From b04daca98e843b4818171c8af560abf3d5a4a676 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sun, 9 Feb 2020 19:13:21 -0500
Subject: [PATCH] Picks a safer default construction.

---
 Outputs/OpenGL/ScanTarget.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Outputs/OpenGL/ScanTarget.hpp b/Outputs/OpenGL/ScanTarget.hpp
index 46300a0ce..f7eeb816e 100644
--- a/Outputs/OpenGL/ScanTarget.hpp
+++ b/Outputs/OpenGL/ScanTarget.hpp
@@ -108,7 +108,7 @@ class ScanTarget: public Outputs::Display::ScanTarget {
 			// The sizes below might be less hassle as something more natural like ints,
 			// but squeezing this struct into 64 bits makes the std::atomics more likely
 			// to be lock free; they are under LLVM x86-64.
-			int write_area = 0;
+			int write_area = 1;	// By convention this points to the vended area. Which is preceded by a guard pixel. So a sensible default construction is write_area = 1.
 			uint16_t scan_buffer = 0;
 			uint16_t line = 0;
 		};