Matrix multiplication (+ small Camera problem)

[Lemage74]

Hi,
Here a big and a small problem.
The big one is about matrix multiplication.
To make an application targeting AS3, I took the example 2_texture as a base. As I wanted the projection matrix to affect the direction of the light (It was a mistake, but it doesn't matter here), so I replaced:
function vertex( mpos : M44, mproj : M44, light : Float3 ) {
out = input.pos.xyzw * mpos * mproj;
var tnorm = (input.norm * mpos).normalize();
lpow = light.dot(tnorm).max(0);
tuv = input.uv;
}
by
function vertex( mpos : M44, mproj : M44, light : Float3 ) {
out = input.pos.xyzw * mpos * mproj;
var tnorm = (input.norm * mpos * mproj).normalize();
lpow = light.dot(tnorm).max(0);
tuv = input.uv;
}
then I wanted to optimize by putting mpos_mproj in an variable, so I changed it for:
function vertex( mpos : M44, mproj : M44, light : Float3 ) {
var mposproj:M44 = mpos_mproj;
out = input.pos.xyzw * mposproj;
var tnorm = (input.norm * mposproj).normalize();
lpow = light.dot(tnorm).max(0);
tuv = input.uv;
}
and got an error on mpos_mproj:
M44 should be M44
I changed mposproj declaration for:
var mposproj = mpos_mproj;
and then got an error on input.pos.xyzw * mposproj:
M44 should be Float4

The small problem come with the Camera class that is given with the examples.
As the X,Y,Z vectors in Stage3D form a left-hand frame (see http://www.adobe.com/devnet/flashplayer/articles/3d-cameras.html) with X axis to right, Y to up and Z to front, the resulting projection matrix of Camera class comes reversing bottom and up.
In my case, I solved the problem replacing line 44:
var ay = az.cross(ax);
by
var ay = ax.cross(az);
It solved the problem with AS3 but it could cause it for other platforms. Maybe a better solution could be fine using precompilation instructions.