From 1e2243661212debfbc1c4e63fb82ecb116f5c3a1 Mon Sep 17 00:00:00 2001
From: faiface <faiface@ksp.sk>
Date: Tue, 14 Mar 2017 21:59:31 +0100
Subject: [PATCH] clarify doc

---
 graphics.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/graphics.go b/graphics.go
index b6812a4..baf4178 100644
--- a/graphics.go
+++ b/graphics.go
@@ -188,6 +188,10 @@ func (imd *IMDraw) SetColorMask(color color.Color) {
 
 // FillConvexPolygon takes all points Pushed into the IM's queue and fills the convex polygon formed
 // by them.
+//
+// The polygon does not need to be exactly convex. The way it's drawn is that for each two adjacent
+// points, a triangle is constructed from those two points and the first Pushed point. You can use
+// this property to draw specific concave graphs.
 func (imd *IMDraw) FillConvexPolygon() {
 	points := imd.points
 	imd.points = nil