Get halsim_gazebo building again (#1201)

simulation/halsim_gazebo/src/main/native/cpp/GazeboAnalogIn.cpp

@@ -0,0 +1,47 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2014-2018 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 "GazeboAnalogIn.h"
+
+#include <string>
+
+#include <HAL/Power.h>
+
+#include "MockData/AnalogInData.h"
+#include "MockData/HAL_Value.h"
+#include "MockData/NotifyListener.h"
+
+static void init_callback(const char* name, void* param,
+                          const struct HAL_Value* value) {
+  GazeboAnalogIn* ain = static_cast<GazeboAnalogIn*>(param);
+  ain->SetInitialized(value->data.v_boolean);
+  if (ain->IsInitialized()) {
+    ain->Listen();
+  }
+}
+
+GazeboAnalogIn::GazeboAnalogIn(int index, HALSimGazebo* halsim) {
+  m_index = index;
+  m_halsim = halsim;
+  m_sub = NULL;
+  HALSIM_RegisterAnalogInInitializedCallback(index, init_callback, this, true);
+}
+
+void GazeboAnalogIn::Listen() {
+  if (!m_sub)
+    m_sub = m_halsim->node.Subscribe<gazebo::msgs::Float64>(
+        "~/simulator/analog/" + std::to_string(m_index),
+        &GazeboAnalogIn::Callback, this);
+}
+
+void GazeboAnalogIn::Callback(const gazebo::msgs::ConstFloat64Ptr& msg) {
+  /* This value is going to be divided by the 5V rail in the HAL, so
+     we multiply by that value to make the change neutral */
+  int32_t status;
+  HALSIM_SetAnalogInVoltage(m_index,
+                            msg->data() * HAL_GetUserVoltage5V(&status));
+}