Rename plugins to external

applications/external/airmouse/tracking/calibration_data.h

@@ -0,0 +1,117 @@
+#pragma once
+
+#include <toolbox/saved_struct.h>
+#include <storage/storage.h>
+#include <vector>
+
+#include "util/vector.h"
+
+#define CALIBRATION_DATA_VER (1)
+#define CALIBRATION_DATA_FILE_NAME ".calibration.data"
+#define CALIBRATION_DATA_PATH INT_PATH(CALIBRATION_DATA_FILE_NAME)
+#define CALIBRATION_DATA_MAGIC (0x23)
+
+#define CALIBRATION_DATA_SAVE(x)   \
+    saved_struct_save(             \
+        CALIBRATION_DATA_PATH,     \
+        (x),                       \
+        sizeof(CalibrationMedian), \
+        CALIBRATION_DATA_MAGIC,    \
+        CALIBRATION_DATA_VER)
+
+#define CALIBRATION_DATA_LOAD(x)   \
+    saved_struct_load(             \
+        CALIBRATION_DATA_PATH,     \
+        (x),                       \
+        sizeof(CalibrationMedian), \
+        CALIBRATION_DATA_MAGIC,    \
+        CALIBRATION_DATA_VER)
+
+typedef struct {
+    double x;
+    double y;
+    double z;
+} CalibrationMedian;
+
+typedef cardboard::Vector3 Vector;
+
+/**
+ * Helper class to gather some stats and store the calibration data. Right now it calculates a lot
+ * more stats than actually needed. Some of them are used for logging the sensors quality (and
+ * filing bugs), other may be required in the future, e.g. for bias.
+ */
+class CalibrationData {
+public:
+    /**
+     * Check if the sensors were calibrated before.
+     *
+     * @return {@code true} if calibration data is available, or {@code false} otherwise.
+     */
+    bool isComplete() {
+        return complete;
+    }
+
+    /** Prepare to collect new calibration data. */
+    void reset();
+
+    /**
+     * Retrieve the median gyroscope readings.
+     *
+     * @return Three-axis median vector.
+     */
+    Vector getMedian() {
+        return median;
+    }
+
+    /**
+     * Retrieve the mean gyroscope readings.
+     *
+     * @return Three-axis mean vector.
+     */
+    Vector getMean() {
+        return mean;
+    }
+
+    /**
+     * Retrieve the standard deviation of gyroscope readings.
+     *
+     * @return Three-axis standard deviation vector.
+     */
+    Vector getSigma() {
+        return sigma;
+    }
+
+    /**
+     * Retrieve the confidence interval size of gyroscope readings.
+     *
+     * @return Three-axis confidence interval size vector.
+     */
+    Vector getDelta() {
+        return delta;
+    }
+
+    /**
+     * Add a new gyroscope reading to the stats.
+     *
+     * @param data gyroscope values vector.
+     * @return {@code true} if we now have enough data for calibration, or {@code false} otherwise.
+     */
+    bool add(Vector& data);
+
+private:
+    // Calculates the confidence interval (mean +- delta) and some other related values, like
+    // standard deviation, etc. See https://en.wikipedia.org/wiki/Student%27s_t-distribution
+    void calcDelta();
+
+    int count;
+    bool complete;
+    Vector sum;
+    Vector sumSq;
+    Vector mean;
+    Vector median;
+    Vector sigma;
+    Vector delta;
+    std::vector<double> xData;
+    std::vector<double> yData;
+    std::vector<double> zData;
+};