From a33ad3c99eff7fcdc99967aee72b0ead5027e4c4 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Sat, 24 Mar 2018 22:42:10 +0100
Subject: [PATCH] - fixed: 3D floor that extend into the real sector's floor
 were not clipped properly.

The only check being done on this was done after processing for the renderer which simply is too late.
---
 src/gl/scene/gl_walls.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/gl/scene/gl_walls.cpp b/src/gl/scene/gl_walls.cpp
index 5db32de049..7b9d47c3fe 100644
--- a/src/gl/scene/gl_walls.cpp
+++ b/src/gl/scene/gl_walls.cpp
@@ -1392,6 +1392,12 @@ void GLWall::DoFFloorBlocks(seg_t * seg, sector_t * frontsector, sector_t * back
 			ff_topleft = topleft;
 			ff_topright = topright;
 		}
+		if (ff_bottomleft < bottomleft && ff_bottomright < bottomright)
+		{
+			// the new section extends into the floor.
+			ff_bottomleft = bottomleft;
+			ff_bottomright = bottomright;
+		}
 
 		// do all inverse floors above the current one it there is a gap between the
 		// last 3D floor and this one.