[rust] new example issue-1573 #1573

rust/examples/issue-1573.rs

@@ -0,0 +1,70 @@
+//! example to figure out issues with visuals and pixels
+//!
+
+use libnotcurses_sys::*;
+
+// background size
+const BG_W: u32 = 64;
+const BG_H: u32 = 32;
+
+// sprite size
+const SP_W: u32 = 32;
+const SP_H: u32 = 64;
+
+
+fn main() -> NcResult<()> {
+    let mut nc = Nc::new()?;
+
+    let pixels: bool = nc.check_pixel_support()?;
+    if !pixels {
+        println!("Current terminal doesn't support pixels. . .");
+        sleep![1];
+    }
+
+    // create the white background buffer
+    let mut bg_buffer = Vec::<u8>::with_capacity(BG_H as usize * BG_W as usize * 4);
+    #[allow(unused_parens)]
+    for _byte in (0..={ BG_H * BG_W }) {
+        bg_buffer.push(251);
+        bg_buffer.push(245);
+        bg_buffer.push(248);
+        bg_buffer.push(255);
+    }
+
+    // create the red sprite buffer
+    let mut sp_buffer = Vec::<u8>::with_capacity((SP_H * SP_W) as usize * 4);
+    #[allow(unused_parens)]
+    for _byte in (0..={ SP_H * SP_W }) {
+        sp_buffer.push(130);
+        sp_buffer.push(40);
+        sp_buffer.push(60);
+        sp_buffer.push(255);
+    }
+
+    // prepare the white background visual
+    let bg = NcVisual::from_rgba(bg_buffer.as_slice(), BG_H, BG_W * 4, BG_W)?;
+    let bg_opt = NcVisualOptions::without_plane(0, 0, 0, 0, BG_H, BG_W, NCBLIT_PIXEL, 0, 0);
+    // if pixels {
+    //     bg.inflate(2)?;
+    // }
+
+    // prepare the red sprite visual
+    let sp = NcVisual::from_rgba(sp_buffer.as_slice(), SP_H, SP_W * 4, SP_W)?;
+    let sp_opt = NcVisualOptions::without_plane(0, 0, 0, 0, SP_H, SP_W, NCBLIT_PIXEL, 0, 0);
+    // if pixels {
+    //     sp.inflate(2)?;
+    // }
+
+    // first render the white background in a new plane
+    let bg_plane = bg.render(&mut nc, &bg_opt)?;
+    // nc.render()?; // ← FIXME: when this render call is commented out,
+                     // the red sprite doesn't show on top in xterm and kitty but
+                     // does show in terminals without pixel support (xterm -ti vt100)
+
+    // then render the red sprite in another plane
+    let sp_plane = sp.render(&mut nc, &sp_opt)?;
+    nc.render()?;
+
+    sleep![2];
+    Ok(())
+}