/// <inheritdoc />
public unsafe override void BuildUVCoordinates(ref ParticleBufferState bufferState, ref ParticleList sorter, AttributeDescription texCoordsDescription)
{
var lifeField = sorter.GetField(ParticleFields.RemainingLife);
if (!lifeField.IsValid())
{
return;
}
var texAttribute = bufferState.GetAccessor(texCoordsDescription);
if (texAttribute.Size == 0 && texAttribute.Offset == 0)
{
return;
}
var texDefault = bufferState.GetAccessor(bufferState.DefaultTexCoords);
if (texDefault.Size == 0 && texDefault.Offset == 0)
{
return;
}
foreach (var particle in sorter)
{
var normalizedTimeline = 1f - *(float *)(particle[lifeField]);
Vector4 uvTransform = Vector4.Lerp(StartFrame, EndFrame, normalizedTimeline);
uvTransform.Z -= uvTransform.X;
uvTransform.W -= uvTransform.Y;
bufferState.TransformAttributePerSegment(texDefault, texAttribute, this, ref uvTransform);
bufferState.NextSegment();
}
bufferState.StartOver();
}