+nframes_t
+SndFileSource::destructive_write_unlocked (Sample* data, nframes_t cnt)
+{
+ nframes_t old_file_pos;
+
+ if (!writable()) {
+ return 0;
+ }
+
+ if (_capture_start && _capture_end) {
+
+ /* start and end of capture both occur within the data we are writing,
+ so do both crossfades.
+ */
+
+ _capture_start = false;
+ _capture_end = false;
+
+ /* move to the correct location place */
+ file_pos = capture_start_frame - timeline_position;
+
+ // split cnt in half
+ nframes_t subcnt = cnt / 2;
+ nframes_t ofilepos = file_pos;
+
+ // fade in
+ if (crossfade (data, subcnt, 1) != subcnt) {
+ return 0;
+ }
+
+ file_pos += subcnt;
+ Sample * tmpdata = data + subcnt;
+
+ // fade out
+ subcnt = cnt - subcnt;
+ if (crossfade (tmpdata, subcnt, 0) != subcnt) {
+ return 0;
+ }
+
+ file_pos = ofilepos; // adjusted below
+
+ } else if (_capture_start) {
+
+ /* start of capture both occur within the data we are writing,
+ so do the fade in
+ */
+
+ _capture_start = false;
+ _capture_end = false;
+
+ /* move to the correct location place */
+ file_pos = capture_start_frame - timeline_position;
+
+ if (crossfade (data, cnt, 1) != cnt) {
+ return 0;
+ }
+
+ } else if (_capture_end) {
+
+ /* end of capture both occur within the data we are writing,
+ so do the fade out
+ */
+
+ _capture_start = false;
+ _capture_end = false;
+
+ if (crossfade (data, cnt, 0) != cnt) {
+ return 0;
+ }
+
+ } else {
+
+ /* in the middle of recording */
+
+ if (write_float (data, file_pos, cnt) != cnt) {
+ return 0;
+ }
+ }
+
+ old_file_pos = file_pos;
+ update_length (file_pos, cnt);
+ file_pos += cnt;
+
+ if (_build_peakfiles) {
+ PeakBuildRecord *pbr = 0;
+
+ if (pending_peak_builds.size()) {
+ pbr = pending_peak_builds.back();
+ }
+
+ if (pbr && pbr->frame + pbr->cnt == old_file_pos) {
+
+ /* the last PBR extended to the start of the current write,
+ so just extend it again.
+ */
+
+ pbr->cnt += cnt;
+ } else {
+ pending_peak_builds.push_back (new PeakBuildRecord (old_file_pos, cnt));
+ }
+
+ _peaks_built = false;
+ }
+
+ if (_build_peakfiles) {
+ queue_for_peaks (shared_from_this ());
+ }
+
+ return cnt;
+}
+