// Sets dst to the demag field, but cells where NoDemagSpins != 0 do not generate nor recieve field.
func setMaskedDemagField(dst *data.Slice) {
// No-demag spins: mask-out geometry with zeros where NoDemagSpins is set,
// so these spins do not generate a field
buf := cuda.Buffer(SCALAR, geometry.Gpu().Size()) // masked-out geometry
defer cuda.Recycle(buf)
// obtain a copy of the geometry mask, which we can overwrite
geom, r := geometry.Slice()
if r {
defer cuda.Recycle(geom)
}
data.Copy(buf, geom)
// mask-out
cuda.ZeroMask(buf, NoDemagSpins.gpuLUT1(), regions.Gpu())
// convolution with masked-out cells.
demagConv().Exec(dst, M.Buffer(), buf, Bsat.gpuLUT1(), regions.Gpu())
// After convolution, mask-out the field in the NoDemagSpins cells
// so they don't feel the field generated by others.
cuda.ZeroMask(dst, NoDemagSpins.gpuLUT1(), regions.Gpu())
}
func FreezeSpins(dst *data.Slice) {
if !FrozenSpins.isZero() {
cuda.ZeroMask(dst, FrozenSpins.gpuLUT1(), regions.Gpu())
}
}