> > We are talking of an FMC but of  course
> > I wanted to redo at least the ehsi display (for the eye candy). 

> Erik mentioned some time ago that it isn't yet really possible to
> do simple animations using Nasal in FlightGear, at least that's
> what Andy indicated when he was asked about that, I think.

I remember but I had the impression that they were afraid for the

> > This would have delayed the ehsi too much.

> is there really that much lag involved when doing
> such things using Nasal - i.e. NO smooth animations ?

I was not clear. I was saying that to do the ehsi I would have to wait
the implementation of some new graphic code. 
Concerning smooth animations, I think it can be the same as current

Now let me open a little parenthesis about a reflexion I had some times

We have a caneva to build 2d and 3d instruments and its doing the job
for a wide variety of gauges. But even if can extend those
there will always be some cases that can't be handled.
Lets call them owner draw gauges. How to draw them ? With pure opengl
code in C.
This is the first bottleneck. It seems stupid the have to build
Flightgear to
use a new gauge when someone release a new panel or new plane.
The other thing that disturb me is that this OD gauge should of course
on a 2d and on a 3d panel.
Let me remind you : a 2D gauge is a stack of layers (textures), a 3d
gauge is
a 3D gemoetry object (textured).
If we use only one texture for both the 2d and 3d gauge we have a
texture that can
be used for both instruments.
So this is my suggestion to have compatible 2d/3d specials gauges, ie
they both
refer to the same texture, this texture is generated by some special
(drawing to texture/pbuffer is something standard for 3d cards).
Now how do we draw in this texture ?
In Nasal of course, with the appropriate graphic library. Not a pseudo
library because there is no more than perhaps 10 api to implement :
draw a line, draw text, draw a texture, etc. I am prety sure we can pair
api to the existing draw code.

What about the performance ?
Imagine a simple gauge with a background and a needle. This could be
drawn with 
3 lines of Nasal code: 
        DrawTexture(background, x,y), 
        Drawtexture(nnedle, x,y)

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