From 637509b5d42bc7cdd76bd3254005464e8a231767 Mon Sep 17 00:00:00 2001
From: Thomas Friedel <tomee6@gmail.com>
Date: Fri, 14 Feb 2020 16:28:24 +0100
Subject: [PATCH] minor fixes

---
 backend/goglbackend/clip.go | 9 +++++----
 backend/goglbackend/fill.go | 2 ++
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/backend/goglbackend/clip.go b/backend/goglbackend/clip.go
index 3ccec5c..be4d75a 100644
--- a/backend/goglbackend/clip.go
+++ b/backend/goglbackend/clip.go
@@ -17,11 +17,12 @@ func (b *GoGLBackend) Clip(pts [][2]float64) {
 	b.activate()
 
 	b.ptsBuf = b.ptsBuf[:0]
+	min, max := extent(pts)
 	b.ptsBuf = append(b.ptsBuf,
-		0, 0,
-		0, float32(b.fh),
-		float32(b.fw), float32(b.fh),
-		float32(b.fw), 0)
+		float32(min[0]), float32(min[1]),
+		float32(min[0]), float32(max[1]),
+		float32(max[0]), float32(max[1]),
+		float32(max[0]), float32(min[1]))
 	for _, pt := range pts {
 		b.ptsBuf = append(b.ptsBuf, float32(pt[0]), float32(pt[1]))
 	}
diff --git a/backend/goglbackend/fill.go b/backend/goglbackend/fill.go
index 39d67c2..fefd4c0 100644
--- a/backend/goglbackend/fill.go
+++ b/backend/goglbackend/fill.go
@@ -72,6 +72,8 @@ func (b *GoGLBackend) clearRect(x, y, w, h int) {
 }
 
 func extent(pts [][2]float64) (min, max vec) {
+	max[0] = -math.MaxFloat64
+	max[1] = -math.MaxFloat64
 	min[0] = math.MaxFloat64
 	min[1] = math.MaxFloat64
 	for _, v := range pts {