Struct Bitmap 

pub struct Bitmap {
    pub width: u32,
    pub height: u32,
    pub data: Vec<u8>,
}

A 1-bit-per-pixel packed bitmap image.

Pixels are packed 8-per-byte, MSB first within each byte. Each row is padded to a byte boundary. Pixel value 1 = black, 0 = white (matching PBM convention).

Fields

width: u32

height: u32

data: Vec<u8>

Packed pixel data, row-major. Row stride = row_stride() bytes.

Implementations

impl Bitmap

pub fn new(width: u32, height: u32) -> Self

Create a new all-white (0) bitmap.

pub fn row_stride(&self) -> usize

Bytes per row (each row padded to byte boundary).

pub fn get(&self, x: u32, y: u32) -> bool

Get pixel value at (x, y). Returns true if black (1). Panics if out of bounds.

pub fn set(&mut self, x: u32, y: u32, val: bool)

Set pixel value at (x, y). val = true means black (1). Panics if out of bounds.

pub fn set_black(&mut self, x: u32, y: u32)

OR a black pixel at (x, y). Used for JB2 blit compositing.

pub fn dilate(&self) -> Bitmap

Return a new bitmap with each black pixel expanded to its 4-connected neighbors (1-pixel morphological dilation). Thickens every stroke by ~2 pixels total, improving legibility at reduced display sizes.

pub fn to_pbm(&self) -> Vec<u8>

Encode as PBM (binary, P4 format). This is the format produced by ddjvu -format=pbm.

pub fn dilate_n(self, passes: u32) -> Self

Perform passes rounds of 4-connected morphological dilation using packed bitwise operations and two pre-allocated ping-pong buffers. Zero allocations after the initial setup; much faster than calling dilate() N times for passes > 1.

Pixel layout (MSB-first): bit 7 of each byte = leftmost pixel in that group of 8. Horizontal dilation uses byte >> 1 (right) and byte << 1 (left) with cross-byte carries; vertical dilation ORs each row into its neighbours.

Trait Implementations

impl Clone for Bitmap

fn clone(&self) -> Bitmap

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Bitmap

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Bitmap

fn default() -> Bitmap

Returns the “default value” for a type.

impl PartialEq for Bitmap

fn eq(&self, other: &Bitmap) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for Bitmap

impl StructuralPartialEq for Bitmap