editor: Represent scroll offset with more precision (#39367)

Closes #5355

Release Notes:

- Fixed rendering glitches with files with more than 16 million lines
(that occured due to floating number rounding errors).

---------

Co-authored-by: Smit Barmase <heysmitbarmase@gmail.com>

crates/vim/src/motion.rs

@@ -1573,12 +1573,12 @@ fn up_down_buffer_rows(
 
     let (goal_wrap, goal_x) = match goal {
         SelectionGoal::WrappedHorizontalPosition((row, x)) => (row, x),
-        SelectionGoal::HorizontalRange { end, .. } => (select_nth_wrapped_row, end),
-        SelectionGoal::HorizontalPosition(x) => (select_nth_wrapped_row, x),
+        SelectionGoal::HorizontalRange { end, .. } => (select_nth_wrapped_row, end as f32),
+        SelectionGoal::HorizontalPosition(x) => (select_nth_wrapped_row, x as f32),
         _ => {
             let x = map.x_for_display_point(point, text_layout_details);
-            goal = SelectionGoal::WrappedHorizontalPosition((select_nth_wrapped_row, x.0));
-            (select_nth_wrapped_row, x.0)
+            goal = SelectionGoal::WrappedHorizontalPosition((select_nth_wrapped_row, x.into()));
+            (select_nth_wrapped_row, x.into())
         }
     };
 

crates/vim/src/normal/scroll.rs

@@ -121,9 +121,9 @@ fn scroll_editor(
     let amount = match (amount.is_full_page(), editor.visible_line_count()) {
         (true, Some(visible_line_count)) => {
             if amount.direction().is_upwards() {
-                ScrollAmount::Line(amount.lines(visible_line_count) + 1.0)
+                ScrollAmount::Line((amount.lines(visible_line_count) + 1.0) as f32)
             } else {
-                ScrollAmount::Line(amount.lines(visible_line_count) - 1.0)
+                ScrollAmount::Line((amount.lines(visible_line_count) - 1.0) as f32)
             }
         }
         _ => amount,
@@ -308,7 +308,7 @@ mod test {
         let window = cx.window;
         let margin = cx
             .update_window(window, |_, window, _cx| {
-                window.viewport_size().height - line_height * visible_line_count
+                window.viewport_size().height - line_height * visible_line_count as f32
             })
             .unwrap();
         cx.simulate_window_resize(

crates/vim/src/test/neovim_backed_test_context.rs

@@ -277,7 +277,7 @@ impl NeovimBackedTestContext {
         let window = self.window;
         let margin = self
             .update_window(window, |_, window, _cx| {
-                window.viewport_size().height - line_height * visible_line_count
+                window.viewport_size().height - line_height * (visible_line_count as f32)
             })
             .unwrap();
 

crates/vim/src/visual.rs

@@ -314,7 +314,7 @@ impl Vim {
             let (start, end) = match s.newest_anchor().goal {
                 SelectionGoal::HorizontalRange { start, end } if preserve_goal => (start, end),
                 SelectionGoal::HorizontalPosition(start) if preserve_goal => (start, start),
-                _ => (tail_x.0, head_x.0),
+                _ => (tail_x.into(), head_x.into()),
             };
             let mut goal = SelectionGoal::HorizontalRange { start, end };
 
@@ -359,8 +359,8 @@ impl Vim {
 
             if !preserve_goal {
                 goal = SelectionGoal::HorizontalRange {
-                    start: positions.start.0,
-                    end: positions.end.0,
+                    start: f64::from(positions.start),
+                    end: f64::from(positions.end),
                 };
             }