Hjg.Pngcs.PngWriter.CopyChunks C# (CSharp) Method

        private void CopyChunks(PngReader reader, int copy_mask, bool onlyAfterIdat)
        {
            bool idatDone = CurrentChunkGroup >= ChunksList.CHUNK_GROUP_4_IDAT;
            if (onlyAfterIdat && reader.CurrentChunkGroup < ChunksList.CHUNK_GROUP_6_END) throw new PngjException("tried to copy last chunks but reader has not ended");
            foreach (PngChunk chunk in reader.GetChunksList().GetChunks()) {
                int group = chunk.ChunkGroup;
                if (group < ChunksList.CHUNK_GROUP_4_IDAT && idatDone)
                    continue;
                bool copy = false;
                if (chunk.Crit) {
                    if (chunk.Id.Equals(ChunkHelper.PLTE)) {
                        if (ImgInfo.Indexed && ChunkHelper.maskMatch(copy_mask, ChunkCopyBehaviour.COPY_PALETTE))
                            copy = true;
                        if (!ImgInfo.Greyscale && ChunkHelper.maskMatch(copy_mask, ChunkCopyBehaviour.COPY_ALL))
                            copy = true;
                    }
                } else { // ancillary
                    bool text = (chunk is PngChunkTextVar);
                    bool safe = chunk.Safe;
                    // notice that these if are not exclusive
                    if (ChunkHelper.maskMatch(copy_mask, ChunkCopyBehaviour.COPY_ALL))
                        copy = true;
                    if (safe && ChunkHelper.maskMatch(copy_mask, ChunkCopyBehaviour.COPY_ALL_SAFE))
                        copy = true;
                    if (chunk.Id.Equals(ChunkHelper.tRNS)
                            && ChunkHelper.maskMatch(copy_mask, ChunkCopyBehaviour.COPY_TRANSPARENCY))
                        copy = true;
                    if (chunk.Id.Equals(ChunkHelper.pHYs) && ChunkHelper.maskMatch(copy_mask, ChunkCopyBehaviour.COPY_PHYS))
                        copy = true;
                    if (text && ChunkHelper.maskMatch(copy_mask, ChunkCopyBehaviour.COPY_TEXTUAL))
                        copy = true;
                    if (ChunkHelper.maskMatch(copy_mask, ChunkCopyBehaviour.COPY_ALMOSTALL)
                            && !(ChunkHelper.IsUnknown(chunk) || text || chunk.Id.Equals(ChunkHelper.hIST) || chunk.Id
                                    .Equals(ChunkHelper.tIME)))
                        copy = true;
                    if (chunk is PngChunkSkipped)
                        copy = false;
                }
                if (copy) {
                    chunksList.Queue(PngChunk.CloneChunk(chunk, ImgInfo));
                }
            }
        }