From f0314c31b1864b081eba2eab31f7e0bc896ff0bd Mon Sep 17 00:00:00 2001
From: Dustin Carlino <dabreegster@gmail.com>
Date: Sun, 24 Nov 2019 07:21:30 -0800
Subject: [PATCH] making an... almost rounded rectangle ;)

---
 ezgui/src/widgets/button.rs |  5 ++---
 geom/src/polygon.rs         | 30 ++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/ezgui/src/widgets/button.rs b/ezgui/src/widgets/button.rs
index 87d0c6b3dd..d1781e65f7 100644
--- a/ezgui/src/widgets/button.rs
+++ b/ezgui/src/widgets/button.rs
@@ -206,11 +206,10 @@ impl TextButton {
         ctx: &EventCtx,
     ) -> TextButton {
         let (w, h) = ctx.canvas.text_dims(&text);
-        // TODO Rounded corners
-        let geom = Polygon::rectangle_topleft(
-            Pt2D::new(0.0, 0.0),
+        let geom = Polygon::rounded_rectangle(
             Distance::meters(w + 2.0 * HORIZ_PADDING),
             Distance::meters(h + 2.0 * VERT_PADDING),
+            Distance::meters(VERT_PADDING),
         );
 
         TextButton {
diff --git a/geom/src/polygon.rs b/geom/src/polygon.rs
index 91c706f4f1..1b0deaf555 100644
--- a/geom/src/polygon.rs
+++ b/geom/src/polygon.rs
@@ -214,6 +214,36 @@ impl Polygon {
     pub fn shrink(&self, distance: f64) -> Vec<Polygon> {
         from_multi(to_geo(self.points()).offset(distance).unwrap())
     }
+
+    // Top-left at the origin; use translate
+    pub fn rounded_rectangle(width: Distance, height: Distance, radius: Distance) -> Polygon {
+        assert!(2.0 * radius <= width);
+        assert!(2.0 * radius <= height);
+
+        let w = width.inner_meters();
+        let h = height.inner_meters();
+        let r = radius.inner_meters();
+
+        // TODO Round arcs on the corners ;)
+
+        let mut pts = vec![];
+        // Top-left corner
+        pts.push(Pt2D::new(0.0, r));
+        pts.push(Pt2D::new(r, 0.0));
+        // Top-right
+        pts.push(Pt2D::new(w - r, 0.0));
+        pts.push(Pt2D::new(w, r));
+        // Bottom-right
+        pts.push(Pt2D::new(w, h - r));
+        pts.push(Pt2D::new(w - r, h));
+        // Bottom-left
+        pts.push(Pt2D::new(r, h));
+        pts.push(Pt2D::new(0.0, h - r));
+        // Close it off
+        pts.push(Pt2D::new(0.0, r));
+
+        Polygon::new(&pts)
+    }
 }
 
 impl fmt::Display for Polygon {