[rust] update example

rust/examples/issue-rgb_packed.rs

@@ -2,19 +2,19 @@ use libnotcurses_sys::*;
 
 // BUGFIX DISCOVERINGS so far:
 //
-// - Height seems to be irrelevant (reference: 32)
-// - using the C API only works with Widths: 1-18, 22-34, 43-50
+// - using a Height of 32, it only works with Widths: 1-18, 22-34, 43-50, …
+// - using a Height of 4, it only works with Widths: 1-34, 43-50, …
 
-const H: NcDim = 32;
+const H: NcDim = 4;
 const W: NcDim = 35;
 
 fn main() -> NcResult<()> {
-    let mut nc = Nc::new()?;
+    let mut nc = Nc::without_altscreen()?;
     let mut plane = NcPlane::new(&mut nc, 0, 0, H, W)?;
 
     let buffer_rgb = vec![255; H as usize * W as usize * 3];
 
-    let visual = NcVisual::from_rgb_packed(buffer_rgb.as_slice(), H, W * 3, W, 255)?;
+    let visual = NcVisual::from_rgb_packed(buffer_rgb.as_slice(), H, W * 3, W, 0xFE)?;
     let voptions = NcVisualOptions::with_plane(
         &mut plane,
         NCSCALE_NONE,
@@ -32,7 +32,7 @@ fn main() -> NcResult<()> {
     plane.render()?;
     plane.rasterize()?;
     sleep![1];
-    plane.destroy();
+    plane.destroy()?;
     visual.destroy();
     nc.stop()?;
     Ok(())