commit 3b13ad3e93cdee896f7e7a06218a763ffe367f3b
parent 9e2576c23ce5be167f71d74abba55c89cf2e2d86
Author: Léo Villeveygoux <l@vgx.fr>
Date: Mon, 6 May 2019 20:18:08 +0200
Cosmetic update
Blank lines, comments, macro cleaning, break → return, GCC warnings.
Diffstat:
| M | chip8.c | | | 133 | ++++++++++++++++++++++++++++++++++++++----------------------------------------- |
1 file changed, 64 insertions(+), 69 deletions(-)
diff --git a/chip8.c b/chip8.c
@@ -133,13 +133,10 @@ char char_sprites[80] = {
#define I_NNN(instr) ((((instr)[0]&15u)<<8u) | (instr)[1])
#define I_ADDR(instr) I_NNN(instr)
#define I_NN(instr) ((instr)[1])
-#define I_KK(instr) I_NN(instr)
#define I_N(instr) ((instr)[1]&15u)
-#define I_NIBBLE(instr) I_N(inst)
#define I_X(instr) ((instr)[0]&15u)
#define I_Y(instr) ((instr)[1]>>4u)
-/*XXX:debug*/
void display();
void step(){
@@ -154,105 +151,101 @@ void step(){
SCREEN[i] = 0;
clear_screen();
send_draw();
- break;
+ return;
case 0x00EE: /* return from a subroutine */
if(SP)
PC=STACK[--SP];
- break;
- default: /*legacy instr*/
+ return;
+ default: /* legacy machine routine call */
/*TODO: warn*/
- break;
+ return;
}
- break;
+ return;
case 1: /* jump */
PC=I_ADDR(instr);
- break;
+ return;
case 2: /* call a subroutine */
STACK[SP++] = PC;
PC=I_ADDR(instr);
- break;
+ return;
case 3:
if(V[I_X(instr)] == I_NN(instr))
PC+=2;
- break;
+ return;
case 4:
if(V[I_X(instr)] != I_NN(instr))
PC+=2;
- break;
+ return;
case 5:
if(V[I_X(instr)] == V[I_Y(instr)])
PC+=2;
- break;
+ return;
case 6:
V[I_X(instr)] = I_NN(instr);
- break;
+ return;
case 7:
V[I_X(instr)] += I_NN(instr);
- break;
+ return;
case 8:
switch(I_N(instr)){
case 0:
V[I_X(instr)] = V[I_Y(instr)];
- break;
+ return;
case 1:
V[I_X(instr)] |= V[I_Y(instr)];
- break;
+ return;
case 2:
V[I_X(instr)] &= V[I_Y(instr)];
- break;
+ return;
case 3:
V[I_X(instr)] ^= V[I_Y(instr)];
- break;
+ return;
case 4:
V[0xf] = V[I_X(instr)] + V[I_Y(instr)] > 0xff ? 1 : 0;
V[I_X(instr)] += V[I_Y(instr)];
- break;
+ return;
case 5:
V[0xf] = V[I_X(instr)] > V[I_Y(instr)] ? 1 : 0;
V[I_X(instr)] -= V[I_Y(instr)];
- break;
+ return;
case 6:
V[0xf] = V[I_X(instr)]&1u;
V[I_X(instr)] >>= 1u;
- break;
+ return;
case 7:
V[0xf] = V[I_X(instr)] < V[I_Y(instr)] ? 1 : 0;
V[I_X(instr)] = V[I_Y(instr)] - V[I_X(instr)] ;
- break;
+ return;
case 0xE:
V[0xf] = V[I_X(instr)]>>7u;
V[I_X(instr)] <<= 1u;
- break;
-
-
+ return;
- default: /*unknown instruction*/
- /*TODO: warn*/
- break;
+ default: /* unknown instruction */
+ /*TODO: warn */
+ return;
}
- break;
+ return;
case 9:
if(V[I_X(instr)] != V[I_Y(instr)])
PC+=2;
- break;
+ return;
case 0xA:
I=I_ADDR(instr);
- break;
+ return;
case 0xB:
PC = I_ADDR(instr) + V[0];
- break;
+ return;
case 0xC:
V[I_X(instr)] = rand() & I_NN(instr);
- break;
- case 0xD: /*display*/
- /*TODO:check OOB coords*/
- /*assert(Vx in [0;63], Vy in [0;31]), Vy+nible in [0;31]*/
+ return;
+ case 0xD: /* display */
V[0xf] = 0;
unsigned char x = V[I_X(instr)];
unsigned char y = V[I_Y(instr)];
unsigned char shift = x%8;
- for(int i=0;i<I_N(instr);i++){
+ for(unsigned i=0;i<I_N(instr);i++){
unsigned char wrapped_y = (y+i)%32;
unsigned char *screen_tile = &SCREEN[wrapped_y*8+x/8];
unsigned char sprite_tile = RAM[I+i]>>shift;
@@ -265,31 +258,32 @@ void step(){
*screen_tile ^= sprite_tile;
}
}
- /*TODO: mybe uptade just the right part*/
+
+ /*TODO: maybe update only written regions */
display();
- //usleep(500000);
- break;
+ return;
+
case 0xE:
switch(I_NN(instr)){
case 0x9E:
if(KEYBOARD & 1<<(V[I_X(instr)]))
PC+=2;
- break;
+ return;
case 0xA1:
if(!(KEYBOARD & 1<<(V[I_X(instr)])))
PC+=2;
- break;
- default: /*unknown instruction*/
- /*TODO: warn*/
- break;
+ return;
+ default: /* unknown instruction */
+ /*TODO: warn */
+ return;
}
- break;
+ return;
case 0xF:
switch(I_NN(instr)){
case 0x07:
V[I_X(instr)]=DT;
- break;
+ return;
case 0x0A:
if(!KEYBOARD)
PC-=2;
@@ -298,42 +292,42 @@ void step(){
for(unsigned char k=KEYBOARD;!(k&1);k>>=1)
V[I_X(instr)]++;
}
- break;
+ return;
case 0x15:
DT=V[I_X(instr)];
- break;
+ return;
case 0x18:
ST=V[I_X(instr)];
- break;
+ return;
case 0x1E:
I+=V[I_X(instr)];
- break;
+ return;
case 0x29:
- /*TODO: warn OOB*/
+ /*TODO: warn OOB */
if(V[I_X(instr)]<=0xF)
I = CHAR_SPRITES_OFFSET + 5*V[I_X(instr)];
- break;
+ return;
case 0x33:
RAM[I+2] = V[I_X(instr)]%10;
RAM[I+1] = (V[I_X(instr)]/10)%10;
RAM[I] = (V[I_X(instr)]/100)%10;
- break;
+ return;
case 0x55:
- for(int i=0 ; i<=I_X(instr) ; i++)
+ for(unsigned i=0 ; i<=I_X(instr) ; i++)
RAM[I+i] = V[i];
- break;
+ return;
case 0x65:
- for(int i=0 ; i<=I_X(instr) ; i++)
+ for(unsigned i=0 ; i<=I_X(instr) ; i++)
V[i] = RAM[I+i];
- break;
- default: /*unknown instruction*/
- /*TODO: warn*/
- break;
+ return;
+ default: /* unknown instruction */
+ /* TODO: warn */
+ return;
}
- break;
- default: /*unknown instr*/
- /*TODO: warn*/
- break;
+ return;
+ default: /* unreachable */
+ /*TODO: assert */
+ return;
}
}
@@ -362,7 +356,7 @@ int main(int argc, char **argv){
return 3;
fclose(rom);
- /*TODO: init more stuff: graphics, input, sound, timer*/
+ /* Init media stuff: graphics, input, sound */
m_init(argc, argv);
/* Let's go */
@@ -373,7 +367,7 @@ int main(int argc, char **argv){
step();
- nanosleep(&(struct timespec){0,(1000000000/840)},NULL);
+ nanosleep(&(struct timespec){0,(1000000000/FREQ)},NULL);
//wait_tick();
if(!(i%(FREQ/60))){
@@ -383,15 +377,16 @@ int main(int argc, char **argv){
if(ST)
ST--;
}
+
set_buzzer_state(ST ? 1 : 0);
printf("i=%5d, DT=%3d, K=[", i, (int)DT);
for(int k=0 ; k<16;k++)
printf("%s", KEYBOARD & 1<<k ? "1":"0");
-
printf("] \r");
}
+ /* Quit media */
m_quit();
return 0;
