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#![cfg_attr(feature = "cargo-clippy", allow(clippy::needless_borrow))]
#![allow(clippy::missing_safety_doc)]
#![allow(non_upper_case_globals)]
use crate::rustimpl::RGBA;
use std::fmt;
use std::io;
use std::num::NonZeroU8;
use std::os::raw::{c_uint, c_void};
#[cfg(not(unix))]
use std::path::PathBuf;
#[cfg(feature = "c_ffi")]
mod functions;
#[repr(C)]
#[derive(Copy, Clone, Eq, PartialEq)]
pub struct ErrorCode(pub c_uint);
/// Type for `decode`, `encode`, etc. Same as standard PNG color types.
#[repr(C)]
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub enum ColorType {
/// greyscale: 1, 2, 4, 8, 16 bit
GREY = 0,
/// RGB: 8, 16 bit
RGB = 2,
/// palette: 1, 2, 4, 8 bit
PALETTE = 3,
/// greyscale with alpha: 8, 16 bit
GREY_ALPHA = 4,
/// RGB with alpha: 8, 16 bit
RGBA = 6,
/// Not PNG standard, for internal use only. BGRA with alpha, 8 bit
BGRA = 6 | 64,
/// Not PNG standard, for internal use only. BGR no alpha, 8 bit
BGR = 2 | 64,
/// Not PNG standard, for internal use only. BGR no alpha, padded, 8 bit
BGRX = 3 | 64,
}
impl ColorType {
/// Bits per pixel
#[must_use]
pub fn bpp(&self, bitdepth: u32) -> u32 {
self.bpp_(bitdepth).get().into()
}
#[inline]
pub(crate) fn bpp_(self, bitdepth: u32) -> NonZeroU8 {
let bitdepth = bitdepth as u8;
/*bits per pixel is amount of channels * bits per channel*/
let ch = self.channels();
NonZeroU8::new(if ch > 1 {
ch * if bitdepth == 8 {
8
} else {
16
}
} else {
debug_assert!((bitdepth > 0 && bitdepth <= 8) || bitdepth == 16, "{bitdepth}x{ch}");
bitdepth.max(1)
}).unwrap()
}
}
/// Color mode of an image. Contains all information required to decode the pixel
/// bits to RGBA colors. This information is the same as used in the PNG file
/// format, and is used both for PNG and raw image data in LodePNG.
#[repr(C)]
#[derive(Clone, Debug)]
pub struct ColorMode {
/// color type, see PNG standard
pub colortype: ColorType,
/// bits per sample, see PNG standard
pub(crate) bitdepth: c_uint,
/// palette (`PLTE` and `tRNS`)
/// Dynamically allocated with the colors of the palette, including alpha.
/// When encoding a PNG, to store your colors in the palette of the ColorMode, first use
/// lodepng_palette_clear, then for each color use lodepng_palette_add.
/// If you encode an image without alpha with palette, don't forget to put value 255 in each A byte of the palette.
///
/// When decoding, by default you can ignore this palette, since LodePNG already
/// fills the palette colors in the pixels of the raw RGBA output.
///
/// The palette is only supported for color type 3.
pub(crate) palette: Option<Box<[RGBA; 256]>>,
/// palette size in number of colors (amount of bytes is 4 * `palettesize`)
pub(crate) palettesize: usize,
/// transparent color key (`tRNS`)
///
/// This color uses the same bit depth as the bitdepth value in this struct, which can be 1-bit to 16-bit.
/// For greyscale PNGs, r, g and b will all 3 be set to the same.
///
/// When decoding, by default you can ignore this information, since LodePNG sets
/// pixels with this key to transparent already in the raw RGBA output.
///
/// The color key is only supported for color types 0 and 2.
pub(crate) key_defined: c_uint,
pub(crate) key_r: c_uint,
pub(crate) key_g: c_uint,
pub(crate) key_b: c_uint,
}
pub type custom_compress_callback = Option<fn(input: &[u8], output: &mut dyn io::Write, context: &CompressSettings) -> Result<(), crate::Error>>;
pub type custom_decompress_callback = Option<fn(input: &[u8], output: &mut dyn io::Write, context: &DecompressSettings) -> Result<(), crate::Error>>;
#[repr(C)]
#[derive(Clone)]
pub struct DecompressSettings {
pub(crate) custom_zlib: custom_decompress_callback,
pub(crate) custom_inflate: custom_decompress_callback,
pub(crate) custom_context: *const c_void,
}
impl fmt::Debug for DecompressSettings {
#[cold]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut s = f.debug_struct("DecompressSettings");
s.field("custom_zlib", &self.custom_zlib.is_some());
s.field("custom_inflate", &self.custom_inflate.is_some());
s.field("custom_context", &self.custom_context);
s.finish()
}
}
/// Settings for zlib compression. Tweaking these settings tweaks the balance between speed and compression ratio.
#[repr(C)]
#[derive(Clone)]
pub struct CompressSettings {
/// Obsolete. No-op.
#[deprecated]
pub windowsize: u32,
/// Compression level 1 (fast) to 9 (best). Use `set_level()` instead.
#[deprecated]
pub minmatch: u16,
/// Obsolete. No-op.
#[deprecated]
pub nicematch: u16,
/// Obsolete. No-op.
#[deprecated]
pub btype: u8,
/// If false, it won't compress at all. Use `set_level(0)`
#[deprecated]
pub use_lz77: bool,
/// Obsolete. No-op.
#[deprecated]
pub lazymatching: bool,
/// use custom zlib encoder instead of built in one (default: None).
///
/// You should configure the `flate2` crate to use another zlib instead.
/// This option will cause unnecessary buffering.
#[deprecated(note = "use features of the flate2 crate instead")]
pub custom_zlib: custom_compress_callback,
/// use custom deflate encoder instead of built in one (default: null)
/// if custom_zlib is used, custom_deflate is ignored since only the built in
/// zlib function will call custom_deflate
///
/// You should configure the `flate2` crate to use another zlib instead.
/// This option will cause unnecessary buffering.
#[deprecated(note = "use features of the flate2 crate instead")]
pub custom_deflate: custom_compress_callback,
/// optional custom settings for custom functions
pub custom_context: *const c_void,
}
impl CompressSettings {
/// 0 (none), 1 (fast) to 9 (best)
#[allow(deprecated)]
pub fn set_level(&mut self, level: u8) {
self.use_lz77 = level != 0;
self.minmatch = level.into();
}
/// zlib compression level
#[allow(deprecated)]
#[must_use]
pub fn level(&self) -> u8 {
if self.use_lz77 {
if self.minmatch > 0 && self.minmatch <= 9 {
self.minmatch as _
} else {
7
}
} else {
0
}
}
}
/// The information of a `Time` chunk in PNG
#[repr(C)]
#[derive(Copy, Clone, Debug, Default)]
pub struct Time {
pub year: u16,
pub month: u8,
pub day: u8,
pub hour: u8,
pub minute: u8,
pub second: u8,
}
/// Information about the PNG image, except pixels, width and height
#[repr(C)]
#[derive(Debug, Clone)]
pub struct Info {
/// interlace method of the original file
pub interlace_method: u8,
/// color type and bits, palette and transparency of the PNG file
pub color: ColorMode,
/// suggested background color chunk (bKGD)
/// This color uses the same color mode as the PNG (except alpha channel), which can be 1-bit to 16-bit.
///
/// For greyscale PNGs, r, g and b will all 3 be set to the same. When encoding
/// the encoder writes the red one. For palette PNGs: When decoding, the RGB value
/// will be stored, not a palette index. But when encoding, specify the index of
/// the palette in background_r, the other two are then ignored.
///
/// The decoder does not use this background color to edit the color of pixels.
pub background_defined: bool,
/// red component of suggested background color
pub background_r: u16,
/// green component of suggested background color
pub background_g: u16,
/// blue component of suggested background color
pub background_b: u16,
/// set to 1 to make the encoder generate a tIME chunk
pub time_defined: bool,
/// time chunk (tIME)
pub time: Time,
/// if 0, there is no pHYs chunk and the values below are undefined, if 1 else there is one
pub phys_defined: bool,
/// pixels per unit in x direction
pub phys_x: c_uint,
/// pixels per unit in y direction
pub phys_y: c_uint,
/// may be 0 (unknown unit) or 1 (metre)
pub phys_unit: u8,
/// There are 3 buffers, one for each position in the PNG where unknown chunks can appear
/// each buffer contains all unknown chunks for that position consecutively
/// The 3 buffers are the unknown chunks between certain critical chunks:
/// 0: IHDR-`PLTE`, 1: `PLTE`-IDAT, 2: IDAT-IEND
/// Must be boxed for FFI hack.
#[allow(clippy::box_collection)]
pub(crate) unknown_chunks: [Box<Vec<u8>>; 3],
/// Ugly hack for back-compat with C FFI
pub(crate) always_zero_for_ffi_hack: [usize; 3],
/// non-international text chunks (tEXt and zTXt)
///
/// The `char**` arrays each contain num strings. The actual messages are in
/// text_strings, while text_keys are keywords that give a short description what
/// the actual text represents, e.g. Title, Author, Description, or anything else.
///
/// A keyword is minimum 1 character and maximum 79 characters long. It's
/// discouraged to use a single line length longer than 79 characters for texts.
pub(crate) texts: Vec<LatinText>,
/// international text chunks (iTXt)
/// Similar to the non-international text chunks, but with additional strings
/// "langtags" and "transkeys".
pub(crate) itexts: Vec<IntlText>,
}
#[derive(Debug, Clone)]
pub(crate) struct LatinText {
pub(crate) key: Box<[u8]>,
pub(crate) value: Box<[u8]>,
}
#[derive(Debug, Clone)]
pub(crate) struct IntlText {
pub(crate) key: Box<str>,
pub(crate) langtag: Box<str>,
pub(crate) transkey: Box<str>,
pub(crate) value: Box<str>,
}
/// Settings for the decoder. This contains settings for the PNG and the Zlib decoder, but not the `Info` settings from the `Info` structs.
#[repr(C)]
#[derive(Clone, Debug)]
pub struct DecoderSettings {
/// in here is the setting to ignore Adler32 checksums
pub zlibsettings: DecompressSettings,
/// ignore CRC checksums
pub ignore_crc: bool,
pub color_convert: bool,
pub read_text_chunks: bool,
pub remember_unknown_chunks: bool,
}
/// automatically use color type with less bits per pixel if losslessly possible. Default: `AUTO`
#[repr(C)]
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub enum FilterStrategy {
/// every filter at zero
ZERO = 0,
/// Use filter that gives minumum sum, as described in the official PNG filter heuristic.
MINSUM,
/// Use the filter type that gives smallest Shannon entropy for this scanline. Depending
/// on the image, this is better or worse than minsum.
ENTROPY,
/// Brute-force-search PNG filters by compressing each filter for each scanline.
/// Experimental, very slow, and only rarely gives better compression than MINSUM.
BRUTE_FORCE,
/// use predefined_filters buffer: you specify the filter type for each scanline.
/// See `Encoder::set_predefined_filters`.
PREDEFINED,
}
#[repr(C)]
#[derive(Clone, Debug)]
pub struct EncoderSettings {
/// settings for the zlib encoder, such as window size, ...
pub zlibsettings: CompressSettings,
/// how to automatically choose output PNG color type, if at all
pub auto_convert: bool,
/// If true, follows the official PNG heuristic: if the PNG uses a palette or lower than
/// 8 bit depth, set all filters to zero. Otherwise use the filter_strategy. Note that to
/// completely follow the official PNG heuristic, filter_palette_zero must be true and
/// filter_strategy must be FilterStrategy::MINSUM
pub filter_palette_zero: bool,
/// Which filter strategy to use when not using zeroes due to filter_palette_zero.
/// Set filter_palette_zero to 0 to ensure always using your chosen strategy. Default: FilterStrategy::MINSUM
pub filter_strategy: FilterStrategy,
/// used if filter_strategy is FilterStrategy::PREDEFINED. In that case, this must point to a buffer with
/// the same length as the amount of scanlines in the image, and each value must <= 5. You
/// have to cleanup this buffer, LodePNG will never free it. Don't forget that filter_palette_zero
/// must be set to 0 to ensure this is also used on palette or low bitdepth images
pub(crate) predefined_filters: *const u8,
/// force creating a `PLTE` chunk if colortype is 2 or 6 (= a suggested palette).
/// If colortype is 3, `PLTE` is _always_ created
pub force_palette: bool,
/// add LodePNG identifier and version as a text chunk, for debugging
pub add_id: bool,
/// encode text chunks as zTXt chunks instead of tEXt chunks, and use compression in iTXt chunks
pub text_compression: bool,
}
unsafe impl Send for EncoderSettings {}
unsafe impl Sync for EncoderSettings {}
/// The settings, state and information for extended encoding and decoding
#[repr(C)]
#[derive(Clone, Debug)]
pub struct State {
pub decoder: DecoderSettings,
pub encoder: EncoderSettings,
/// specifies the format in which you would like to get the raw pixel buffer
pub info_raw: ColorMode,
/// info of the PNG image obtained after decoding
pub info_png: Info,
pub error: ErrorCode,
}
/// Gives characteristics about the colors of the image, which helps decide which color model to use for encoding.
/// Used internally by default if `auto_convert` is enabled. Public because it's useful for custom algorithms.
#[repr(C)]
#[derive(Debug)]
pub struct ColorProfile {
/// not greyscale
pub colored: bool,
/// image is not opaque and color key is possible instead of full alpha
pub key: bool,
/// key values, always as 16-bit, in 8-bit case the byte is duplicated, e.g. 65535 means 255
pub key_r: u16,
pub key_g: u16,
pub key_b: u16,
/// image is not opaque and alpha channel or alpha palette required
pub alpha: bool,
/// amount of colors, up to 257. Not valid if bits == 16.
/// bits per channel (not for palette). 1,2 or 4 for greyscale only. 16 if 16-bit per channel required.
pub bits: u8,
pub numcolors: u16,
/// Remembers up to the first 256 RGBA colors, in no particular order
pub palette: [crate::RGBA; 256],
}
impl fmt::Debug for CompressSettings {
#[allow(deprecated)]
#[cold]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut s = f.debug_struct("CompressSettings");
s.field("minmatch", &self.minmatch);
s.field("use_lz77", &self.use_lz77);
s.field("custom_zlib", &self.custom_zlib.is_some());
s.field("custom_deflate", &self.custom_deflate.is_some());
s.field("custom_context", &self.custom_context);
s.finish()
}
}