fix vec len, add moving transparent line example

examples/moving_transparent_line/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "moving_transparent_line"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+servicepoint2 = { path = "../.." }
+clap = { version = "4.5.4", features = ["derive"] }
+env_logger = "0.11.3"
+log = "0.4.21"

examples/moving_transparent_line/src/main.rs

@@ -0,0 +1,47 @@
+use std::thread;
+use std::time::Duration;
+
+use clap::Parser;
+
+use servicepoint2::{BitVec, Connection, PIXEL_HEIGHT, PIXEL_WIDTH, PixelGrid};
+use servicepoint2::Command::{BitmapLinearOr, BitmapLinearXor};
+
+#[derive(Parser, Debug)]
+struct Cli {
+    #[arg(short, long, default_value = "localhost:2342")]
+    destination: String,
+}
+
+fn main() {
+    env_logger::builder()
+        .filter_level(log::LevelFilter::Debug)
+        .init();
+
+    let connection = Connection::open(Cli::parse().destination).unwrap();
+
+    loop {
+        let mut last = BitVec::new(PIXEL_WIDTH as usize * PIXEL_HEIGHT as usize);
+        for x_offset in 0..PIXEL_WIDTH as usize {
+            let mut pixels = PixelGrid::max_sized();
+            pixels.fill(false);
+
+            for y in 0..PIXEL_HEIGHT as usize {
+                pixels.set((y + x_offset) % PIXEL_WIDTH as usize, y, true);
+            }
+
+            // this works because the pixel grid has max size
+            let pixel_data: Vec<u8> = pixels.into();
+            let bit_vec = BitVec::load(&*pixel_data);
+
+            // remove pixels from last iteration
+            connection.send(BitmapLinearXor(0, last)).unwrap();
+            // reduces dropped packages
+            thread::sleep(Duration::from_millis(1));
+            // add pixels from this iteration
+            connection.send(BitmapLinearOr(0, bit_vec.clone())).unwrap();
+
+            last = bit_vec;
+            thread::sleep(Duration::from_millis(1000));
+        }
+    }
+}