From 39f761e1715220e35b731e8ec5d5f847b1abef80 Mon Sep 17 00:00:00 2001
From: James Turner <james@flightgear.org>
Date: Mon, 26 Jul 2021 11:20:01 +0100
Subject: [PATCH] Terrain wetness: reimstate clamping term

Re-add this clamping of the terrain wetness value, to avoid out of bounds
values in shaders appearing as black. Thanks to Colin Geniet for the testing and fix.

SF-Id: https://sourceforge.net/p/flightgear/codetickets/2604/
---
 src/Environment/climate.cxx | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/Environment/climate.cxx b/src/Environment/climate.cxx
index ac8586495..e83d8b897 100644
--- a/src/Environment/climate.cxx
+++ b/src/Environment/climate.cxx
@@ -882,6 +882,9 @@ void FGClimate::set_environment()
         {
             // https://weatherins.com/rain-guidelines/
             _wetness = 12.0*std::max(_gl.precipitation-50.0, 0.0)/990.0;
+
+            // clamping term, see https://sourceforge.net/p/flightgear/codetickets/2604/
+            _wetness = pow(sin(atan(SGD_PI*_wetness)), 2.0);
         } else {
             _wetness = 0.0;
         }