1 files changed, 96 insertions, 0 deletions
diff --git a/src/engine/ConnectionBase.cpp b/src/engine/ConnectionBase.cpp
new file mode 100644
index 00000000..c8936818
--- /dev/null
+++ b/src/engine/ConnectionBase.cpp
@@ -0,0 +1,96 @@
+/* This file is part of Om.  Copyright (C) 2006 Dave Robillard.
+ * 
+ * Om 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.
+ * 
+ * Om 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 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.,
+ * 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "ConnectionBase.h"
+#include "util.h"
+#include "InputPort.h"
+#include "OutputPort.h"
+#include "Node.h"
+#include "Om.h"
+#include "Port.h"
+
+namespace Om {
+
+
+/** Constructor for a connection from a node's output port.
+ *
+ * This handles both polyphonic and monophonic nodes, transparently to the 
+ * user (InputPort).
+ */
+template <typename T>
+ConnectionBase<T>::ConnectionBase(OutputPort<T>* const src_port, InputPort<T>* const dst_port)
+: Connection(src_port, dst_port),
+  m_local_buffer(NULL),
+  m_is_poly_to_mono( (src_port->parent_node()->poly() > dst_port->parent_node()->poly()) ),
+  m_buffer_size(src_port->buffer_size()),
+  m_pending_disconnection(false)
+{
+	assert((src_port->parent_node()->poly() == dst_port->parent_node()->poly())
+		|| (src_port->parent_node()->poly() == 1 || dst_port->parent_node()->poly() == 1));
+
+	if (m_is_poly_to_mono) // Poly -> Mono connection, need a buffer to mix in to
+		m_local_buffer = new Buffer<T>(m_buffer_size);
+}
+template ConnectionBase<sample>::ConnectionBase(OutputPort<sample>* const src_port, InputPort<sample>* const dst_port);
+template ConnectionBase<MidiMessage>::ConnectionBase(OutputPort<MidiMessage>* const src_port, InputPort<MidiMessage>* const dst_port);
+
+
+template <typename T>
+ConnectionBase<T>::~ConnectionBase()
+{
+	delete m_local_buffer;
+}
+template ConnectionBase<sample>::~ConnectionBase();
+template ConnectionBase<MidiMessage>::~ConnectionBase();
+
+
+template <typename sample>
+void
+ConnectionBase<sample>::prepare_buffers()
+{
+	/* Thought:  A poly output port can be connected to multiple mono input
+	 * ports, which means this mix down would have to happen many times.
+	 * Adding a method to OutputPort that mixes down all it's outputs into
+	 * a buffer (if it hasn't been done already this cycle) and returns that
+	 * would avoid having to mix multiple times.  Probably not a very common
+	 * case, but it would be faster anyway. */
+	
+	if (m_is_poly_to_mono) {
+		m_local_buffer->copy(src_port()->buffer(0), 0, m_buffer_size-1);
+	
+		// Mix all the source's voices down into local buffer starting at the second
+		// voice (buffer is already set to first voice above)
+		for (size_t j=1; j < src_port()->poly(); ++j)
+			m_local_buffer->accumulate(src_port()->buffer(j), 0, m_buffer_size-1);
+
+		// Scale the buffer down.
+		if (src_port()->poly() > 1)
+			m_local_buffer->scale(1.0f/(float)src_port()->poly(), 0, m_buffer_size-1);
+	}
+}
+template void ConnectionBase<sample>::prepare_buffers();
+
+
+// FIXME: MIDI mixing not implemented
+template <>
+void
+ConnectionBase<MidiMessage>::prepare_buffers()
+{
+}
+
+
+} // namespace Om
+