From e5e895838b1ab2d07606f53c1ed0a497be2c3426 Mon Sep 17 00:00:00 2001
From: Murray Stevenson <50844517+murraystevenson@users.noreply.github.com>
Date: Sat, 16 Mar 2024 16:13:51 -0700
Subject: [PATCH] ViewportGadget : Avoid rendering selection ids with
 `GL_BLEND` enabled

Otherwise this leads to corrupted ids when rendering overlays such as the CropWindowTool on Intel graphics hardware.
---
 src/GafferUI/ViewportGadget.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/GafferUI/ViewportGadget.cpp b/src/GafferUI/ViewportGadget.cpp
index 43471d67acb..a05e3314680 100644
--- a/src/GafferUI/ViewportGadget.cpp
+++ b/src/GafferUI/ViewportGadget.cpp
@@ -1288,7 +1288,9 @@ void ViewportGadget::renderInternal( RenderReason reason, Gadget::Layer filterLa
 		if( reason != RenderReason::Draw )
 		{
 			// We're doing selection so post-processing doesn't matter. Just
-			// render direct to output buffer.
+			// render direct to output buffer without blending as that can
+			// corrupt the selection buffer on some graphics hardware.
+			glDisable( GL_BLEND );
 			renderLayerInternal( reason, layer, viewTransform, bound, selector );
 			continue;
 		}