1 files changed, 146 insertions, 0 deletions
diff --git a/alacritty_terminal/src/graphics/mod.rs b/alacritty_terminal/src/graphics/mod.rs
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+++ b/alacritty_terminal/src/graphics/mod.rs
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+//! This module implements the logic to manage graphic items included in a
+//! `Grid` instance.
+
+pub mod sixel;
+
+use std::mem;
+use std::sync::{Arc, Weak};
+
+use parking_lot::Mutex;
+use serde::{Deserialize, Serialize};
+
+use crate::term::color::Rgb;
+
+/// Max allowed dimensions (width, height) for the graphic, in pixels.
+pub const MAX_GRAPHIC_DIMENSIONS: (usize, usize) = (4096, 4096);
+
+/// Unique identifier for every graphic added to a grid.
+#[derive(Serialize, Deserialize, Eq, PartialEq, Clone, Debug, Copy, Hash, PartialOrd, Ord)]
+pub struct GraphicId(u64);
+
+/// Reference to a texture stored in the display.
+///
+/// When all references to a single texture are removed, its identifier is
+/// added to the remove queue.
+#[derive(Clone, Debug)]
+pub struct TextureRef {
+    /// Graphic identifier.
+    pub id: GraphicId,
+
+    /// Queue to track removed references.
+    pub remove_queue: Weak<Mutex<Vec<GraphicId>>>,
+}
+
+impl PartialEq for TextureRef {
+    fn eq(&self, t: &Self) -> bool {
+        // Ignore remove_queue.
+        self.id == t.id
+    }
+}
+
+impl Eq for TextureRef {}
+
+impl Drop for TextureRef {
+    fn drop(&mut self) {
+        if let Some(remove_queue) = self.remove_queue.upgrade() {
+            remove_queue.lock().push(self.id);
+        }
+    }
+}
+
+/// Graphic data stored in a single cell.
+#[derive(Eq, PartialEq, Clone, Debug)]
+pub struct GraphicCell {
+    /// Texture to draw the graphic in this cell.
+    pub texture: Arc<TextureRef>,
+
+    /// Offset in the x direction.
+    pub offset_x: u16,
+
+    /// Offset in the y direction.
+    pub offset_y: u16,
+}
+
+impl GraphicCell {
+    /// Graphic identifier of the texture in this cell.
+    #[inline]
+    pub fn graphic_id(&self) -> GraphicId {
+        self.texture.id
+    }
+}
+
+/// Specifies the format of the pixel data.
+#[derive(Serialize, Deserialize, Eq, PartialEq, Clone, Debug, Copy)]
+pub enum ColorType {
+    /// 3 bytes per pixel (red, green, blue).
+    Rgb,
+
+    /// 4 bytes per pixel (red, green, blue, alpha).
+    Rgba,
+}
+
+/// Defines a single graphic read from the PTY.
+#[derive(Serialize, Deserialize, Eq, PartialEq, Clone, Debug)]
+pub struct GraphicData {
+    /// Graphics identifier.
+    pub id: GraphicId,
+
+    /// Width, in pixels, of the graphic.
+    pub width: usize,
+
+    /// Height, in pixels, of the graphic.
+    pub height: usize,
+
+    /// Color type of the pixels.
+    pub color_type: ColorType,
+
+    /// Pixels data.
+    pub pixels: Vec<u8>,
+}
+
+/// Queues to add or to remove the textures in the display.
+pub struct UpdateQueues {
+    /// Graphics read from the PTY.
+    pub pending: Vec<GraphicData>,
+
+    /// Graphics removed from the grid.
+    pub remove_queue: Vec<GraphicId>,
+}
+
+/// Track changes in the grid to add or to remove graphics.
+#[derive(Clone, Debug, Default)]
+pub struct Graphics {
+    /// Last generated identifier.
+    pub last_id: u64,
+
+    /// New graphics, received from the PTY.
+    pub pending: Vec<GraphicData>,
+
+    /// Graphics removed from the grid.
+    pub remove_queue: Arc<Mutex<Vec<GraphicId>>>,
+
+    /// Shared palette for Sixel graphics.
+    pub sixel_shared_palette: Option<Vec<Rgb>>,
+}
+
+impl Graphics {
+    /// Generate a new graphic identifier.
+    pub fn next_id(&mut self) -> GraphicId {
+        self.last_id += 1;
+        GraphicId(self.last_id)
+    }
+
+    /// Get queues to update graphics in the grid.
+    ///
+    /// If all queues are empty, it returns `None`.
+    pub fn take_queues(&mut self) -> Option<UpdateQueues> {
+        let mut remove_queue = self.remove_queue.lock();
+        if remove_queue.is_empty() && self.pending.is_empty() {
+            return None;
+        }
+
+        let remove_queue = mem::take(&mut *remove_queue);
+
+        Some(UpdateQueues { pending: mem::take(&mut self.pending), remove_queue })
+    }
+}