public Matrix32 CalcWeightedRelativeTransform(SkinningWeights weights)
{
Matrix32 skinningMatrix = new Matrix32();
skinningMatrix.T = ApplySkinningToVector(Vector2.Zero, weights);
skinningMatrix.U = ApplySkinningToVector(Vector2.Right, weights) - skinningMatrix.T;
skinningMatrix.V = ApplySkinningToVector(Vector2.Down, weights) - skinningMatrix.T;
return(skinningMatrix);
}
public static SkinningWeights CalcSkinningWeight(SkinningWeights oldSkinningWeights, Vector2 position, List <Bone> bones)
{
var skinningWeights = new SkinningWeights();
var i = 0;
var overallWeight = 0f;
while (oldSkinningWeights[i].Index != 0)
{
skinningWeights[i] = oldSkinningWeights[i];
overallWeight += skinningWeights[i].Weight;
i++;
}
var j = 0;
while (j < bones.Count && i < 4)
{
var weight = bones[j].CalcWeightForPoint(position);
if (Mathf.Abs(weight) > Mathf.ZeroTolerance)
{
skinningWeights[i] = new BoneWeight {
Weight = weight,
Index = bones[j].Index
};
overallWeight += skinningWeights[i].Weight;
i++;
}
j++;
}
if (overallWeight != 0)
{
for (i = 0; i < 4; i++)
{
var bw = skinningWeights[i];
bw.Weight /= overallWeight;
skinningWeights[i] = bw;
}
}
return(skinningWeights);
}
public Vector2 ApplySkinningToVector(Vector2 vector, SkinningWeights weights)
{
Vector2 result = Vector2.Zero;
float overallWeight = 0;
ApplyBone(weights.Bone0, vector, ref result, ref overallWeight);
ApplyBone(weights.Bone1, vector, ref result, ref overallWeight);
ApplyBone(weights.Bone2, vector, ref result, ref overallWeight);
ApplyBone(weights.Bone3, vector, ref result, ref overallWeight);
if (overallWeight < 0)
{
result = vector;
}
else if (overallWeight >= 0 && overallWeight < 1)
{
result += (1 - overallWeight) * vector;
}
else
{
result.X /= overallWeight;
result.Y /= overallWeight;
}
return(result);
}