Half-width graph support (#50)

* Implement --graph-width option

* Add tests

* Update README

* Update README

README.md

@@ -95,11 +95,12 @@ Serie - A rich git commit graph in your terminal, like magic 📚
 Usage: serie [OPTIONS]
 
 Options:
-  -p, --protocol <TYPE>  Image protocol to render graph [default: auto] [possible values: auto, iterm, kitty]
-  -o, --order <TYPE>     Commit ordering algorithm [default: chrono] [possible values: chrono, topo]
-      --preload          Preload all graph images
-  -h, --help             Print help
-  -V, --version          Print version
+  -p, --protocol <TYPE>     Image protocol to render graph [default: auto] [possible values: auto, iterm, kitty]
+  -o, --order <TYPE>        Commit ordering algorithm [default: chrono] [possible values: chrono, topo]
+  -g, --graph-width <TYPE>  Commit graph image cell width [possible values: double, single]
+      --preload             Preload all graph images
+  -h, --help                Print help
+  -V, --version             Print version
 ```
 
 #### -p, --protocol \<TYPE\>
@@ -115,11 +116,39 @@ Refer to [Compatibility](#compatibility) for details.
 
 `--order chrono` will order commits by commit date if possible.
 
-<img src="./img/order-chrono.png" width=500>
-
 `--order topo` will order commits on the same branch consecutively if possible.
 
-<img src="./img/order-topo.png" width=500>
+<details>
+<summary>Screenshots</summary>
+
+<img src="./img/order-chrono.png" width=400>
+
+`--order chrono`
+
+<img src="./img/order-topo.png" width=400>
+
+`--order topo`
+
+</details>
+
+#### -g, --graph-width \<TYPE\>
+
+The character width that a graph image unit cell occupies.
+
+If not specified, `double` will be used automatically if there is enough width to display it, `single` otherwise.
+
+<details>
+<summary>Screenshots</summary>
+
+<img src="./img/graph-width-double.png" width=300>
+
+`--graph-width double`
+
+<img src="./img/graph-width-single.png" width=300>
+
+`--graph-width single`
+
+</details>
 
 #### --preload
 

src/app.rs

@@ -15,7 +15,7 @@ use crate::{
     event::{AppEvent, Receiver, Sender, UserEvent},
     external::copy_to_clipboard,
     git::Repository,
-    graph::{Graph, GraphImageManager},
+    graph::{CellWidthType, Graph, GraphImageManager},
     keybind::KeyBind,
     protocol::ImageProtocol,
     view::View,
@@ -61,6 +61,7 @@ impl<'a> App<'a> {
         keybind: &'a KeyBind,
         ui_config: &'a UiConfig,
         color_set: &'a ColorSet,
+        cell_width_type: CellWidthType,
         image_protocol: ImageProtocol,
         tx: Sender,
     ) -> Self {
@@ -79,7 +80,10 @@ impl<'a> App<'a> {
                 CommitInfo::new(commit, refs, graph_color)
             })
             .collect();
-        let graph_cell_width = (graph.max_pos_x + 1) as u16 * 2;
+        let graph_cell_width = match cell_width_type {
+            CellWidthType::Double => (graph.max_pos_x + 1) as u16 * 2,
+            CellWidthType::Single => (graph.max_pos_x + 1) as u16,
+        };
         let head = repository.head();
         let commit_list_state = CommitListState::new(
             commits,

src/check.rs

@@ -1,13 +1,53 @@
 use ratatui::crossterm::terminal;
 
-use crate::graph::Graph;
+use crate::graph::{CellWidthType, Graph};
 
-pub fn term_size(graph: &Graph) -> std::io::Result<()> {
+pub fn decide_cell_width_type(
+    graph: &Graph,
+    cell_width_type: Option<CellWidthType>,
+) -> std::io::Result<CellWidthType> {
     let (w, h) = terminal::size()?;
-    let image_cell_width = (graph.max_pos_x + 1) * 2;
-    let required_width = image_cell_width + 2;
-    if required_width > w as usize {
-        panic!("Terminal size {w}x{h} is too small. Required width is {required_width}.");
+    let cell_width_type =
+        decide_cell_width_type_from(graph.max_pos_x, w as usize, h as usize, cell_width_type);
+    Ok(cell_width_type)
+}
+
+fn decide_cell_width_type_from(
+    max_pos_x: usize,
+    term_width: usize,
+    term_height: usize,
+    cell_width_type: Option<CellWidthType>,
+) -> CellWidthType {
+    let single_image_cell_width = max_pos_x + 1;
+    let double_image_cell_width = single_image_cell_width * 2;
+
+    match cell_width_type {
+        Some(CellWidthType::Double) => {
+            let required_width = double_image_cell_width + 2;
+            if required_width > term_width {
+                panic!("Terminal size {term_width}x{term_height} is too small. Required width is {required_width} (graph_width = double).");
+            }
+            CellWidthType::Double
+        }
+        Some(CellWidthType::Single) => {
+            let required_width = single_image_cell_width + 2;
+            if required_width > term_width {
+                panic!("Terminal size {term_width}x{term_height} is too small. Required width is {required_width} (graph_width = single).");
+            }
+            CellWidthType::Single
+        }
+        None => {
+            let double_required_width = double_image_cell_width + 2;
+            if double_required_width <= term_width {
+                return CellWidthType::Double;
+            }
+            let single_required_width = single_image_cell_width + 2;
+            if single_required_width <= term_width {
+                return CellWidthType::Single;
+            }
+            panic!(
+                "Terminal size {term_width}x{term_height} is too small. Required width is {single_required_width} (graph_width = single) or {double_required_width} (graph_width = double)."
+            );
+        }
     }
-    Ok(())
 }

src/graph/image.rs

@@ -18,6 +18,7 @@ pub struct GraphImageManager<'a> {
     encoded_image_map: FxHashMap<CommitHash, String>,
 
     graph: &'a Graph<'a>,
+    cell_width_type: CellWidthType,
     image_params: ImageParams,
     drawing_pixels: DrawingPixels,
     image_protocol: ImageProtocol,
@@ -27,17 +28,19 @@ impl<'a> GraphImageManager<'a> {
     pub fn new(
         graph: &'a Graph,
         options: GraphImageOptions,
+        cell_width_type: CellWidthType,
         image_protocol: ImageProtocol,
         preload: bool,
     ) -> Self {
-        let image_params = ImageParams::new(&options.color_set);
+        let image_params = ImageParams::new(&options.color_set, cell_width_type);
         let drawing_pixels = DrawingPixels::new(&image_params);
 
         let mut m = GraphImageManager {
             encoded_image_map: FxHashMap::default(),
             image_params,
             drawing_pixels,
             graph,
+            cell_width_type,
             image_protocol,
         };
         if preload {
@@ -59,7 +62,8 @@ impl<'a> GraphImageManager<'a> {
             .enumerate()
             .map(|(i, commit)| {
                 let edges = &self.graph.edges[i];
-                let image = graph_image.images[edges].encode(self.image_protocol);
+                let image =
+                    graph_image.images[edges].encode(self.cell_width_type, self.image_protocol);
                 (commit.commit_hash.clone(), image)
             })
             .collect()
@@ -75,7 +79,7 @@ impl<'a> GraphImageManager<'a> {
             &self.drawing_pixels,
             commit_hash,
         );
-        let image = graph_row_image.encode(self.image_protocol);
+        let image = graph_row_image.encode(self.cell_width_type, self.image_protocol);
         self.encoded_image_map.insert(commit_hash.clone(), image);
     }
 }
@@ -102,8 +106,11 @@ impl Debug for GraphRowImage {
 }
 
 impl GraphRowImage {
-    fn encode(&self, image_protocol: ImageProtocol) -> String {
-        let image_cell_width = self.cell_count * 2;
+    fn encode(&self, cell_width_type: CellWidthType, image_protocol: ImageProtocol) -> String {
+        let image_cell_width = match cell_width_type {
+            CellWidthType::Double => self.cell_count * 2,
+            CellWidthType::Single => self.cell_count,
+        };
         image_protocol.encode(&self.bytes, image_cell_width)
     }
 }
@@ -120,13 +127,19 @@ pub struct ImageParams {
     background_color: image::Rgba<u8>,
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum CellWidthType {
+    Double, // 2 cells
+    Single,
+}
+
 impl ImageParams {
-    pub fn new(color_set: &ColorSet) -> Self {
-        let width = 50;
-        let height = 50;
-        let line_width = 5;
-        let circle_inner_radius = 10;
-        let circle_outer_radius = 13;
+    pub fn new(color_set: &ColorSet, cell_width_type: CellWidthType) -> Self {
+        let (width, height, line_width, circle_inner_radius, circle_outer_radius) =
+            match cell_width_type {
+                CellWidthType::Double => (50, 50, 5, 10, 13),
+                CellWidthType::Single => (25, 50, 3, 7, 10),
+            };
         let edge_colors = color_set
             .colors
             .iter()
@@ -696,7 +709,8 @@ mod tests {
         let cell_count = 4;
         let graph_color_config = GraphColorConfig::default();
         let color_set = ColorSet::new(&graph_color_config);
-        let image_params = ImageParams::new(&color_set);
+        let cell_width_type = CellWidthType::Double;
+        let image_params = ImageParams::new(&color_set, cell_width_type);
         let drawing_pixels = DrawingPixels::new(&image_params);
         let file_name = "default_params";
 
@@ -709,7 +723,8 @@ mod tests {
         let cell_count = 4;
         let graph_color_config = GraphColorConfig::default();
         let color_set = ColorSet::new(&graph_color_config);
-        let mut image_params = ImageParams::new(&color_set);
+        let cell_width_type = CellWidthType::Double;
+        let mut image_params = ImageParams::new(&color_set, cell_width_type);
         image_params.width = 100;
         let drawing_pixels = DrawingPixels::new(&image_params);
         let file_name = "wide_image";
@@ -723,21 +738,37 @@ mod tests {
         let cell_count = 4;
         let graph_color_config = GraphColorConfig::default();
         let color_set = ColorSet::new(&graph_color_config);
-        let mut image_params = ImageParams::new(&color_set);
+        let cell_width_type = CellWidthType::Double;
+        let mut image_params = ImageParams::new(&color_set, cell_width_type);
         image_params.height = 100;
         let drawing_pixels = DrawingPixels::new(&image_params);
         let file_name = "tall_image";
 
         test_calc_graph_row_image(params, cell_count, image_params, drawing_pixels, file_name);
     }
 
+    #[test]
+    fn test_calc_graph_row_image_single_cell_width() {
+        let params = simple_test_params();
+        let cell_count = 4;
+        let graph_color_config = GraphColorConfig::default();
+        let color_set = ColorSet::new(&graph_color_config);
+        let cell_width_type = CellWidthType::Single;
+        let image_params = ImageParams::new(&color_set, cell_width_type);
+        let drawing_pixels = DrawingPixels::new(&image_params);
+        let file_name = "single_cell_width";
+
+        test_calc_graph_row_image(params, cell_count, image_params, drawing_pixels, file_name);
+    }
+
     #[test]
     fn test_calc_graph_row_image_circle_radius() {
         let params = straight_test_params();
         let cell_count = 2;
         let graph_color_config = GraphColorConfig::default();
         let color_set = ColorSet::new(&graph_color_config);
-        let mut image_params = ImageParams::new(&color_set);
+        let cell_width_type = CellWidthType::Double;
+        let mut image_params = ImageParams::new(&color_set, cell_width_type);
         image_params.circle_inner_radius = 5;
         image_params.circle_outer_radius = 12;
         let drawing_pixels = DrawingPixels::new(&image_params);
@@ -752,7 +783,8 @@ mod tests {
         let cell_count = 2;
         let graph_color_config = GraphColorConfig::default();
         let color_set = ColorSet::new(&graph_color_config);
-        let mut image_params = ImageParams::new(&color_set);
+        let cell_width_type = CellWidthType::Double;
+        let mut image_params = ImageParams::new(&color_set, cell_width_type);
         image_params.line_width = 1;
         let drawing_pixels = DrawingPixels::new(&image_params);
         let file_name = "line_width";
@@ -775,7 +807,8 @@ mod tests {
             background: "#00ff0070".into(),
         };
         let color_set = ColorSet::new(&graph_color_config);
-        let image_params = ImageParams::new(&color_set);
+        let cell_width_type = CellWidthType::Double;
+        let image_params = ImageParams::new(&color_set, cell_width_type);
         let drawing_pixels = DrawingPixels::new(&image_params);
         let file_name = "color";
 

src/lib.rs

@@ -31,6 +31,10 @@ struct Args {
     #[arg(short, long, value_name = "TYPE", default_value = "chrono")]
     order: CommitOrderType,
 
+    /// Commit graph image cell width
+    #[arg(short, long, value_name = "TYPE")]
+    graph_width: Option<GraphWidthType>,
+
     /// Preload all graph images
     #[arg(long, default_value = "false")]
     preload: bool,
@@ -68,6 +72,21 @@ impl From<CommitOrderType> for graph::SortCommit {
     }
 }
 
+#[derive(Debug, Clone, ValueEnum)]
+enum GraphWidthType {
+    Double,
+    Single,
+}
+
+impl From<GraphWidthType> for graph::CellWidthType {
+    fn from(width: GraphWidthType) -> Self {
+        match width {
+            GraphWidthType::Double => graph::CellWidthType::Double,
+            GraphWidthType::Single => graph::CellWidthType::Single,
+        }
+    }
+}
+
 pub fn run() -> std::io::Result<()> {
     color_eyre::install().unwrap();
     let args = Args::parse();
@@ -81,11 +100,17 @@ pub fn run() -> std::io::Result<()> {
 
     let graph = graph::calc_graph(&repository);
 
-    check::term_size(&graph)?;
+    let cell_width_type =
+        check::decide_cell_width_type(&graph, args.graph_width.map(|w| w.into()))?;
 
     let graph_image_options = graph::GraphImageOptions::new(color_set.clone());
-    let graph_image_manager =
-        GraphImageManager::new(&graph, graph_image_options, image_protocol, args.preload);
+    let graph_image_manager = GraphImageManager::new(
+        &graph,
+        graph_image_options,
+        cell_width_type,
+        image_protocol,
+        args.preload,
+    );
 
     let mut terminal = ratatui::init();
 
@@ -98,6 +123,7 @@ pub fn run() -> std::io::Result<()> {
         &key_bind,
         &ui_config,
         &color_set,
+        cell_width_type,
         image_protocol,
         tx,
     );