Function tryValidityAwareSourceOver

Composite with explicit validity flags. Validity is not alpha and is never inferred from the pixel values. An invalid source contributes nothing; when only one contributor is valid, that contributor is returned unchanged.

imagery.compositing.source_over.SourceOverError tryValidityAwareSourceOver(
  imagery.compositing.source_over.RgbaNormalized source,
  bool sourceValid,
  imagery.compositing.source_over.RgbaNormalized destination,
  bool destinationValid,
  imagery.compositing.source_over.AlphaAssociation association,
  out imagery.compositing.source_over.RgbaNormalized result,
  out bool resultValid
) pure nothrow @nogc @safe;