From 5049ebd0bc24387c6939c2f03f324b83119e784f Mon Sep 17 00:00:00 2001
From: Erik Hofman <erik@ehofman.com>
Date: Tue, 11 Apr 2017 13:39:25 +0200
Subject: [PATCH] Prepare for windsock turbulence animation

---
 Nasal/windsock.nas | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 Nasal/windsock.nas

diff --git a/Nasal/windsock.nas b/Nasal/windsock.nas
new file mode 100644
index 000000000..2f4448563
--- /dev/null
+++ b/Nasal/windsock.nas
@@ -0,0 +1,28 @@
+###############################################################################
+##
+## Windsock turbulence animation
+##
+###############################################################################
+
+var dt = 0.0;
+var windsock = func {
+  var wind = getprop("/environment/wind-speed-kt") or 0;
+  var mag1 = getprop("/environment/turbulence/magnitude-norm") or 0;
+  var mag2 = getprop("/environment/turbulence/raw-magnitude-norm") or 0;
+  var sens = getprop("/environment/turbulence/sensitivity") or 0;
+  var rate = 3.1514*getprop("/environment/turbulence/rate-hz") or 0;
+  var tot1 = math.sin(dt*rate)*mag1*mag1;
+  var tot2 = math.sin(3.33*dt*rate/sens)*sens*mag2*mag2;
+  tot2 = mag2*tot2 + (1-mag2)*math.tan(dt/10)/5;
+  var total = wind + tot2 + tot1*tot2;
+
+  interpolate("/environment/windsock/wind-speed-kt", total, 0.3);
+
+  total += 5*mag2;
+  interpolate("/environment/windsock/wind-speed-12.5kt", total, 0.1);
+
+  dt += 0.08 + 0.02*(math.sin(dt)+math.cos(dt/(mag2+0.01))*0.33);
+  settimer(windsock, 0.25);
+}
+
+windsock();