+/*
+ Copyright (C) 2006-2015 Paul Davis
+ Author: David Robillard
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "ardour/buffer_set.h"
+#include "ardour/midi_buffer.h"
+#include "ardour/midi_channel_filter.h"
+#include "pbd/ffs.h"
+
+namespace ARDOUR {
+
+MidiChannelFilter::MidiChannelFilter()
+ : _mode_mask(0x0000FFFF)
+{}
+
+void
+MidiChannelFilter::filter(BufferSet& bufs)
+{
+ ChannelMode mode;
+ uint16_t mask;
+ get_mode_and_mask(&mode, &mask);
+
+ if (mode == AllChannels) {
+ return;
+ }
+
+ MidiBuffer& buf = bufs.get_midi(0);
+
+ for (MidiBuffer::iterator e = buf.begin(); e != buf.end(); ) {
+ Evoral::MIDIEvent<framepos_t> ev(*e, false);
+
+ if (ev.is_channel_event()) {
+ switch (mode) {
+ case FilterChannels:
+ if (0 == ((1 << ev.channel()) & mask)) {
+ e = buf.erase (e);
+ } else {
+ ++e;
+ }
+ break;
+ case ForceChannel:
+ ev.set_channel(PBD::ffs(mask) - 1);
+ ++e;
+ break;
+ case AllChannels:
+ /* handled by the opening if() */
+ ++e;
+ break;
+ }
+ } else {
+ ++e;
+ }
+ }
+}
+
+bool
+MidiChannelFilter::filter(uint8_t* buf, uint32_t len)
+{
+ ChannelMode mode;
+ uint16_t mask;
+ get_mode_and_mask(&mode, &mask);
+
+ const uint8_t type = buf[0] & 0xF0;
+ const bool is_channel_event = (0x80 <= type) && (type <= 0xE0);
+ if (!is_channel_event) {
+ return false;
+ }
+
+ const uint8_t channel = buf[0] & 0x0F;
+ switch (mode) {
+ case AllChannels:
+ return false;
+ case FilterChannels:
+ return !((1 << channel) & mask);
+ case ForceChannel:
+ buf[0] = (0xF0 & buf[0]) | (0x0F & (PBD::ffs(mask) - 1));
+ return false;
+ }
+
+ return false;
+}
+
+/** If mode is ForceChannel, force mask to the lowest set channel or 1 if no
+ * channels are set.
+ */
+static inline uint16_t
+force_mask(const ChannelMode mode, const uint16_t mask)
+{
+ return ((mode == ForceChannel)
+ ? (mask ? (1 << (PBD::ffs(mask) - 1)) : 1)
+ : mask);
+}
+
+bool
+MidiChannelFilter::set_channel_mode(ChannelMode mode, uint16_t mask)
+{
+ ChannelMode old_mode;
+ uint16_t old_mask;
+ get_mode_and_mask(&old_mode, &old_mask);
+
+ if (old_mode != mode || old_mask != mask) {
+ mask = force_mask(mode, mask);
+ g_atomic_int_set(&_mode_mask, (uint32_t(mode) << 16) | uint32_t(mask));
+ ChannelModeChanged();
+ return true;
+ }
+
+ return false;
+}
+
+bool
+MidiChannelFilter::set_channel_mask(uint16_t mask)
+{
+ ChannelMode mode;
+ uint16_t old_mask;
+ get_mode_and_mask(&mode, &old_mask);
+
+ if (old_mask != mask) {
+ mask = force_mask(mode, mask);
+ g_atomic_int_set(&_mode_mask, (uint32_t(mode) << 16) | uint32_t(mask));
+ ChannelMaskChanged();
+ return true;
+ }
+
+ return false;
+}
+
+} /* namespace ARDOUR */