Struct MaskFixed 

pub struct MaskFixed<const W: usize, const H: usize, const MASK_N: usize> {
    pub bits: [u8; MASK_N],
}

A packed binary visibility mask with one bit per image pixel.

Set bits are drawn and clear bits are transparent. Create a mask from an Image888Fixed with Image888Fixed::to_mask_magenta, then pass it to MaskedDrawable::draw_masked.

Example

use device_envoy_core::{
    UnwrapInfallible,
    cyd::{
        Cyd, CydDisplay,
        display::{
            CydFrame, Image565Fixed, Image888Fixed, MaskFixed, MaskedDrawable,
            mask_byte_count, tga,
        },
    },
};
use embedded_graphics::{Drawable, prelude::Point};

const SOURCE: Image888Fixed<45, 73, { 45 * 73 }> = tga!(concat!(
    env!("CARGO_MANIFEST_DIR"),
    "/docs/assets/cyd_fill_contiguous.tga"
));
const IMAGE: Image565Fixed<45, 73, { 45 * 73 }> = SOURCE.to_565();
const MASK: MaskFixed<45, 73, { mask_byte_count(45, 73) }> =
    SOURCE.to_mask_magenta();

async fn draw<C: Cyd>(cyd: &mut C) -> Result<(), C::Error> {
    let display = cyd.display();
    let mut frame = display.full_frame_mut();
    IMAGE
        .at(Point::new(80, 84))
        .draw(&mut frame)
        .unwrap_infallible();
    IMAGE
        .at(Point::new(200, 84))
        .draw_masked(&MASK, &mut frame)
        .unwrap_infallible();
    frame.flush().await
}

assert!(!MASK.is_set(0));

The opaque RGB565 image is on the left. The masked drawing on the right skips the magenta background:

Fields

bits: [u8; MASK_N]

Row-major visibility bits, least-significant bit first within each byte.

Implementations

impl<const W: usize, const H: usize, const MASK_N: usize> MaskFixed<W, H, MASK_N>

pub const fn is_set(&self, index: usize) -> bool

Returns whether the row-major pixel at index is visible.

See the MaskFixed example.