MIDI transform dialog.

1 files changed, 162 insertions, 0 deletions

diff --git a/libs/ardour/transform.cc b/libs/ardour/transform.cc
new file mode 100644
index 0000000000..ddf23aeecc
--- /dev/null
+++ b/libs/ardour/transform.cc
@@ -0,0 +1,162 @@
+/*
+    Copyright (C) 2014 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 <glib.h>
+
+#include "ardour/transform.h"
+#include "ardour/midi_model.h"
+
+namespace ARDOUR {
+
+Transform::Transform(const Program& prog)
+	: _prog(prog)
+{}
+
+Variant
+Transform::Context::pop()
+{
+	if (stack.empty()) {
+		return Variant();
+	}
+
+	const Variant top = stack.top();
+	stack.pop();
+	return top;
+}
+
+Variant
+Transform::Value::eval(const Context& ctx) const
+{
+	switch (source) {
+	case NOWHERE:
+		return Variant();
+	case THIS_NOTE:
+		return MidiModel::NoteDiffCommand::get_value(ctx.this_note, prop);
+	case PREV_NOTE:
+		if (!ctx.prev_note) {
+			return Variant();
+		}
+		return MidiModel::NoteDiffCommand::get_value(ctx.prev_note, prop);
+	case INDEX:
+		return Variant(Variant::INT, ctx.index);
+	case N_NOTES:
+		return Variant(Variant::INT, ctx.n_notes);
+	case LITERAL:
+		return value;
+	case RANDOM:
+		return Variant(g_random_double());
+	}
+}
+
+void
+Transform::Operation::eval(Context& ctx) const
+{
+	if (op == PUSH) {
+		const Variant a = arg.eval(ctx);
+		if (!!a) {
+			/* Argument evaluated to a value, push it to the stack.  Otherwise,
+			   there was a reference to the previous note, but this is the
+			   first, so skip this operation and do nothing. */
+			ctx.stack.push(a);
+		}
+		return;
+	}
+
+	// Pop operands off the stack
+	const Variant rhs = ctx.pop();
+	const Variant lhs = ctx.pop();
+	if (!lhs || !rhs) {
+		// Stack underflow (probably previous note reference), do nothing
+		return;
+	}
+
+	// We can get away with just using double math and converting twice
+	double value = lhs.to_double();
+	switch (op) {
+	case ADD:
+		value += rhs.to_double();
+		break;
+	case SUB:
+		value -= rhs.to_double();
+		break;
+	case MULT:
+		value *= rhs.to_double();
+		break;
+	case DIV:
+		if (rhs.to_double() == 0.0) {
+			return;  // Program will fail safely
+		}
+		value /= rhs.to_double();
+		break;
+	default: break;
+	}
+
+	// Push result on to the stack
+	ctx.stack.push(Variant(lhs.type(), value));
+}
+
+Command*
+Transform::operator()(boost::shared_ptr<MidiModel> model,
+                      Evoral::MusicalTime          position,
+                      std::vector<Notes>&          seqs)
+{
+	typedef MidiModel::NoteDiffCommand Command;
+
+	Command* cmd = new Command(model, name());
+
+	for (std::vector<Notes>::iterator s = seqs.begin(); s != seqs.end(); ++s) {
+		Context ctx;
+		ctx.n_notes = (*s).size();
+		for (Notes::const_iterator i = (*s).begin(); i != (*s).end(); ++i) {
+			const NotePtr note = *i;
+
+			// Clear stack and run program
+			ctx.stack     = std::stack<Variant>();
+			ctx.this_note = note;
+			for (std::list<Operation>::const_iterator o = _prog.ops.begin();
+			     o != _prog.ops.end();
+			     ++o) {
+				(*o).eval(ctx);
+			}
+
+			// Result is on top of the stack
+			if (!ctx.stack.empty() && !!ctx.stack.top()) {
+				// Get the result from the top of the stack
+				Variant result = ctx.stack.top();
+				if (result.type() != Command::value_type(_prog.prop)) {
+					// Coerce to appropriate type
+					result = Variant(Command::value_type(_prog.prop),
+					                 result.to_double());
+				}
+
+				// Apply change
+				cmd->change(note, _prog.prop, result);
+			}
+			// else error or reference to note before the first, skip
+
+			// Move forward
+			ctx.prev_note = note;
+			++ctx.index;
+		}
+	}
+
+	return cmd;
+}
+
+}  // namespace ARDOUR