// Description: Convenience function to set spotlight parameters.
//
// Arguments: light HW light ID.
// cutoff Cut off angle.
// spot_func Spot function characteristics.
public Vector3 GetLightSpot(int frame)
{
float a0, a1, a2, r, d, cr;
SpotFn spot_func = SpotFunction;
float cutoff = _spotCut.GetFrameValue(frame);
if (cutoff <= 0.0f || cutoff > 90.0f)
{
spot_func = SpotFn.Off;
}
r = cutoff * Maths._deg2radf;
cr = (float)Math.Cos(r);
switch (spot_func)
{
case SpotFn.Flat:
a0 = -1000.0f * cr;
a1 = 1000.0f;
a2 = 0.0f;
break;
case SpotFn.Cos:
a0 = -cr / (1.0f - cr);
a1 = 1.0f / (1.0f - cr);
a2 = 0.0f;
break;
case SpotFn.Cos2:
a0 = 0.0f;
a1 = -cr / (1.0f - cr);
a2 = 1.0f / (1.0f - cr);
break;
case SpotFn.Sharp:
d = (1.0f - cr) * (1.0f - cr);
a0 = cr * (cr - 2.0f) / d;
a1 = 2.0f / d;
a2 = -1.0f / d;
break;
case SpotFn.Ring:
d = (1.0f - cr) * (1.0f - cr);
a0 = -4.0f * cr / d;
a1 = 4.0f * (1.0f + cr) / d;
a2 = -4.0f / d;
break;
case SpotFn.Ring2:
d = (1.0f - cr) * (1.0f - cr);
a0 = 1.0f - 2.0f * cr * cr / d;
a1 = 4.0f * cr / d;
a2 = -2.0f / d;
break;
case SpotFn.Off:
default:
a0 = 1.0f;
a1 = 0.0f;
a2 = 0.0f;
break;
}
return(new Vector3(a0, a1, a2));
}
public static Vector3 GetLightSpotCoefs(float cutoff, SpotFn spotFunc)
{
//a2x^2 + a1x + a0
float a0, a1, a2, d, cr = (float)Math.Cos(cutoff * Maths._deg2radf);
if (cutoff <= 0.0f || cutoff > 90.0f)
{
spotFunc = SpotFn.Off;
}
switch (spotFunc)
{
case SpotFn.Flat:
a0 = -1000.0f * cr;
a1 = 1000.0f;
a2 = 0.0f;
break;
case SpotFn.Cos:
a0 = -cr / (1.0f - cr);
a1 = 1.0f / (1.0f - cr);
a2 = 0.0f;
break;
case SpotFn.Cos2:
a0 = 0.0f;
a1 = -cr / (1.0f - cr);
a2 = 1.0f / (1.0f - cr);
break;
case SpotFn.Sharp:
d = (1.0f - cr) * (1.0f - cr);
a0 = cr * (cr - 2.0f) / d;
a1 = 2.0f / d;
a2 = -1.0f / d;
break;
case SpotFn.Ring:
d = (1.0f - cr) * (1.0f - cr);
a0 = -4.0f * cr / d;
a1 = 4.0f * (1.0f + cr) / d;
a2 = -4.0f / d;
break;
case SpotFn.Ring2:
d = (1.0f - cr) * (1.0f - cr);
a0 = 1.0f - 2.0f * cr * cr / d;
a1 = 4.0f * cr / d;
a2 = -2.0f / d;
break;
case SpotFn.Off:
default:
a0 = 1.0f;
a1 = 0.0f;
a2 = 0.0f;
break;
}
return(new Vector3(a0, a1, a2));
}
