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|
use std::collections::{self, HashMap};
use byte_encode_derive::ByteEncode;
use crate::{byte_encode::ByteEncode, crc::update_crc, image::{ColorType, Image, ImageBase}, reader::FileReader, zlib::{zlib_decode, ByteBuffer}};
#[derive(Default)]
pub struct PNGImage
{
IHDR: Option<IHDR>,
IDAT: Option<IDAT>,
IEND: Option<IEND>,
tEXt: Option<tEXt>,
}
trait Mergable: Sized
{
fn merge(a: Self, b: Self) -> Self;
}
impl<T: Mergable + Sized + Clone> Mergable for Option<T>
{
fn merge(a: Option<T>, b: Option<T>) -> Option<T>
{
if let Some(ref a_content) = a
{
if let Some(b_content) = b
{
Some(T::merge(a_content.clone(), b_content))
}
else
{
a
}
}
else
{
b
}
}
}
trait PNGChunk: Mergable
{
fn read(reader: &mut FileReader, length: usize) -> Self;
const CHUNK_TYPE: [char; 4];
}
#[derive(ByteEncode, Clone)]
struct IHDR
{
pub width: u32,
pub height: u32,
pub bit_depth: u8,
pub color_type: u8,
pub compression_method: u8,
pub filter_method: u8,
pub interlace_method: u8
}
impl PNGChunk for IHDR
{
const CHUNK_TYPE: [char; 4] = ['I', 'H', 'D', 'R'];
fn read(reader: &mut FileReader, length: usize) -> Self {
reader.read()
}
}
impl Mergable for IHDR {
fn merge(a: Self, b: Self) -> Self {
todo!()
}
}
#[derive(ByteEncode, Clone)]
struct IEND
{
}
impl PNGChunk for IEND
{
const CHUNK_TYPE: [char; 4] = ['I', 'E', 'N', 'D'];
fn read(reader: &mut FileReader, length: usize) -> Self {
Self {}
}
}
impl Mergable for IEND {
fn merge(a: Self, b: Self) -> Self {
todo!()
}
}
#[derive(Clone)]
struct tEXt
{
keywords: HashMap<String, String>
}
impl PNGChunk for tEXt
{
const CHUNK_TYPE: [char; 4] = ['t', 'E', 'X', 't'];
fn read(reader: &mut FileReader, length: usize) -> Self
{
let mut i = 0;
let mut keyword = String::new();
let mut c: u8 = reader.read();
i += 1;
while c != 0
{
keyword.push(c as char);
c = reader.read::<1, u8>();
i += 1;
}
let mut text_string = String::new();
while i < length
{
text_string.push(reader.read::<1, u8>() as char);
i += 1;
}
let mut keywords = HashMap::new();
keywords.insert(keyword, text_string);
Self
{
keywords
}
}
}
impl Mergable for tEXt {
fn merge(a: Self, b: Self) -> Self {
let mut keywords = HashMap::new();
keywords.extend(a.keywords);
keywords.extend(b.keywords);
Self
{
keywords
}
}
}
#[derive(Clone)]
struct IDAT
{
data: Vec<u8>
}
impl PNGChunk for IDAT
{
fn read(reader: &mut FileReader, length: usize) -> Self {
let data = reader.get_bytes(length);
Self
{
data
}
}
const CHUNK_TYPE: [char; 4] = ['I', 'D', 'A', 'T'];
}
impl Mergable for IDAT
{
fn merge(a: Self, b: Self) -> Self {
let mut data = Vec::new();
data.extend(a.data);
data.extend(b.data);
Self
{
data
}
}
}
impl<T: ColorType> Image<T> for PNGImage
{
fn read_image(reader: &mut FileReader) -> Result<ImageBase<T>, String> {
let magic: [u8; 8] = reader.read_array();
if magic != [0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A]
{
return Err("Not a PNG!".to_owned());
}
reader.set_endianness(false);
reader.set_checksum_handler(update_crc, 0xffffffffu32);
let mut p = PNGImage::default();
while p.IEND.is_none()
{
let length: usize = reader.read::<4, u32>() as usize;
reader.reset_checksum();
let chunk_type: [char; 4] = reader.read_array::<1, u8, 4>().map(|x| x as char);
let chunk_flags = chunk_type.map(|x| x.is_lowercase());
println!("type: {chunk_type:?}");
println!("length: {length}");
match chunk_type
{
IHDR::CHUNK_TYPE => { p.IHDR = Option::<IHDR>::merge(p.IHDR, Some(IHDR::read(reader, length))) }
IDAT::CHUNK_TYPE => { p.IDAT = Option::<IDAT>::merge(p.IDAT, Some(IDAT::read(reader, length))) }
IEND::CHUNK_TYPE => { p.IEND = Option::<IEND>::merge(p.IEND, Some(IEND::read(reader, length))) }
tEXt::CHUNK_TYPE => { p.tEXt = Option::<tEXt>::merge(p.tEXt, Some(tEXt::read(reader, length))) }
_ => {
if chunk_flags[0]
{
println!("Skipping ancillary chunk");
println!("{}", if chunk_flags[1] { "Private (can find definition)" } else { "Public" })
}
else
{
println!("Skipping important chunk!!!");
}
reader.skip(length)
}
}
let mut calculated_crc = reader.get_checksum();
let crc: u32 = reader.read();
if crc ^ calculated_crc != 0xffffffffu32 && !chunk_flags[0]
{
calculated_crc ^= 0xffffffffu32;
println!("Bad crc: {crc} {calculated_crc}");
}
}
if let Some(ref tEXt) = p.tEXt
{
for x in tEXt.keywords.iter()
{
println!("{0}: {1}", x.0, x.1);
}
}
if p.IEND.is_none()
{
return Err("IEND not present".to_owned());
}
let Some(IHDR) = p.IHDR else { return Err("IHDR not present".to_owned()); };
let Some(IDAT) = p.IDAT else { return Err("IDAT not present".to_owned()); };
let colors_per_pixel: u8 = if IHDR.color_type == 4 || IHDR.color_type == 6 { 4 } else { 3 };
let bpp: u8 = IHDR.bit_depth * colors_per_pixel;
let width: u32 = IHDR.width;
let height: u32 = IHDR.height;
println!("{bpp}, {width}, {height}");
let compression_method: u8 = IDAT.data[0];
let additional_flags: u8 = IDAT.data[1];
let decoded = zlib_decode(ByteBuffer::new(&IDAT.data[2..]));
todo!("PNG not finished")
}
fn write_image(image: &crate::image::ImageBase<T>, writer: &mut crate::writer::FileWriter)-> () {
todo!()
}
}
|
