WiimoteEmu: Add option to use system battery level

Only supports Windows and Mac right now.

Source/Core/Core/CMakeLists.txt

@@ -291,6 +291,8 @@ add_library(core
   HW/WiimoteEmu/MotionPlus.h
   HW/WiimoteEmu/Speaker.cpp
   HW/WiimoteEmu/Speaker.h
+  HW/WiimoteEmu/SystemBattery.cpp
+  HW/WiimoteEmu/SystemBattery.h
   HW/WiimoteEmu/WiimoteEmu.cpp
   HW/WiimoteEmu/WiimoteEmu.h
   HW/WiimoteEmu/Extension/Classic.cpp

Source/Core/Core/Core.vcxproj

@@ -190,6 +190,7 @@
     <ClCompile Include="HW\WiimoteEmu\I2CBus.cpp" />
     <ClCompile Include="HW\WiimoteEmu\MotionPlus.cpp" />
     <ClCompile Include="HW\WiimoteEmu\Speaker.cpp" />
+    <ClCompile Include="HW\WiimoteEmu\SystemBattery.cpp" />
     <ClCompile Include="HW\WiimoteEmu\WiimoteEmu.cpp" />
     <ClCompile Include="HW\WiimoteReal\IOWin.cpp" />
     <ClCompile Include="HW\WiimoteReal\WiimoteReal.cpp" />
@@ -465,6 +466,7 @@
     <ClInclude Include="HW\WiimoteEmu\I2CBus.h" />
     <ClInclude Include="HW\WiimoteEmu\MotionPlus.h" />
     <ClInclude Include="HW\WiimoteEmu\Speaker.h" />
+    <ClInclude Include="HW\WiimoteEmu\SystemBattery.h" />
     <ClInclude Include="HW\WiimoteEmu\WiimoteEmu.h" />
     <ClInclude Include="HW\WiimoteReal\WiimoteReal.h" />
     <ClInclude Include="HW\WiimoteReal\WiimoteRealBase.h" />

Source/Core/Core/Core.vcxproj.filters

@@ -526,6 +526,9 @@
     <ClCompile Include="HW\WiimoteEmu\Encryption.cpp">
       <Filter>HW %28Flipper/Hollywood%29\Wiimote\Emu</Filter>
     </ClCompile>
+    <ClCompile Include="HW\WiimoteEmu\SystemBattery.cpp">
+      <Filter>HW %28Flipper/Hollywood%29\Wiimote\Emu</Filter>
+    </ClCompile>
     <ClCompile Include="HW\WiimoteEmu\WiimoteEmu.cpp">
       <Filter>HW %28Flipper/Hollywood%29\Wiimote\Emu</Filter>
     </ClCompile>
@@ -1238,6 +1241,9 @@
     <ClInclude Include="HW\WiimoteEmu\Encryption.h">
       <Filter>HW %28Flipper/Hollywood%29\Wiimote\Emu</Filter>
     </ClInclude>
+    <ClInclude Include="HW\WiimoteEmu\SystemBattery.h">
+      <Filter>HW %28Flipper/Hollywood%29\Wiimote\Emu</Filter>
+    </ClInclude>
     <ClInclude Include="HW\WiimoteEmu\WiimoteEmu.h">
       <Filter>HW %28Flipper/Hollywood%29\Wiimote\Emu</Filter>
     </ClInclude>

Source/Core/Core/HW/WiimoteEmu/EmuSubroutines.cpp

@@ -16,6 +16,7 @@
 #include "Core/Analytics.h"
 #include "Core/Core.h"
 #include "Core/HW/WiimoteCommon/WiimoteHid.h"
+#include "Core/HW/WiimoteEmu/SystemBattery.h"
 #include "Core/HW/WiimoteEmu/WiimoteEmu.h"
 #include "Core/HW/WiimoteReal/WiimoteReal.h"
 #include "InputCommon/ControllerEmu/ControlGroup/Attachments.h"
@@ -240,13 +241,35 @@ void Wiimote::HandleRequestStatus(const OutputReportRequestStatus&)
   // Max battery level seems to be 0xc8 (decimal 200)
   constexpr u8 MAX_BATTERY_LEVEL = 0xc8;
 
-  m_status.battery = u8(std::lround(m_battery_setting.GetValue() / 100 * MAX_BATTERY_LEVEL));
-
+  std::optional<float> battery;
   if (Core::WantsDeterminism())
   {
     // One less thing to break determinism:
     m_status.battery = MAX_BATTERY_LEVEL;
   }
+  else if (m_system_battery_setting.GetValue() && (battery = GetSystemBatteryLevel()))
+  {
+    // The HOME Menu and Metroid Prime 3 battery bars work like:
+    // 84+ => 4/4, 67+ => 3/4, 51+ => 2/4, 3+ 1/4, 2 or less => 0/4
+    // Something that fits those values is more useful than just multiplying
+    // by MAX_BATTERY_LEVEL (otherwise e.g. 50% battery status shows up as 4/4)
+    // The following math is not based on real battery behaviour, it just makes
+    // good-looking numbers..
+    constexpr float LOW = 0.3f;
+    if (*battery > LOW)
+    {
+      *battery = std::exp(*battery)/M_E;
+    }
+    else
+    {
+      *battery *= std::exp(LOW)/M_E / LOW;
+    }
+    m_status.battery = u8(std::lround(*battery * 100));
+  }
+  else
+  {
+    m_status.battery = u8(std::lround(m_battery_setting.GetValue() / 100 * MAX_BATTERY_LEVEL));
+  }
 
   // Less than 0x20 triggers the low-battery flag:
   m_status.battery_low = m_status.battery < 0x20;

Source/Core/Core/HW/WiimoteEmu/SystemBattery.cpp

@@ -0,0 +1,109 @@
+// Copyright 2019 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "Core/HW/WiimoteEmu/SystemBattery.h"
+
+#include "Common/ScopeGuard.h"
+
+#if defined(_WIN32)
+#include <Windows.h>
+#elif defined(__APPLE__)
+#include <CoreFoundation/CFDictionary.h>
+#include <IOKit/ps/IOPSKeys.h>
+#include <IOKit/ps/IOPowerSources.h>
+#endif
+
+namespace WiimoteEmu
+{
+
+#if defined(_WIN32)
+
+std::optional<float> GetSystemBatteryLevel()
+{
+  SYSTEM_POWER_STATUS power_status;
+  if (!GetSystemPowerStatus(&power_status))
+  {
+    return std::nullopt;
+  }
+
+  // Not on battery power, treat as 100%
+  if (power_status.ACLineStatus == 1)
+  {
+    return 1.0;
+  }
+
+  if (power_status.BatteryLifePercent != 255)
+  {
+    return power_status.BatteryLifePercent / 100.0f;
+  }
+
+  return std::nullopt;
+}
+
+#elif defined(__APPLE__)
+
+std::optional<float> GetSystemBatteryLevel()
+{
+  CFTypeRef power_blob = IOPSCopyPowerSourcesInfo();
+  if (!power_blob)
+  {
+    return std::nullopt;
+  }
+  Common::ScopeGuard power_blob_guard([power_blob] { CFRelease(power_blob); });
+
+  CFArrayRef power_sources = IOPSCopyPowerSourcesList(power_blob);
+  if (!power_sources)
+  {
+    return std::nullopt;
+  }
+  Common::ScopeGuard power_sources_guard([power_sources] { CFRelease(power_sources); });
+
+  CFStringRef current_power = IOPSGetProvidingPowerSourceType(power_blob);
+  // Not on battery power, treat as 100%
+  if (kCFCompareEqualTo != CFStringCompare(current_power, CFSTR(kIOPMBatteryPowerKey), 0))
+  {
+    return 1.0;
+  }
+
+  for (CFIndex i = 0; i < CFArrayGetCount(power_sources); i++)
+  {
+    CFTypeRef power_source = CFArrayGetValueAtIndex(power_sources, i);
+    CFDictionaryRef power_source_desc = IOPSGetPowerSourceDescription(power_blob, power_source);
+    if (!power_source_desc)
+    {
+      continue;
+    }
+
+    CFNumberRef capacity_current, capacity_max;
+    if (!CFDictionaryGetValueIfPresent(power_source_desc, CFSTR(kIOPSCurrentCapacityKey),
+                                       (const void**)&capacity_current) ||
+        !CFDictionaryGetValueIfPresent(power_source_desc, CFSTR(kIOPSMaxCapacityKey),
+                                       (const void**)&capacity_max))
+    {
+      continue;
+    }
+
+    float cur, max;
+    if (!CFNumberGetValue(capacity_current, kCFNumberFloat32Type, &cur) ||
+        !CFNumberGetValue(capacity_max, kCFNumberFloat32Type, &max))
+    {
+      continue;
+    }
+
+    return cur / max;
+  }
+
+  return std::nullopt;
+}
+
+#else
+
+std::optional<float> GetSystemBatteryLevel()
+{
+  return std::nullopt;
+}
+
+#endif
+
+};

Source/Core/Core/HW/WiimoteEmu/SystemBattery.h

@@ -0,0 +1,14 @@
+// Copyright 2019 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <optional>
+
+namespace WiimoteEmu
+{
+
+std::optional<float> GetSystemBatteryLevel(void);
+
+};

Source/Core/Core/HW/WiimoteEmu/WiimoteEmu.cpp

@@ -196,6 +196,9 @@ Wiimote::Wiimote(const unsigned int index) : m_index(index)
                          _trans("%")},
                         95, 0, 100);
 
+  m_options->AddSetting(&m_system_battery_setting,
+                        {_trans("Use system battery status if possible")}, true);
+
   // Note: "Upright" and "Sideways" options can be enabled at the same time which produces an
   // orientation where the wiimote points towards the left with the buttons towards you.
   m_options->AddSetting(&m_upright_setting,

Source/Core/Core/HW/WiimoteEmu/WiimoteEmu.h

@@ -245,6 +245,7 @@ class Wiimote : public ControllerEmu::EmulatedController
   ControllerEmu::SettingValue<bool> m_sideways_setting;
   ControllerEmu::SettingValue<bool> m_upright_setting;
   ControllerEmu::SettingValue<double> m_battery_setting;
+  ControllerEmu::SettingValue<bool> m_system_battery_setting;
   ControllerEmu::SettingValue<double> m_speaker_pan_setting;
   ControllerEmu::SettingValue<bool> m_motion_plus_setting;