From 43258d7dd7114b9b1c28511fe3fe1c0c1f02513d Mon Sep 17 00:00:00 2001
From: Michael Fogleman <fogleman@gmail.com>
Date: Fri, 19 Feb 2016 21:00:56 -0500
Subject: [PATCH] InvertY

---
 README.md  | 1 +
 context.go | 8 +++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 8dd6cdb..34a1a8e 100644
--- a/README.md
+++ b/README.md
@@ -94,6 +94,7 @@ Rotate(angle float64)
 RotateAbout(angle, x, y float64)
 Shear(x, y float64)
 TransformPoint(x, y float64) (tx, ty float64)
+InvertY()
 Push()
 Pop()
 ```
diff --git a/context.go b/context.go
index bacc9f5..090da64 100644
--- a/context.go
+++ b/context.go
@@ -257,7 +257,8 @@ func (dc *Context) Fill() {
 // Convenient Drawing Functions
 
 func (dc *Context) Clear() {
-	draw.Draw(dc.im, dc.im.Bounds(), image.NewUniform(dc.color), image.ZP, draw.Src)
+	src := image.NewUniform(dc.color)
+	draw.Draw(dc.im, dc.im.Bounds(), src, image.ZP, draw.Src)
 }
 
 func (dc *Context) DrawLine(x1, y1, x2, y2 float64) {
@@ -375,6 +376,11 @@ func (dc *Context) TransformPoint(x, y float64) (tx, ty float64) {
 	return dc.matrix.TransformPoint(x, y)
 }
 
+func (dc *Context) InvertY() {
+	dc.Translate(0, float64(dc.height))
+	dc.Scale(1, -1)
+}
+
 // Stack
 
 func (dc *Context) Push() {