From abe835c734a68775c3f0885c2439743aa8f84bd0 Mon Sep 17 00:00:00 2001
From: Michael Fogleman <fogleman@gmail.com>
Date: Fri, 19 Feb 2016 21:15:22 -0500
Subject: [PATCH] DrawRoundedRectangle

---
 README.md  |  1 +
 context.go | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/README.md b/README.md
index 34a1a8e..585f35c 100644
--- a/README.md
+++ b/README.md
@@ -42,6 +42,7 @@ or circles? What a pain!
 ```go
 DrawLine(x1, y1, x2, y2 float64)
 DrawRectangle(x, y, w, h float64)
+DrawRoundedRectangle(x, y, w, h, r float64)
 DrawCircle(x, y, r float64)
 DrawArc(x, y, r, angle1, angle2 float64)
 DrawEllipse(x, y, rx, ry float64)
diff --git a/context.go b/context.go
index 090da64..041d200 100644
--- a/context.go
+++ b/context.go
@@ -274,6 +274,20 @@ func (dc *Context) DrawRectangle(x, y, w, h float64) {
 	dc.LineTo(x, y)
 }
 
+func (dc *Context) DrawRoundedRectangle(x, y, w, h, r float64) {
+	x0, x1, x2, x3 := x, x+r, x+w-r, x+w
+	y0, y1, y2, y3 := y, y+r, y+h-r, y+h
+	dc.MoveTo(x1, y0)
+	dc.LineTo(x2, y0)
+	dc.DrawArc(x2, y1, r, Radians(270), Radians(360))
+	dc.LineTo(x3, y2)
+	dc.DrawArc(x2, y2, r, Radians(0), Radians(90))
+	dc.LineTo(x1, y3)
+	dc.DrawArc(x1, y2, r, Radians(90), Radians(180))
+	dc.LineTo(x0, y1)
+	dc.DrawArc(x1, y1, r, Radians(180), Radians(270))
+}
+
 func (dc *Context) DrawEllipticalArc(x, y, rx, ry, angle1, angle2 float64) {
 	const n = 16
 	for i := 0; i < n; i++ {