many fixed and changes

Cargo.lock

@@ -514,6 +514,15 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d9c4f5dac5e15c24eb999c26181a6ca40b39fe946cbe4c263c7209467bc83af2"
 
+[[package]]
+name = "fontconfig"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b19c4bca8c705ea23bfb3e3403a9e699344d1ee3205b631f03fe4dbf1e52429f"
+dependencies = [
+ "yeslogic-fontconfig-sys",
+]
+
 [[package]]
 name = "fontdue"
 version = "0.9.3"
@@ -2580,6 +2589,17 @@ version = "0.8.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3ae8337f8a065cfc972643663ea4279e04e7256de865aa66fe25cec5fb912d3f"
 
+[[package]]
+name = "yeslogic-fontconfig-sys"
+version = "6.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "503a066b4c037c440169d995b869046827dbc71263f6e8f3be6d77d4f3229dbd"
+dependencies = [
+ "dlib",
+ "once_cell",
+ "pkg-config",
+]
+
 [[package]]
 name = "zerocopy"
 version = "0.8.31"
@@ -2609,6 +2629,7 @@ dependencies = [
  "bytemuck",
  "dirs",
  "env_logger",
+ "fontconfig",
  "fontdue",
  "libc",
  "log",
@@ -2624,4 +2645,5 @@ dependencies = [
  "ttf-parser 0.25.1",
  "wgpu",
  "winit",
+ "yeslogic-fontconfig-sys",
 ]

Cargo.toml

@@ -39,6 +39,8 @@ bitflags = "2"
 fontdue = "0.9"
 rustybuzz = "0.20"
 ttf-parser = "0.25"
+fontconfig = "0.10"
+fontconfig-sys = { package = "yeslogic-fontconfig-sys", version = "6.0" }
 
 # Configuration
 serde = { version = "1", features = ["derive"] }

PKGBUILD

@@ -0,0 +1,31 @@
+# Maintainer: Zach <zach@brohn.se>
+pkgname=zterm
+pkgver=0.1.0
+pkgrel=1
+pkgdesc="A GPU-accelerated terminal emulator for Wayland"
+arch=('x86_64')
+url="https://github.com/Zacharias-Brohn/zterm"
+license=('MIT')
+depends=(
+	'fontconfig'
+	'freetype2'
+	'wayland'
+	'libxkbcommon'
+	'vulkan-icd-loader'
+)
+makedepends=('rust' 'cargo')
+source=()
+
+build() {
+	cd "$startdir"
+	cargo build --release --locked
+}
+
+package() {
+	cd "$startdir"
+	install -Dm755 "target/release/zterm" "$pkgdir/usr/bin/zterm"
+	install -Dm644 "zterm.terminfo" "$pkgdir/usr/share/zterm/zterm.terminfo"
+
+	# Compile and install terminfo
+	tic -x -o "$pkgdir/usr/share/terminfo" zterm.terminfo
+}

src/bin/test_ligatures.rs

@@ -0,0 +1,87 @@
+//! Test ligature detection - compare individual vs combined shaping
+use rustybuzz::{Face, UnicodeBuffer, Feature};
+use ttf_parser::Tag;
+use fontdue::Font;
+use std::fs;
+
+fn main() {
+    let path = "/usr/share/fonts/TTF/0xProtoNerdFontMono-Regular.ttf";
+    println!("Using font: {}", path);
+    
+    let font_data = fs::read(path).expect("Failed to read font");
+    let face = Face::from_slice(&font_data, 0).expect("Failed to parse font");
+    let fontdue_font = Font::from_bytes(&font_data[..], fontdue::FontSettings::default()).unwrap();
+    
+    let font_size = 16.0;
+    let units_per_em = face.units_per_em() as f32;
+    
+    println!("Font units per em: {}", units_per_em);
+    
+    // Get cell width from a regular character
+    let (hyphen_metrics, _) = fontdue_font.rasterize('-', font_size);
+    let cell_width = hyphen_metrics.advance_width;
+    println!("Cell width (from '-'): {:.2}px", cell_width);
+    
+    let features = vec![
+        Feature::new(Tag::from_bytes(b"liga"), 1, ..),
+        Feature::new(Tag::from_bytes(b"calt"), 1, ..),
+        Feature::new(Tag::from_bytes(b"dlig"), 1, ..),
+    ];
+    
+    let test_strings = ["->", "=>", "==", "!=", ">=", "<="];
+    
+    for s in &test_strings {
+        // Shape combined string
+        let mut buffer = UnicodeBuffer::new();
+        buffer.push_str(s);
+        let combined = rustybuzz::shape(&face, &features, buffer);
+        let combined_infos = combined.glyph_infos();
+        let combined_positions = combined.glyph_positions();
+        
+        // Shape each character individually  
+        let mut individual_glyphs = Vec::new();
+        for c in s.chars() {
+            let mut buf = UnicodeBuffer::new();
+            buf.push_str(&c.to_string());
+            let shaped = rustybuzz::shape(&face, &features, buf);
+            individual_glyphs.push(shaped.glyph_infos()[0].glyph_id);
+        }
+        
+        println!("\n'{}' analysis:", s);
+        println!("  Combined glyphs:   {:?}", combined_infos.iter().map(|i| i.glyph_id).collect::<Vec<_>>());
+        println!("  Individual glyphs: {:?}", individual_glyphs);
+        
+        // Show advances for each glyph
+        for (i, (info, pos)) in combined_infos.iter().zip(combined_positions.iter()).enumerate() {
+            let advance_px = pos.x_advance as f32 * font_size / units_per_em;
+            println!("  Glyph {}: id={}, advance={} units ({:.2}px)", i, info.glyph_id, pos.x_advance, advance_px);
+            
+            // Rasterize and show metrics
+            let (metrics, _) = fontdue_font.rasterize_indexed(info.glyph_id as u16, font_size);
+            println!("    Rasterized: {}x{} px, xmin={}, ymin={}, advance_width={:.2}", 
+                metrics.width, metrics.height, metrics.xmin, metrics.ymin, metrics.advance_width);
+        }
+        
+        // Check if any glyph was substituted
+        let has_substitution = combined_infos.iter().zip(individual_glyphs.iter())
+            .any(|(combined, &individual)| combined.glyph_id != individual);
+        println!("  Has substitution: {}", has_substitution);
+    }
+    
+    // Also test what Kitty does - check glyph names
+    println!("\n=== Checking glyph names via ttf-parser ===");
+    let ttf_face = ttf_parser::Face::parse(&font_data, 0).unwrap();
+    
+    // Shape "->" and get glyph names
+    let mut buffer = UnicodeBuffer::new();
+    buffer.push_str("->");
+    let combined = rustybuzz::shape(&face, &features, buffer);
+    for info in combined.glyph_infos() {
+        let glyph_id = ttf_parser::GlyphId(info.glyph_id as u16);
+        if let Some(name) = ttf_face.glyph_name(glyph_id) {
+            println!("  Glyph {} name: {}", info.glyph_id, name);
+        } else {
+            println!("  Glyph {} has no name", info.glyph_id);
+        }
+    }
+}

src/config.rs

@@ -362,6 +362,11 @@ pub struct Config {
     pub background_opacity: f32,
     /// Number of lines to keep in scrollback buffer.
     pub scrollback_lines: usize,
+    /// Duration in milliseconds for the inactive pane fade animation.
+    /// Set to 0 for instant transitions.
+    pub inactive_pane_fade_ms: u64,
+    /// Dim factor for inactive panes (0.0 = fully dimmed/black, 1.0 = no dimming).
+    pub inactive_pane_dim: f32,
     /// Keybindings.
     pub keybindings: Keybindings,
 }
@@ -373,6 +378,8 @@ impl Default for Config {
             tab_bar_position: TabBarPosition::Top,
             background_opacity: 1.0,
             scrollback_lines: 50_000,
+            inactive_pane_fade_ms: 150,
+            inactive_pane_dim: 0.6,
             keybindings: Keybindings::default(),
         }
     }

src/main.rs

@@ -6,7 +6,7 @@
 use zterm::config::{Action, Config};
 use zterm::keyboard::{FunctionalKey, KeyEncoder, KeyEventType, KeyboardState, Modifiers};
 use zterm::pty::Pty;
-use zterm::renderer::Renderer;
+use zterm::renderer::{PaneRenderInfo, Renderer};
 use zterm::terminal::{Terminal, MouseTrackingMode};
 
 use std::collections::HashMap;
@@ -146,6 +146,10 @@ struct Pane {
     is_selecting: bool,
     /// Last scrollback length for tracking changes.
     last_scrollback_len: u32,
+    /// When the focus animation started (for smooth fade).
+    focus_animation_start: std::time::Instant,
+    /// Whether this pane was focused before the current animation.
+    was_focused: bool,
 }
 
 impl Pane {
@@ -170,6 +174,8 @@ impl Pane {
             selection: None,
             is_selecting: false,
             last_scrollback_len: 0,
+            focus_animation_start: std::time::Instant::now(),
+            was_focused: true, // New panes start as focused
         })
     }
     
@@ -192,6 +198,36 @@ impl Pane {
     fn child_exited(&self) -> bool {
         self.pty.child_exited()
     }
+    
+    /// Calculate the current dim factor based on animation progress.
+    /// Returns a value between `inactive_dim` (for unfocused) and 1.0 (for focused).
+    fn calculate_dim_factor(&mut self, is_focused: bool, fade_duration_ms: u64, inactive_dim: f32) -> f32 {
+        // Detect focus change
+        if is_focused != self.was_focused {
+            self.focus_animation_start = std::time::Instant::now();
+            self.was_focused = is_focused;
+        }
+        
+        // If no animation (instant), return target value immediately
+        if fade_duration_ms == 0 {
+            return if is_focused { 1.0 } else { inactive_dim };
+        }
+        
+        let elapsed = self.focus_animation_start.elapsed().as_millis() as f32;
+        let duration = fade_duration_ms as f32;
+        let progress = (elapsed / duration).min(1.0);
+        
+        // Smooth easing (ease-out cubic)
+        let eased = 1.0 - (1.0 - progress).powi(3);
+        
+        if is_focused {
+            // Fading in: from inactive_dim to 1.0
+            inactive_dim + (1.0 - inactive_dim) * eased
+        } else {
+            // Fading out: from 1.0 to inactive_dim
+            1.0 - (1.0 - inactive_dim) * eased
+        }
+    }
 }
 
 /// Geometry of a pane in pixels.
@@ -308,17 +344,6 @@ impl SplitNode {
         }
     }
     
-    /// Collect all pane IDs.
-    fn collect_pane_ids(&self, ids: &mut Vec<PaneId>) {
-        match self {
-            SplitNode::Leaf { pane_id, .. } => ids.push(*pane_id),
-            SplitNode::Split { first, second, .. } => {
-                first.collect_pane_ids(ids);
-                second.collect_pane_ids(ids);
-            }
-        }
-    }
-    
     /// Collect all pane geometries.
     fn collect_geometries(&self, geometries: &mut Vec<(PaneId, PaneGeometry)>) {
         match self {
@@ -507,6 +532,7 @@ impl TabId {
 /// A single tab containing one or more panes arranged in a split tree.
 struct Tab {
     /// Unique identifier for this tab.
+    #[allow(dead_code)]
     id: TabId,
     /// All panes in this tab, keyed by PaneId.
     panes: HashMap<PaneId, Pane>,
@@ -515,6 +541,7 @@ struct Tab {
     /// Currently active pane ID.
     active_pane: PaneId,
     /// Tab title (from OSC or shell).
+    #[allow(dead_code)]
     title: String,
 }
 
@@ -637,11 +664,6 @@ impl Tab {
         }
     }
     
-    /// Get all pane IDs.
-    fn pane_ids(&self) -> Vec<PaneId> {
-        self.panes.keys().copied().collect()
-    }
-    
     /// Get pane by ID.
     fn get_pane(&self, pane_id: PaneId) -> Option<&Pane> {
         self.panes.get(&pane_id)
@@ -1191,6 +1213,8 @@ impl App {
                 if let Some(renderer) = &self.renderer {
                     let (cols, rows) = renderer.terminal_size();
                     self.create_tab(cols, rows);
+                    // Resize the new tab to calculate pane geometries
+                    self.resize_all_panes();
                     if let Some(window) = &self.window {
                         window.request_redraw();
                     }
@@ -1751,22 +1775,83 @@ impl ApplicationHandler<UserEvent> for App {
                     }
                 }
                 
-                // Render
+                // Render all panes
                 let render_start = std::time::Instant::now();
                 let num_tabs = self.tabs.len();
                 let active_tab_idx = self.active_tab;
+                let fade_duration_ms = self.config.inactive_pane_fade_ms;
+                let inactive_dim = self.config.inactive_pane_dim;
                 
                 if let Some(renderer) = &mut self.renderer {
-                    if let Some(tab) = self.tabs.get(active_tab_idx) {
+                    if let Some(tab) = self.tabs.get_mut(active_tab_idx) {
-                        if let Some(pane) = tab.active_pane() {
+                        // Collect all pane geometries
+                        let geometries = tab.collect_pane_geometries();
+                        let active_pane_id = tab.active_pane;
+                        
+                        // First pass: calculate dim factors (needs mutable access)
+                        let mut dim_factors: Vec<(PaneId, f32)> = Vec::new();
+                        for (pane_id, _) in &geometries {
+                            if let Some(pane) = tab.panes.get_mut(pane_id) {
+                                let is_active = *pane_id == active_pane_id;
+                                let dim_factor = pane.calculate_dim_factor(is_active, fade_duration_ms, inactive_dim);
+                                dim_factors.push((*pane_id, dim_factor));
+                            }
+                        }
+                        
+                        // Build render info for all panes
+                        let mut pane_render_data: Vec<(&Terminal, PaneRenderInfo, Option<(usize, usize, usize, usize)>)> = Vec::new();
+                        
+                        for (pane_id, geom) in &geometries {
+                            if let Some(pane) = tab.panes.get(pane_id) {
+                                let is_active = *pane_id == active_pane_id;
                                 let scroll_offset = pane.terminal.scroll_offset;
-                            let visible_rows = renderer.terminal_size().1;
-                            let renderer_selection = pane.selection.as_ref()
-                                .and_then(|sel| sel.to_screen_coords(scroll_offset, visible_rows));
                                 
-                            renderer.set_selection(renderer_selection);
+                                // Get pre-calculated dim factor
+                                let dim_factor = dim_factors.iter()
+                                    .find(|(id, _)| id == pane_id)
+                                    .map(|(_, f)| *f)
+                                    .unwrap_or(if is_active { 1.0 } else { inactive_dim });
                                 
-                            match renderer.render_from_terminal(&pane.terminal, num_tabs, active_tab_idx) {
+                                // Convert selection to screen coords for this pane
+                                let selection = if is_active {
+                                    pane.selection.as_ref()
+                                        .and_then(|sel| sel.to_screen_coords(scroll_offset, geom.rows))
+                                } else {
+                                    None
+                                };
+                                
+                                let render_info = PaneRenderInfo {
+                                    x: geom.x,
+                                    y: geom.y,
+                                    width: geom.width,
+                                    height: geom.height,
+                                    cols: geom.cols,
+                                    rows: geom.rows,
+                                    is_active,
+                                    dim_factor,
+                                };
+                                
+                                pane_render_data.push((&pane.terminal, render_info, selection));
+                            }
+                        }
+                        
+                        // Request redraw if any animation is in progress
+                        let animation_in_progress = dim_factors.iter().any(|(id, factor)| {
+                            let is_active = *id == active_pane_id;
+                            if is_active {
+                                *factor < 1.0
+                            } else {
+                                *factor > inactive_dim
+                            }
+                        });
+                        
+                        if animation_in_progress {
+                            if let Some(window) = &self.window {
+                                window.request_redraw();
+                            }
+                        }
+                        
+                        match renderer.render_panes(&pane_render_data, num_tabs, active_tab_idx) {
                             Ok(_) => {}
                             Err(wgpu::SurfaceError::Lost) => {
                                 renderer.resize(renderer.width, renderer.height);
@@ -1781,7 +1866,6 @@ impl ApplicationHandler<UserEvent> for App {
                         }
                     }
                 }
-                }
                 let render_time = render_start.elapsed();
                 let frame_time = frame_start.elapsed();
                 

src/terminal.rs

@@ -144,292 +144,6 @@ impl Default for ColorPalette {
     }
 }
 
-/// Packed color value for GPU transfer (Kitty-style encoding).
-/// Layout: type in low 8 bits, RGB value in upper 24 bits.
-/// - Type 0: Default (use color table entries 256/257 for fg/bg)
-/// - Type 1: Indexed (index in bits 8-15, look up in color table)
-/// - Type 2: RGB (R in bits 8-15, G in bits 16-23, B in bits 24-31)
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
-#[repr(transparent)]
-pub struct PackedColor(pub u32);
-
-impl PackedColor {
-    /// Color type: default (resolved from color table)
-    pub const TYPE_DEFAULT: u8 = 0;
-    /// Color type: indexed (look up in 256-color palette)
-    pub const TYPE_INDEXED: u8 = 1;
-    /// Color type: direct RGB
-    pub const TYPE_RGB: u8 = 2;
-
-    /// Create a default color (resolved at render time from palette).
-    #[inline]
-    pub const fn default_color() -> Self {
-        Self(Self::TYPE_DEFAULT as u32)
-    }
-
-    /// Create an indexed color (0-255 palette index).
-    #[inline]
-    pub const fn indexed(index: u8) -> Self {
-        Self(Self::TYPE_INDEXED as u32 | ((index as u32) << 8))
-    }
-
-    /// Create a direct RGB color.
-    #[inline]
-    pub const fn rgb(r: u8, g: u8, b: u8) -> Self {
-        Self(Self::TYPE_RGB as u32 | ((r as u32) << 8) | ((g as u32) << 16) | ((b as u32) << 24))
-    }
-
-    /// Get the color type.
-    #[inline]
-    pub const fn color_type(self) -> u8 {
-        (self.0 & 0xFF) as u8
-    }
-
-    /// Get the index for indexed colors.
-    #[inline]
-    pub const fn index(self) -> u8 {
-        ((self.0 >> 8) & 0xFF) as u8
-    }
-
-    /// Get RGB components for RGB colors.
-    #[inline]
-    pub const fn rgb_components(self) -> (u8, u8, u8) {
-        (
-            ((self.0 >> 8) & 0xFF) as u8,
-            ((self.0 >> 16) & 0xFF) as u8,
-            ((self.0 >> 24) & 0xFF) as u8,
-        )
-    }
-}
-
-impl From<Color> for PackedColor {
-    fn from(color: Color) -> Self {
-        match color {
-            Color::Default => Self::default_color(),
-            Color::Indexed(idx) => Self::indexed(idx),
-            Color::Rgb(r, g, b) => Self::rgb(r, g, b),
-        }
-    }
-}
-
-impl From<&Color> for PackedColor {
-    fn from(color: &Color) -> Self {
-        (*color).into()
-    }
-}
-
-/// Packed cell attributes for GPU transfer (Kitty-style).
-/// Layout (32-bit bitfield):
-/// - bits 0-2: decoration (underline style, 0=none, 1=single, 2=double, 3=curly, etc.)
-/// - bit 3: bold
-/// - bit 4: italic
-/// - bit 5: reverse
-/// - bit 6: strike
-/// - bit 7: dim
-/// - bits 8-31: reserved for future use
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
-#[repr(transparent)]
-pub struct CellAttrs(pub u32);
-
-impl CellAttrs {
-    pub const DECORATION_MASK: u32 = 0b111;
-    pub const BOLD_BIT: u32 = 1 << 3;
-    pub const ITALIC_BIT: u32 = 1 << 4;
-    pub const REVERSE_BIT: u32 = 1 << 5;
-    pub const STRIKE_BIT: u32 = 1 << 6;
-    pub const DIM_BIT: u32 = 1 << 7;
-
-    /// Decoration values
-    pub const DECO_NONE: u32 = 0;
-    pub const DECO_SINGLE: u32 = 1;
-    pub const DECO_DOUBLE: u32 = 2;
-    pub const DECO_CURLY: u32 = 3;
-    pub const DECO_DOTTED: u32 = 4;
-    pub const DECO_DASHED: u32 = 5;
-
-    #[inline]
-    pub const fn new() -> Self {
-        Self(0)
-    }
-
-    #[inline]
-    pub const fn with_underline(self, style: u32) -> Self {
-        Self((self.0 & !Self::DECORATION_MASK) | (style & Self::DECORATION_MASK))
-    }
-
-    #[inline]
-    pub const fn with_bold(self, bold: bool) -> Self {
-        if bold {
-            Self(self.0 | Self::BOLD_BIT)
-        } else {
-            Self(self.0 & !Self::BOLD_BIT)
-        }
-    }
-
-    #[inline]
-    pub const fn with_italic(self, italic: bool) -> Self {
-        if italic {
-            Self(self.0 | Self::ITALIC_BIT)
-        } else {
-            Self(self.0 & !Self::ITALIC_BIT)
-        }
-    }
-
-    #[inline]
-    pub const fn with_reverse(self, reverse: bool) -> Self {
-        if reverse {
-            Self(self.0 | Self::REVERSE_BIT)
-        } else {
-            Self(self.0 & !Self::REVERSE_BIT)
-        }
-    }
-
-    #[inline]
-    pub const fn with_strike(self, strike: bool) -> Self {
-        if strike {
-            Self(self.0 | Self::STRIKE_BIT)
-        } else {
-            Self(self.0 & !Self::STRIKE_BIT)
-        }
-    }
-
-    #[inline]
-    pub const fn with_dim(self, dim: bool) -> Self {
-        if dim {
-            Self(self.0 | Self::DIM_BIT)
-        } else {
-            Self(self.0 & !Self::DIM_BIT)
-        }
-    }
-
-    #[inline]
-    pub const fn decoration(self) -> u32 {
-        self.0 & Self::DECORATION_MASK
-    }
-
-    #[inline]
-    pub const fn is_bold(self) -> bool {
-        (self.0 & Self::BOLD_BIT) != 0
-    }
-
-    #[inline]
-    pub const fn is_italic(self) -> bool {
-        (self.0 & Self::ITALIC_BIT) != 0
-    }
-
-    #[inline]
-    pub const fn is_reverse(self) -> bool {
-        (self.0 & Self::REVERSE_BIT) != 0
-    }
-
-    #[inline]
-    pub const fn is_strike(self) -> bool {
-        (self.0 & Self::STRIKE_BIT) != 0
-    }
-
-    #[inline]
-    pub const fn is_dim(self) -> bool {
-        (self.0 & Self::DIM_BIT) != 0
-    }
-}
-
-/// GPU cell data for instanced rendering (Kitty-style).
-/// 
-/// This struct is uploaded directly to the GPU for each cell.
-/// The shader uses instanced rendering where each cell is one instance.
-/// 
-/// Layout: 20 bytes total
-/// - fg: 4 bytes (packed color)
-/// - bg: 4 bytes (packed color)  
-/// - decoration_fg: 4 bytes (packed color for underline/strikethrough)
-/// - sprite_idx: 4 bytes (glyph atlas index, bit 31 = colored glyph flag)
-/// - attrs: 4 bytes (packed attributes)
-#[repr(C)]
-#[derive(Clone, Copy, Debug, Default, bytemuck::Pod, bytemuck::Zeroable)]
-pub struct GPUCell {
-    /// Foreground color (packed)
-    pub fg: u32,
-    /// Background color (packed)
-    pub bg: u32,
-    /// Decoration color for underline/strikethrough (packed)
-    pub decoration_fg: u32,
-    /// Sprite index in glyph atlas (bit 31 = colored glyph flag)
-    pub sprite_idx: u32,
-    /// Packed attributes (bold, italic, underline style, etc.)
-    pub attrs: u32,
-}
-
-impl GPUCell {
-    /// Flag indicating this glyph is colored (e.g., emoji) and should not be tinted
-    pub const COLORED_GLYPH_FLAG: u32 = 1 << 31;
-    /// Sprite index indicating no glyph (space/empty)
-    pub const NO_GLYPH: u32 = 0;
-
-    /// Create an empty cell (space with default colors)
-    #[inline]
-    pub const fn empty() -> Self {
-        Self {
-            fg: PackedColor::TYPE_DEFAULT as u32,
-            bg: PackedColor::TYPE_DEFAULT as u32,
-            decoration_fg: PackedColor::TYPE_DEFAULT as u32,
-            sprite_idx: Self::NO_GLYPH,
-            attrs: 0,
-        }
-    }
-
-    /// Create a GPUCell from terminal Cell and a sprite index
-    #[inline]
-    pub fn from_cell(cell: &Cell, sprite_idx: u32) -> Self {
-        let fg = PackedColor::from(&cell.fg_color);
-        let bg = PackedColor::from(&cell.bg_color);
-        
-        let mut attrs = CellAttrs::new();
-        if cell.bold {
-            attrs = attrs.with_bold(true);
-        }
-        if cell.italic {
-            attrs = attrs.with_italic(true);
-        }
-        if cell.underline {
-            attrs = attrs.with_underline(CellAttrs::DECO_SINGLE);
-        }
-
-        Self {
-            fg: fg.0,
-            bg: bg.0,
-            decoration_fg: fg.0, // Use fg color for decoration by default
-            sprite_idx,
-            attrs: attrs.0,
-        }
-    }
-
-    /// Set the sprite index
-    #[inline]
-    pub fn with_sprite(mut self, idx: u32) -> Self {
-        self.sprite_idx = idx;
-        self
-    }
-
-    /// Mark this glyph as colored (emoji)
-    #[inline]
-    pub fn with_colored_glyph(mut self) -> Self {
-        self.sprite_idx |= Self::COLORED_GLYPH_FLAG;
-        self
-    }
-
-    /// Get the sprite index (without the colored flag)
-    #[inline]
-    pub const fn get_sprite_idx(self) -> u32 {
-        self.sprite_idx & !Self::COLORED_GLYPH_FLAG
-    }
-
-    /// Check if this is a colored glyph
-    #[inline]
-    pub const fn is_colored_glyph(self) -> bool {
-        (self.sprite_idx & Self::COLORED_GLYPH_FLAG) != 0
-    }
-}
-
 impl ColorPalette {
     /// Parse a color specification like "#RRGGBB" or "rgb:RR/GG/BB".
     pub fn parse_color_spec(spec: &str) -> Option<[u8; 3]> {
@@ -886,7 +600,10 @@ impl Terminal {
     #[inline]
     fn clear_grid_row(&mut self, grid_row: usize) {
         let blank = self.blank_cell();
-        self.grid[grid_row].fill(blank);
+        let row = &mut self.grid[grid_row];
+        // Ensure row has correct width (may differ after swap with scrollback post-resize)
+        row.resize(self.cols, blank.clone());
+        row.fill(blank);
     }
 
     /// Create a blank cell with the current background color (BCE - Background Color Erase).
@@ -930,13 +647,18 @@ impl Terminal {
             return;
         }
 
+        let old_cols = self.cols;
+        let old_rows = self.rows;
+
         // Create new grid
         let mut new_grid = vec![vec![Cell::default(); cols]; rows];
 
         // Copy existing content using line_map for correct visual ordering
         for visual_row in 0..rows.min(self.rows) {
             let old_grid_row = self.line_map[visual_row];
-            for col in 0..cols.min(self.cols) {
+            // Use actual row length - may differ from self.cols after scrollback swap
+            let old_row_len = self.grid[old_grid_row].len();
+            for col in 0..cols.min(old_row_len) {
                 new_grid[visual_row][col] = self.grid[old_grid_row][col].clone();
             }
         }
@@ -954,6 +676,28 @@ impl Terminal {
         // Adjust cursor position
         self.cursor_col = self.cursor_col.min(cols.saturating_sub(1));
         self.cursor_row = self.cursor_row.min(rows.saturating_sub(1));
+
+        // Also resize the saved alternate screen if it exists
+        if let Some(ref mut saved) = self.alternate_screen {
+            let mut new_saved_grid = vec![vec![Cell::default(); cols]; rows];
+            for visual_row in 0..rows.min(old_rows) {
+                let old_grid_row = saved.line_map.get(visual_row).copied().unwrap_or(visual_row);
+                if old_grid_row < saved.grid.len() {
+                    for col in 0..cols.min(old_cols) {
+                        if col < saved.grid[old_grid_row].len() {
+                            new_saved_grid[visual_row][col] = saved.grid[old_grid_row][col].clone();
+                        }
+                    }
+                }
+            }
+            saved.grid = new_saved_grid;
+            saved.line_map = (0..rows).collect();
+            saved.cursor_col = saved.cursor_col.min(cols.saturating_sub(1));
+            saved.cursor_row = saved.cursor_row.min(rows.saturating_sub(1));
+            saved.scroll_top = 0;
+            saved.scroll_bottom = rows.saturating_sub(1);
+        }
+
         self.dirty = true;
         self.mark_all_lines_dirty();
     }
@@ -1004,11 +748,12 @@ impl Terminal {
         if let Some(saved) = self.alternate_screen.take() {
             self.grid = saved.grid;
             self.line_map = saved.line_map;
-            self.cursor_col = saved.cursor_col;
-            self.cursor_row = saved.cursor_row;
             self.saved_cursor = saved.saved_cursor;
             self.scroll_top = saved.scroll_top;
             self.scroll_bottom = saved.scroll_bottom;
+            // Clamp cursor positions to current grid dimensions (defensive)
+            self.cursor_col = saved.cursor_col.min(self.cols.saturating_sub(1));
+            self.cursor_row = saved.cursor_row.min(self.rows.saturating_sub(1));
         }
 
         self.using_alternate_screen = false;
@@ -1486,6 +1231,10 @@ impl Handler for Terminal {
                     }
                     
                     // Write character directly using cached grid_row
+                    // Safety: ensure grid row has correct width (may differ after scrollback swap)
+                    if self.grid[grid_row].len() != self.cols {
+                        self.grid[grid_row].resize(self.cols, Cell::default());
+                    }
                     self.grid[grid_row][self.cursor_col] = Cell {
                         character: c,
                         fg_color: self.current_fg,