Improved getAnglesFromVector

The "getAnglesFromVector" function sacrifices accuracy for speed. This isn't a problem if a rough estimate is all you need - but it's horribly noticeable if you are using it to, say, point a camera at a moving target.

The problem is that it the pitch calculation doesn't use the true horizontal distance - it just takes takes the x or y component, whichever is more significant. The end result is that you get kind of an octagonal approximation of pitch, not a true smooth pitch calculation.

So, for your enjoyment, here's a new, improved - somewhat slower but more accurate version. If you want to keep access to the old version, just rename this to "newGetAnglesFromVector" or something.

This change goes into mathUtils.cc, at approxmately line 80:

void getAnglesFromVector( VectorF &vec, F32 &yawAng, F32 &pitchAng )
{
    yawAng = mAtan( vec.x, vec.y );

    if( yawAng < 0.0 )
    {
         yawAng += M_2PI;
    }

    // Begin modified code

    F32 horizontalValue, verticalValue;
    F32 dist = mSqrt((vec.x * vec.x) + (vec.y * vec.y));
    horizontalValue = 1.0f;
    verticalValue = vec.z / dist;
    pitchAng = mAtan( fabs(verticalValue),fabs(horizontalValue));

    // End Code Modification

    if( vec.z < 0.0 )
    {
        pitchAng = -pitchAng;
    }

}