dos_drvr.c

小型游戏引擎

						koutp(0x3cf,0x7c<<(8-(daxpos&7)));
						readpixel(p+1), drawpixel(p+1,backcol);
					}
				}
				dat = fontptr[(((long)ch)<<3)+zz];
				if (charxsiz == 8)
				{
					koutp(0x3cf,mask&(dat>>(daxpos&7)));
					readpixel(p), drawpixel(p,col);
					koutp(0x3cf,(~mask)&(dat<<(8-(daxpos&7))));
					readpixel(p+1), drawpixel(p+1,col);
				}
				else
				{
					koutp(0x3cf,(0x7c&dat)>>(daxpos&7));
					readpixel(p), drawpixel(p,col);
					koutp(0x3cf,(0x7c&dat)<<(8-(daxpos&7)));
					readpixel(p+1), drawpixel(p+1,col);
				}
				p += 80;    //Do not make bytesperline!
			}
		}

		daxpos += charxsiz;
	}
	koutp(0x3ce,0x5); koutp(0x3cf,(kinp(0x3cf)&(255-3))+0);
}

void _nextpage(void)
{
	switch(qsetmode)
	{
		case 200:
			switch(vidoption)
			{
				case 1:
					if (stereomode)
					{
						stereonextpage();
						if (!origbuffermode) buffermode = transarea = totalarea = 0;
					}
					else
					{
						visualpage = activepage;
						setvisualpage(visualpage);
						if (!origbuffermode)
						{
							buffermode = ((transarea<<3) > totalarea);
							transarea = totalarea = 0;
						}
						activepage++; if (activepage >= numpages) activepage = 0;
						setactivepage(activepage);
					}
					break;
				case 2:
					copybuf((void *)frameplace,(void *)0xa0000,64000>>2);
					break;
				case 6:
					if (!activepage) redblueblit(screen,&screen[65536],64000L);
					activepage ^= 1;
					break;
			}
			break;

		case 350:
			koutpw(0x3d4,0xc+((pageoffset>>11)<<8));
			limitrate();
			pageoffset = 225280-pageoffset; //225280 is 352(multiple of 16)*640
			break;

		case 480:
			koutpw(0x3d4,0xc+((pageoffset>>11)<<8));
			limitrate();
			pageoffset = 399360-pageoffset;
			break;
	}
} // _nextpage


void interrupt stereohandler1(void)
{
		//VR flag
	if (kinp(0x3c2)&128)
	{
		laststereoint = 0;
		koutpw(0x3d4,((long)(overtbits)<<8)+0x11);
		koutp(0x3d5,overtbits+16);
	}
	if (laststereoint == 1)
	{
		visualpage ^= 1;
		setvisualpage(visualpage|0x80000000);  //0x80000000 to ignore qlimitrate
	}
	laststereoint++;
	koutp(0x70,0xc); kinp(0x71);
	koutp(0xa0,0x20);
	koutp(0x20,0x20);
}

void interrupt stereohandler2(void)
{
		//VR flag
	if (kinp(0x3c2)&128)
	{
		laststereoint = 0;
		koutp(0x378,0xfb+((visualpage&1^1)<<2));
		koutpw(0x3d4,((long)overtbits<<8)+0x11);
		koutp(0x3d5,overtbits+16);
	}
	if (laststereoint == 1)
	{
		visualpage ^= 1;
		setvisualpage(visualpage|0x80000000);  //0x80000000 to ignore qlimitrate
	}
	laststereoint++;
	koutp(0x70,0xc); kinp(0x71);
	koutp(0xa0,0x20);
	koutp(0x20,0x20);
}

void stereonextpage(void)
{
	koutp(0x70,0xc); kinp(0x71);
	//koutpw(0x70,0x420b);
	if ((activepage&1) == 0)
	{
		if (stereomode == 1)
		{
			clearbuf((void *)(ylookup[ydim-1]+frameplace),xdim>>4,whiteband);
			clearbuf((void *)(ylookup[ydim-1]+frameplace+(xdim>>2)),(xdim>>2)-(xdim>>4),blackband);
		}
		activepage++;
		setactivepage(activepage);
		return;
	}
	if (stereomode == 1)
	{
		clearbuf((void *)(ylookup[ydim-1]+frameplace),(xdim>>2)-(xdim>>4),whiteband);
		clearbuf((void *)(ylookup[ydim-1]+frameplace+xdim-(xdim>>2)),xdim>>4,blackband);
	}
	if (visualpage < (numpages&~1)-2) visualpage += 2; else visualpage &= 1;
	if (activepage < (numpages&~1)-1) activepage++; else activepage = 0;
	setactivepage(activepage);
}

void setstereo(long dastereomode)
{
	//long i, dist, blackdist, whitedist, t1, t2, numlines;
	//char c1, c2;
	long i, dist, blackdist, whitedist;

	if ((vidoption != 1) || (numpages < 2)) return;

	if (stereomode)  //---------------Uninitialize old stereo mode
	{
		if ((xdim == 320) && (ydim == 200))
		{
				//back to 70 hz
			koutp(0x3c2,o3c2);
		}

			//Uninit VR flag
		koutpw(0x3d4,(((long)overtbits+32)<<8)+0x11);

			//Uninit RTC
		_disable();
		koutp(0xa1,(kinp(0xa1)&~1)|(oa1&1));
		koutp(0x70,0xa); koutp(0x71,ortca);
		koutp(0x70,0xb); koutp(0x71,ortcb);
		uninstallbistereohandlers();
		_enable();

		stereomode = 0;
		ostereopixelwidth = -1;
		setview(windowx1,windowy1,windowx2,windowy2);
		if (stereomode == 1)
		{
			for(i=0;i<numpages;i++)
			{
				setactivepage(i);
				clearbuf((void *)(ylookup[ydim-1]+frameplace),xdim>>2,blackband);
			}
			setactivepage(activepage);
		}
	}

	//------------------------------------- Initialize new stereo mode
	stereomode = dastereomode; if (!stereomode) return;

	activepage = (visualpage & ~1)+2;
	if (activepage >= numpages-1) activepage = 0;

	if (stereomode == 1)
	{
		blackdist = 0x7fffffff; whitedist = 0x80000000;
		koutp(0x3c7,0);
		for(i=0;i<256;i++)
		{
			dist = (kinp(0x3c9)&255)+(kinp(0x3c9)&255)+(kinp(0x3c9)&255);
			if (dist < blackdist) { blackdist = dist; blackband = i; }
			if (dist > whitedist) { whitedist = dist; whiteband = i; }
		}
		blackband += (blackband<<8); blackband += (blackband<<16);
		whiteband += (whiteband<<8); whiteband += (whiteband<<16);
	}

	if ((xdim == 320) && (ydim == 200))
	{
			//80 hz
		o3c2 = kinp(0x3cc);
		koutp(0x3c2,(o3c2&0xf3)+4);
	}

		//Init RTC
	_disable();
	if (stereomode == 1) installbistereohandlers(stereohandler1);
	if (stereomode == 2) installbistereohandlers(stereohandler2);
	koutp(0x70,0xa); ortca = kinp(0x71);
	if (stereomode == 1) koutp(0x71,0x28); //+8 = 256hz
	if (stereomode == 2) koutp(0x71,0x26); //+6 = 1024hz
	koutp(0x70,0xb); ortcb = kinp(0x71); koutp(0x71,0x42);
	koutp(0x70,0xc); kinp(0x71);
	oa1 = kinp(0xa1); koutp(0xa1,oa1&~1);
	_enable();

		//Init VR flag
	koutp(0x3d4,0x11);
	overtbits = kinp(0x3d5) & ~(16+32);
	koutp(0x3d5,overtbits);
	koutp(0x3d5,overtbits+16);
}

#define RTCBUFSIZ 16
static unsigned short rtcopmsel, rtcormseg, rtcormoff;
static unsigned long rtcopmoff;
//Use bicomc.asm as a template if this asm code needs re-writing
static char rtcrmbuffer[RTCBUFSIZ] =
{
	0x50,          //push ax
	0xb0,0x0c,     //mov al, 0ch
	0xe6,0x70,     //out 70h, al
	0xe4,0x71,     //in al, 71h
	0xb0,0x20,     //mov al, 20h
	0xe6,0xa0,     //out 0a0h, al
	0xe6,0x20,     //out 20h, al
	0x58,          //pop ax
	0xcf           //iret
};
void *engconvalloc32 (unsigned long size)
{
	 union REGS r;

	 r.x.eax = 0x0100;           //DPMI allocate DOS memory
	 r.x.ebx = ((size+15)>>4);   //Number of paragraphs requested
	 int386(0x31,&r,&r);

	 if (r.x.cflag != 0)         //Failed
		 return ((unsigned long)0);
	 return ((void *)((r.x.eax&0xffff)<<4));   //Returns full 32-bit offset
}

void installbistereohandlers(void far *stereohan)
{
	//char *ptr;
	union REGS r;
	struct SREGS sr;
	void *lowp;
	//int c;

		//Get old protected mode handler
	r.x.eax = 0x3500+0x70;   /* DOS get vector (INT 0Ch) */
	sr.ds = sr.es = 0;
	int386x(0x21,&r,&r,&sr);
	rtcopmsel = (unsigned short)sr.es;
	rtcopmoff = r.x.ebx;

		//Get old real mode handler
	r.x.eax = 0x0200;   /* DPMI get real mode vector */
	r.h.bl = 0x70;
	int386(0x31,&r,&r);
	rtcormseg = (unsigned short)r.x.ecx;
	rtcormoff = (unsigned short)r.x.edx;

		//Allocate memory in low memory to store real mode handler
	if ((lowp = engconvalloc32(RTCBUFSIZ)) == 0)
	{
		printf("Couldn't allocate conventional memory.\n");
		exit(1);
	}

	memcpy(lowp,(void *)rtcrmbuffer,RTCBUFSIZ);

		//Set new protected mode handler
	r.x.eax = 0x2500+0x70;   /* DOS set vector (INT 0Ch) */
	r.x.edx = FP_OFF(stereohan);
	sr.ds = FP_SEG(stereohan);      //DS:EDX == &handler
	sr.es = 0;
	int386x(0x21,&r,&r,&sr);

		//Set new real mode handler (must be after setting protected mode)
	r.x.eax = 0x0201;
	r.h.bl = 0x70;              //CX:DX == real mode &handler
	r.x.ecx = ((((long)lowp)>>4)&0xffff);   //D32realseg
	r.x.edx = (((long)lowp)&0xf);           //D32realoff
	int386(0x31,&r,&r);
}

void uninstallbistereohandlers(void)
{
	union REGS r;
	struct SREGS sr;

		//restore old protected mode handler
	r.x.eax = 0x2500+0x70;   /* DOS set vector (INT 0Ch) */
	r.x.edx = rtcopmoff;
	sr.ds = rtcopmsel;    /* DS:EDX == &handler */
	sr.es = 0;
	int386x(0x21,&r,&r,&sr);

		//restore old real mode handler
	r.x.eax = 0x0201;   /* DPMI set real mode vector */
	r.h.bl = 0x70;
	r.x.ecx = (unsigned long)rtcormseg;     //CX:DX == real mode &handler
	r.x.edx = (unsigned long)rtcormoff;
	int386(0x31,&r,&r);
}

void inittimer(void)
{
	outp(0x43,0x34); outp(0x40,(1193181/120)&255); outp(0x40,(1193181/120)>>8);
	oldtimerhandler = _dos_getvect(0x8);
	_disable(); _dos_setvect(0x8, timerhandler); _enable();
}

void uninittimer(void)
{
	outp(0x43,0x34); outp(0x40,0); outp(0x40,0);           //18.2 times/sec
	_disable(); _dos_setvect(0x8, oldtimerhandler); _enable();
}

void initkeys(void)
{
	oldkeyhandler = _dos_getvect(0x9);
	_disable(); _dos_setvect(0x9, keyhandler); _enable();
}

void uninitkeys(void)
{
	short *ptr;

	_dos_setvect(0x9, oldkeyhandler);
		//Turn off shifts to prevent stucks with quitting
	ptr = (short *)0x417; *ptr &= ~0x030f;
}

int _setgamemode(char davidoption, long daxdim, long daydim)
{
        long i, j, ostereomode;

        if ((qsetmode == 200) && (vidoption == davidoption) && (xdim == daxdim) && (ydim == daydim))
                return(0);
        vidoption = davidoption; xdim = daxdim; ydim = daydim;

        strcpy(kensmessage,"!!!! BUILD engine&tools programmed by Ken Silverman of E.G. RI.  (c) Copyright 1995 Ken Silverman.  Summary:  BUILD = Ken. !!!!");
        if (getkensmessagecrc(FP_OFF(kensmessage)) != 0x56c764d4)
                { setvmode(0x3); printf("Nice try.\n"); exit(0); }

        ostereomode = stereomode; if (stereomode) setstereo(0L);

        activepage = visualpage = 0;
        switch(vidoption)
        {
                case 1: i = xdim*ydim; break;
                case 2: xdim = 320; ydim = 200; i = xdim*ydim; break;
                case 6: xdim = 320; ydim = 200; i = 131072; break;
                default: return(-1);
        }
        j = ydim*4*sizeof(long);  //Leave room for horizlookup&horizlookup2

        if (screen != NULL)
        {
                if (screenalloctype == 0) kkfree((void *)screen);
                if (screenalloctype == 1) suckcache((long *)screen);
                screen = NULL;
        }
        screenalloctype = 0;
        if ((screen = (char *)kkmalloc(i+(j<<1))) == NULL)
        {
                 allocache((long *)&screen,i+(j<<1),&permanentlock);
                 screenalloctype = 1;
        }

        frameplace = FP_OFF(screen);
        horizlookup = (long *)(frameplace+i);
        horizlookup2 = (long *)(frameplace+i+j);
        horizycent = ((ydim*4)>>1);


        switch(vidoption)
        {
                case 1:
                                //bytesperline is set in this function
                        if (setvesa(xdim,ydim) < 0) return(-1);
                        break;
                case 2:
                        horizycent = ((ydim*4)>>1);  //HACK for switching to this mode
                case 6:
                        bytesperline = xdim;
                        setvmode(0x13);
                        break;
                default: return(-1);
        }

                //Force drawrooms to call dosetaspect & recalculate stuff
        oxyaspect = oxdimen = oviewingrange = -1;

        setvlinebpl(bytesperline);
        j = 0;
        for(i=0;i<=ydim;i++) ylookup[i] = j, j += bytesperline;

        numpages = 1;
        if (vidoption == 1) numpages = min(maxpages,8);

        setview(0L,0L,xdim-1,ydim-1);
        clearallviews(0L);
        setbrightness(curbrightness, &palette[0]);

        if (searchx < 0) { searchx = halfxdimen; searchy = (ydimen>>1); }

        if (ostereomode) setstereo(ostereomode);

        qsetmode = 200;
        return(0);
}


void _platform_init(int argc, char **argv, const char *title, const char *icon)
{
    // no op in DOS, currently.  --ryan.
}

void clear2dscreen(void)
{
	if (qsetmode == 350)
		fillscreen16(pageoffset>>3,0L,640L*350L);
	else if (qsetmode == 480)
	{
		if (ydim16 <= 336) fillscreen16(pageoffset>>3,0L,640L*336L);
						  else fillscreen16(pageoffset>>3,0L,640L*480L);
	}
}

void _idle(void)
{
    // no-op in DOS, which is non-multitasking. However, if someone were to
    //  add Desqview/win95/OS2/etc support, timeslicing would be good.
}


void *_getVideoBase(void)
{
    return((void *) 0xa0000);
}

void _updateScreenRect(long x, long y, long w, long h)
{
}

int using_opengl(void)
{
    return(0);
}

// end of dos_driver.c ...