Tone generator class

firmware/baseband/tone_gen.cpp

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
+ * Copyright (C) 2017 Furrtek
+ * 
+ * This file is part of PortaPack.
+ *
+ * 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, 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; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "tone_gen.hpp"
+#include "sine_table_int8.hpp"
+
+void ToneGen::configure(const uint32_t delta, const float tone_mix_weight) {
+	delta_ = delta;
+	tone_mix_weight_ = tone_mix_weight;
+	input_mix_weight_ = 1.0 - tone_mix_weight;
+}
+
+int32_t ToneGen::process(const int32_t sample_in) {
+	if (!delta_)
+		return sample_in;
+	
+	int32_t tone_sample = sine_table_i8[(tone_phase_ & 0xFF000000U) >> 24];
+	tone_phase_ += delta_;
+	
+	return (sample_in * input_mix_weight_) + (tone_sample * tone_mix_weight_);
+}