || self.width == 0) {
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return Err(Error::EmptyImage { width: self.width, height: self.height });
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} else if unlikely(self.channels < 3 || self.channels > 4) {
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return Err(Error::InvalidChannels { channels: self.channels });
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}
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Ok(())
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}
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}
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