Struct FlateScanlineDecoder 

pub struct FlateScanlineDecoder { /* private fields */ }

Scanline decoder for FlateDecode (zlib/deflate) data.

Decompresses the full data internally on construction, then yields row_stride bytes per decode_scanline call.

Implementations

impl FlateScanlineDecoder

pub fn new( compressed: &[u8], width: u32, height: u32, comps: u8, bpc: u8, ) -> Result<Self, DecodeError>

Create a new scanline decoder from compressed Flate data.

The row stride is computed automatically as (width * comps * bpc + 7) / 8, matching PDFium’s pitch formula.

pub fn from_decoded( data: Vec<u8>, width: u32, height: u32, comps: u8, bpc: u8, ) -> Self

Create from already-decompressed pixel data.

Trait Implementations

impl ScanlineDecoder for FlateScanlineDecoder

fn width(&self) -> u32

Image width in pixels. Mirrors PDFium’s GetWidth().

fn height(&self) -> u32

Image height in pixels. Mirrors PDFium’s GetHeight().

fn comps_count(&self) -> u8

Number of color components per pixel (e.g. 1 for gray, 3 for RGB, 4 for CMYK). Mirrors PDFium’s CountComps().

fn bpc(&self) -> u8

Bits per color component (e.g. 1, 8, 16). Mirrors PDFium’s GetBPC().

fn row_stride(&self) -> usize

Number of bytes per row: (width * comps_count * bpc + 7) / 8.

fn decode_scanline(&mut self) -> Result<Option<&[u8]>, DecodeError>

Decode and return the next scanline.

fn reset(&mut self) -> Result<(), DecodeError>

Reset the decoder to the first scanline.

fn current_line(&self) -> Option<usize>

Current line index (0-based), or None if no lines have been read yet.

fn get_width(&self) -> u32

Upstream alias for width(). Mirrors PDFium’s GetWidth().

fn get_height(&self) -> u32

Upstream alias for height(). Mirrors PDFium’s GetHeight().

fn count_comps(&self) -> u8

Upstream alias for comps_count(). Mirrors PDFium’s CountComps().

fn get_bpc(&self) -> u8

Upstream alias for bpc(). Mirrors PDFium’s GetBPC().

fn skip_to_scanline(&mut self, target: usize)

Skip ahead to scanline target by decoding and discarding intermediate lines.

fn src_offset(&self) -> Option<usize>

Returns the byte offset of the current source position in the compressed stream, if available.

fn get_src_offset(&self) -> Option<usize>

Upstream alias for src_offset(). Mirrors PDFium’s GetSrcOffset().