detection of color count

Cargo.toml

@@ -26,6 +26,7 @@ minifb = { version = "0.25.0", default-features = false, features = [
 wgpu = { version = "0.19.1", default-features = false, optional = true }
 atools = "0.1.0"
 qwant = { version = "1.0.0", optional = true }
+libc = "0.2.153"
 
 [target.'cfg(windows)'.dependencies]
 windows = { version = "0.53.0", features = [
@@ -67,7 +68,7 @@ text = ["fontdue"]
 blur = ["slur"]
 term = ["qwant", "save", "scale", "windows"]
 real-show = ["minifb", "text"]
-default = ["save", "scale"]
+default = ["save", "scale", "term"]
 wgpu-convert = ["dep:wgpu"]
 
 [profile.release]

src/lib.rs

@@ -68,6 +68,7 @@
     const_option,
     array_chunks,
     let_chains,
+    try_blocks,
     test
 )]
 #![warn(

src/term.rs

@@ -114,9 +114,27 @@ where
     #[cfg(unix)]
     // https://github.com/benjajaja/ratatui-image/blob/master/src/picker.rs#L226
     fn guess_harder(&self, to: &mut impl Write) -> Option<Result> {
-        extern crate libc;
-        use std::{io::Read, mem::MaybeUninit};
+        // contains a kitty gfx and sixel query, the `\x1b[c` is for sixels
+        let buf = query(r"_Gi=31,s=1,v=1,a=q,t=d,f=24;AAAA\")?;
+        if buf.contains("_Gi=31;OK") {
+            Some(Kitty(self.as_ref()).write(to))
+        } else if buf.contains(";4;")
+            || buf.contains("?4;")
+            || buf.contains(";4c")
+            || buf.contains("?4c")
+        {
+            Some(Sixel(self.as_ref()).write(to))
+        } else {
+            None
+        }
+    }
+}
 
+#[cfg(unix)]
+// https://github.com/benjajaja/ratatui-image/blob/master/src/picker.rs#L226
+fn query(device_query_code: &'static str) -> Option<String> {
+    extern crate libc;
+    use std::mem::MaybeUninit;
     fn r(result: i32) -> Option<()> {
         (result != -1).then_some(())
     }
@@ -138,41 +156,41 @@ where
             },
         )
     };
-        let buf = {
-            // contains a kitty gfx and sixel query, the `\x1b[c` is for sixels
-            println!(r"_Gi=31,s=1,v=1,a=q,t=d,f=24;AAAA\");
-            let mut stdin = std::io::stdin();
-            let mut buf = String::new();
 
-            let mut b = [0; 16];
-            'l: loop {
-                let n = stdin.read(&mut b).ok()?;
-                if n == 0 {
-                    continue;
+    let buf = try {
+        // SAFETY: linux time out'd reading
+        unsafe {
+            println!("{device_query_code}");
+            let mut buf = Vec::new();
+            let mut tmp = [0; 1 << 5];
+            loop {
+                let mut x = std::mem::zeroed::<libc::fd_set>();
+                libc::FD_SET(0, &mut x);
+                match libc::select(
+                    1,
+                    &mut x,
+                    0 as _,
+                    0 as _,
+                    &mut libc::timeval {
+                        tv_sec: 0,
+                        tv_usec: 5e5 as _,
+                    },
+                ) {
+                    0 => break,
+                    -1 => return None,
+                    _ => {}
                 }
-                for b in b {
-                    buf.push(b as char);
-                    if b == b'c' {
-                        break 'l;
+                match libc::read(libc::STDIN_FILENO, tmp.as_mut_ptr().cast(), tmp.len()) {
+                    0 => continue,
+                    -1 => return None,
+                    n => buf.extend_from_slice(&tmp[..n as _]),
                 }
             }
+            String::from_utf8(buf).ok()?
         }
-            buf
     };
 
     // SAFETY: reset attrs to what they were before we became nosy
     unsafe { libc::tcsetattr(0, libc::TCSADRAIN, &termios) };
-
-        if buf.contains("_Gi=31;OK") {
-            Some(Kitty(self.as_ref()).write(to))
-        } else if buf.contains(";4;")
-            || buf.contains("?4;")
-            || buf.contains(";4c")
-            || buf.contains("?4c")
-        {
-            Some(Sixel(self.as_ref()).write(to))
-        } else {
-            None
-        }
-    }
+    buf
 }

src/term/b64.rs

@@ -39,7 +39,7 @@ where
     LaneCount<N>: SupportedLaneCount,
 {
     fn cas<U>(self) -> U {
-        assert!(std::mem::size_of::<U>() == std::mem::size_of::<Simd<T, N>>());
+        assert!(std::mem::size_of::<U>() == std::mem::size_of::<Self>());
         unsafe { transmute_unchecked(self) }
     }
 }
@@ -49,7 +49,7 @@ where
     LaneCount<N>: SupportedLaneCount,
 {
     fn cas<U>(self) -> U {
-        assert!(std::mem::size_of::<U>() == std::mem::size_of::<Mask<T, N>>());
+        assert!(std::mem::size_of::<U>() == std::mem::size_of::<Self>());
         unsafe { transmute_unchecked(self) }
     }
 }

src/term/sixel.rs

@@ -40,6 +40,34 @@ impl<T: AsRef<[u8]>, const N: usize> Sixel<T, N> {
     where
         [(); N]: Basic,
     {
+        #[cfg(unix)]
+        let q = {
+            extern crate libc;
+            // SAFETY: is stdout a tty
+            (unsafe { libc::isatty(0) } == 1)
+        };
+        #[cfg(not(unix))]
+        let q = true;
+        let colors = q
+            .then_some(super::query("[?1;1;0S").and_then(|x| {
+                // [?1;0;65536S
+                if let [b'?', b'1', b';', b'0', b';', n @ ..] = x.as_bytes() {
+                    Some(
+                        n.iter()
+                            .copied()
+                            .take_while(u8::is_ascii_digit)
+                            .fold(0u16, |acc, x| {
+                                acc.saturating_mul(10).saturating_add((x - b'0') as u16)
+                            })
+                            .max(64)
+                            .min(0xfff),
+                    )
+                } else {
+                    None
+                }
+            }))
+            .flatten()
+            .unwrap_or(255);
         to.write_str("Pq")?;
         write!(to, r#""1;1;{};{}"#, self.width(), self.height())?;
         let buf;
@@ -63,14 +91,15 @@ impl<T: AsRef<[u8]>, const N: usize> Sixel<T, N> {
             &*buf
         };
 
-        let q = qwant::NeuQuant::new(15, 255, rgba);
+        let q = qwant::NeuQuant::new(15, colors as _, rgba);
+
         // TODO: don't colllect
-        let pixels: Vec<u8> = rgba.iter().map(|&pix| q.index_of(pix) as u8).collect();
+        let pixels: Vec<u16> = rgba.iter().map(|&pix| q.index_of(pix) as _).collect();
 
         for ([r, g, b], i) in q
             .color_map_rgb()
             .map(|x| x.map(|x| (x as f32 * (100. / 255.)) as u32))
-            .zip(0u8..)
+            .zip(0u64..)
         {
             write!(to, "#{i};2;{r};{g};{b}")?;
         }