Refactored unwrap class from y2018 code to frc971 directory.

Change-Id: I375e1a2cf875e89944d514f333295867d1a3437b
diff --git a/y2018/control_loops/superstructure/intake/BUILD b/y2018/control_loops/superstructure/intake/BUILD
index ea44c7a..dde7c63 100644
--- a/y2018/control_loops/superstructure/intake/BUILD
+++ b/y2018/control_loops/superstructure/intake/BUILD
@@ -39,7 +39,6 @@
     visibility = ["//visibility:public"],
     deps = [
         ":intake_plants",
-        ":sensor_unwrap",
         "//aos:math",
         "//aos/controls:control_loop",
         "//frc971/control_loops:control_loops_fbs",
@@ -50,25 +49,3 @@
         "//y2018/control_loops/superstructure:superstructure_status_fbs",
     ],
 )
-
-cc_library(
-    name = "sensor_unwrap",
-    srcs = [
-        "sensor_unwrap.cc",
-    ],
-    hdrs = [
-        "sensor_unwrap.h",
-    ],
-    visibility = ["//visibility:public"],
-)
-
-cc_test(
-    name = "unwrap_test",
-    srcs = [
-        "unwrap_test.cc",
-    ],
-    deps = [
-        ":sensor_unwrap",
-        "//aos/testing:googletest",
-    ],
-)
diff --git a/y2018/control_loops/superstructure/intake/intake.h b/y2018/control_loops/superstructure/intake/intake.h
index ac4f971..e064c0e 100644
--- a/y2018/control_loops/superstructure/intake/intake.h
+++ b/y2018/control_loops/superstructure/intake/intake.h
@@ -5,11 +5,11 @@
 
 #include "aos/commonmath.h"
 #include "aos/controls/control_loop.h"
+#include "frc971/zeroing/wrap.h"
 #include "frc971/zeroing/zeroing.h"
 #include "y2018/constants.h"
 #include "y2018/control_loops/superstructure/intake/intake_delayed_plant.h"
 #include "y2018/control_loops/superstructure/intake/intake_plant.h"
-#include "y2018/control_loops/superstructure/intake/sensor_unwrap.h"
 #include "y2018/control_loops/superstructure/superstructure_output_generated.h"
 #include "y2018/control_loops/superstructure/superstructure_position_generated.h"
 #include "y2018/control_loops/superstructure/superstructure_status_generated.h"
@@ -121,7 +121,8 @@
     return ::y2018::constants::Values::kIntakeSpringRatio() * (2 * M_PI);
   }
 
-  UnwrapSensor spring_unwrap_{spring_offset_, spring_range()};
+  ::frc971::zeroing::UnwrapSensor spring_unwrap_{spring_offset_,
+                                                 spring_range()};
 
   State state_ = State::UNINITIALIZED;
 
diff --git a/y2018/control_loops/superstructure/intake/sensor_unwrap.cc b/y2018/control_loops/superstructure/intake/sensor_unwrap.cc
deleted file mode 100644
index c7d2a03..0000000
--- a/y2018/control_loops/superstructure/intake/sensor_unwrap.cc
+++ /dev/null
@@ -1,64 +0,0 @@
-#include "y2018/control_loops/superstructure/intake/sensor_unwrap.h"
-
-#include <cmath>
-
-namespace y2018 {
-namespace control_loops {
-namespace superstructure {
-namespace intake {
-
-UnwrapSensor::UnwrapSensor(double sensor_offset, double sensor_range)
-    : sensor_offset_(sensor_offset), sensor_range_(sensor_range) {
-  Reset();
-}
-
-double UnwrapSensor::Unwrap(double current_sensor_value) {
-  // First time the function is called it will use that value to initialize the
-  // wrap calculation. This catches cases where the offset and first value
-  // difference triggers an unwanted wrap at the first calculation.
-  if (uninitialized_ == true) {
-    uninitialized_ = false;
-  } else {
-    // Calculates the lower sensor value and set the max sensor range
-    // If offset is not 0, this will correct the zeroing offset
-    const double sensor_min_value = sensor_offset_;
-    const double sensor_max_value = sensor_range_ + sensor_min_value;
-
-    // Check if provided sensor value is within the range. This to prevent the
-    // function to get out of sync. Will not throw an error, but continue and
-    // return the value + wrapped factor and not process this value.
-    if (current_sensor_value < sensor_min_value ||
-        current_sensor_value > sensor_max_value) {
-      return current_sensor_value + (sensor_range_ * wrap_count_);
-    }
-
-    // Calculate the positive or negative movement
-    const double sensor_move = current_sensor_value - sensor_last_value_;
-
-    // Function assumes that a movement of more then 1/2 of the range
-    // indicates that we wrapped, instead of moved very fast.
-    if (std::abs(sensor_move) > (sensor_range_ / 2)) {
-      if (sensor_move >= 0) {
-        // sensor moved past the sensor_min_value
-        wrap_count_ -= 1;
-      } else {
-        // sensor moved past the sensor_max_value
-        wrap_count_ += 1;
-      }
-    }
-  }
-  sensor_last_value_ = current_sensor_value;
-  // return the unwrapped sensor value
-  return current_sensor_value + (sensor_range_ * wrap_count_);
-}
-
-void UnwrapSensor::Reset() {
-  wrap_count_ = 0;
-  sensor_last_value_ = sensor_offset_;
-  uninitialized_ = true;
-}
-
-}  // namespace intake
-}  // namespace superstructure
-}  // namespace control_loops
-}  // namespace y2018
diff --git a/y2018/control_loops/superstructure/intake/sensor_unwrap.h b/y2018/control_loops/superstructure/intake/sensor_unwrap.h
deleted file mode 100644
index ccb1b52..0000000
--- a/y2018/control_loops/superstructure/intake/sensor_unwrap.h
+++ /dev/null
@@ -1,48 +0,0 @@
-#ifndef Y2018_CONTROL_LOOPS_SUPERSTRUCTURE_INTAKE_SENSOR_UNWRAP_H_
-#define Y2018_CONTROL_LOOPS_SUPERSTRUCTURE_INTAKE_SENSOR_UNWRAP_H_
-
-namespace y2018 {
-namespace control_loops {
-namespace superstructure {
-namespace intake {
-
-// UnwrapSensor takes in a sensor value from a sensor that loops in a certain
-// interval. ex(the sensor moves from 0 to 10 and back to 0 while moving the
-// same direction) By checking for big gaps in sensor readings it assumes you
-// have wrapped either back or forwards and handles accordingly. It returns the
-// overall sensor value.
-
-class UnwrapSensor {
- public:
-  // The sensor_offset (+ or -) present the sensor value that is 'zero'
-  // The sensor_range presents the absolute value of the sensor range from 0 to
-  // sensor_range. This will be adjusted using the sensor_offset
-  UnwrapSensor(double sensor_offset, double sensor_range);
-
-  // Takes a wrapped sensor value and unwraps it to give you its total position.
-  double Unwrap(double current_sensor_value);
-
-  void Reset();
-
-  int sensor_wrapped() const { return wrap_count_; }
-
- private:
-  const double sensor_offset_, sensor_range_;
-
-  // The last value given from set_position, starts at offset
-  double sensor_last_value_ = sensor_offset_;
-
-  // Log if sensor is in wrapped state in either direction
-  int wrap_count_ = 0;
-
-  // function waits for first call with a value to set sensor_last_value_. Will
-  // start to calculate the spring unwrap at the second function call.
-  bool uninitialized_ = true;
-};
-
-}  // namespace intake
-}  // namespace superstructure
-}  // namespace control_loops
-}  // namespace y2018
-
-#endif  // Y2018_CONTROL_LOOPS_SUPERSTRUCTURE_INTAKE_SENSOR_UNWRAP_H_
diff --git a/y2018/control_loops/superstructure/intake/unwrap_test.cc b/y2018/control_loops/superstructure/intake/unwrap_test.cc
deleted file mode 100644
index 6211846..0000000
--- a/y2018/control_loops/superstructure/intake/unwrap_test.cc
+++ /dev/null
@@ -1,71 +0,0 @@
-#include "gtest/gtest.h"
-#include "y2018/control_loops/superstructure/intake/sensor_unwrap.h"
-
-namespace y2018 {
-namespace control_loops {
-namespace superstructure {
-namespace intake {
-namespace testing {
-
-TEST(SensorTest, UnwrapOnce) {
-  // Test the sensor moving over the maximum range value and wrapping once
-  // then move sensor in oppsite direction to unwrap and test result.
-
-  // Initialize with the offset and range
-  UnwrapSensor sensor(-1.5, 6);        // min = -1.5 & max = 4.5 & move > 3
-  EXPECT_EQ(sensor.Unwrap(1.5), 1.5);  //  move n/a
-  EXPECT_EQ(sensor.sensor_wrapped(), 0);
-  EXPECT_EQ(sensor.Unwrap(4.0), 4.0);   // move 2.5
-  EXPECT_EQ(sensor.Unwrap(-1.0), 5.0);  // move -5.0 -> wrap+
-  EXPECT_EQ(sensor.sensor_wrapped(), 1);
-  EXPECT_EQ(sensor.Unwrap(-1.5), 4.5);  // move -0.5
-  EXPECT_EQ(sensor.Unwrap(4.0), 4.0);   // move 5.5 -> wrap-
-  EXPECT_EQ(sensor.sensor_wrapped(), 0);
-  sensor.Reset();
-}
-
-TEST(SensorTest, UnwrapTwice) {
-  // Test the sensor wrapping twice over the lower value of the range.
-
-  // Initialize with the offset and range
-  UnwrapSensor sensor(-1.5, 6);
-  EXPECT_EQ(sensor.Unwrap(1.0), 1.0);
-  EXPECT_EQ(sensor.Unwrap(-1.0), -1.0);
-  EXPECT_EQ(sensor.Unwrap(4.0), -2.0);
-  EXPECT_EQ(sensor.sensor_wrapped(), -1);
-  EXPECT_EQ(sensor.Unwrap(2.0), -4.0);
-  EXPECT_EQ(sensor.Unwrap(-1.0), -7.0);
-  EXPECT_EQ(sensor.Unwrap(4.0), -8.0);
-  EXPECT_EQ(sensor.sensor_wrapped(), -2);
-}
-
-TEST(SensorTest, UnwrapOutRange) {
-  // Test if values out side range are handled proporly.
-  // Not wrapped scenario only.
-
-  UnwrapSensor sensor(-1.5, 6);
-  EXPECT_EQ(sensor.Unwrap(-3.0), -3.0);  // Passed by the init stage
-  EXPECT_EQ(sensor.Unwrap(-3.0), -3.0);  // Caught by the exeption handler
-  EXPECT_EQ(sensor.Unwrap(6.5), 6.5);
-}
-
-TEST(SensorTest, UnwrapInit) {
-  // Test the case where the start value and offset will be far enough apart to
-  // trigger a wrap. By ignoring the fisrt value for evaluation and set that for
-  // the next evaluation, this should not trigger the wrap.
-
-  UnwrapSensor sensor(-0.6, 1.0);      // min = -0.6 & max = 0.4 & move > 0.5
-  EXPECT_EQ(sensor.Unwrap(0.0), 0.0);  // move = n/a
-  EXPECT_EQ(sensor.sensor_wrapped(), 0);
-  EXPECT_EQ(sensor.Unwrap(0.0), 0.0);
-  sensor.Reset();
-  EXPECT_EQ(sensor.Unwrap(0.4), 0.4);   // move = n/a
-  EXPECT_EQ(sensor.Unwrap(-0.4), 0.6);  // move = -0.8, wrap 1
-  EXPECT_EQ(sensor.Unwrap(0.2), 0.2);   // move = 1.0, wrap -1
-}
-
-}  // namespace testing
-}  // namespace intake
-}  // namespace superstructure
-}  // namespace control_loops
-}  // namespace y2018