public static void InterpolateA(LdrColorA c0, LdrColorA c1, int wa, int waprec, LdrColorA outt)
{
DebugGuard.MustBeBetweenOrEqualTo(waprec, 2, 4, nameof(waprec));
int[] aWeights;
switch (waprec)
{
case 2:
{
aWeights = Constants.Weights2;
Debug.Assert(wa < 4, "wc is expected to be smaller then 4");
break;
}
case 3:
{
aWeights = Constants.Weights3;
Debug.Assert(wa < 8, "wc is expected to be smaller then 8");
break;
}
case 4:
{
aWeights = Constants.Weights4;
Debug.Assert(wa < 16, "wc is expected to be smaller then 16");
break;
}
default:
outt.A = 0;
return;
}
outt.A = (byte)(((c0.A * (uint)(Constants.BC67_WEIGHT_MAX - aWeights[wa])) + (c1.A * (uint)aWeights[wa]) + Constants.BC67_WEIGHT_ROUND) >> Constants.BC67_WEIGHT_SHIFT);
}
public static void TransformInverseUnsigned(IntEndPntPair[] aEndPts, LdrColorA prec)
{
var wrapMask = new IntColor((1 << prec.R) - 1, (1 << prec.G) - 1, (1 << prec.B) - 1);
aEndPts[0].B += aEndPts[0].A;
aEndPts[0].B &= wrapMask;
aEndPts[1].A += aEndPts[0].A;
aEndPts[1].A &= wrapMask;
aEndPts[1].B += aEndPts[0].A;
aEndPts[1].B &= wrapMask;
}
public static void Interpolate(LdrColorA c0, LdrColorA c1, int wc, int wa, int wcprec, int waprec, LdrColorA outt)
{
InterpolateRgb(c0, c1, wc, wcprec, outt);
InterpolateA(c0, c1, wa, waprec, outt);
}
