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         if (lpddraw->lpvtbl->fnCreateSurface(lpddraw,&sdesc,&lpddsurf,NULL)||(!lpddsurf)) {
  43             ERR(ddraw,"DirectDraw surface is not available\n");
  44             lpddraw->lpvtbl->fnRelease(lpddraw);
  45             lpddraw=NULL;
  46             return 1;
  47         }
  48         vga_refresh=0;
  49         InitializeCriticalSection(&vga_crit);
  50         MakeCriticalSectionGlobal(&vga_crit);
  51         /* poll every 20ms (50fps should provide adequate responsiveness) */
  52         poll_timer = CreateSystemTimer( 20, VGA_Poll );
  53     }
  54     return 0;
  55 }
  56
  57 int VGA_GetMode(unsigned*Height,unsigned*Width,unsigned*Depth)
  58 {
  59     if (!lpddraw) return 1;
  60     if (!lpddsurf) return 1;
  61     if (Height) *Height=sdesc.dwHeight;
  62     if (Width) *Width=sdesc.dwWidth;
  63     if (Depth) *Depth=sdesc.ddpfPixelFormat.x.dwRGBBitCount;
  64     return 0;
  65 }
  66
  67 void VGA_Exit(void)
  68 {
  69     if (lpddraw) {
  70         SYSTEM_KillSystemTimer(poll_timer);
  71         DeleteCriticalSection(&vga_crit);
  72         lpddsurf->lpvtbl->fnRelease(lpddsurf);
  73         lpddsurf=NULL;
  74         lpddraw->lpvtbl->fnRelease(lpddraw);
  75         lpddraw=NULL;
  76     }
  77 }
  78
  79 void VGA_SetPalette(PALETTEENTRY*pal,int start,int len)
  80 {
  81     if (!lpddraw) return;
  82     lpddpal->lpvtbl->fnSetEntries(lpddpal,0,start,len,pal);
  83     lpddsurf->lpvtbl->fnSetPalette(lpddsurf,lpddpal);
  84 }
  85
  86 void VGA_SetQuadPalette(RGBQUAD*color,int start,int len)
  87 {
  88     PALETTEENTRY pal[256];
  89     int c;
  90
  91     if (!lpddraw) return;
  92     for (c=0; c<len; c++) {
  93         pal[c].peRed  =color[c].rgbRed;
  94         pal[c].peGreen=color[c].rgbGreen;
  95         pal[c].peBlue =color[c].rgbBlue;
  96         pal[c].peFlags=0;
  97     }
  98     lpddpal->lpvtbl->fnSetEntries(lpddpal,0,start,len,pal);
  99     lpddsurf->lpvtbl->fnSetPalette(lpddsurf,lpddpal);
 100 }
 101
 102 LPSTR VGA_Lock(unsigned*Pitch,unsigned*Height,unsigned*Width,unsigned*Depth)
 103 {
 104     if (!lpddraw) return NULL;
 105     if (!lpddsurf) return NULL;
 106     if (lpddsurf->lpvtbl->fnLock(lpddsurf,NULL,&sdesc,0,0)) {
 107         ERR(ddraw,"could not lock surface!\n");
 108         return NULL;
 109     }
 110     if (Pitch) *Pitch=sdesc.lPitch;
 111     if (Height) *Height=sdesc.dwHeight;
 112     if (Width) *Width=sdesc.dwWidth;
 113     if (Depth) *Depth=sdesc.ddpfPixelFormat.x.dwRGBBitCount;
 114     return sdesc.y.lpSurface;
 115 }
 116
 117 void VGA_Unlock(void)
 118 {
 119     lpddsurf->lpvtbl->fnUnlock(lpddsurf,sdesc.y.lpSurface);
 120 }
 121
 122 void VGA_Poll( WORD timer )
 123 {
 124     char *dat;
 125     unsigned Pitch,Height,Width;
 126     char *surf;
 127     int Y,X;
 128
 129     EnterCriticalSection(&vga_crit);
 130     if (!vga_polling) {
 131         vga_polling++;
 132         LeaveCriticalSection(&vga_crit);
 133         /* FIXME: optimize by doing this only if the data has actually changed
 134          *        (in a way similar to DIBSection, perhaps) */
 135         surf = VGA_Lock(&Pitch,&Height,&Width,NULL);
 136         if (!surf) return;
 137         dat = DOSMEM_MapDosToLinear(0xa0000);
 138         /* copy from virtual VGA frame buffer to DirectDraw surface */
 139         for (Y=0; Y<Height; Y++,surf+=Pitch,dat+=Width) {
 140             memcpy(surf,dat,Width);
 141             for (X=0; X<Width; X++) if (dat[X]) TRACE(ddraw,"data(%d) at (%d,%d)\n",dat[X],X,Y);
 142         }
 143         VGA_Unlock();
 144         vga_refresh=1;
 145         EnterCriticalSection(&vga_crit);
 146         vga_polling--;
 147     }
 148     LeaveCriticalSection(&vga_crit);
 149 }
 150
 151 static BYTE palreg,palcnt;
 152 static PALETTEENTRY paldat;
 153
 154 void VGA_ioport_out( WORD port, BYTE val )
 155 {
 156     switch (port) {
 157         case 0x3c8:
 158             palreg=val; palcnt=0; break;
 159         case 0x3c9:
 160             ((BYTE*)&paldat)[palcnt++]=val << 2;
 161             if (palcnt==3) {
 162                 VGA_SetPalette(&paldat,palreg,1);
 163                 palreg++;
 164             }
 165             break;
 166     }
 167 }
 168
 169 BYTE VGA_ioport_in( WORD port )
 170 {
 171     BYTE ret;
 172
 173     switch (port) {
 174         case 0x3da:
 175             /* since we don't (yet?) serve DOS VM requests while VGA_Poll is running,
 176                we need to fake the occurrence of the vertical refresh */
 177             if (lpddraw) {
 178                 ret=vga_refresh?0x00:0x08;
 179                 vga_refresh=0;
 180             } else ret=0x08;
 181             break;
 182         default:
 183             ret=0xff;
 184     }
 185     return ret;
 186 }