From 06c0c64c1ae649625aaa6bffe62612756ee3fc39 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sat, 17 Nov 2018 17:31:32 -0500
Subject: [PATCH] Shifts intermediate buffer sampling into the middle of each
 pixel row.

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

diff --git a/Outputs/OpenGL/ScanTargetGLSLFragments.cpp b/Outputs/OpenGL/ScanTargetGLSLFragments.cpp
index 80ad6fb95..7cadc4107 100644
--- a/Outputs/OpenGL/ScanTargetGLSLFragments.cpp
+++ b/Outputs/OpenGL/ScanTargetGLSLFragments.cpp
@@ -74,7 +74,7 @@ std::string ScanTarget::glsl_default_vertex_shader(ShaderType type) {
 				"float lateral = float(gl_VertexID & 1);"
 				"float longitudinal = float((gl_VertexID & 2) >> 1);"
 
-				"textureCoordinate = vec2(lateral * processingWidth, lineY) / vec2(1.0, textureSize(textureName, 0).y);"
+				"textureCoordinate = vec2(lateral * processingWidth, lineY + 0.5) / vec2(1.0, textureSize(textureName, 0).y);"
 
 				"vec2 centrePoint = mix(startPoint, endPoint, lateral) / scale;"
 				"vec2 height = normalize(endPoint - startPoint).yx * (longitudinal - 0.5) * rowHeight;"