diff options
Diffstat (limited to 'sources/meta/exec.c')
| -rw-r--r-- | sources/meta/exec.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/sources/meta/exec.c b/sources/meta/exec.c index b5aaba4..663a2ae 100644 --- a/sources/meta/exec.c +++ b/sources/meta/exec.c @@ -34,6 +34,7 @@ BEGIN \ if(c8->st) c8->st--; \ } \ c8->pc += 2; \ + c8->prevkeys = c8->keys; \ END #define X_C8_ILL \ @@ -104,12 +105,12 @@ END #define X_C8_SKP \ BEGIN \ - if(c8->keys & c8->V[x]) c8->pc += 2; \ + if(c8->keys & bit(c8->V[x])) c8->pc += 2; \ END #define X_C8_SKNP \ BEGIN \ - if(!(c8->keys & c8->V[x])) c8->pc += 2; \ + if(!(c8->keys & bit(c8->V[x]))) c8->pc += 2; \ END #define X_C8_MVDT \ @@ -117,10 +118,19 @@ BEGIN \ c8->V[x] = c8->dt; \ END -/* TODO: implement */ #define X_C8_LDK \ BEGIN \ - if(!c8->keys) c8->pc -= 2; \ + int i; \ + if(c8->keys == c8->prevkeys) c8->pc -= 2; \ + else \ + { \ + for(i = 7; i >= 0; i--) \ + if(c8->keys & bit(i)) \ + { \ + c8->V[x] = i; \ + break; \ + } \ + } \ END #define X_C8_LDDT \ @@ -227,8 +237,6 @@ BEGIN \ if(c8->V[x] != c8->V[y]) c8->pc += 2; \ END - -/* TODO: actually implement */ #define X_C8_DRW \ BEGIN \ u8 l; \ @@ -236,7 +244,11 @@ BEGIN \ u8 cy = c8->V[y]; \ \ for(l = 0; l < n; l++) \ - c8->DISPLAY[cy + l * cx] ^= c8->RAM[c8->i + l]; \ + { \ + u64 pix = (u64)c8->RAM[c8->i + l]; \ + pix = (pix << (64 - cx)) | (pix >> cx); \ + c8->DISPLAY[(cy + l) % 32] ^= pix; \ + } \ END c8_decode_generate(exec) |