graphics/vga.c

   1 /*
   2  * VGA hardware emulation
   3  *
   4  * Copyright 1998 Ove Kåven (with some help from Marcus Meissner)
   5  *
   6  */
   7
   8 #include <string.h>
   9 #include "windows.h"
  10 #include "winbase.h"
  11 #include "miscemu.h"
  12 #include "vga.h"
  13 #include "ddraw.h"
  14 #include "debug.h"
  15
  16 static IDirectDraw *lpddraw = NULL;
  17 static IDirectDrawSurface *lpddsurf;
  18 static IDirectDrawPalette *lpddpal;
  19 static DDSURFACEDESC sdesc;
  20 static WORD poll_timer;
  21 static CRITICAL_SECTION vga_crit;
  22 static int vga_polling,vga_refresh;
  23
  24 int VGA_SetMode(unsigned Xres,unsigned Yres,unsigned Depth)
  25 {
  26     if (lpddraw) VGA_Exit();
  27     if (!lpddraw) {
  28         DirectDrawCreate(NULL,&lpddraw,NULL);
  29         if (!lpddraw) {
  30             ERR(ddraw,"DirectDraw is not available\n");
  31             return 1;
  32         }
  33         if (lpddraw->lpvtbl->fnSetDisplayMode(lpddraw,Xres,Yres,Depth)) {
  34             ERR(ddraw,"DirectDraw does not support requested display mode\n");
  35             lpddraw->lpvtbl->fnRelease(lpddraw);
  36             lpddraw=NULL;
  37             return 1;
  38         }
  39         lpddraw->lpvtbl->fnCreatePalette(lpddraw,0,NULL,&lpddpal,NULL);
  40         memset(&sdesc,0,sizeof(sdesc));
  41         sdesc.dwSize=sizeof(sdesc);
  42         sdesc.dwFlags = DDSD_CAPS;
  43         sdesc.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE;
  44         if (lpddraw->lpvtbl->fnCreateSurface(lpddraw,&sdesc,&lpddsurf,NULL)||(!lpddsurf)) {
  45             ERR(ddraw,"DirectDraw surface is not available\n");
  46             lpddraw->lpvtbl->fnRelease(lpddraw);
  47             lpddraw=NULL;
  48             return 1;
  49         }
  50         vga_refresh=0;
  51         InitializeCriticalSection(&vga_crit);
  52         MakeCriticalSectionGlobal(&vga_crit);
  53         /* poll every 20ms (50fps should provide adequate responsiveness) */
  54         poll_timer = CreateSystemTimer( 20, VGA_Poll );
  55     }
  56     return 0;
  57 }
  58
  59 int VGA_GetMode(unsigned*Height,unsigned*Width,unsigned*Depth)
  60 {
  61     if (!lpddraw) return 1;
  62     if (!lpddsurf) return 1;
  63     if (Height) *Height=sdesc.dwHeight;
  64     if (Width) *Width=sdesc.dwWidth;
  65     if (Depth) *Depth=sdesc.ddpfPixelFormat.x.dwRGBBitCount;
  66     return 0;
  67 }
  68
  69 void VGA_Exit(void)
  70 {
  71     if (lpddraw) {
  72         SYSTEM_KillSystemTimer(poll_timer);
  73         DeleteCriticalSection(&vga_crit);
  74         lpddsurf->lpvtbl->fnRelease(lpddsurf);
  75         lpddsurf=NULL;
  76         lpddraw->lpvtbl->fnRelease(lpddraw);
  77         lpddraw=NULL;
  78     }
  79 }
  80
  81 void VGA_SetPalette(PALETTEENTRY*pal,int start,int len)
  82 {
  83     if (!lpddraw) return;
  84     lpddpal->lpvtbl->fnSetEntries(lpddpal,0,start,len,pal);
  85     lpddsurf->lpvtbl->fnSetPalette(lpddsurf,lpddpal);
  86 }
  87
  88 void VGA_SetQuadPalette(RGBQUAD*color,int start,int len)
  89 {
  90     PALETTEENTRY pal[256];
  91     int c;
  92
  93     if (!lpddraw) return;
  94     for (c=0; c<len; c++) {
  95         pal[c].peRed  =color[c].rgbRed;
  96         pal[c].peGreen=color[c].rgbGreen;
  97         pal[c].peBlue =color[c].rgbBlue;
  98         pal[c].peFlags=0;
  99     }
 100     lpddpal->lpvtbl->fnSetEntries(lpddpal,0,start,len,pal);
 101     lpddsurf->lpvtbl->fnSetPalette(lpddsurf,lpddpal);
 102 }
 103
 104 LPSTR VGA_Lock(unsigned*Pitch,unsigned*Height,unsigned*Width,unsigned*Depth)
 105 {
 106     if (!lpddraw) return NULL;
 107     if (!lpddsurf) return NULL;
 108     if (lpddsurf->lpvtbl->fnLock(lpddsurf,NULL,&sdesc,0,0)) {
 109         ERR(ddraw,"could not lock surface!\n");
 110         return NULL;
 111     }
 112     if (Pitch) *Pitch=sdesc.lPitch;
 113     if (Height) *Height=sdesc.dwHeight;
 114     if (Width) *Width=sdesc.dwWidth;
 115     if (Depth) *Depth=sdesc.ddpfPixelFormat.x.dwRGBBitCount;
 116     return sdesc.y.lpSurface;
 117 }
 118
 119 void VGA_Unlock(void)
 120 {
 121     lpddsurf->lpvtbl->fnUnlock(lpddsurf,sdesc.y.lpSurface);
 122 }
 123
 124 /* We are called from SIGALRM, aren't we? We should _NOT_ do synchronization
 125  * stuff!
 126  */
 127 void VGA_Poll( WORD timer )
 128 {
 129     char *dat;
 130     unsigned Pitch,Height,Width;
 131     char *surf;
 132     int Y,X;
 133
 134     EnterCriticalSection(&vga_crit);
 135     if (!vga_polling) {
 136         vga_polling++;
 137         LeaveCriticalSection(&vga_crit);
 138         /* FIXME: optimize by doing this only if the data has actually changed
 139          *        (in a way similar to DIBSection, perhaps) */
 140         surf = VGA_Lock(&Pitch,&Height,&Width,NULL);
 141         if (!surf) return;
 142         dat = DOSMEM_MapDosToLinear(0xa0000);
 143         /* copy from virtual VGA frame buffer to DirectDraw surface */
 144         for (Y=0; Y<Height; Y++,surf+=Pitch,dat+=Width) {
 145             memcpy(surf,dat,Width);
 146             /*for (X=0; X<Width; X++) if (dat[X]) TRACE(ddraw,"data(%d) at (%d,%d)\n",dat[X],X,Y);*/
 147         }
 148         VGA_Unlock();
 149         vga_refresh=1;
 150         EnterCriticalSection(&vga_crit);
 151         vga_polling--;
 152     }
 153     LeaveCriticalSection(&vga_crit);
 154 }
 155
 156 static BYTE palreg,palcnt;
 157 static PALETTEENTRY paldat;
 158
 159 void VGA_ioport_out( WORD port, BYTE val )
 160 {
 161     switch (port) {
 162         case 0x3c8:
 163             palreg=val; palcnt=0; break;
 164         case 0x3c9:
 165             ((BYTE*)&paldat)[palcnt++]=val << 2;
 166             if (palcnt==3) {
 167                 VGA_SetPalette(&paldat,palreg,1);
 168                 palreg++;
 169             }
 170             break;
 171     }
 172 }
 173
 174 BYTE VGA_ioport_in( WORD port )
 175 {
 176     BYTE ret;
 177
 178     switch (port) {
 179         case 0x3da:
 180             /* since we don't (yet?) serve DOS VM requests while VGA_Poll is running,
 181                we need to fake the occurrence of the vertical refresh */
 182             if (lpddraw) {
 183                 ret=vga_refresh?0x00:0x08;
 184                 vga_refresh=0;
 185             } else ret=0x08;
 186             break;
 187         default:
 188             ret=0xff;
 189     }
 190     return ret;
 191 }