From e6bd6587fdd294fa4e5dd189a2c5d5c6155a0b95 Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <stenzek@gmail.com>
Date: Sun, 26 Apr 2020 01:18:42 +1000
Subject: [PATCH] Controller: Add emulation of Namco GunCon

---
 src/core/CMakeLists.txt       |   2 +
 src/core/controller.cpp       |  21 +++-
 src/core/controller.h         |   3 +-
 src/core/core.vcxproj         |   2 +
 src/core/core.vcxproj.filters |   2 +
 src/core/namco_guncon.cpp     | 219 ++++++++++++++++++++++++++++++++++
 src/core/namco_guncon.h       |  66 ++++++++++
 src/core/pad.cpp              |   2 +-
 src/core/settings.cpp         |   7 +-
 src/core/system.cpp           |   2 +-
 src/core/types.h              |   1 +
 11 files changed, 320 insertions(+), 7 deletions(-)
 create mode 100644 src/core/namco_guncon.cpp
 create mode 100644 src/core/namco_guncon.h

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index 9f9c02ca6..af3b0bb5d 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -52,6 +52,8 @@ add_library(core
     mdec.h
     memory_card.cpp
     memory_card.h
+    namco_guncon.cpp
+    namco_guncon.h
     pad.cpp
     pad.h
     psf_loader.cpp
diff --git a/src/core/controller.cpp b/src/core/controller.cpp
index 1ec67eab5..1690a88f8 100644
--- a/src/core/controller.cpp
+++ b/src/core/controller.cpp
@@ -1,6 +1,7 @@
 #include "controller.h"
 #include "analog_controller.h"
 #include "common/state_wrapper.h"
+#include "namco_guncon.h"
 #include "digital_controller.h"
 
 Controller::Controller() = default;
@@ -36,7 +37,7 @@ float Controller::GetVibrationMotorStrength(u32 motor)
   return 0.0f;
 }
 
-std::unique_ptr<Controller> Controller::Create(ControllerType type)
+std::unique_ptr<Controller> Controller::Create(System* system, ControllerType type)
 {
   switch (type)
   {
@@ -46,6 +47,9 @@ std::unique_ptr<Controller> Controller::Create(ControllerType type)
     case ControllerType::AnalogController:
       return AnalogController::Create();
 
+    case ControllerType::NamcoGunCon:
+      return NamcoGunCon::Create(system);
+
     case ControllerType::None:
     default:
       return {};
@@ -72,6 +76,9 @@ Controller::AxisList Controller::GetAxisNames(ControllerType type)
     case ControllerType::AnalogController:
       return AnalogController::StaticGetAxisNames();
 
+    case ControllerType::NamcoGunCon:
+      return NamcoGunCon::StaticGetAxisNames();
+
     case ControllerType::None:
     default:
       return {};
@@ -88,6 +95,9 @@ Controller::ButtonList Controller::GetButtonNames(ControllerType type)
     case ControllerType::AnalogController:
       return AnalogController::StaticGetButtonNames();
 
+    case ControllerType::NamcoGunCon:
+      return NamcoGunCon::StaticGetButtonNames();
+
     case ControllerType::None:
     default:
       return {};
@@ -104,6 +114,9 @@ u32 Controller::GetVibrationMotorCount(ControllerType type)
     case ControllerType::AnalogController:
       return AnalogController::StaticGetVibrationMotorCount();
 
+    case ControllerType::NamcoGunCon:
+      return NamcoGunCon::StaticGetVibrationMotorCount();
+
     case ControllerType::None:
     default:
       return 0;
@@ -120,6 +133,9 @@ std::optional<s32> Controller::GetAxisCodeByName(ControllerType type, std::strin
     case ControllerType::AnalogController:
       return AnalogController::StaticGetAxisCodeByName(axis_name);
 
+    case ControllerType::NamcoGunCon:
+      return NamcoGunCon::StaticGetAxisCodeByName(axis_name);
+
     case ControllerType::None:
     default:
       return std::nullopt;
@@ -136,6 +152,9 @@ std::optional<s32> Controller::GetButtonCodeByName(ControllerType type, std::str
     case ControllerType::AnalogController:
       return AnalogController::StaticGetButtonCodeByName(button_name);
 
+    case ControllerType::NamcoGunCon:
+      return NamcoGunCon::StaticGetButtonCodeByName(button_name);
+
     case ControllerType::None:
     default:
       return std::nullopt;
diff --git a/src/core/controller.h b/src/core/controller.h
index 5f05deae0..1833c29f0 100644
--- a/src/core/controller.h
+++ b/src/core/controller.h
@@ -7,6 +7,7 @@
 #include <vector>
 
 class StateWrapper;
+class System;
 
 class Controller
 {
@@ -48,7 +49,7 @@ public:
   virtual float GetVibrationMotorStrength(u32 motor);
 
   /// Creates a new controller of the specified type.
-  static std::unique_ptr<Controller> Create(ControllerType type);
+  static std::unique_ptr<Controller> Create(System* system, ControllerType type);
 
   /// Gets the integer code for an axis in the specified controller type.
   static std::optional<s32> GetAxisCodeByName(ControllerType type, std::string_view axis_name);
diff --git a/src/core/core.vcxproj b/src/core/core.vcxproj
index b4802b6c1..9aa2e829e 100644
--- a/src/core/core.vcxproj
+++ b/src/core/core.vcxproj
@@ -75,6 +75,7 @@
     <ClCompile Include="interrupt_controller.cpp" />
     <ClCompile Include="mdec.cpp" />
     <ClCompile Include="memory_card.cpp" />
+    <ClCompile Include="namco_guncon.cpp" />
     <ClCompile Include="pad.cpp" />
     <ClCompile Include="controller.cpp" />
     <ClCompile Include="psf_loader.cpp" />
@@ -115,6 +116,7 @@
     <ClInclude Include="interrupt_controller.h" />
     <ClInclude Include="mdec.h" />
     <ClInclude Include="memory_card.h" />
+    <ClInclude Include="namco_guncon.h" />
     <ClInclude Include="pad.h" />
     <ClInclude Include="controller.h" />
     <ClInclude Include="psf_loader.h" />
diff --git a/src/core/core.vcxproj.filters b/src/core/core.vcxproj.filters
index f2bbbf7f2..e15248cc7 100644
--- a/src/core/core.vcxproj.filters
+++ b/src/core/core.vcxproj.filters
@@ -41,6 +41,7 @@
     <ClCompile Include="timing_event.cpp" />
     <ClCompile Include="cdrom_async_reader.cpp" />
     <ClCompile Include="psf_loader.cpp" />
+    <ClCompile Include="namco_guncon.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="types.h" />
@@ -83,6 +84,7 @@
     <ClInclude Include="timing_event.h" />
     <ClInclude Include="cdrom_async_reader.h" />
     <ClInclude Include="psf_loader.h" />
+    <ClInclude Include="namco_guncon.h" />
   </ItemGroup>
   <ItemGroup>
     <None Include="cpu_core.inl" />
diff --git a/src/core/namco_guncon.cpp b/src/core/namco_guncon.cpp
new file mode 100644
index 000000000..6d90fecc2
--- /dev/null
+++ b/src/core/namco_guncon.cpp
@@ -0,0 +1,219 @@
+#include "namco_guncon.h"
+#include "common/assert.h"
+#include "common/log.h"
+#include "common/state_wrapper.h"
+#include "gpu.h"
+#include "imgui.h"
+#include "system.h"
+#include <array>
+Log_SetChannel(NamcoGunCon);
+
+NamcoGunCon::NamcoGunCon(System* system) : m_system(system) {}
+
+NamcoGunCon::~NamcoGunCon() = default;
+
+ControllerType NamcoGunCon::GetType() const
+{
+  return ControllerType::NamcoGunCon;
+}
+
+std::optional<s32> NamcoGunCon::GetAxisCodeByName(std::string_view axis_name) const
+{
+  return StaticGetAxisCodeByName(axis_name);
+}
+
+std::optional<s32> NamcoGunCon::GetButtonCodeByName(std::string_view button_name) const
+{
+  return StaticGetButtonCodeByName(button_name);
+}
+
+void NamcoGunCon::Reset()
+{
+  m_transfer_state = TransferState::Idle;
+}
+
+bool NamcoGunCon::DoState(StateWrapper& sw)
+{
+  if (!Controller::DoState(sw))
+    return false;
+
+  sw.Do(&m_button_state);
+  sw.Do(&m_position_x);
+  sw.Do(&m_position_y);
+  sw.Do(&m_transfer_state);
+  return true;
+}
+
+void NamcoGunCon::SetAxisState(s32 axis_code, float value) {}
+
+void NamcoGunCon::SetButtonState(Button button, bool pressed)
+{
+  static constexpr std::array<u8, static_cast<size_t>(Button::Count)> indices = {{13, 3, 14}};
+  if (pressed)
+    m_button_state &= ~(u16(1) << indices[static_cast<u8>(button)]);
+  else
+    m_button_state |= u16(1) << indices[static_cast<u8>(button)];
+}
+
+void NamcoGunCon::SetButtonState(s32 button_code, bool pressed)
+{
+  if (button_code < 0 || button_code >= static_cast<s32>(Button::Count))
+    return;
+
+  SetButtonState(static_cast<Button>(button_code), pressed);
+}
+
+void NamcoGunCon::ResetTransferState()
+{
+  m_transfer_state = TransferState::Idle;
+}
+
+bool NamcoGunCon::Transfer(const u8 data_in, u8* data_out)
+{
+  static constexpr u16 ID = 0x5A63;
+
+  switch (m_transfer_state)
+  {
+    case TransferState::Idle:
+    {
+      // ack when sent 0x01, send ID for 0x42
+      if (data_in == 0x42)
+      {
+        *data_out = Truncate8(ID);
+        m_transfer_state = TransferState::IDMSB;
+        return true;
+      }
+      else
+      {
+        *data_out = 0xFF;
+        return (data_in == 0x01);
+      }
+    }
+
+    case TransferState::IDMSB:
+    {
+      *data_out = Truncate8(ID >> 8);
+      m_transfer_state = TransferState::ButtonsLSB;
+      return true;
+    }
+
+    case TransferState::ButtonsLSB:
+    {
+      *data_out = Truncate8(m_button_state);
+      m_transfer_state = TransferState::ButtonsMSB;
+      return true;
+    }
+
+    case TransferState::ButtonsMSB:
+    {
+      *data_out = Truncate8(m_button_state >> 8);
+      m_transfer_state = TransferState::XLSB;
+      return true;
+    }
+
+    case TransferState::XLSB:
+    {
+      UpdatePosition();
+      *data_out = Truncate8(m_position_x);
+      m_transfer_state = TransferState::XMSB;
+      return true;
+    }
+
+    case TransferState::XMSB:
+    {
+      *data_out = Truncate8(m_position_x >> 8);
+      m_transfer_state = TransferState::YLSB;
+      return true;
+    }
+
+    case TransferState::YLSB:
+    {
+      *data_out = Truncate8(m_position_y);
+      m_transfer_state = TransferState::YMSB;
+      return true;
+    }
+
+    case TransferState::YMSB:
+    {
+      *data_out = Truncate8(m_position_y >> 8);
+      m_transfer_state = TransferState::Idle;
+      return false;
+    }
+
+    default:
+    {
+      UnreachableCode();
+      return false;
+    }
+  }
+}
+
+void NamcoGunCon::UpdatePosition()
+{
+  // get screen coordinates. TODO better way
+  const s32 mouse_x = static_cast<s32>(ImGui::GetIO().MousePos.x);
+  const s32 mouse_y = static_cast<s32>(ImGui::GetIO().MousePos.y);
+
+  // are we within the active display area?
+  u32 tick, line;
+  if (mouse_x < 0 || mouse_y < 0 ||
+      !m_system->GetGPU()->ConvertScreenCoordinatesToBeamTicksAndLines(mouse_x, mouse_y, &tick, &line))
+  {
+    Log_DebugPrintf("Lightgun out of range for window coordinates %d,%d", mouse_x, mouse_y);
+    m_position_x = 0x01;
+    m_position_y = 0x0A;
+    return;
+  }
+
+  // 8MHz units for X = 44100*768*11/7 = 53222400 / 8000000 = 6.6528
+  m_position_x = static_cast<u16>(static_cast<float>(tick) * (1.0f / 6.6528f));
+  m_position_y = static_cast<u16>(line);
+  Log_DebugPrintf("Lightgun window coordinates %d,%d -> tick %u line %u 8mhz ticks %u", tick, line, m_position_x);
+}
+
+std::unique_ptr<NamcoGunCon> NamcoGunCon::Create(System* system)
+{
+  return std::make_unique<NamcoGunCon>(system);
+}
+
+std::optional<s32> NamcoGunCon::StaticGetAxisCodeByName(std::string_view button_name)
+{
+  return std::nullopt;
+}
+
+std::optional<s32> NamcoGunCon::StaticGetButtonCodeByName(std::string_view button_name)
+{
+#define BUTTON(name)                                                                                                   \
+  if (button_name == #name)                                                                                            \
+  {                                                                                                                    \
+    return static_cast<s32>(ZeroExtend32(static_cast<u8>(Button::name)));                                              \
+  }
+
+  BUTTON(Trigger);
+  BUTTON(A);
+  BUTTON(B);
+
+  return std::nullopt;
+
+#undef BUTTON
+}
+
+Controller::AxisList NamcoGunCon::StaticGetAxisNames()
+{
+  return {};
+}
+
+Controller::ButtonList NamcoGunCon::StaticGetButtonNames()
+{
+#define B(n)                                                                                                           \
+  {                                                                                                                    \
+#n, static_cast < s32>(Button::n)                                                                                  \
+  }
+  return {B(Trigger), B(A), B(B)};
+#undef B
+}
+
+u32 NamcoGunCon::StaticGetVibrationMotorCount()
+{
+  return 0;
+}
diff --git a/src/core/namco_guncon.h b/src/core/namco_guncon.h
new file mode 100644
index 000000000..341e986dd
--- /dev/null
+++ b/src/core/namco_guncon.h
@@ -0,0 +1,66 @@
+#pragma once
+#include "controller.h"
+#include <memory>
+#include <optional>
+#include <string_view>
+
+class NamcoGunCon final : public Controller
+{
+public:
+  enum class Button : u8
+  {
+    Trigger = 0,
+    A = 1,
+    B = 2,
+    Count
+  };
+
+  NamcoGunCon(System* system);
+  ~NamcoGunCon() override;
+
+  static std::unique_ptr<NamcoGunCon> Create(System* system);
+  static std::optional<s32> StaticGetAxisCodeByName(std::string_view button_name);
+  static std::optional<s32> StaticGetButtonCodeByName(std::string_view button_name);
+  static AxisList StaticGetAxisNames();
+  static ButtonList StaticGetButtonNames();
+  static u32 StaticGetVibrationMotorCount();
+
+  ControllerType GetType() const override;
+  std::optional<s32> GetAxisCodeByName(std::string_view axis_name) const override;
+  std::optional<s32> GetButtonCodeByName(std::string_view button_name) const override;
+
+  void Reset() override;
+  bool DoState(StateWrapper& sw) override;
+
+  void SetAxisState(s32 axis_code, float value) override;
+  void SetButtonState(s32 button_code, bool pressed) override;
+
+  void ResetTransferState() override;
+  bool Transfer(const u8 data_in, u8* data_out) override;
+
+  void SetButtonState(Button button, bool pressed);
+
+private:
+  void UpdatePosition();
+
+  enum class TransferState : u8
+  {
+    Idle,
+    IDMSB,
+    ButtonsLSB,
+    ButtonsMSB,
+    XLSB,
+    XMSB,
+    YLSB,
+    YMSB
+  };
+
+  System* m_system;
+
+  // buttons are active low
+  u16 m_button_state = UINT16_C(0xFFFF);
+  u16 m_position_x = 0;
+  u16 m_position_y = 0;
+
+  TransferState m_transfer_state = TransferState::Idle;
+};
diff --git a/src/core/pad.cpp b/src/core/pad.cpp
index 19fe48904..384bb3442 100644
--- a/src/core/pad.cpp
+++ b/src/core/pad.cpp
@@ -50,7 +50,7 @@ bool Pad::DoState(StateWrapper& sw)
 
       m_controllers[i].reset();
       if (state_controller_type != ControllerType::None)
-        m_controllers[i] = Controller::Create(state_controller_type);
+        m_controllers[i] = Controller::Create(m_system, state_controller_type);
     }
 
     if (m_controllers[i])
diff --git a/src/core/settings.cpp b/src/core/settings.cpp
index 10bcffb1c..d6e8c0552 100644
--- a/src/core/settings.cpp
+++ b/src/core/settings.cpp
@@ -349,9 +349,10 @@ const char* Settings::GetAudioBackendDisplayName(AudioBackend backend)
   return s_audio_backend_display_names[static_cast<int>(backend)];
 }
 
-static std::array<const char*, 3> s_controller_type_names = {{"None", "DigitalController", "AnalogController"}};
-static std::array<const char*, 3> s_controller_display_names = {
-  {"None", "Digital Controller", "Analog Controller (DualShock)"}};
+static std::array<const char*, 4> s_controller_type_names = {
+  {"None", "DigitalController", "AnalogController", "NamcoGunCon"}};
+static std::array<const char*, 4> s_controller_display_names = {
+  {"None", "Digital Controller", "Analog Controller (DualShock)", "Namco GunCon"}};
 
 std::optional<ControllerType> Settings::ParseControllerTypeName(const char* str)
 {
diff --git a/src/core/system.cpp b/src/core/system.cpp
index 75b01bbde..1d103d720 100644
--- a/src/core/system.cpp
+++ b/src/core/system.cpp
@@ -785,7 +785,7 @@ void System::UpdateControllers()
     const ControllerType type = settings.controller_types[i];
     if (type != ControllerType::None)
     {
-      std::unique_ptr<Controller> controller = Controller::Create(type);
+      std::unique_ptr<Controller> controller = Controller::Create(this, type);
       if (controller)
         m_pad->SetController(i, std::move(controller));
     }
diff --git a/src/core/types.h b/src/core/types.h
index d7f3e6529..a918a1ce6 100644
--- a/src/core/types.h
+++ b/src/core/types.h
@@ -87,6 +87,7 @@ enum class ControllerType
   None,
   DigitalController,
   AnalogController,
+  NamcoGunCon,
   Count
 };