From ea9829946d90b09113f599ad93b8466ebaeb1b3d Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <stenzek@gmail.com>
Date: Sun, 6 Dec 2020 15:47:00 +1000
Subject: [PATCH] Cheats: Implement D4/D5/D6 code types

---
 src/core/analog_controller.cpp  |  6 +++
 src/core/analog_controller.h    |  1 +
 src/core/analog_joystick.cpp    |  5 +++
 src/core/analog_joystick.h      |  1 +
 src/core/cheats.cpp             | 76 +++++++++++++++++++++++++++++++--
 src/core/cheats.h               |  3 ++
 src/core/controller.cpp         |  5 +++
 src/core/controller.h           |  3 ++
 src/core/digital_controller.cpp |  5 +++
 src/core/digital_controller.h   |  1 +
 10 files changed, 103 insertions(+), 3 deletions(-)

diff --git a/src/core/analog_controller.cpp b/src/core/analog_controller.cpp
index 3cfb8b8d8..15b1ddbc8 100644
--- a/src/core/analog_controller.cpp
+++ b/src/core/analog_controller.cpp
@@ -127,6 +127,12 @@ void AnalogController::SetButtonState(s32 button_code, bool pressed)
   SetButtonState(static_cast<Button>(button_code), pressed);
 }
 
+u32 AnalogController::GetButtonStateBits() const
+{
+  // flip bits, native data is active low
+  return m_button_state ^ 0xFFFF;
+}
+
 u32 AnalogController::GetVibrationMotorCount() const
 {
   return NUM_MOTORS;
diff --git a/src/core/analog_controller.h b/src/core/analog_controller.h
index e658296b9..5bae9fa06 100644
--- a/src/core/analog_controller.h
+++ b/src/core/analog_controller.h
@@ -61,6 +61,7 @@ public:
 
   void SetAxisState(s32 axis_code, float value) override;
   void SetButtonState(s32 button_code, bool pressed) override;
+  u32 GetButtonStateBits() const override;
 
   void ResetTransferState() override;
   bool Transfer(const u8 data_in, u8* data_out) override;
diff --git a/src/core/analog_joystick.cpp b/src/core/analog_joystick.cpp
index ff5fef729..a40e6ab95 100644
--- a/src/core/analog_joystick.cpp
+++ b/src/core/analog_joystick.cpp
@@ -100,6 +100,11 @@ void AnalogJoystick::SetButtonState(s32 button_code, bool pressed)
   SetButtonState(static_cast<Button>(button_code), pressed);
 }
 
+u32 AnalogJoystick::GetButtonStateBits() const
+{
+  return m_button_state ^ 0xFFFF;
+}
+
 void AnalogJoystick::ResetTransferState()
 {
   m_transfer_state = TransferState::Idle;
diff --git a/src/core/analog_joystick.h b/src/core/analog_joystick.h
index b586187b1..fc76ded9d 100644
--- a/src/core/analog_joystick.h
+++ b/src/core/analog_joystick.h
@@ -59,6 +59,7 @@ public:
 
   void SetAxisState(s32 axis_code, float value) override;
   void SetButtonState(s32 button_code, bool pressed) override;
+  u32 GetButtonStateBits() const override;
 
   void ResetTransferState() override;
   bool Transfer(const u8 data_in, u8* data_out) override;
diff --git a/src/core/cheats.cpp b/src/core/cheats.cpp
index 191e45540..34fe08dfc 100644
--- a/src/core/cheats.cpp
+++ b/src/core/cheats.cpp
@@ -6,9 +6,11 @@
 #include "common/log.h"
 #include "common/string.h"
 #include "common/string_util.h"
+#include "controller.h"
 #include "cpu_code_cache.h"
 #include "cpu_core.h"
 #include "host_interface.h"
+#include "system.h"
 #include <cctype>
 #include <iomanip>
 #include <sstream>
@@ -95,6 +97,47 @@ static void DoMemoryWrite(PhysicalMemoryAddress address, T value)
   }
 }
 
+static u32 GetControllerButtonBits()
+{
+  static constexpr std::array<u16, 16> button_mapping = {{
+    0x0100, // Select
+    0x0200, // L3
+    0x0400, // R3
+    0x0800, // Start
+    0x1000, // Up
+    0x2000, // Right
+    0x4000, // Down
+    0x8000, // Left
+    0x0001, // L2
+    0x0002, // R2
+    0x0004, // L1
+    0x0008, // R1
+    0x0010, // Triangle
+    0x0020, // Circle
+    0x0040, // Cross
+    0x0080, // Square
+  }};
+
+  u32 bits = 0;
+  for (u32 i = 0; i < NUM_CONTROLLER_AND_CARD_PORTS; i++)
+  {
+    Controller* controller = System::GetController(i);
+    if (!controller)
+      continue;
+
+    bits |= controller->GetButtonStateBits();
+  }
+
+  u32 translated_bits = 0;
+  for (u32 i = 0, bit = 1; i < static_cast<u32>(button_mapping.size()); i++, bit <<= 1)
+  {
+    if (bits & bit)
+      translated_bits |= button_mapping[i];
+  }
+
+  return translated_bits;
+}
+
 CheatList::CheatList() = default;
 
 CheatList::~CheatList() = default;
@@ -921,12 +964,39 @@ void CheatCode::Apply() const
       }
       break;
 
-      case InstructionCode::SkipIfNotEqual16: // C0
+      case InstructionCode::CompareButtons: // D4
+      {
+        if (inst.value16 == GetControllerButtonBits())
+          index++;
+        else
+          index += 2;
+      }
+      break;
+
+      case InstructionCode::SkipIfNotEqual16:      // C0
+      case InstructionCode::SkipIfButtonsNotEqual: // D5
+      case InstructionCode::SkipIfButtonsEqual:    // D6
       {
-        const u16 value = DoMemoryRead<u16>(inst.address);
         index++;
 
-        if (value == inst.value16)
+        bool activate_codes;
+        switch (inst.code)
+        {
+          case InstructionCode::SkipIfNotEqual16: // C0
+            activate_codes = (DoMemoryRead<u16>(inst.address) == inst.value16);
+            break;
+          case InstructionCode::SkipIfButtonsNotEqual: // D5
+            activate_codes = (GetControllerButtonBits() == inst.value16);
+            break;
+          case InstructionCode::SkipIfButtonsEqual: // D6
+            activate_codes = (GetControllerButtonBits() != inst.value16);
+            break;
+          default:
+            activate_codes = false;
+            break;
+        }
+
+        if (activate_codes)
         {
           // execute following instructions
           continue;
diff --git a/src/core/cheats.h b/src/core/cheats.h
index d7be430e9..f8eb64edb 100644
--- a/src/core/cheats.h
+++ b/src/core/cheats.h
@@ -31,6 +31,9 @@ struct CheatCode
     Increment8 = 0x20,
     Decrement8 = 0x21,
     SkipIfNotEqual16 = 0xC0,
+    SkipIfButtonsNotEqual = 0xD5,
+    SkipIfButtonsEqual = 0xD6,
+    CompareButtons = 0xD4,
     CompareEqual16 = 0xD0,
     CompareNotEqual16 = 0xD1,
     CompareLess16 = 0xD2,
diff --git a/src/core/controller.cpp b/src/core/controller.cpp
index 344942e83..f3ff50e37 100644
--- a/src/core/controller.cpp
+++ b/src/core/controller.cpp
@@ -30,6 +30,11 @@ void Controller::SetAxisState(s32 axis_code, float value) {}
 
 void Controller::SetButtonState(s32 button_code, bool pressed) {}
 
+u32 Controller::GetButtonStateBits() const
+{
+  return 0;
+}
+
 u32 Controller::GetVibrationMotorCount() const
 {
   return 0;
diff --git a/src/core/controller.h b/src/core/controller.h
index 2f2a83eb4..ad281eec3 100644
--- a/src/core/controller.h
+++ b/src/core/controller.h
@@ -51,6 +51,9 @@ public:
   /// Changes the specified button state.
   virtual void SetButtonState(s32 button_code, bool pressed);
 
+  /// Returns a bitmask of the current button states, 1 = on.
+  virtual u32 GetButtonStateBits() const;
+
   /// Returns the number of vibration motors.
   virtual u32 GetVibrationMotorCount() const;
 
diff --git a/src/core/digital_controller.cpp b/src/core/digital_controller.cpp
index 8ab5d7bbc..eb7c53b3c 100644
--- a/src/core/digital_controller.cpp
+++ b/src/core/digital_controller.cpp
@@ -55,6 +55,11 @@ void DigitalController::SetButtonState(s32 button_code, bool pressed)
   SetButtonState(static_cast<Button>(button_code), pressed);
 }
 
+u32 DigitalController::GetButtonStateBits() const
+{
+  return m_button_state ^ 0xFFFF;
+}
+
 void DigitalController::ResetTransferState()
 {
   m_transfer_state = TransferState::Idle;
diff --git a/src/core/digital_controller.h b/src/core/digital_controller.h
index 113283b8b..6b7489567 100644
--- a/src/core/digital_controller.h
+++ b/src/core/digital_controller.h
@@ -47,6 +47,7 @@ public:
 
   void SetAxisState(s32 axis_code, float value) override;
   void SetButtonState(s32 button_code, bool pressed) override;
+  u32 GetButtonStateBits() const override;
 
   void ResetTransferState() override;
   bool Transfer(const u8 data_in, u8* data_out) override;