From ca2a52dd535f56860e3decff46780bc973f1dd00 Mon Sep 17 00:00:00 2001
From: Mike Walters <mike@flomp.net>
Date: Sun, 24 Dec 2017 15:32:31 +0000
Subject: [PATCH] Don't try to draw an empty traceplot

fixes #102
---
 traceplot.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/traceplot.cpp b/traceplot.cpp
index 66abb03..3704d24 100644
--- a/traceplot.cpp
+++ b/traceplot.cpp
@@ -29,6 +29,8 @@ TracePlot::TracePlot(std::shared_ptr<AbstractSampleSource> source) : Plot(source
 
 void TracePlot::paintMid(QPainter &painter, QRect &rect, range_t<size_t> sampleRange)
 {
+    if (sampleRange.length() == 0) return;
+
     int samplesPerColumn = sampleRange.length() / rect.width();
     int samplesPerTile = tileWidth * samplesPerColumn;
     size_t tileID = sampleRange.minimum / samplesPerTile;