small updates

Author: raphamorim

rio-backend/src/crosswords/mod.rs

@@ -4416,16 +4416,27 @@ impl<U: EventListener> Crosswords<U> {
         // Absolute row = history_size + screen-relative row
         let dest_row = self.history_size() as i64 + cursor_row as i64;
 
-        // Compute cell-based size
+        // kitty spec the `X=`/`Y=` sub-cell offset must be smaller
+        // than the cell size; kitty clamps out-of-range values to the
+        // cell box
+        let cell_x_offset = (placement.cell_x_offset as usize).min(cell_width - 1);
+        let cell_y_offset = (placement.cell_y_offset as usize).min(cell_height - 1);
+
+        // Compute cell-based size.
+        //
+        // the trick is the sub-cell offset shifts the image
+        // within its first cell, so it can spill into one extra
+        // row/column. Include it so cursor movement and row occupation
+        // cover the full image.
         let columns = if placement.columns > 0 {
             placement.columns
         } else {
-            display_w.div_ceil(cell_width) as u32
+            (display_w + cell_x_offset).div_ceil(cell_width) as u32
         };
         let rows = if placement.rows > 0 {
             placement.rows
         } else {
-            display_h.div_ceil(cell_height) as u32
+            (display_h + cell_y_offset).div_ceil(cell_height) as u32
         };
 
         // Create overlay placement.
@@ -4454,8 +4465,8 @@ impl<U: EventListener> Crosswords<U> {
             rows,
             pixel_width: display_w as u32,
             pixel_height: display_h as u32,
-            cell_x_offset: placement.cell_x_offset,
-            cell_y_offset: placement.cell_y_offset,
+            cell_x_offset: cell_x_offset as u32,
+            cell_y_offset: cell_y_offset as u32,
             z_index: placement.z_index,
             transmit_time,
         };

rio-backend/src/graphics/kitty/mod.rs

@@ -617,6 +617,163 @@ fn test_image_row_occupation_exact_fit() {
     );
 }
 
+#[test]
+fn test_subcell_offset_forwarded_and_clamped() {
+    let event_listener = TestEventListener;
+    let window_id = unsafe { WindowId::dummy() };
+
+    let mut term: Crosswords<TestEventListener> = Crosswords::new(
+        crate::crosswords::CrosswordsSize::new(80, 24),
+        crate::ansi::CursorShape::Block,
+        event_listener,
+        window_id,
+        0,
+        10_000,
+    );
+
+    term.graphics.cell_width = 10.0;
+    term.graphics.cell_height = 20.0;
+
+    let pixels = vec![255u8; 40 * 40 * 4];
+    let graphic = GraphicData {
+        id: GraphicId::new(1),
+        width: 40,
+        height: 40,
+        color_type: ColorType::Rgba,
+        pixels,
+        is_opaque: true,
+        resize: None,
+        display_width: None,
+        display_height: None,
+        transmit_time: std::time::Instant::now(),
+    };
+    term.store_graphic(graphic);
+
+    // In-range `X=`/`Y=` flows through to the stored placement.
+    let placement = kitty_graphics_protocol::PlacementRequest {
+        image_id: 1,
+        placement_id: 7,
+        x: 0,
+        y: 0,
+        width: 0,
+        height: 0,
+        columns: 0,
+        rows: 0,
+        z_index: 0,
+        virtual_placement: false,
+        unicode_placeholder: 0,
+        cursor_movement: 1,
+        cell_x_offset: 7,
+        cell_y_offset: 9,
+    };
+    term.place_graphic(placement);
+
+    let stored = term
+        .graphics
+        .kitty_placements
+        .get(&(1, 7))
+        .expect("placement stored");
+    assert_eq!(stored.cell_x_offset, 7);
+    assert_eq!(stored.cell_y_offset, 9);
+
+    // Per kitty spec the offset must be smaller than the cell size;
+    // out-of-range values are clamped to the cell box.
+    let placement = kitty_graphics_protocol::PlacementRequest {
+        image_id: 1,
+        placement_id: 8,
+        x: 0,
+        y: 0,
+        width: 0,
+        height: 0,
+        columns: 0,
+        rows: 0,
+        z_index: 0,
+        virtual_placement: false,
+        unicode_placeholder: 0,
+        cursor_movement: 1,
+        cell_x_offset: 999,
+        cell_y_offset: 999,
+    };
+    term.place_graphic(placement);
+
+    let stored = term
+        .graphics
+        .kitty_placements
+        .get(&(1, 8))
+        .expect("placement stored");
+    assert_eq!(stored.cell_x_offset, 9, "clamped to cell_width - 1");
+    assert_eq!(stored.cell_y_offset, 19, "clamped to cell_height - 1");
+}
+
+#[test]
+fn test_subcell_offset_extends_row_occupation() {
+    let event_listener = TestEventListener;
+    let window_id = unsafe { WindowId::dummy() };
+
+    let mut term: Crosswords<TestEventListener> = Crosswords::new(
+        crate::crosswords::CrosswordsSize::new(80, 24),
+        crate::ansi::CursorShape::Block,
+        event_listener,
+        window_id,
+        0,
+        10_000,
+    );
+
+    term.graphics.cell_width = 10.0;
+    term.graphics.cell_height = 20.0;
+
+    // 40px tall image on 20px cells: exactly 2 rows without an offset.
+    let pixels = vec![255u8; 40 * 40 * 4];
+    let graphic = GraphicData {
+        id: GraphicId::new(1),
+        width: 40,
+        height: 40,
+        color_type: ColorType::Rgba,
+        pixels,
+        is_opaque: true,
+        resize: None,
+        display_width: None,
+        display_height: None,
+        transmit_time: std::time::Instant::now(),
+    };
+    term.store_graphic(graphic);
+
+    // `Y=15` shifts the image down within its first cell, so it spills
+    // into a third row: ceil((40 + 15) / 20) = 3. Cursor movement and
+    // occupation must cover that extra row.
+    let placement = kitty_graphics_protocol::PlacementRequest {
+        image_id: 1,
+        placement_id: 7,
+        x: 0,
+        y: 0,
+        width: 0,
+        height: 0,
+        columns: 0,
+        rows: 0,
+        z_index: 0,
+        virtual_placement: false,
+        unicode_placeholder: 0,
+        cursor_movement: 0,
+        cell_x_offset: 0,
+        cell_y_offset: 15,
+    };
+    term.place_graphic(placement);
+
+    let stored = term
+        .graphics
+        .kitty_placements
+        .get(&(1, 7))
+        .expect("placement stored");
+    assert_eq!(stored.rows, 3, "Y offset spills the image into a 3rd row");
+    assert_eq!(stored.columns, 4, "no X offset: 40px / 10px = 4 columns");
+
+    // C=0: cursor lands on the last row of the image (row index rows - 1).
+    assert_eq!(
+        term.grid.cursor.pos.row.0, 2,
+        "cursor advances to the extra row created by the Y offset"
+    );
+}
+
 #[test]
 fn test_image_row_occupation_single_row() {
     let event_listener = TestEventListener;