Struct SubpixelBitmap 

pub struct SubpixelBitmap {
    pub left: i32,
    pub top: i32,
    pub width: i32,
    pub height: i32,
    pub channels: Vec<u8>,
}

One glyph rasterized to three coverages per pixel — one per LCD stripe.

The same bitmap GlyphBitmap holds, with the 3× subpixel triples kept apart instead of averaged. It is produced for exactly one kind of text on a page: a live edit’s, which is drawn with ClearType on while the rest of the page is not.

The three bytes are the destination’s red, green and blue coverages in that order — the oracle assumes RGB-ordered stripes, mapping the leftmost subpixel to red. Each is gamma-adjusted and merged into its own destination channel independently, which is what puts colour on the fringes of a glyph drawn in a single colour.

use pdfrum_render::glyph::SubpixelBitmap;

let bitmap = SubpixelBitmap {
    left: 0,
    top: 0,
    width: 2,
    height: 1,
    channels: vec![255, 0, 0, 0, 0, 0],
};

// The three bytes are the destination's red, green and blue
// coverages, each merged into its own channel.
assert_eq!(bitmap.at(0, 0), [255, 0, 0]);

Fields

left: i32

The device x of column 0, relative to the glyph’s snapped origin.

top: i32

The device y of row 0, relative to the glyph’s snapped origin.

width: i32

Columns.

height: i32

Rows.

channels: Vec<u8>

height * width * 3 gamma-adjusted coverages, row-major, [r, g, b] per pixel.

Implementations

impl SubpixelBitmap

pub fn at(&self, x: i32, y: i32) -> [u8; 3]

The [r, g, b] coverages at (x, y), or zeroes outside the bitmap.

use pdfrum_render::glyph::SubpixelBitmap;

let bitmap = SubpixelBitmap {
    left: 0,
    top: 0,
    width: 2,
    height: 1,
    channels: vec![255, 0, 0, 0, 0, 0],
};

assert_eq!(bitmap.at(1, 0), [0, 0, 0]);
// Outside the bitmap is zeroes, not a panic.
assert_eq!(bitmap.at(-1, 0), [0, 0, 0]);
assert_eq!(bitmap.at(9, 9), [0, 0, 0]);

pub fn is_empty(&self) -> bool

Whether the bitmap has no pixels at all, which a blank glyph produces.

use pdfrum_render::glyph::SubpixelBitmap;

let bitmap = SubpixelBitmap {
    left: 0,
    top: 0,
    width: 2,
    height: 1,
    channels: vec![255, 0, 0, 0, 0, 0],
};

assert!(!bitmap.is_empty());
// What a blank glyph produces.
let blank = SubpixelBitmap { width: 0, height: 0, ..bitmap };
assert!(blank.is_empty());

Trait Implementations

impl Clone for SubpixelBitmap

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SubpixelBitmap

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

Formats the value using the given formatter.

impl Eq for SubpixelBitmap

impl PartialEq for SubpixelBitmap

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for SubpixelBitmap