Handle horizontal and vertical retrace separately.

This commit is contained in:
Jukka Heinonen 2003-01-28 00:16:15 +00:00 committed by Alexandre Julliard
parent 1f5e6994af
commit 6758f027fa

View file

@ -38,7 +38,9 @@ static IDirectDraw *lpddraw = NULL;
static IDirectDrawSurface *lpddsurf;
static IDirectDrawPalette *lpddpal;
static DDSURFACEDESC sdesc;
static LONG vga_refresh;
static BOOL vga_retrace_vertical;
static BOOL vga_retrace_horizontal;
/*
* VGA controller memory is emulated using linear framebuffer.
@ -391,7 +393,7 @@ static void WINAPI VGA_DoSetMode(ULONG_PTR arg)
return;
}
IDirectDrawSurface_SetPalette(lpddsurf,lpddpal);
vga_refresh=0;
vga_retrace_vertical = vga_retrace_horizontal = FALSE;
/* poll every 20ms (50fps should provide adequate responsiveness) */
VGA_InstallTimer(20);
}
@ -953,7 +955,10 @@ static void CALLBACK VGA_Poll( LPVOID arg, DWORD low, DWORD high )
VGA_Poll_Text();
}
vga_refresh=1;
/*
* Fake start of retrace.
*/
vga_retrace_vertical = TRUE;
LeaveCriticalSection(&vga_lock);
}
@ -1045,21 +1050,48 @@ BYTE VGA_ioport_in( WORD port )
FIXME("Unsupported index, register 0x3d4: 0x%02x\n",
vga_index_3d4);
return 0xff;
case 0x3da:
/*
* Read from this register resets register 0x3c0 address flip-flop.
*/
vga_address_3c0 = TRUE;
/* since we don't (yet?) serve DOS VM requests while VGA_Poll is running,
we need to fake the occurrence of the vertical refresh */
ret=vga_refresh?0x00:0x0b; /* toggle video RAM and lightpen and VGA refresh bits ! */
/*
* Read from this register resets register 0x3c0 address flip-flop.
*/
vga_address_3c0 = TRUE;
/*
* Read from this register returns following bits:
* xxxx1xxx = Vertical retrace in progress if set.
* xxxxx1xx = Light pen switched on.
* xxxxxx1x = Light pen trigger set.
* xxxxxxx1 = Either vertical or horizontal retrace
* in progress if set.
*/
ret = 0;
if (vga_retrace_vertical)
ret |= 9;
if (vga_retrace_horizontal)
ret |= 3;
/*
* If VGA mode has been set, vertical retrace is
* turned on once a frame and cleared after each read.
* This might cause applications that synchronize with
* vertical retrace to actually skip one frame but that
* is probably not a problem.
*
* If no VGA mode has been set, vertical retrace is faked
* by toggling the value after every read.
*/
if (VGA_IsTimerRunning())
vga_refresh=0;
vga_retrace_vertical = FALSE;
else
/* Also fake the occurence of the vertical refresh when no graphic
mode has been set */
vga_refresh=!vga_refresh;
vga_retrace_vertical = !vga_retrace_vertical;
/*
* Toggle horizontal retrace.
*/
vga_retrace_horizontal = !vga_retrace_horizontal;
break;
default:
ret=0xff;
FIXME("Unsupported VGA register: 0x%04x\n", port);