1 files changed, 92 insertions, 0 deletions
diff --git a/alacritty/src/display/cursor.rs b/alacritty/src/display/cursor.rs
new file mode 100644
index 00000000..0750459d
--- /dev/null
+++ b/alacritty/src/display/cursor.rs
@@ -0,0 +1,92 @@
+//! Convert a cursor into an iterator of rects.
+
+use alacritty_terminal::ansi::CursorShape;
+use alacritty_terminal::term::color::Rgb;
+use alacritty_terminal::term::SizeInfo;
+
+use crate::display::content::RenderableCursor;
+use crate::renderer::rects::RenderRect;
+
+/// Trait for conversion into the iterator.
+pub trait IntoRects {
+    /// Consume the cursor for an iterator of rects.
+    fn rects(self, size_info: &SizeInfo, thickness: f32) -> CursorRects;
+}
+
+impl IntoRects for RenderableCursor {
+    fn rects(self, size_info: &SizeInfo, thickness: f32) -> CursorRects {
+        let point = self.point();
+        let x = point.column.0 as f32 * size_info.cell_width() + size_info.padding_x();
+        let y = point.line.0 as f32 * size_info.cell_height() + size_info.padding_y();
+
+        let mut width = size_info.cell_width();
+        let height = size_info.cell_height();
+
+        if self.is_wide() {
+            width *= 2.;
+        }
+
+        let thickness = (thickness * width as f32).round().max(1.);
+
+        match self.shape() {
+            CursorShape::Beam => beam(x, y, height, thickness, self.color()),
+            CursorShape::Underline => underline(x, y, width, height, thickness, self.color()),
+            CursorShape::HollowBlock => hollow(x, y, width, height, thickness, self.color()),
+            _ => CursorRects::default(),
+        }
+    }
+}
+
+/// Cursor rect iterator.
+#[derive(Default)]
+pub struct CursorRects {
+    rects: [Option<RenderRect>; 4],
+    index: usize,
+}
+
+impl From<RenderRect> for CursorRects {
+    fn from(rect: RenderRect) -> Self {
+        Self { rects: [Some(rect), None, None, None], index: 0 }
+    }
+}
+
+impl Iterator for CursorRects {
+    type Item = RenderRect;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let rect = self.rects.get_mut(self.index)?;
+        self.index += 1;
+        rect.take()
+    }
+}
+
+/// Create an iterator yielding a single beam rect.
+fn beam(x: f32, y: f32, height: f32, thickness: f32, color: Rgb) -> CursorRects {
+    RenderRect::new(x, y, thickness, height, color, 1.).into()
+}
+
+/// Create an iterator yielding a single underline rect.
+fn underline(x: f32, y: f32, width: f32, height: f32, thickness: f32, color: Rgb) -> CursorRects {
+    let y = y + height - thickness;
+    RenderRect::new(x, y, width, thickness, color, 1.).into()
+}
+
+/// Create an iterator yielding a rect for each side of the hollow block cursor.
+fn hollow(x: f32, y: f32, width: f32, height: f32, thickness: f32, color: Rgb) -> CursorRects {
+    let top_line = RenderRect::new(x, y, width, thickness, color, 1.);
+
+    let vertical_y = y + thickness;
+    let vertical_height = height - 2. * thickness;
+    let left_line = RenderRect::new(x, vertical_y, thickness, vertical_height, color, 1.);
+
+    let bottom_y = y + height - thickness;
+    let bottom_line = RenderRect::new(x, bottom_y, width, thickness, color, 1.);
+
+    let right_x = x + width - thickness;
+    let right_line = RenderRect::new(right_x, vertical_y, thickness, vertical_height, color, 1.);
+
+    CursorRects {
+        rects: [Some(top_line), Some(bottom_line), Some(left_line), Some(right_line)],
+        index: 0,
+    }
+}