1 files changed, 112 insertions, 0 deletions
diff --git a/src/server/mix.cpp b/src/server/mix.cpp
new file mode 100644
index 00000000..065e3efc
--- /dev/null
+++ b/src/server/mix.cpp
@@ -0,0 +1,112 @@
+/*
+  This file is part of Ingen.
+  Copyright 2007-2015 David Robillard <http://drobilla.net/>
+
+  Ingen is free software: you can redistribute it and/or modify it under the
+  terms of the GNU Affero General Public License as published by the Free
+  Software Foundation, either version 3 of the License, or any later version.
+
+  Ingen 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 Affero General Public License for details.
+
+  You should have received a copy of the GNU Affero General Public License
+  along with Ingen.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "lv2/atom/util.h"
+
+#include "Buffer.hpp"
+#include "RunContext.hpp"
+#include "mix.hpp"
+
+namespace ingen {
+namespace server {
+
+static inline bool
+is_end(const Buffer* buf, const LV2_Atom_Event* ev)
+{
+	const LV2_Atom* atom = buf->get<const LV2_Atom>();
+	return lv2_atom_sequence_is_end(
+		(const LV2_Atom_Sequence_Body*)LV2_ATOM_BODY_CONST(atom),
+		atom->size,
+		ev);
+}
+
+void
+mix(const RunContext&   context,
+    Buffer*             dst,
+    const Buffer*const* srcs,
+    uint32_t            num_srcs)
+{
+	if (num_srcs == 1) {
+		dst->copy(context, srcs[0]);
+	} else if (dst->is_control()) {
+		Sample* const out = dst->samples();
+		out[0] = srcs[0]->value_at(0);
+		for (uint32_t i = 1; i < num_srcs; ++i) {
+			out[0] += srcs[i]->value_at(0);
+		}
+	} else if (dst->is_audio()) {
+		// Copy the first source
+		dst->copy(context, srcs[0]);
+
+		// Mix in the rest
+		Sample* __restrict const out = dst->samples();
+		const SampleCount        end = context.nframes();
+		for (uint32_t i = 1; i < num_srcs; ++i) {
+			const Sample* __restrict const in = srcs[i]->samples();
+			if (srcs[i]->is_control()) {  // control => audio
+				for (SampleCount i = 0; i < end; ++i) {
+					out[i] += in[0];
+				}
+			} else if (srcs[i]->is_audio()) {  // audio => audio
+				for (SampleCount i = 0; i < end; ++i) {
+					out[i] += in[i];
+				}
+			} else if (srcs[i]->is_sequence()) {  // sequence => audio
+				dst->render_sequence(context, srcs[i], true);
+			}
+		}
+	} else if (dst->is_sequence()) {
+		const LV2_Atom_Event* iters[num_srcs];
+		for (uint32_t i = 0; i < num_srcs; ++i) {
+			iters[i] = nullptr;
+			if (srcs[i]->is_sequence()) {
+				const LV2_Atom_Sequence* seq = srcs[i]->get<const LV2_Atom_Sequence>();
+				iters[i] = lv2_atom_sequence_begin(&seq->body);
+				if (is_end(srcs[i], iters[i])) {
+					iters[i] = nullptr;
+				}
+			}
+		}
+
+		while (true) {
+			const LV2_Atom_Event* first   = nullptr;
+			uint32_t              first_i = 0;
+			for (uint32_t i = 0; i < num_srcs; ++i) {
+				const LV2_Atom_Event* const ev = iters[i];
+				if (!first || (ev && ev->time.frames < first->time.frames)) {
+					first   = ev;
+					first_i = i;
+				}
+			}
+
+			if (first) {
+				dst->append_event(
+					first->time.frames, first->body.size, first->body.type,
+					(const uint8_t*)LV2_ATOM_BODY_CONST(&first->body));
+
+				iters[first_i] = lv2_atom_sequence_next(first);
+				if (is_end(srcs[first_i], iters[first_i])) {
+					iters[first_i] = nullptr;
+				}
+			} else {
+				break;
+			}
+		}
+	}
+}
+
+} // namespace server
+} // namespace ingen