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This commit is contained in:
Loïc Guégan 2023-12-25 18:36:53 +01:00
parent 90c372fc35
commit ab71de02f4
2 changed files with 17 additions and 24 deletions
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2
src/main.c
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@ -13,7 +13,7 @@ int main(int argc, char *argv[])
// Initialize
MemInit();
MemLoadROM("../roms/chip8-test-suite/3-corax+.ch8");
MemLoadROM("../roms/chip8-test-suite/4-flags.ch8");
ScreenInit(800,400);
VCPUInit();

39
src/vcpu.c
View file

@ -122,43 +122,36 @@ void VCPUExecute(){
break;
case 0x4: // VX = VX + VY
if((State.V[State.X] + State.V[State.Y]) > 255)
State.V[REG_FLAG]=1;
else
State.V[REG_FLAG]=0;
State.V[State.X]=State.V[State.X] + State.V[State.Y];
unsigned char x=State.V[State.X];
unsigned char y=State.V[State.Y];
State.V[State.X]=x+y;
State.V[REG_FLAG]=((x+y) > 255);
break;
case 0x5: // VX = VX - VY
if(State.V[State.X] > State.V[State.Y])
State.V[REG_FLAG]=1;
else
State.V[REG_FLAG]=0;
State.V[State.X]=State.V[State.X] - State.V[State.Y];
unsigned char x2=State.V[State.X];
unsigned char y2=State.V[State.Y];
State.V[State.X]=x2-y2;
State.V[REG_FLAG]=(x2>=y2);
break;
case 0x6: // VX = VX SHR 1
if(State.V[State.X] & 0x1 == 1)
State.V[REG_FLAG]=1;
else
State.V[REG_FLAG]=0;
char flag=State.V[State.X] & 0x1 == 1;
State.V[State.X]=State.V[State.X] >> 1;
State.V[REG_FLAG]=flag;
break;
case 0x7: // VX = VY - VX
if(State.V[State.Y] > State.V[State.X])
State.V[REG_FLAG]=1;
else
State.V[REG_FLAG]=0;
State.V[State.X]=State.V[State.Y] - State.V[State.X];
unsigned char x3=State.V[State.X];
unsigned char y3=State.V[State.Y];
State.V[State.X]=y3-x3;
State.V[REG_FLAG]=(y3>=x3);
break;
case 0xE: // VX = VX SHL 1
if(State.V[State.X] >> 7 == 1)
State.V[REG_FLAG]=1;
else
State.V[REG_FLAG]=0;
char flag2=State.V[State.X] >> 7 == 1;
State.V[State.X]=State.V[State.X] << 1;
State.V[REG_FLAG]=flag2;
break;
}