<?xml version="1.0"?>
<!-- Angle of Attack indexer, as used on US Navy carrier aircraft.  The
     operation of these things is simple.  When the AoA is too low, the
     bottom arrow glows red.  This indicates to the pilot that they
     should pull back on the stick to raise the nose and slow down.
     When the AoA is too high, the pilot gets a green, downward
     pointing top arrow telling him to push the stick forward, lower
     the nose, and speed up.

     This instrument needs its angle thresholds supplied externally
     (probably from the aircraft -set file), in these four properties:
       /sim/aoa-indexer/too-slow-deg  (usually target +1.5 deg)
       /sim/aoa-indexer/slow-deg      (target +0.5 deg)
       /sim/aoa-indexer/fast-deg      (target -0.5 deg)
       /sim/aoa-indexer/too-fast-deg  (target -1.5 deg)

     Note that there is no instrument background texture.  This just
     applies alpha-blended "lights" to something else in the 3D
     cockpit.
-->

<PropertyList>

 <name>Angle of Attack Indexer</name>
 <w-base>2.0</w-base>
 <h-base>5.0</h-base>

 <layers>

  <layer>
   <name>too slow</name>
   <w>2</w>
   <h>5</h>
   <texture>
    <path>Aircraft/Instruments/Textures/aoa-indexer.rgb</path>
    <x1>0.0</x1>
    <y1>0.0</y1>
    <x2>0.2</x2>
    <y2>1.0</y2>
   </texture>
   <condition>
    <greater-than>
     <property>/velocities/alpha-deg</property>
     <property>/sim/aoa-indexer/too-slow-deg</property>
    </greater-than>
   </condition>
  </layer>

  <layer>
   <name>slow</name>
   <w>2</w>
   <h>5</h>
   <texture>
    <path>Aircraft/Instruments/Textures/aoa-indexer.rgb</path>
    <x1>0.2</x1>
    <y1>0.0</y1>
    <x2>0.4</x2>
    <y2>1.0</y2>
   </texture>
   <condition>
    <less-than>
     <property>/velocities/alpha-deg</property>
     <property>/sim/aoa-indexer/too-slow-deg</property>
    </less-than>
    <greater-than>
     <property>/velocities/alpha-deg</property>
     <property>/sim/aoa-indexer/slow-deg</property>
    </greater-than>
   </condition>
  </layer>

  <layer>
   <name>on-speed</name>
   <w>2</w>
   <h>5</h>
   <texture>
    <path>Aircraft/Instruments/Textures/aoa-indexer.rgb</path>
    <x1>0.4</x1>
    <y1>0.0</y1>
    <x2>0.6</x2>
    <y2>1.0</y2>
   </texture>
   <condition>
    <less-than>
     <property>/velocities/alpha-deg</property>
     <property>/sim/aoa-indexer/slow-deg</property>
    </less-than>
    <greater-than>
     <property>/velocities/alpha-deg</property>
     <property>/sim/aoa-indexer/fast-deg</property>
    </greater-than>
   </condition>
  </layer>

  <layer>
   <name>fast</name>
   <w>2</w>
   <h>5</h>
   <texture>
    <path>Aircraft/Instruments/Textures/aoa-indexer.rgb</path>
    <x1>0.6</x1>
    <y1>0.0</y1>
    <x2>0.8</x2>
    <y2>1.0</y2>
   </texture>
   <condition>
    <less-than>
     <property>/velocities/alpha-deg</property>
     <property>/sim/aoa-indexer/fast-deg</property>
    </less-than>
    <greater-than>
     <property>/velocities/alpha-deg</property>
     <property>/sim/aoa-indexer/too-fast-deg</property>
    </greater-than>
   </condition>
  </layer>

  <layer>
   <name>too fast</name>
   <w>2</w>
   <h>5</h>
   <texture>
    <path>Aircraft/Instruments/Textures/aoa-indexer.rgb</path>
    <x1>0.8</x1>
    <y1>0.0</y1>
    <x2>1.0</x2>
    <y2>1.0</y2>
   </texture>
   <condition>
    <less-than>
     <property>/velocities/alpha-deg</property>
     <property>/sim/aoa-indexer/too-fast-deg</property>
    </less-than>
   </condition>
  </layer>

 </layers>
</PropertyList>


