Update to 2018_v4 image and new build system. (#598)

* Revert "Force OpenCV to 3.1.0 (#602)"

This reverts commit 50ed55e8e2.

* Removes Simulation

* Removes old build system

* Removes old gtest

* Adds new gmock and gtest

* Updates to new ni-libraries

* removes MyRobot (to be replaced)

* moves files to new location

* Adds new sim backend and new test executables

* updates .styleguide and .gitignore

* Changes cpp WPILibVersion to a function

MSVC throws an AV with the old version.

* Disables USBCamera on all systems except for linux

* 2018 NI Libraries

* New build system

wpilibc/src/main/native/cpp/Timer.cpp

@@ -0,0 +1,193 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2008-2017. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "Timer.h"
+
+#include <chrono>
+#include <thread>
+
+#include "DriverStation.h"
+#include "HAL/HAL.h"
+#include "Utility.h"
+
+namespace frc {
+
+/**
+ * Pause the task for a specified time.
+ *
+ * Pause the execution of the program for a specified period of time given in
+ * seconds. Motors will continue to run at their last assigned values, and
+ * sensors will continue to update. Only the task containing the wait will
+ * pause until the wait time is expired.
+ *
+ * @param seconds Length of time to pause, in seconds.
+ */
+void Wait(double seconds) {
+  if (seconds < 0.0) return;
+  std::this_thread::sleep_for(std::chrono::duration<double>(seconds));
+}
+
+/**
+ * Return the FPGA system clock time in seconds.
+ * This is deprecated and just forwards to Timer::GetFPGATimestamp().
+ * @return Robot running time in seconds.
+ */
+double GetClock() { return Timer::GetFPGATimestamp(); }
+
+/**
+ * @brief Gives real-time clock system time with nanosecond resolution
+ * @return The time, just in case you want the robot to start autonomous at 8pm
+ *         on Saturday.
+ */
+double GetTime() {
+  using std::chrono::duration;
+  using std::chrono::duration_cast;
+  using std::chrono::system_clock;
+
+  return duration_cast<duration<double>>(system_clock::now().time_since_epoch())
+      .count();
+}
+
+}  // namespace frc
+
+using namespace frc;
+
+// for compatibility with msvc12--see C2864
+const double Timer::kRolloverTime = (1ll << 32) / 1e6;
+/**
+ * Create a new timer object.
+ *
+ * Create a new timer object and reset the time to zero. The timer is initially
+ * not running and
+ * must be started.
+ */
+Timer::Timer() {
+  // Creates a semaphore to control access to critical regions.
+  // Initially 'open'
+  Reset();
+}
+
+/**
+ * Get the current time from the timer. If the clock is running it is derived
+ * from the current system clock the start time stored in the timer class. If
+ * the clock is not running, then return the time when it was last stopped.
+ *
+ * @return Current time value for this timer in seconds
+ */
+double Timer::Get() const {
+  double result;
+  double currentTime = GetFPGATimestamp();
+
+  std::lock_guard<hal::priority_mutex> sync(m_mutex);
+  if (m_running) {
+    // If the current time is before the start time, then the FPGA clock
+    // rolled over.  Compensate by adding the ~71 minutes that it takes
+    // to roll over to the current time.
+    if (currentTime < m_startTime) {
+      currentTime += kRolloverTime;
+    }
+
+    result = (currentTime - m_startTime) + m_accumulatedTime;
+  } else {
+    result = m_accumulatedTime;
+  }
+
+  return result;
+}
+
+/**
+ * Reset the timer by setting the time to 0.
+ *
+ * Make the timer startTime the current time so new requests will be relative to
+ * now.
+ */
+void Timer::Reset() {
+  std::lock_guard<hal::priority_mutex> sync(m_mutex);
+  m_accumulatedTime = 0;
+  m_startTime = GetFPGATimestamp();
+}
+
+/**
+ * Start the timer running.
+ *
+ * Just set the running flag to true indicating that all time requests should be
+ * relative to the system clock.
+ */
+void Timer::Start() {
+  std::lock_guard<hal::priority_mutex> sync(m_mutex);
+  if (!m_running) {
+    m_startTime = GetFPGATimestamp();
+    m_running = true;
+  }
+}
+
+/**
+ * Stop the timer.
+ *
+ * This computes the time as of now and clears the running flag, causing all
+ * subsequent time requests to be read from the accumulated time rather than
+ * looking at the system clock.
+ */
+void Timer::Stop() {
+  double temp = Get();
+
+  std::lock_guard<hal::priority_mutex> sync(m_mutex);
+  if (m_running) {
+    m_accumulatedTime = temp;
+    m_running = false;
+  }
+}
+
+/**
+ * Check if the period specified has passed and if it has, advance the start
+ * time by that period. This is useful to decide if it's time to do periodic
+ * work without drifting later by the time it took to get around to checking.
+ *
+ * @param period The period to check for (in seconds).
+ * @return True if the period has passed.
+ */
+bool Timer::HasPeriodPassed(double period) {
+  if (Get() > period) {
+    std::lock_guard<hal::priority_mutex> sync(m_mutex);
+    // Advance the start time by the period.
+    m_startTime += period;
+    // Don't set it to the current time... we want to avoid drift.
+    return true;
+  }
+  return false;
+}
+
+/**
+ * Return the FPGA system clock time in seconds.
+ *
+ * Return the time from the FPGA hardware clock in seconds since the FPGA
+ * started. Rolls over after 71 minutes.
+ *
+ * @returns Robot running time in seconds.
+ */
+double Timer::GetFPGATimestamp() {
+  // FPGA returns the timestamp in microseconds
+  // Call the helper GetFPGATime() in Utility.cpp
+  return GetFPGATime() * 1.0e-6;
+}
+
+/**
+ * Return the approximate match time The FMS does not currently send the
+ * official match time to
+ * the robots This returns the time since the enable signal sent from the Driver
+ * Station At the
+ * beginning of autonomous, the time is reset to 0.0 seconds At the beginning of
+ * teleop, the time
+ * is reset to +15.0 seconds If the robot is disabled, this returns 0.0 seconds
+ * Warning: This is
+ * not an official time (so it cannot be used to argue with referees).
+ *
+ * @return Match time in seconds since the beginning of autonomous
+ */
+double Timer::GetMatchTime() {
+  return DriverStation::GetInstance().GetMatchTime();
+}