Prevent zoomout in both dimensions using double-pass system

* wip; start working on making it not flash when transferring new images

* don't delete the images, just clear them

* add changelog entry

* fmt

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 - Added windows support! (thank you to [@jarjk](https://github.com/jarjk) for helping out!)
 - Added keybindings (`0`/`$`) to scroll to left or right side of zoomed-in image ([#131](https://github.com/itsjunetime/tdf/pull/131), thank you [@IshDeshpa](https://github.com/IshDeshpa)!)
+- Fixed issue with images clearing/flashing after displaying a certain number on kitty
 - (Internal) decreased runtime footprint of tokio runtime
 
 # v0.5.0

Cargo.lock

@@ -1573,9 +1573,9 @@ checksum = "7a79a3332a6609480d7d0c9eab957bca6b455b91bb84e66d19f5ff66294b85b8"
 
 [[package]]
 name = "libc"
-version = "0.2.185"
+version = "0.2.186"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "52ff2c0fe9bc6cb6b14a0592c2ff4fa9ceb83eea9db979b0487cd054946a2b8f"
+checksum = "68ab91017fe16c622486840e4c83c9a37afeff978bd239b5293d61ece587de66"
 
 [[package]]
 name = "libfuzzer-sys"
@@ -1605,12 +1605,11 @@ checksum = "b6d2cec3eae94f9f509c767b45932f1ada8350c4bdb85af2fcab4a3c14807981"
 
 [[package]]
 name = "libmimalloc-sys"
-version = "0.1.44"
+version = "0.1.47"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "667f4fec20f29dfc6bc7357c582d91796c169ad7e2fce709468aefeb2c099870"
+checksum = "2d1eacfa31c33ec25e873c136ba5669f00f9866d0688bea7be4d3f7e43067df6"
 dependencies = [
  "cc",
- "libc",
 ]
 
 [[package]]
@@ -1727,9 +1726,9 @@ dependencies = [
 
 [[package]]
 name = "mimalloc"
-version = "0.1.48"
+version = "0.1.50"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e1ee66a4b64c74f4ef288bcbb9192ad9c3feaad75193129ac8509af543894fd8"
+checksum = "b3627c4272df786b9260cabaa46aec1d59c93ede723d4c3ef646c503816b0640"
 dependencies = [
  "libmimalloc-sys",
 ]
@@ -2081,7 +2080,7 @@ dependencies = [
 [[package]]
 name = "pathfinder_simd"
 version = "0.5.5"
-source = "git+https://github.com/itsjunetime/pathfinder.git?branch=fix_nightly_arm_simd#814671e162a1829e074521446317b915311d3d4d"
+source = "git+https://github.com/itsjunetime/pathfinder.git?rev=814671e162a1829e074521446317b915311d3d4d#814671e162a1829e074521446317b915311d3d4d"
 dependencies = [
  "rustc_version",
 ]

Cargo.toml

@@ -55,7 +55,7 @@ flexi_logger = "0.31"
 console-subscriber = { version = "0.5.0", optional = true }
 
 [patch.crates-io]
-pathfinder_simd = { git = "https://github.com/itsjunetime/pathfinder.git", branch = "fix_nightly_arm_simd" }
+pathfinder_simd = { git = "https://github.com/itsjunetime/pathfinder.git", rev = "814671e162a1829e074521446317b915311d3d4d" }
 
 [profile.production]
 inherits = "release"

src/kitty.rs

@@ -139,12 +139,13 @@ impl Display for DisplayErrSource<'_> {
 
 pub async fn display_kitty_images<'es>(
 	display: KittyDisplay<'_>,
-	ev_stream: &'es mut EventStream
+	ev_stream: &'es mut EventStream,
+	last_z_index: &mut i32
 ) -> Result<(), DisplayErr<'es>> {
 	let images = match display {
 		KittyDisplay::NoChange => return Ok(()),
-		KittyDisplay::DisplayImages(_) | KittyDisplay::ClearImages => {
-			run_action(
+		KittyDisplay::ClearImages =>
+			return run_action(
 				Action::Delete(DeleteConfig {
 					effect: ClearOrDelete::Clear,
 					which: WhichToDelete::All
@@ -152,24 +153,23 @@ pub async fn display_kitty_images<'es>(
 				ev_stream
 			)
 			.await
-			.map_err(|e| DisplayErr::empty("Couldn't clear previous images", e))?;
-
-			let KittyDisplay::DisplayImages(images) = display else {
-				return Ok(());
-			};
-
-			images
-		}
+			.map_err(|e| DisplayErr::empty("Couldn't clear previous images", e))
+			.map(|_: Option<ImageId>| ()),
+		KittyDisplay::DisplayImages(imgs) => imgs
 	};
 
+	let new_z_index = last_z_index.wrapping_add_unsigned(1);
+
 	let mut err = Ok::<(), (SmallVec<[usize; 2]>, DisplayErrSource<'es>)>(());
 	for KittyReadyToDisplay {
 		img,
 		page_num,
 		pos,
-		display_loc
+		mut display_loc
 	} in images
 	{
+		display_loc.z_index = new_z_index;
+
 		let config = DisplayConfig {
 			location: display_loc,
 			cursor_movement: CursorMovementPolicy::DontMove,
@@ -199,7 +199,7 @@ pub async fn display_kitty_images<'es>(
 				};
 				std::mem::swap(image, &mut fake_image);
 
-				let res = run_action(
+				run_action(
 					Action::TransmitAndDisplay {
 						image: fake_image,
 						config,
@@ -207,16 +207,13 @@ pub async fn display_kitty_images<'es>(
 					},
 					ev_stream
 				)
-				.await;
-
-				match res {
-					Ok(Some(img_id)) => {
-						*img = MaybeTransferred::Transferred(img_id);
-						Ok(())
-					}
-					Ok(None) => Err((page_num, DisplayErrSource::KittageReturnedNoId)),
-					Err(e) => Err((page_num, DisplayErrSource::Transmission(e)))
-				}
+				.await
+				.map_err(DisplayErrSource::Transmission)
+				.and_then(|img_id| {
+					img_id
+						.map(|id| *img = MaybeTransferred::Transferred(id))
+						.ok_or(DisplayErrSource::KittageReturnedNoId)
+				})
 			}
 			MaybeTransferred::Transferred(image_id) => run_action(
 				Action::Display {
@@ -229,22 +226,37 @@ pub async fn display_kitty_images<'es>(
 			.await
 			// don't need the return id 'cause we already know it
 			.map(|_: Option<ImageId>| ())
-			.map_err(|e| (page_num, DisplayErrSource::Transmission(e)))
+			.map_err(DisplayErrSource::Transmission)
 		};
 
 		log::debug!("this_err is {this_err:#?}");
 
-		if let Err((id, e)) = this_err {
+		if let Err(e) = this_err {
 			match err.as_mut() {
-				Ok(()) => err = Err((SmallVec::from([id].as_slice()), e)),
-				Err((v, _)) => v.push(id)
+				Ok(()) => err = Err((SmallVec::from([page_num].as_slice()), e)),
+				Err((v, _)) => v.push(page_num)
 			}
 		}
 	}
 
-	err.map_err(|(failed_pages, source)| DisplayErr {
-		failed_pages,
-		user_facing_err: "Couldn't transfer image to the terminal",
-		source
-	})
+	let z_idxes_to_remove = *last_z_index;
+	*last_z_index = new_z_index;
+
+	match err {
+		Err((failed_pages, source)) => Err(DisplayErr {
+			failed_pages,
+			user_facing_err: "Couldn't transfer image to the terminal",
+			source
+		}),
+		Ok(()) => run_action(
+			Action::Delete(DeleteConfig {
+				effect: ClearOrDelete::Clear,
+				which: WhichToDelete::PlacementsWithZIndex(z_idxes_to_remove)
+			}),
+			ev_stream
+		)
+		.await
+		.map_err(|e| DisplayErr::empty("Couldn't clear previously-sent images", e))
+		.map(|_| ())
+	}
 }

src/main.rs

@@ -390,6 +390,8 @@ async fn enter_redraw_loop(
 	mut main_area: tdf::tui::RenderLayout,
 	font_size: FontSize
 ) -> Result<(), Box<dyn Error>> {
+	let mut kitty_z_idx = i32::MIN;
+
 	loop {
 		let mut needs_redraw = true;
 		let next_ev = ev_stream.next().fuse();
@@ -462,7 +464,8 @@ async fn enter_redraw_loop(
 				to_display = tui.render(f, &main_area, font_size);
 			})?;
 
-			let maybe_err = display_kitty_images(to_display, &mut ev_stream).await;
+			let maybe_err =
+				display_kitty_images(to_display, &mut ev_stream, &mut kitty_z_idx).await;
 
 			if let Err(DisplayErr {
 				failed_pages,

src/tui.rs

@@ -72,7 +72,7 @@ struct PageConstraints {
 	r_to_l: bool
 }
 
-#[derive(Default, Debug)]
+#[derive(Default, Debug, Clone, Copy)]
 struct Zoom {
 	// just how much 'zoom' you have. 0 means it fills the screen (instead of fits), such
 	// that one axis is fully on-screen
@@ -86,7 +86,7 @@ struct Zoom {
 }
 impl Zoom {
 	/// Returns the zoom factor, where 1 is the default and means fill-screen
-	fn factor(&self) -> f32 {
+	fn factor(self) -> f32 {
 		// TODO: Make these configurable once we have a good way to set options after startup
 		const ZOOM_RATE: f32 = 1.1;
 		const ZOOM_RATE_GRANULAR: f32 = 1.05;
@@ -262,7 +262,7 @@ impl Tui {
 			let img_page_w_ratio = img_section_w / initial_page_w;
 			let img_page_h_ratio = img_section_h / initial_page_h;
 
-			let shrink_move_page = |dim: &mut u16, pos: &mut u16, axis_zoom_factor: f32| {
+			fn shrink_move_page(dim: &mut u16, pos: &mut u16, axis_zoom_factor: f32) {
 				let old_dim = *dim;
 				// The axis zoom factor tells us what portion of the axis
 				// we need to show.
@@ -272,26 +272,56 @@ impl Tui {
 					.checked_sub(*dim)
 					.expect("zooming out should shrink the image")
 					/ 2;
-			};
-
-			// TODO: Detect max zoom-out in zoom levels
-			if img_page_w_ratio < img_page_h_ratio {
-				// vertical scroll / tall image. zooming out means decreasing the width of the page area
-				shrink_move_page(
-					&mut img_area.width,
-					&mut img_area.x,
-					// disallow zooming out past fit-screen
-					zoom_factor.max(1.0 / img_page_h_ratio)
-				);
-			} else {
-				// horizontal scroll / wide image. zooming out means decreasing the width of the page area
-				shrink_move_page(
-					&mut img_area.height,
-					&mut img_area.y,
-					// disallow zooming out past fit-screen
-					zoom_factor.max(1.0 / img_page_w_ratio)
-				);
 			}
+
+			fn shrink_move_two_pass(
+				zoom: &mut Zoom,
+				dim: &mut u16,
+				pos: &mut u16,
+				zoom_factor: f32,
+				axis_zoom_factor: f32
+			) {
+				// To detect if we're already at fit-screen, we perform a first
+				// pass on `img_area` that emulates the last call to
+				// `render_zoomed` by subtracting from the `zoom`'s level. This
+				// holds because the `img_area` that gets passed is always the
+				// same.
+				let mut first_pass_dim = *dim;
+				let mut first_pass_pos = *pos;
+				let mut first_pass_zoom = *zoom;
+
+				if first_pass_zoom.level.is_negative() {
+					first_pass_zoom.step_in();
+				}
+				let first_pass_zoom_factor = first_pass_zoom.factor();
+				shrink_move_page(
+					&mut first_pass_dim,
+					&mut first_pass_pos,
+					first_pass_zoom_factor.max(1.0 / axis_zoom_factor)
+				);
+
+				log::debug!("first_pass_dim: {first_pass_dim}, first_pass_pos: {first_pass_pos}");
+				// vertical scroll / tall image. zooming out means decreasing
+				// the width of the page area
+				// use `max` to disallow zooming out past fit-screen
+				shrink_move_page(dim, pos, zoom_factor.max(1.0 / axis_zoom_factor));
+
+				log::debug!("new dim: {dim}, new pos: {pos}");
+				// The moment the image area is left unmodified, we've hit
+				// fit-screen and the zoom level ought be normalized.
+				if first_pass_dim == *dim && first_pass_pos == *pos {
+					zoom.step_in();
+				}
+			}
+
+			let (dim, pos, axis_zoom_factor) = if img_page_w_ratio < img_page_h_ratio {
+				(&mut img_area.width, &mut img_area.x, img_page_h_ratio)
+			} else {
+				// horizontal scroll / wide image. zooming out means decreasing
+				// the height of the page area
+				(&mut img_area.height, &mut img_area.y, img_page_w_ratio)
+			};
+			shrink_move_two_pass(zoom, dim, pos, zoom_factor, axis_zoom_factor);
 		}
 		log::debug!("after adjustment, page area is {img_area:#?}");