[rust] fix `check_pixel_support`; #2162

- add new type `NcPixelImpl`.
- change `check_pixel_support` return type to `NcPixelImpl`.
- update `pixel-cell` example.
- remove remaining reference to removed `blink`.
- remove reference to removed `ncvisual_default_blitter`.
- rustfmt

rust/examples/pixel-cell.rs

@@ -14,7 +14,7 @@ use libnotcurses_sys::*;
 fn main() -> NcResult<()> {
     let mut nc = Nc::new()?;
 
-    if !nc.check_pixel_support()? {
+    if nc.check_pixel_support() == NCPIXEL_NONE {
         nc.stop()?;
         return Err(NcError::new_msg("Current terminal doesn't support pixels."));
     }

rust/src/notcurses/methods.rs

@@ -4,10 +4,10 @@ use core::ptr::{null, null_mut};
 
 use crate::{
     cstring, error, error_ref_mut, notcurses_init, rstring, Nc, NcAlign, NcBlitter, NcChannels,
-    NcDim, NcError, NcFile, NcInput, NcLogLevel, NcOptions, NcPlane, NcResult, NcScale, NcStats,
-    NcStyle, NcStyleMethods, NcTime, NCOPTION_NO_ALTERNATE_SCREEN, NCOPTION_SUPPRESS_BANNERS,
-    NCRESULT_ERR, NCSTYLE_BOLD, NCSTYLE_ITALIC, NCSTYLE_NONE, NCSTYLE_STRUCK,
-    NCSTYLE_UNDERCURL, NCSTYLE_UNDERLINE,
+    NcDim, NcError, NcFile, NcInput, NcLogLevel, NcOptions, NcPixelImpl, NcPlane, NcResult,
+    NcScale, NcStats, NcStyle, NcStyleMethods, NcTime, NCOPTION_NO_ALTERNATE_SCREEN,
+    NCOPTION_SUPPRESS_BANNERS, NCRESULT_ERR, NCSTYLE_BOLD, NCSTYLE_ITALIC, NCSTYLE_NONE,
+    NCSTYLE_STRUCK, NCSTYLE_UNDERCURL, NCSTYLE_UNDERLINE,
 };
 
 /// # `NcOptions` Constructors
@@ -251,22 +251,14 @@ impl Nc {
 
     /// Checks for pixel support.
     ///
-    /// Returns `false` for no support, or `true` if pixel output is supported.
-    ///
-    /// This function must successfully return before
-    /// [NCBLIT_PIXEL][crate::NCBLIT_PIXEL] is available.
-    ///
-    /// Must not be called concurrently with either input or rasterization.
+    /// Returns [`NcPixelImpl`] with a non-zero constant corresponding to some
+    /// pixel-blitting mechanism if bitmap support (via any mechanism) has been
+    /// detected, or else 0 (NCPIXEL_NONE).
     ///
     /// *C style function: [notcurses_check_pixel_support()][crate::notcurses_check-pixel_support].*
     #[allow(clippy::wildcard_in_or_patterns)]
-    pub fn check_pixel_support(&self) -> NcResult<bool> {
-        let res: i32 = unsafe { crate::notcurses_check_pixel_support(self) as i32 };
-        match res {
-            0 => Ok(false),
-            1 => Ok(true),
-            NCRESULT_ERR | _ => Err(NcError::with_msg(res, "Notcuses.check_pixel_support()")),
-        }
+    pub fn check_pixel_support(&self) -> NcPixelImpl {
+        unsafe { crate::notcurses_check_pixel_support(self) }
     }
 
     /// Disables the terminal's cursor, if supported.
@@ -432,7 +424,7 @@ impl Nc {
     /// spaces.
     ///
     /// The supported styles are: `italic`, `underline`, `undercurl`,
-    /// `struck`, `bold`, `blink` and `none`.
+    /// `struck`, `bold`, and `none`.
     ///
     /// If a style is are not recognized returns an error.
     ///

rust/src/notcurses/mod.rs

@@ -196,7 +196,7 @@ pub const NCLOGLEVEL_VERBOSE: NcLogLevel = crate::bindings::ffi::ncloglevel_e_NC
 /// you probably don't want what's happening to happen
 pub const NCLOGLEVEL_WARNING: NcLogLevel = crate::bindings::ffi::ncloglevel_e_NCLOGLEVEL_WARNING;
 
-// NcAlign -- ------------------------------------------------------------------
+// NcAlign ---------------------------------------------------------------------
 
 /// Alignment within a plane or terminal.
 /// Left/right-justified, or centered.

rust/src/visual/mod.rs

@@ -10,7 +10,6 @@
 //W  ncvisual_at_yx
 //W  ncvisual_decode
 //W  ncvisual_decode_loop
-//   ncvisual_default_blitter
 //W  ncvisual_destroy
 //W  ncvisual_from_bgra
 //W  ncvisual_from_file
@@ -236,6 +235,29 @@ pub const NCBLIT_DEFAULT: NcBlitter = crate::bindings::ffi::ncblitter_e_NCBLIT_D
 /// See [Sixel in Wikipedia](https://en.wikipedia.org/wiki/Sixel).
 pub const NCBLIT_PIXEL: NcBlitter = crate::bindings::ffi::ncblitter_e_NCBLIT_PIXEL;
 
+/// Pixel blitting implementations. (Informative only).
+///
+/// Returned by [`check_pixel_support`][Notcurses#method.check_pixel_support].
+pub type NcPixelImpl = crate::bindings::ffi::ncpixelimpl_e;
+
+/// No pixel support.
+pub const NCPIXEL_NONE: NcPixelImpl = crate::bindings::ffi::ncpixelimpl_e_NCPIXEL_NONE;
+/// Sixel
+pub const NCPIXEL_SIXEL: NcPixelImpl = crate::bindings::ffi::ncpixelimpl_e_NCPIXEL_SIXEL;
+/// Linux framebuffer.
+pub const NCPIXEL_LINUXFB: NcPixelImpl = crate::bindings::ffi::ncpixelimpl_e_NCPIXEL_LINUXFB;
+/// iTerm2
+pub const NCPIXEL_ITERM2: NcPixelImpl = crate::bindings::ffi::ncpixelimpl_e_NCPIXEL_ITERM2;
+/// Kitty prior to C=1 and animation.
+pub const NCPIXEL_KITTY_STATIC: NcPixelImpl =
+    crate::bindings::ffi::ncpixelimpl_e_NCPIXEL_KITTY_STATIC;
+/// Kitty with animation but not reflexive composition.
+pub const NCPIXEL_KITTY_ANIMATED: NcPixelImpl =
+    crate::bindings::ffi::ncpixelimpl_e_NCPIXEL_KITTY_ANIMATED;
+/// Kitty with reflexive composition.
+pub const NCPIXEL_KITTY_SELFREF: NcPixelImpl =
+    crate::bindings::ffi::ncpixelimpl_e_NCPIXEL_KITTY_SELFREF;
+
 /// Contains the pixel geometry information as returned by the
 /// NcPlane.[pixelgeom()][crate::NcPlane#method.pixelgeom] method.
 ///