diff options
| author | Jacob Moody <moody@posixcafe.org> | 2023-02-11 03:38:26 +0000 |
|---|---|---|
| committer | Jacob Moody <moody@posixcafe.org> | 2023-02-11 03:38:26 +0000 |
| commit | 28e362d368805ad91e0662fcc9577cb74ef13d4e (patch) | |
| tree | a590506cf549e9821e84e48ad20d5845e3e0d5f2 /sys/src/games | |
| parent | 9651e5cbd6d9f6064b3ad63246b09194e32139e3 (diff) | |
games/gb: implement internal window line counter
The y offset used for windows is not based on LY
but another internal window counter that is incremented
alongside LY but only when the window is on screen. This
fixes an issue with the dmg-acid2 and cgb-acid2 test roms.
https://github.com/mattcurrie/dmg-acid2
https://gbdev.io/pandocs/Tile_Maps.html#window
Diffstat (limited to 'sys/src/games')
| -rw-r--r-- | sys/src/games/gb/dat.h | 2 | ||||
| -rw-r--r-- | sys/src/games/gb/mem.c | 1 | ||||
| -rw-r--r-- | sys/src/games/gb/ppu.c | 11 |
3 files changed, 10 insertions, 4 deletions
diff --git a/sys/src/games/gb/dat.h b/sys/src/games/gb/dat.h index 890856663..e6bc54453 100644 --- a/sys/src/games/gb/dat.h +++ b/sys/src/games/gb/dat.h @@ -14,7 +14,7 @@ extern u32int divclock; extern Event *elist; extern ulong clock; -extern u8int ppuy, ppustate; +extern u8int ppuy, ppustate, ppuw; extern u8int apustatus; diff --git a/sys/src/games/gb/mem.c b/sys/src/games/gb/mem.c index 13509877f..165445870 100644 --- a/sys/src/games/gb/mem.c +++ b/sys/src/games/gb/mem.c @@ -109,6 +109,7 @@ regwrite(u8int a, u8int v) ppusync(); if((~v & reg[a] & LCDEN) != 0){ ppuy = 0; + ppuw = 0; ppustate = 0; delevent(&evhblank); } diff --git a/sys/src/games/gb/ppu.c b/sys/src/games/gb/ppu.c index 9043420eb..82f0510aa 100644 --- a/sys/src/games/gb/ppu.c +++ b/sys/src/games/gb/ppu.c @@ -5,7 +5,7 @@ #include "dat.h" #include "fns.h" -u8int ppustate, ppuy; +u8int ppustate, ppuy, ppuw; ulong hblclock, rendclock; jmp_buf mainjmp, renderjmp; static int cyc, done, ppux, ppux0; @@ -118,8 +118,8 @@ ppurender(void) }while(m > 8); if(win == -1){ win = 1; - ta = 0x1800 | reg[LCDC] << 4 & 0x400 | ppuy - reg[WY] << 2 & 0x3e0; - y = ppuy - reg[WY] << 1 & 14; + ta = 0x1800 | reg[LCDC] << 4 & 0x400 | ppuw - reg[WY] << 2 & 0x3e0; + y = ppuw - reg[WY] << 1 & 14; cyc += 2; m = 175 - reg[WX]; goto restart; @@ -292,6 +292,8 @@ hblanktick(void *) switch(ppustate){ case 0: hblclock = clock + evhblank.time; + if(reg[WX] <= 166 && reg[WY] <= 143) + ppuw++; if(++ppuy == 144){ ppustate = 1; if((reg[STAT] & IRQM1) != 0) @@ -310,8 +312,11 @@ hblanktick(void *) break; case 1: hblclock = clock + evhblank.time; + if(reg[WX] <= 166 && reg[WY] <= 143) + ppuw++; if(++ppuy == 154){ ppuy = 0; + ppuw = 0; ppustate = 2; if((reg[STAT] & IRQM2) != 0) reg[IF] |= IRQLCDS; |