1 files changed, 152 insertions, 0 deletions
diff --git a/src/modules/systemlib/mixer/mixer.cpp b/src/modules/systemlib/mixer/mixer.cpp
new file mode 100644
index 000000000..df0dfe838
--- /dev/null
+++ b/src/modules/systemlib/mixer/mixer.cpp
@@ -0,0 +1,152 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file mixer.cpp
+ *
+ * Programmable multi-channel mixer library.
+ */
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <errno.h>
+#include <stdio.h>
+#include <math.h>
+#include <unistd.h>
+
+#include "mixer.h"
+
+Mixer::Mixer(ControlCallback control_cb, uintptr_t cb_handle) :
+	_next(nullptr),
+	_control_cb(control_cb),
+	_cb_handle(cb_handle)
+{
+}
+
+float
+Mixer::get_control(uint8_t group, uint8_t index)
+{
+	float	value;
+
+	_control_cb(_cb_handle, group, index, value);
+
+	return value;
+}
+
+
+float
+Mixer::scale(const mixer_scaler_s &scaler, float input)
+{
+	float output;
+
+	if (input < 0.0f) {
+		output = (input * scaler.negative_scale) + scaler.offset;
+
+	} else {
+		output = (input * scaler.positive_scale) + scaler.offset;
+	}
+
+	if (output > scaler.max_output) {
+		output = scaler.max_output;
+
+	} else if (output < scaler.min_output) {
+		output = scaler.min_output;
+	}
+
+	return output;
+}
+
+int
+Mixer::scale_check(struct mixer_scaler_s &scaler)
+{
+	if (scaler.offset > 1.001f)
+		return 1;
+
+	if (scaler.offset < -1.001f)
+		return 2;
+
+	if (scaler.min_output > scaler.max_output)
+		return 3;
+
+	if (scaler.min_output < -1.001f)
+		return 4;
+
+	if (scaler.max_output > 1.001f)
+		return 5;
+
+	return 0;
+}
+
+/****************************************************************************/
+
+NullMixer::NullMixer() :
+	Mixer(nullptr, 0)
+{
+}
+
+unsigned
+NullMixer::mix(float *outputs, unsigned space)
+{
+	if (space > 0) {
+		*outputs = 0.0f;
+		return 1;
+	}
+
+	return 0;
+}
+
+void
+NullMixer::groups_required(uint32_t &groups)
+{
+
+}
+
+NullMixer *
+NullMixer::from_text(const char *buf, unsigned &buflen)
+{
+	NullMixer *nm = nullptr;
+
+	if ((buflen >= 2) && (buf[0] == 'Z') && (buf[1] == ':')) {
+		nm = new NullMixer;
+		buflen -= 2;
+	}
+
+	return nm;
+}