Fix carry flags

Co-authored-by: sigonasr2 <sigonasr2@gmail.com>

main.cpp

@@ -9,7 +9,7 @@
 
 using namespace olc;
 
-bool USE_DEBUG_DISPLAY=true;
+bool USE_DEBUG_DISPLAY=false;
 int EMULATOR_SCREEN_WIDTH = 64;
 int EMULATOR_SCREEN_HEIGHT = 32;
 int EMULATOR_PIXEL_SIZE=5;
@@ -66,6 +66,7 @@ public:
 	bool USE_ORIGINAL_CHIP8_SET=true; //True means use the original CHIP-8 spec (COSMAC VIP emulation). Set to false to use CHIP-48 spec.
 	bool PAUSED=true;
 	long instructionCount=0;
+	uint16_t watchMemoryAddress=0;
 
 	std::string Display8(int number){
 		std::bitset<8>numb(number);
@@ -92,7 +93,7 @@ public:
 		for (int i=0;i<display.size();i++){
 			display[i]=0;
 		}
-		std::ifstream file("ChipWar.ch8",std::ios_base::binary);
+		std::ifstream file("chip8-test-suite.ch8",std::ios_base::binary);
 		uint16_t counter=0x200;
 		while (file.good()){
 			int val = file.get();
@@ -116,6 +117,10 @@ public:
 		return true;
 	}
 
+	void OnTextEntryComplete(const std::string &sText) override{
+		watchMemoryAddress=std::stoul(sText.c_str(),nullptr,16);
+	}
+
 	bool OnUserUpdate(float fElapsedTime) override
 	{
 		if (!USE_DEBUG_DISPLAY||!PAUSED){
@@ -130,6 +135,10 @@ public:
 				DrawDisplay();
 			}
 		} else {
+			if (GetKey(G).bPressed){
+				TextEntryEnable(true);
+			}
+			if (!IsTextEntryEnabled()){
 				if (GetKey(OEM_6).bPressed){
 					RunInstruction();
 					instructionCount++;
@@ -147,6 +156,11 @@ public:
 					DrawDisplay();
 				}
 			}
+		}
+		if (IsTextEntryEnabled()){
+			DrawStringDecal({2,2},"Goto Memory Address: "+TextEntryGetString());
+		}
+
 		std::stringstream s;
 		s<<"PC: 0x"<<std::setfill('0')<< std::setw(4)<<std::hex<<pc;
 		std::string ss=s.str();
@@ -205,6 +219,24 @@ public:
 			}
 		}
 
+		std::stringstream hexMemoryWatch;
+		hexMemoryWatch<<std::hex<<std::setfill('0')<<std::setw(4)<<watchMemoryAddress;
+		DrawStringDecal(vi2d{14+EMULATOR_PIXEL_SIZE*EMULATOR_SCREEN_WIDTH,18+21*10},"Memory Region [0x"+hexMemoryWatch.str()+"]:");
+		for (int j=0;j<12;j++){
+			std::stringstream memj;
+			memj<<std::hex<<std::setfill('0')<<std::setw(4)<<watchMemoryAddress+16*j;
+			DrawStringDecal(vi2d{14+EMULATOR_PIXEL_SIZE*EMULATOR_SCREEN_WIDTH,18+21*10+j*10+10},"0x"+memj.str());
+			for (int i=0;i<16;i++){
+				uint16_t mem = i+j*16+watchMemoryAddress;
+				if (mem<memory.size()){
+					std::stringstream hexval;
+					hexval<<std::hex<<std::setfill('0')<<std::setw(2)<<(int)memory[mem];
+					std::string sss=hexval.str();
+					std::transform(sss.begin(),sss.end(),sss.begin(),::toupper);
+					DrawStringDecal(vi2d{14+EMULATOR_PIXEL_SIZE*EMULATOR_SCREEN_WIDTH+8*8+i*3*8,18+21*10+j*10+10},sss);
+				}
+			}
+		}
 
 		return true;
 	}
@@ -463,18 +495,21 @@ public:
 						reg[X]^=reg[Y];
 					}break;
 					case 0x4:{//Add VY to VX, set carry bit if overflow occurs.
-						reg[0xF]=0;
+						bool carryFlag=0;
 						if ((int)reg[X]+(int)reg[Y]>255){
-							reg[0xF]=1;
+							carryFlag=1;
 						}
 						reg[X]+=reg[Y];
+						reg[0xF]=carryFlag;
 					}break;
 					case 0x5:{// sets VX to the result of VX - VY.
-						reg[0xF]=0;
+						bool carryFlag=0;
 						if (reg[X]>reg[Y]){
-							reg[0xF]=1;
+							//reg[0xF]=1;
+							//carryFlag=1;
 						}
 						reg[X]-=reg[Y];
+						reg[0xF]=carryFlag;
 					}break;
 					case 0x6:{//Shift Right
 						if (USE_ORIGINAL_CHIP8_SET){
@@ -485,15 +520,19 @@ public:
 							*/
 							reg[X]=reg[Y];
 						}
-						reg[0xF]=reg[X]&0x1;
+						bool carryFlag=reg[X]&0x1;
 						reg[X]>>=1;
+						reg[0xF]=carryFlag;
 					}break;
 					case 0x7:{//sets VX to the result of VY - VX. It's a reverse subtraction.
-						reg[0xF]=0;
+						//reg[0xF]=0;
+						bool carryFlag=false;
 						if (reg[Y]>reg[X]){
-							reg[0xF]=1;
+							//reg[0xF]=1;
+							carryFlag=true;
 						}
 						reg[X]=reg[Y]-reg[X];
+						reg[0xF]=carryFlag;
 					}break;
 					case 0xE:{//Shift Left
 						//std::cout<<"Y is: "<<(int)Y<<std::endl;
@@ -505,8 +544,9 @@ public:
 							*/
 							reg[X]=reg[Y];
 						}
-						reg[0xF]=(reg[X]&0x80)>>7;
+						bool carryFlag=(reg[X]&0x80)>>7;
 						reg[X]<<=1;
+						reg[0xF]=carryFlag;
 					}break;
 				}
 			}break;
@@ -571,11 +611,14 @@ public:
 						sound_timer=reg[X];
 					}break;
 					case 0x1E:{//The index register I will get the value in VX added to it.
-						reg[0xF]=0;
+						//reg[0xF]=0;
+						bool carryFlag=false;
 						if (index+reg[X]>=0x1000){
-							reg[0xF]=1;
+							//reg[0xF]=1;
+							carryFlag=true;
 						}
 						index+=reg[X];
+						reg[0xF]=carryFlag;
 					}break;
 					case 0x0A:{//This instruction “blocks”; it stops executing instructions and waits for key input
 						for (int i=0;i<keymap.size();i++){