FLT - pitch ladder

The pitch ladder (sometimes called the artificial horizon) represents the aircraft's angle of bank (left/right) and the angle of pitch (forward/back) relative to the ground.

The finishing touch was to add numerics on the ladder. Now it's looking nearly complete.

And again with the video underlay. I tried it with masked numbers (darkened background) but found that it doesn't look as nice. Digits are aligned correctly with the doglegs on the ladder.

The pop-up repeater is shown bottom right.

FLT - bank angle

I missed this from the initial spec, the bank angle is above the pitch latter which will be installed next.

The angle of bank indicator is a fixed 60 degree arc. Major ticks every 10 degrees. The aircraft bank is indicated by a small upward arrow under the indicator that points in the direction of the sky. At more than 20 degrees of bank, the scale will turn white.

Bank angle

Drawing such an indicator is trivial: In GLpsuedo code...

   glRotatef(-30,0,0,1);
   { drawTickLine + glRotate(5,0,0,1) } x 13

Airspeed in knots has also been added to act as a reference for the the horizon / waterline.

Moving onto the pitch ladder

The pitch ladder has different properties to the one used in the heads-up display. It's staggered for one, probably uses a circular mask, I might just use a rectangular mask for sake of efficiency, seems a but much to have to add a stencil mask to the buffer just for this. I'm not sure how you do that with a Leadwerks instantiated buffer anyway.

The pitch ladder displays 60 degrees, +-30 degrees in 10 degree increments with small ticks at 5 degrees. In all it consists if four elements

• There's one horizon line
• Small ticks (6)
• 6 Numbered ladder segments
• Waterline ("It's a big W I tell ya")

The pitch ladder needs an offset applied (bias) set by pressing the "-W-" button. Apparently this is down to pilot preference, some will stick with one method for the duration of their career.

Numbered ladder segments have doglegs pointing to the horizon. Those below the horizon have a dotted or broken appearance.

OK time for tea, we'll get back to this later today and update this entry when we're done.

*update*

Pitch ladder is now in place along with the horizon line and waterline. There's some text to add at the ends of the ladders to indicate degrees. Also I resorted to using a glScissor test to clip the ladder to a rectangular region. I'll replace it with a circular mask if I come up with a fast way of doing it.

Pitch ladder minus text

What's left to do? The VSI vertical scale indicator against the right side. Altitude and combined torque. Then we can go about adding some page logic to add functions to the non-default buttons. We'll finish this off tomorrow.