From 3c5cf067c9562baf26965c8b4ae2367711e8bab5 Mon Sep 17 00:00:00 2001
From: Torsten Dreyer <Torsten@t3r.de>
Date: Sat, 20 Nov 2010 11:11:59 +0100
Subject: [PATCH] Weather: better cloud altitude interpolation

- Easier altitude interpolation rule
- Don't interpolate to large altitude offsets
---
 Environment/clouds-altitude-interpolate.xml | 41 ++++++++++++++-----
 Environment/clouds-altitude-set.xml         | 44 ---------------------
 Environment/metarinterpolator.xml           | 27 -------------
 3 files changed, 31 insertions(+), 81 deletions(-)
 delete mode 100644 Environment/clouds-altitude-set.xml

diff --git a/Environment/clouds-altitude-interpolate.xml b/Environment/clouds-altitude-interpolate.xml
index e499ac79a..207cbc35f 100644
--- a/Environment/clouds-altitude-interpolate.xml
+++ b/Environment/clouds-altitude-interpolate.xml
@@ -21,20 +21,41 @@
     <to>/environment/clouds/layer[0]/elevation-ft</to>
   </params>
   <name>MetarController:clouds:altitude_interpolate</name>
-  <type>noise-spike</type>
-  <max-rate-of-change>8.333</max-rate-of-change>
+  <type>exponential</type>
+  <filter-time>
+    <condition>
+      <!-- dont't interpolate to -9999 or if more than 2000ft offset -->
+      <or>
+        <less-than>
+          <property alias="../../../../../params/from"/>
+          <value>-9000</value>
+        </less-than>
+        <less-than>
+          <property alias="../../../../../params/to"/>
+          <value>-9000</value>
+        </less-than>
+        <greater-than>
+          <expression>
+            <abs>
+              <difference>
+                <property alias="../../../../../../../../params/from"/>
+                <property alias="../../../../../../../../params/to"/>
+              </difference>
+            </abs>
+          </expression>
+          <value>2000</value>
+        </greater-than>
+      </or>
+    </condition>
+    <value>0</value>
+  </filter-time>
+  
+  <filter-time>60</filter-time>
+  
   <enable>
     <condition>
       <property>/environment/metar/valid</property>
       <property>/environment/params/metar-updates-environment</property>
-      <greater-than>
-        <property alias="../../../../params/from"/>
-        <value>-9000</value>
-      </greater-than>
-      <greater-than>
-        <property alias="../../../../params/to"/>
-        <value>-9000</value>
-      </greater-than>
     </condition>
   </enable>
   <input alias="../params/from"/>
diff --git a/Environment/clouds-altitude-set.xml b/Environment/clouds-altitude-set.xml
deleted file mode 100644
index 933020733..000000000
--- a/Environment/clouds-altitude-set.xml
+++ /dev/null
@@ -1,44 +0,0 @@
-<?xml version="1.0" ?>
-<!--
- This file is part of FlightGear, the free flight simulator
- http://www.flightgear.org/
-
- Copyright (C) 2009 Torsten Dreyer, Torsten (at) t3r _dot_ de
-
- This program is free software; you can redistribute it and/or
- modify it under the terms of the GNU General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
-
- This program is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- General Public License for more details.
--->
-<PropertyList>
-  <params>
-    <from>environment/metar/clouds/layer[0]/elevation-ft</from>
-    <to>/environment/clouds/layer[0]/elevation-ft</to>
-  </params>
-  <name>MetarController:clouds:altitude_set</name>
-  <type>gain</type>
-  <gain>1.0</gain>
-  <enable>
-    <condition>
-      <property>/environment/metar/valid</property>
-      <property>/environment/params/metar-updates-environment</property>
-      <or>
-        <less-than>
-          <property alias="../../../../../params/from"/>
-          <value>-9000</value>
-        </less-than>
-        <less-than>
-          <property alias="../../../../../params/to"/>
-          <value>-9000</value>
-        </less-than>
-      </or>
-    </condition>
-  </enable>
-  <input alias="../params/from"/>
-  <output alias="../params/to"/>
-</PropertyList>
diff --git a/Environment/metarinterpolator.xml b/Environment/metarinterpolator.xml
index c67cb2ab5..348f7bb92 100644
--- a/Environment/metarinterpolator.xml
+++ b/Environment/metarinterpolator.xml
@@ -282,33 +282,6 @@
   </filter>
 
   <!-- Clouds -->
-  <!-- don't interpolate to/from altitude -9999 -->
-  <filter include="clouds-altitude-set.xml"/>
-  <filter include="clouds-altitude-set.xml">
-    <params>
-      <from>/environment/metar/clouds/layer[1]/elevation-ft</from>
-      <to>/environment/clouds/layer[1]/elevation-ft</to>
-    </params>
-  </filter>
-  <filter include="clouds-altitude-set.xml">
-    <params>
-      <from>/environment/metar/clouds/layer[2]/elevation-ft</from>
-      <to>/environment/clouds/layer[2]/elevation-ft</to>
-    </params>
-  </filter>
-  <filter include="clouds-altitude-set.xml">
-    <params>
-      <from>/environment/metar/clouds/layer[3]/elevation-ft</from>
-      <to>/environment/clouds/layer[3]/elevation-ft</to>
-    </params>
-  </filter>
-  <filter include="clouds-altitude-set.xml">
-    <params>
-      <from>/environment/metar/clouds/layer[4]/elevation-ft</from>
-      <to>/environment/clouds/layer[4]/elevation-ft</to>
-    </params>
-  </filter>
-
   <filter include="clouds-altitude-interpolate.xml"/>
   <filter include="clouds-altitude-interpolate.xml">
     <params>