Vendor ratatui temporarily (#835)

* Vendor ratatui temporarily

Once https://github.com/tui-rs-revival/ratatui/pull/114 has been merged,
we can undo this! But otherwise we can't publish to crates.io with a git
dependency.

* make tests pass

* Shush.

* these literally just fail in nix, nowhere else

idk how to work with nix properly, and they're also not our tests

1 files changed, 95 insertions, 0 deletions

diff --git a/src/ratatui/widgets/canvas/line.rs b/src/ratatui/widgets/canvas/line.rs
new file mode 100644
index 00000000..84d121ce
--- /dev/null
+++ b/src/ratatui/widgets/canvas/line.rs
@@ -0,0 +1,95 @@
+use crate::ratatui::{
+    style::Color,
+    widgets::canvas::{Painter, Shape},
+};
+
+/// Shape to draw a line from (x1, y1) to (x2, y2) with the given color
+#[derive(Debug, Clone)]
+pub struct Line {
+    pub x1: f64,
+    pub y1: f64,
+    pub x2: f64,
+    pub y2: f64,
+    pub color: Color,
+}
+
+impl Shape for Line {
+    fn draw(&self, painter: &mut Painter) {
+        let (x1, y1) = match painter.get_point(self.x1, self.y1) {
+            Some(c) => c,
+            None => return,
+        };
+        let (x2, y2) = match painter.get_point(self.x2, self.y2) {
+            Some(c) => c,
+            None => return,
+        };
+        let (dx, x_range) = if x2 >= x1 {
+            (x2 - x1, x1..=x2)
+        } else {
+            (x1 - x2, x2..=x1)
+        };
+        let (dy, y_range) = if y2 >= y1 {
+            (y2 - y1, y1..=y2)
+        } else {
+            (y1 - y2, y2..=y1)
+        };
+
+        if dx == 0 {
+            for y in y_range {
+                painter.paint(x1, y, self.color);
+            }
+        } else if dy == 0 {
+            for x in x_range {
+                painter.paint(x, y1, self.color);
+            }
+        } else if dy < dx {
+            if x1 > x2 {
+                draw_line_low(painter, x2, y2, x1, y1, self.color);
+            } else {
+                draw_line_low(painter, x1, y1, x2, y2, self.color);
+            }
+        } else if y1 > y2 {
+            draw_line_high(painter, x2, y2, x1, y1, self.color);
+        } else {
+            draw_line_high(painter, x1, y1, x2, y2, self.color);
+        }
+    }
+}
+
+fn draw_line_low(painter: &mut Painter, x1: usize, y1: usize, x2: usize, y2: usize, color: Color) {
+    let dx = (x2 - x1) as isize;
+    let dy = (y2 as isize - y1 as isize).abs();
+    let mut d = 2 * dy - dx;
+    let mut y = y1;
+    for x in x1..=x2 {
+        painter.paint(x, y, color);
+        if d > 0 {
+            y = if y1 > y2 {
+                y.saturating_sub(1)
+            } else {
+                y.saturating_add(1)
+            };
+            d -= 2 * dx;
+        }
+        d += 2 * dy;
+    }
+}
+
+fn draw_line_high(painter: &mut Painter, x1: usize, y1: usize, x2: usize, y2: usize, color: Color) {
+    let dx = (x2 as isize - x1 as isize).abs();
+    let dy = (y2 - y1) as isize;
+    let mut d = 2 * dx - dy;
+    let mut x = x1;
+    for y in y1..=y2 {
+        painter.paint(x, y, color);
+        if d > 0 {
+            x = if x1 > x2 {
+                x.saturating_sub(1)
+            } else {
+                x.saturating_add(1)
+            };
+            d -= 2 * dy;
+        }
+        d += 2 * dx;
+    }
+}