[sim] Add AnalogEncoderSim (#2647)

wpilibc/src/test/native/cpp/simulation/AnalogEncoderSimTest.cpp

@@ -0,0 +1,30 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2020 FIRST. 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 <hal/HAL.h>
+#include <units/math.h>
+#include <wpi/math>
+
+#include "frc/AnalogEncoder.h"
+#include "frc/AnalogInput.h"
+#include "frc/simulation/AnalogEncoderSim.h"
+#include "gtest/gtest.h"
+
+#define EXPECT_NEAR_UNITS(val1, val2, eps) \
+  EXPECT_LE(units::math::abs(val1 - val2), eps)
+
+TEST(AnalogEncoderSimTest, TestBasic) {
+  frc::AnalogInput ai(0);
+  frc::AnalogEncoder encoder{ai};
+  frc::sim::AnalogEncoderSim encoderSim{encoder};
+
+  encoderSim.SetPosition(180_deg);
+  EXPECT_NEAR(encoder.Get().to<double>(), 0.5, 1E-8);
+  EXPECT_NEAR(encoderSim.GetTurns().to<double>(), 0.5, 1E-8);
+  EXPECT_NEAR(encoderSim.GetPosition().Radians().to<double>(), wpi::math::pi,
+              1E-8);
+}