'Sample & Hold' node.

noisicaa/node_lib/sample_and_hold/audio.cpp

@@ -0,0 +1,59 @@
+/*
+ * @begin:license
+ *
+ * Copyright (c) 2015-2021, Ben Niemann <pink@odahoda.de>
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * @end:license
+ */
+
+#include <cmath>
+#include <string>
+#include <vector>
+
+#include "noisicaa/engine/engine_impl.h"
+#include "noisicaa/engine/buffers.h"
+#include "noisicaa/engine/block_context.h"
+#include "noisicaa/engine/node_db.h"
+#include "noisicaa/node_lib/sample_and_hold/audio.h"
+
+namespace noisicaa::engine::sample_and_hold {
+
+Node::Node(EngineImpl* engine, uint64_t id)
+  : ProcessorNode(engine, id, "noisicaa.node_lib.sample_and_hold") {}
+
+Status Node::run(BlockContext* ctxt, const std::vector<Buffer*>* buffers) {
+  float* in = (float*)buffers->at(0)->data();
+  float* trigger = (float*)buffers->at(1)->data();
+  float* out = (float*)buffers->at(2)->data();
+
+  for (uint32_t smpl = 0 ; smpl < ctxt->block_size ; ++smpl, ++in, ++trigger) {
+    if (*trigger >= 0.55 && !_trig) {
+      _trig = true;
+      _hold = *in;
+    } else if (*trigger < 0.45 && _trig) {
+      _trig = false;
+    }
+    *out++ = _hold;
+  }
+
+  return Status::Ok();
+}
+
+NOISICAA_REGISTER_NODE_CLASS(Node, "node://sample-and-hold")
+
+}  // namespace noisicaa::engine::sample_and_hold
+

noisicaa/node_lib/sample_and_hold/audio.h

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+// -*- mode: c++ -*-
+
+/*
+ * @begin:license
+ *
+ * Copyright (c) 2015-2021, Ben Niemann <pink@odahoda.de>
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * @end:license
+ */
+
+#ifndef _NOISICAA_NODE_LIB_SAMPLE_AND_HOLD_H
+#define _NOISICAA_NODE_LIB_SAMPLE_AND_HOLD_H
+
+#include <memory>
+#include <vector>
+
+#include "noisicaa/core/status.h"
+#include "noisicaa/engine/processor_node.h"
+
+namespace noisicaa::engine {
+
+class EngineImpl;
+class Program;
+
+namespace sample_and_hold {
+
+class Node : public ProcessorNode {
+public:
+  Node(EngineImpl* engine, uint64_t id);
+
+  Status run(BlockContext* ctxt, const std::vector<Buffer*>* buffers) override;
+
+private:
+  float _hold = 0.0;
+  bool _trig = false;
+};
+
+}  // namespace sample_and_hold
+}  // namespace noisicaa::engine
+
+#endif

noisicaa/node_lib/sample_and_hold/description.yaml

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+uri: builtin://sample-and-hold
+audio_class_uri: node://sample-and-hold
+display_name: Sample & Hold
+ports:
+- name: in
+  direction: INPUT
+  type: AUDIO
+- name: trigger
+  direction: INPUT
+  type: AUDIO
+- name: out
+  direction: OUTPUT
+  type: AUDIO

noisicaa/node_lib/sample_and_hold/wscript

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+# @begin:license
+#
+# Copyright (c) 2015-2021, Ben Niemann <pink@odahoda.de>
+#
+# 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.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# @end:license
+
+def build(ctx):
+    ctx.noise_node(
+        has_audio=True,
+    )