kdmeng.c

小型游戏引擎

	sndbufsiz = bytespertic*(120/intspersec);

	if (sndseg == 0)    //Allocate DMA buffer in conventional memory
	{
		if ((sndseg = convallocate(((sndbufsiz<<(bytespersample+numspeakers))+15)>>4)) == 0)
		{
			printf("Could not allocation conventional memory for digitized music\n");
			exit(0);
		}
		sndoffs = (((long)sndseg)<<4);

		if ((sndoffs&65535)+(sndbufsiz<<(bytespersample+numspeakers-1)) >= 65536)   //64K DMA page check
			sndoffs += (sndbufsiz<<(bytespersample+numspeakers-1));

		sndoffsplc = sndoffs;
		sndoffsxor = sndoffsplc ^ (sndoffsplc+(sndbufsiz<<(bytespersample+numspeakers-2)));
	}
	
	j = (((11025L*2093)/samplerate)<<13);
	for(i=1;i<76;i++)
	{
		frqtable[i] = j;
		j = mulscale30(j,1137589835);  //(pow(2,1/12)<<30) = 1137589835
	}
	for(i=0;i>=-14;i--) frqtable[i&255] = (frqtable[(i+12)&255]>>1);

	loadwaves("WAVES.KWV");

	timecount = notecnt = musicstatus = musicrepeat = 0;

	clearbuf((void *)(FP_OFF(stemp)),sizeof(stemp)>>2,32768L);
	for(i=0;i<256;i++)
		for(j=0;j<16;j++)
		{
			qualookup[(j<<9)+i] = (((-i)*j+8)>>4);
			qualookup[(j<<9)+i+256] = (((256-i)*j+8)>>4);
		}
	for(i=0;i<(samplerate>>11);i++)
	{
		j = 1536 - (i<<10)/(samplerate>>11);
		fsin(&j);
		ramplookup[i] = ((16384-j)<<1);
	}

	for(i=0;i<256;i++)
	{
		j = i*90; fsin(&j);
		eff[0][i] = 65536+j/9;
		eff[1][i] = min(58386+((i*(65536-58386))/30),65536);
		eff[2][i] = max(69433+((i*(65536-69433))/30),65536);
		j = (i*2048)/120; fsin(&j);
		eff[3][i] = 65536+(j<<2);
		j = (i*2048)/30; fsin(&j);
		eff[4][i] = 65536+j;
		switch((i>>1)%3)
		{
			case 0: eff[5][i] = 65536; break;
			case 1: eff[5][i] = 65536*330/262; break;
			case 2: eff[5][i] = 65536*392/262; break;
		}
		eff[6][i] = min((i<<16)/120,65536);
		eff[7][i] = max(65536-(i<<16)/120,0);
	}

	switch(digistat)
	{
		case 1: case 2:
			if (sbirq < 8)
			{
				oldsbhandler = _dos_getvect(sbirq+0x8);           //Set new IRQ7 vector
				_disable(); _dos_setvect(sbirq+0x8, sbhandler); _enable();
				koutp(0x21,kinp(0x21) & ~(1<<(sbirq&7)));
			}
			else
			{
				oldsbhandler = _dos_getvect(sbirq+0x68);    //Set new SB IRQ vector
				_disable(); _dos_setvect(sbirq+0x68, sbhandler); _enable();
				koutp(0xa1,kinp(0xa1) & ~(1<<(sbirq&7)));
			}
			break;
	}

	musicoff();

	if (digistat != 255)
	{
		preparesndbuf();
		if (digistat != 13) preparesndbuf();

		if ((digistat == 1) || (digistat == 2))
		{
			if (sbdma < 4)
			{
				dmacheckport = (sbdma<<1)+1;
				dmachecksiz = (sndbufsiz<<(bytespersample+numspeakers-1))-1;

				koutp(0xa,sbdma+4);             //Set up DMA REGISTERS
				koutp(0xc,0);
				koutp(0xb,0x58+sbdma);          //&H58 - auto-init, &H48 - 1 block only
				koutp(sbdma<<1,sndoffs&255);
				koutp(sbdma<<1,(sndoffs>>8)&255);
				koutp(dmacheckport,dmachecksiz&255);
				koutp(dmacheckport,(dmachecksiz>>8)&255);
				koutp(dmapagenum[sbdma],((sndoffs>>16)&255));
				koutp(0xa,sbdma);
			}
			else
			{
				dmacheckport = ((sbdma&3)<<2)+0xc2;
				dmachecksiz = ((sndbufsiz<<(bytespersample+numspeakers-1))>>1)-1;

				koutp(0xd4,sbdma);               //Set up DMA REGISTERS
				koutp(0xd8,0);
				koutp(0xd6,0x58+(sbdma&3));      //&H58 - auto-init, &H48 - 1 block only
				koutp(dmacheckport-2,(sndoffs>>1)&255);
				koutp(dmacheckport-2,((sndoffs>>1)>>8)&255);
				koutp(dmacheckport,dmachecksiz&255);
				koutp(dmacheckport,(dmachecksiz>>8)&255);
				koutp(dmapagenum[sbdma],((sndoffs>>16)&255));
				koutp(0xd4,sbdma&3);
			}
		}

		switch(digistat)
		{
			case 1:
				sbout(0xd1);                                    //SB Speaker on

				if (sbver < 0x0400)
				{
					sbout(0x40);                            //SB Set speed
					sbout(256-(1000000/(samplerate<<(numspeakers-1))));
				}

				if (sbver < 0x0200)
				{
					sbout(0x14);                                 //SB 1-shot mode
					i = sndbufsiz-1;
					sbout(i&255);
					sbout((i>>8)&255);
				}
				else
				{
					if (sbver < 0x0400)
					{
							//Set length for auto-init mode
						i = (sndbufsiz<<(numspeakers+bytespersample-2))-1;
						sbout(0x48);
						sbout(i&255);
						sbout((i>>8)&255);
						if (numspeakers == 2)                   //SB set stereo
						{
							sbmixout(0L,0L);
							sbmixout(0xe,sbmixin(0xe)|2);
						}
						if ((samplerate<<(numspeakers-1)) <= 22050)
							sbout(0x1c);                         //Start SB interrupts!
						else
							sbout(0x90);                         //High Speed DMA
					}
					else
					{
						sbout(0x41);
						sbout((samplerate>>8)&255);
						sbout(samplerate&255);

						sbout(0xc6-((bytespersample-1)<<4));
						sbout(((bytespersample-1)<<4)+((numspeakers-1)<<5));
						i = (sndbufsiz<<(numspeakers-1))-1;
						sbout(i&255);
						sbout((i>>8)&255);
					}
				}
				break;
			case 2:
				koutp(0xf88,128);
				koutp(0xb8a,0);

				i = (1193180L>>(numspeakers-1)) / samplerate;
				koutp(0x138b,0x36); koutp(0x1388,i&255); koutp(0x1388,i>>8);
				i = (sndbufsiz<<(bytespersample+numspeakers-2));
				koutp(0x138b,0x74); koutp(0x1389,i&255); koutp(0x1389,i>>8);

				koutp(0x8389,0x3+((bytespersample-1)<<2)); //0x3=8bit/0x7=16bit
				koutp(0xb89,0xdf);
				koutp(0xb8b,0x8);
				koutp(0xf8a,0xd9+((2-numspeakers)<<5));    //0xd9=play/0xc9=record
				koutp(0xb8a,0xe1);
				break;
			case 13:
				samplecount = sndbufsiz;
				pcsndptr = (char *)sndoffs;
				bufferside = 0;
				pcsndbufsiz = sndbufsiz;
				pcrealmodeint = 0;

				samplediv = 1193280L / samplerate;

				j = 0;
				for(i=0;i<256;i++)
				{
						 //Scale (65536 normal)
					k = mulscale24(j-(samplediv<<7),160000) + (samplediv>>1);
					if (k < 0) k = 0;
					if (k > samplerate) k = samplerate;
					pcsndlookup[i] = (char)(k+1);
					j += samplediv;
				}

				oldtimerfreq = gettimerval();
				chainbackstart = oldtimerfreq/samplediv;
				chainbackcnt = chainbackstart;
				setuppctimerhandler(sndoffs+sndbufsiz,oldtimerfreq,0L,0L,0L,0L);

				_disable();
				oldpctimerhandler = _dos_getvect(0x8);
				installbikdmhandlers();
				koutp(0x43,0x34); koutp(0x40,samplediv&255); koutp(0x40,(samplediv>>8)&255);
				koutp(0x43,0x90);
				koutp(97,kinp(97)|3);
				_enable();
				break;
		}
	}
#else
	fprintf(stderr, "%s line %d; initsb() called\n", __FILE__, __LINE__);
#endif	
}

void getsbset(void)
{
	char *sbset;
	long i;

	sbset = getenv("BLASTER");

	i = 0;
	while (sbset[i] > 0)
	{
		switch(sbset[i])
		{
			case 'A': case 'a':
				i++;
				sbport = 0;
				while (((sbset[i] >= 48) && (sbset[i] <= 57)) ||
						 ((sbset[i] >= 'A') && (sbset[i] <= 'F')) ||
						 ((sbset[i] >= 'a') && (sbset[i] <= 'f')))
				{
					sbport *= 16;
					if ((sbset[i] >= 48) && (sbset[i] <= 57)) sbport += sbset[i]-48;
					if ((sbset[i] >= 'A') && (sbset[i] <= 'F')) sbport += sbset[i]-55;
					if ((sbset[i] >= 'a') && (sbset[i] <= 'f')) sbport += sbset[i]-55-32;
					i++;
				}
				break;
			case 'I': case 'i':
				i++;
				sbirq = 0;
				while ((sbset[i] >= 48) && (sbset[i] <= 57))
				{
					sbirq *= 10;
					sbirq += sbset[i]-48;
					i++;
				}
				break;
			case 'D': case 'd':
				i++;
				sbdma8 = 0;
				while ((sbset[i] >= 48) && (sbset[i] <= 57))
				{
					sbdma8 *= 10;
					sbdma8 += sbset[i]-48;
					i++;
				}
				break;
			case 'H': case 'h':
				i++;
				sbdma16 = 0;
				while ((sbset[i] >= 48) && (sbset[i] <= 57))
				{
					sbdma16 *= 10;
					sbdma16 += sbset[i]-48;
					i++;
				}
				break;
			default:
				i++;
				break;
		}
	}
}

#ifdef PLATFORM_DOS
void __interrupt __far sbhandler()
{
	switch(digistat)
	{
		case 1:
			if (sbver < 0x0200)
			{
				sbout(0x14);                           //SB 1-shot mode
				sbout((sndbufsiz-1)&255);
				sbout(((sndbufsiz-1)>>8)&255);
				kinp(sbport+0xe);                      //Acknowledge SB
			}
			else
			{
				mixerval = sbmixin(0x82);
				if (mixerval&1) kinp(sbport+0xe);      //Acknowledge 8-bit DMA
				if (mixerval&2) kinp(sbport+0xf);      //Acknowledge 16-bit DMA
			}
			break;
		case 2:
			if ((kinp(0xb89)&8) > 0) koutp(0xb89,0);
			break;
	}
	if (sbirq >= 8) koutp(0xa0,0x20);
	koutp(0x20,0x20);
	_enable(); preparesndbuf();
}
#endif

uninitsb()
{
#ifdef PLATFORM_DOS	
	if ((digistat == 0) && (musistat != 1))
		return;

	if (digistat != 255)
	{
		if ((digistat == 1) || (digistat == 2))  //Mask off DMA
		{
			if (sbdma < 4) koutp(0xa,sbdma+4); else koutp(0xd4,sbdma);
		}

		switch(digistat)
		{
			case 1:
				if (sbver >= 0x0400) sbout(0xda-(bytespersample-1));
				resetsb();
				sbout(0xd3);                           //Turn speaker off
				break;
			case 2:
				koutp(0xb8a,32);                       //Stop interrupts
				koutp(0xf8a,0x9);                      //DMA stop
				break;
			case 13:
				koutp(97,kinp(97)&252);
				koutp(0x43,0x34); koutp(0x40,0); koutp(0x40,0);
				koutp(0x43,0xbc);
				uninstallbikdmhandlers();
				break;
		}
	}

	if (snd != 0) free(snd), snd = 0;
	if (sndseg != 0) convdeallocate(sndseg), sndseg = 0;

	switch(digistat)
	{
		case 1: case 2:
			if (sbirq < 8)
			{
				koutp(0x21,kinp(0x21) | (1<<(sbirq&7)));
				_disable(); _dos_setvect(sbirq+0x8, oldsbhandler); _enable();
			}
			else
			{
				koutp(0xa1,kinp(0xa1) | (1<<(sbirq&7)));
				_disable(); _dos_setvect(sbirq+0x68, oldsbhandler); _enable();
			}
			break;
	}
#else
	fprintf (stderr, "%s line %d, uninitsb() called\n",__FILE__,__LINE__);
#endif	
}

void startwave(long wavnum, long dafreq, long davolume1, long davolume2, long dafrqeff, long davoleff, long dapaneff)
{
	long i, /*j,*/ chanum;

	if ((davolume1|davolume2) == 0) return;

	chanum = 0;
	for(i=NUMCHANNELS-1;i>0;i--)
		if (splc[i] > splc[chanum])
			chanum = i;

	splc[chanum] = 0;     //Disable channel temporarily for clean switch

	if (numspeakers == 1)
		calcvolookupmono(FP_OFF(volookup)+(chanum<<(9+2)),-(davolume1+davolume2)<<6,(davolume1+davolume2)>>1);
	else
		calcvolookupstereo(FP_OFF(volookup)+(chanum<<(9+2)),-(davolume1<<7),davolume1,-(davolume2<<7),davolume2);

	sinc[chanum] = dafreq;
	svol1[chanum] = davolume1;
	svol2[chanum] = davolume2;
	soff[chanum] = wavoffs[wavnum]+wavleng[wavnum];
	splc[chanum] = -(wavleng[wavnum]<<12);              //splc's modified last
	swavenum[chanum] = wavnum;
	frqeff[chanum] = dafrqeff; frqoff[chanum] = 0;
	voleff[chanum] = davoleff; voloff[chanum] = 0;
	paneff[chanum] = dapaneff; panoff[chanum] = 0;
	chanstat[chanum] = 0; sincoffs[chanum] = 0;
}

void setears(long daposx, long daposy, long daxvect, long dayvect)
{
	globposx = daposx;
	globposy = daposy;
	globxvect = daxvect;
	globyvect = dayvect;
}

void wsayfollow(char *dafilename, long dafreq, long davol, long *daxplc, long *dayplc, char followstat)
{
	char ch1, ch2, bad;
	long i, wavnum, chanum;

	if (digistat == 0) return;
	if (davol <= 0) return;

	for(wavnum=numwaves-1;wavnum>=0;wavnum--)
	{
		bad = 0;

		i = 0;
		while ((dafilename[i] > 0) && (i < 16))
		{
			ch1 = dafilename[i]; if ((ch1 >= 97) && (ch1 <= 123)) ch1 -= 32;
			ch2 = instname[wavnum][i]; if ((ch2 >= 97) && (ch2 <= 123)) ch2 -= 32;
			if (ch1 != ch2) {bad = 1; break;}
			i++;
		}
		if (bad != 0) continue;

		chanum = 0;
		for(i=NUMCHANNELS-1;i>0;i--) if (splc[i] > splc[chanum]) chanum = i;

		splc[chanum] = 0;     //Disable channel temporarily for clean switch

		if (followstat == 0)
		{
			xplc[chanum] = *daxplc;
			yplc[chanum] = *dayplc;
		}
		else
		{
			xplc[chanum] = ((long)daxplc);
			yplc[chanum] = ((long)dayplc);
		}
		vol[chanum] = davol;
		vdist[chanum] = 0;
		sinc[chanum] = (dafreq*11025)/samplerate;
		svol1[chanum] = davol;
		svol2[chanum] = davol;
		sincoffs[chanum] = 0;
		soff[chanum] = wavoffs[wavnum]+wavleng[wavnum];
		splc[chanum] = -(wavleng[wavnum]<<12);              //splc's modified last
		swavenum[chanum] = wavnum;
		chanstat[chanum] = followstat+1;