From e1b838355e94702fa0724de06f903864dfb0488e Mon Sep 17 00:00:00 2001
From: "Adrian.Conlon" <adrian.conlon@gmail.com>
Date: Fri, 15 Sep 2017 00:53:56 +0100
Subject: [PATCH] Add P1 (i.e. keyboard) support.  Interestingly, gets Tetris
 *much* further.

Signed-off-by: Adrian.Conlon <adrian.conlon@gmail.com>
---
 LR35902/inc/GameBoyBus.h   | 33 +++++++++++++++++++++++++++++++++
 LR35902/src/GameBoyBus.cpp | 25 ++++++++++++++++++++++---
 2 files changed, 55 insertions(+), 3 deletions(-)

diff --git a/LR35902/inc/GameBoyBus.h b/LR35902/inc/GameBoyBus.h
index 530598c..c1ecb83 100644
--- a/LR35902/inc/GameBoyBus.h
+++ b/LR35902/inc/GameBoyBus.h
@@ -217,6 +217,30 @@ namespace EightBit {
 			void loadBootRom(const std::string& path);
 			void loadGameRom(const std::string& path);
 
+			void pressUp() { m_upPressed = true; }
+			void releaseUp() { m_upPressed = false; }
+
+			void pressDown() { m_downPressed = true; }
+			void releaseDown() { m_downPressed = false; }
+
+			void pressLeft() { m_leftPressed = true; }
+			void releaseLeft() { m_leftPressed = false; }
+
+			void pressRight() { m_rightPressed = true; }
+			void releaseRight() { m_rightPressed = false; }
+
+			void pressA() { m_aPressed = true; }
+			void releaseA() { m_aPressed = false; }
+
+			void pressB() { m_bPressed = true; }
+			void releaseB() { m_bPressed = false; }
+
+			void pressSelect() { m_selectPressed = true; }
+			void releaseSelect() { m_selectPressed = false; }
+
+			void pressStart() { m_startPressed = true; }
+			void releaseStart() { m_startPressed = false; }
+
 		protected:
 			virtual uint8_t& reference(uint16_t address, bool& rom) {
 
@@ -280,6 +304,15 @@ namespace EightBit {
 			std::array<bool, 4> m_soundChannelEnabled;
 			bool m_soundEnabled;
 
+			bool m_upPressed;
+			bool m_downPressed;
+			bool m_leftPressed;
+			bool m_rightPressed;
+			bool m_aPressed;
+			bool m_bPressed;
+			bool m_selectPressed;
+			bool m_startPressed;
+
 			void checkTimer(int cycles);
 
 			void validateCartridgeType();
diff --git a/LR35902/src/GameBoyBus.cpp b/LR35902/src/GameBoyBus.cpp
index c3b6453..5a16e26 100644
--- a/LR35902/src/GameBoyBus.cpp
+++ b/LR35902/src/GameBoyBus.cpp
@@ -22,7 +22,16 @@ EightBit::GameBoy::Bus::Bus()
   m_ramBank(0),
   m_timerCounter(0),
   m_timerRate(0),
-  m_dmaTransferActive(false) {
+  m_dmaTransferActive(false),
+  m_upPressed(false),
+  m_downPressed(false),
+  m_leftPressed(false),
+  m_rightPressed(false),
+  m_aPressed(false),
+  m_bPressed(false),
+  m_selectPressed(false),
+  m_startPressed(false)
+{
 	ReadingByte.connect(std::bind(&GameBoy::Bus::Bus_ReadingByte, this, std::placeholders::_1));
 	ReadByte.connect(std::bind(&GameBoy::Bus::Bus_ReadByte, this, std::placeholders::_1));
 	WritingByte.connect(std::bind(&GameBoy::Bus::Bus_WritingByte, this, std::placeholders::_1));
@@ -67,8 +76,18 @@ void EightBit::GameBoy::Bus::Bus_ReadingByte(const uint16_t address) {
 		switch (ioRegister) {
 
 		// Port/Mode Registers
-		case P1:
-			mask(Processor::Mask5);
+		case P1: {
+				auto direction = m_rightPressed || m_leftPressed || m_upPressed || m_downPressed;
+				auto button = m_aPressed || m_bPressed || m_selectPressed || m_startPressed;
+				pokeRegister(P1,
+					  (int)!(m_rightPressed || m_aPressed)
+					| ((int)!(m_leftPressed || m_bPressed) << 1)
+					| ((int)!(m_upPressed || m_selectPressed) << 2)
+					| ((int)!(m_downPressed || m_startPressed) << 3)
+					| (direction << 4)
+					| (button << 5)
+					| Processor::Bit6 | Processor::Bit7);
+			}
 			break;
 		case SB:
 			break;