? stack 10*1024    // 20k stack
  
? include "WRITE.H--"
? include "FILE.H--"       // include readfile() and writefile()
? include "PORTS.H--"
? include "STRING.H--"
? include "DOS.H--"
? include "MOUSE.H--"
? include "KEYCODES.H--"
? include "VGA.H--"
? include "VIDEO.H--"      // include video mode values


? define  CLEARCOLOR  0   // transparent color for icons


? define MAXB 4*4*256-512
? define MAXBUF 16*1024

 // Most of this works fine as it is thus far, after some 
 // corrections in the malloc equivalent MEMGET division, 
 // but I'm quite sure its possible that my array indexing, 
 // though copied from the maker of sphinx c, contains 
 // pointer hazards, knowing that segments are mod 16.

byte b[MAXB], bo[MAXB], bo2[MAXB], tc, co, c1,c2,c3, offset;
word w1,w2;
int i,j,k,k1,k2,k3,o,p, sammax;
int x1,x2,x3, y1,y2,y3, z1,z2,z3,z4, u1,u2,u3;
long l1,l2,l3;
int choice, lastset, sap, maxcomp;
char ss[128];
word buf;
int v[64], v1[64], v2[64];

word x,y;      /* global variable for mouse pointer x and y coordinates */ 
byte buttons;  /* global variable mouse button status */ 
byte oldbuttons;

void getmouse ()
{@ GETMOUSEXY();
y = DX;
buttons = BL;
x = CX /2;     /* adjust x after so as not to undefine the regs */
}


clearm(int m)
{
   i = 0;
   do {
      BX=i;
      b[BX]= 128;
      bo[BX]= 128;
      bo2[BX]= 128;
      i++;
   } while (i<m);
}

void clearscreen ()
{@ FILLSCREEN19(byte CLEARCOLOR);
}


prhex(byte bc)
{
   k1=bc/16;
   k2=bc%16;
   if (k1 >= 10) k1=k1+65-10; else k1=k1+48;
   WRITE(k1);
   if (k2 >= 10) k2=k2+65-10; else k2=k2+48;
   WRITE(k2);
}

word readsamples()
{
   k1=PARAMCOUNT();
   if (k1 != 1) { WRITESTR("Use: zds <samplefilename 1>"); return(-1); }
   strcpy(#ss,PARAMSTR(0));
   WRITESTR("In "); WRITESTR(#ss);  WRITESTR(",len ");
   w2 = b; k1 = readfile(#ss,buf,0,MAXBUF);
   WRITEINT(k1-8); WRITESTR(" ");
   if (k1 <= 0) return(-1);

   i=7;j=0;sammax = k1-8;
   k3 = 4*1024;
   k3 -= 0*256;     // Now overwrites possible stack and variable space
   k3 -= 0;
   k3 = MAXB;
   offset = 0x80;   // add 128 to make positive numbers
   do {
      if (i >= k1){ sammax = j-1;  return(0); }
      BX = i;
      ES=buf;
      AL = ESBYTE[BX];
      BX = j;
      b[BX] = AL;
      i++; j++;
   } while (j< k3);       // only fill 4k - stack + var space
   sammax = j;
   return(0);
}



fillz80noprint(int m)
{
   // WRITESTR("#=");WRITEINT(m);
   i = 0;
      OUTPORTB(0, , ,0x37A);                  // start DMA cycle
      WAITVSYNC();
      i = 0 ; do { i++; } while (i < 1000);   // Give the dma unit time
      WAITVSYNC();
      WAITVSYNC();
   i = 0;
   do {
      BX=i;
  //    tc=bo[BX];
      tc=bo2[BX];
      if (i<-1) {WRITEINT(tc);WRITESTR(" "); }
      OUTPORTB(tc, , ,0x378);
        k = tc;
      OUTPORTB(0, , ,0x37A);
      OUTPORTB(1, , ,0x37A);
      i++;
   } while (i<m);
   OUTPORTB(1, , ,0x37A);
}

add_reverb(int m)
{
   i=0;j=900;k=1300;
   do {
      BX=i;
      c1=b[BX];
      BX=j;
      k = c1;
      k-=128;
      k = k * 3;
      k = k / 8;
  //    k+= 128;
      b[BX] += k;
      i++; j++;
      if (i>=m) return;
   } while (j<MAXB);
}

filter_sample()
{
   z1=128*8; z2=128*8; z3=128*8; z4=128*8;
   y1=101-v[32]; y1=y1/1;      // Cutoff
   y2=101-v[34]; y2=y2/1;      // Resonance
   i=1;                      // First and last output sample are 0 always now
 // WRITEINT(y1);WRITESTR(" ");
 // WRITEINT(y2);WRITESTR(" ");
   do {

         BX = 32; x2 = v1[BX]; y2 = v2[BX];

         u1 = x2;  u2 = i/16;  u1 = MAXB-16 ;
         u1 = u1/16; u1 = u1 - u2; u1 = u1 * x2;
         u3 = y2*u2; u1 = u1 + u3; u2 = MAXB-16;
         u2 = u2 / 16;  k1 = u1 / u2;

         BX = 34; x2 = v1[BX]; y2 = v2[BX];

         u1 = x2; u2 = i/16; u1 = MAXB-16 ;
         u1 = u1/16; u1 = u1 - u2; u1 = u1 * x2;
         u3 = y2*u2; u1 = u1 + u3; u2 = MAXB-16;
         u2 = u2 / 16; y2 = u1 / u2; y1 = k1;
         y1 = 101 - y1; y2 = 101 - y2;

         u3 = i % 256;
         if (u3 == 1) {
            GOTOXY(2,1);
            WRITESTR(" y1=");WRITEINT(y1);
            WRITESTR(" y2="); WRITEINT(y2); WRITESTR("  ");
          }

      j = i -1; BX = j;
      x3= bo[BX];
      BX = i;
      x1=bo[BX];
      x3 = x3 + x1 + x1;
      j = i +1; BX = j;
      x1=bo[BX];
      x3= x3 + x1;

      x1 = 2*x3;
      x1 = x1 - z1;
      x1 = x1 * 8;
      x1 = x1 / y1;

      x3 = y1 * y2;
      x3 = x3 / 50;
      x3 = x3 + 1;
      x2 = z1 - z4;
      x2 = x2 * 8;
      x2 = x2 / x3;
      z1 = z1 + x1 + x2;

      x1 = z1 - z2;
      x1 = x1 * 8;
      x1 = x1/ y1;
      z2 = z2 + x1;

      x1 = z2 - z3;
      x1 = x1 * 8;
      x1 = x1/ y1;
      z3 = z3 + x1;

      x1 = z3 - z4;
      x1 = x1 * 8;
      x1 = x1/ y1;
      z4 = z4 + x1;

      y3 = z4 / 8;
      if (y3 >255) y3 = 255;
      if (y3 < 0 ) y3 = 0;
      BX = i;
      bo2[BX] = y3;
      i++;
   } while (i < MAXB-1);

/*   
7005 FOR J = 0 TO 14
7010 FOR I = 0 TO 255 : K=K+1-.15*SIN((I+256*J)/ 96): F =2.2+1*K/ ( 512*1.5) : 
FF=-(1!+K/ 780) : FF=-(1.35+1)
7020 A = A + ((PEEK(&H7000 + I) + 2*PEEK(&H7000 + I + 1) + PEEK(&H7000 + I - 1)
) / 4 - A) / F + (D - A) / (F*FF/2)
7030 B = B + (A - B) / F
7035 C = C + (B - C) / F
7040 D = D + (C - D) / F
7045 PSET (I, 349 - D )
7055 IF D<0 THEN POKE &H7800+I+256*J,0 ELSE IF D>255 THEN POKE &H7800+I+256*J,255 ELSE POKE &H7800+I+256*J,INT(D)
7060 NEXT I : PRINT K,F,FF
7065 NEXT J
*/
}

envelope_sample(int m)
{
   y1= 100-v[36]; y1=y1/1;  // Attack rate
   y2= 100-v[38]; y2=y2/1;  // Decay rate
   y3= v[40]; y3=y3/1;      // Sustain level
   i=0;
   z1 = 32 * y1;            // end of attack section
   z2 = z1;
   z2+= 32 * y2;            // end of decay section

   z3 = m;
   if (z3 > MAXB) z3 = MAXB;
   if (z1 > z3) z1 = z3;
   if (z2 > z3) z2 = z3;


   do {
      BX = i; z3=bo[BX]; z3 -= 128;
      // y1= (10* i) / ((z2-z1)/10) 
      x2 = i-0; x2 = x2 * 10;
      x3 = z1-0; x3 = x3 / 10; x3 = x3 + 1;
      x2 = x2 / x3;
      z3 = z3 * x2; z3 = z3 / 100;
      z3 += 128; BX = i; bo[BX] = z3;
      i++;
   } while (i < z1);
   do {
      BX = i; z3=bo[BX]; z3 -= 128;
      // y1= (10* i) / ((z2-z1)/10) 
      x2 = i-z1; x2 = x2 * 10;
      x3 = z2-z1; x3 = x3 / 10; x3 = x3 + 1;
      x2 = x2 / x3; x1=100-y3; x2=x2*x1; x2 = x2 / 100 ; x2=100-x2;
      z3 = z3 * x2; z3 = z3 / 100;
      z3 += 128; BX = i; bo[BX] = z3;
      i++;
   } while (i < z2);
   do {
      BX = i; z3=bo[BX]; z3 -= 128;
      // y1= (10* i) / ((z2-z1)/10) 
      x2 = y3; 
      z3= z3 * x2; z3 = z3 / 100;
      z3 += 128; BX = i; bo[BX] = z3;
      i++;
   } while (i < MAXB);

}

make_sample(int m)
{
   i=0;j=0;
   do {
      x1 = 0;
      k2 = 0;
      do {
         y1 = x1;
         y1 = y1 * 2;
         BX = y1;
         x2 = v1[BX];
         y2 = v2[BX];
         x3 = 0;
         if (x2 != 0) x3 =1;
         if (y2 != 0) x3 =2;
         if (x3 != 0) {
          x3 = x1+1;
          x3 = x3 * j;
          x3 = x3 % m;
          BX = x3;
          c1=b[BX];
          k = c1;
          k-=128;
          z1 = x2;
           z2 = i/16;
          z1 = MAXB-16 ;
          z1 = z1/16;
          z1 = z1 - z2;
          z1 = z1 * x2;
          z3 = y2*z2;
          z1 = z1 + z3;
           z2 = MAXB-16;
           z2 = z2 / 16;
          z1 = z1 / z2;
             y1 = x1;
             y1 = y1 * 2;
             BX = y1;
          //  v[BX] = z1;
          k = z1*k;
          k = k/100;
          k2 = k2 + k;
         }
         x1++;
      } while (x1 < 16);

      z3 = i % 200;
  /*    lastset = 1; */
      if (z3 == 0) {
         x1 = 0; 
            GOTOXY(2,0);
            WRITESTR(" computing sample ");WRITEINT(i); WRITESTR("  "); 
      }

      BX = i;
      k2+= 128;
      bo[BX] = k2;
      i++;
      j++;
      j = j % m;
   } while (i<maxcomp);

   envelope_sample(maxcomp);
   filter_sample();
}

vol_sample(int m, j4,j5)
{
   i=0;
   do {
      BX=i;
      c1=b[BX];
      k = c1;
  //    if (i < 100) { WRITEINT(k); WRITESTR(" "); }
      k-=128;
      k = j4*k;
      k = k/j5;
  //    if (i < 100) { WRITEINT(k); WRITESTR("    "); }
      BX = i;
  //    k1 = b[BX];
  //    k1 += k;
      k+= 128;
      b[BX] = k;
      i++;
      if (i>=m) return;
   } while (i<MAXB);

}

int init()
{
   @ALLOCBESTFIT();
   buf = GETMEM(MAXBUF);
   if (buf == 0 ) return(-1);
   return(0);
}

/*   WRITE(BIOSREADKEY()); */

dobars()
{
   x1 = x /10; 
   if (x1 >= 21) return();
   j = x1;
   x1 = x1 * 10; 
   x1 = x1 + 2;
 //  y1 = 190 - y;
   y2 = y;
   if (y < 90) y2 = 90;
   if (y > 190) y2 = 190;
   y1 = 191 - y2;
   y3 =  y2 - 89;
 //  if ( y1 < 0  ) y1 = 0;
   bar19( x1, y2, 8, y1, 1);
   bar19( x1, 89, 8, y3 , 0);
   y2 = 190 - y2;
   x1 = x /10;
   j = j*2;
   BX = j;
   v[BX] = y2;
   x1 = x1 + 1;
   if (lastset == 1) v1[BX] = y2;
   if (lastset == 2) v2[BX] = y2;
/*      GOTOXY(35,5);
      WRITEINT(y2); WRITESTR(" "); 
      GOTOXY(35,6);
      WRITEINT(x1); WRITESTR(" "); */
}

setbars()
{
   i=0;
   do {
      j = i*2;
      x1 = 10 * i;
      x1 = x1 + 2;
      BX = j;
      y2 = v[BX];
      if (y2 < 0) y2 = 0;
      if (y2 > 100) y2 = 100;
      y1 = 190 - y2;
      y3 =  101 - y2;
      y2 = y2 + 1;
      bar19( x1, y1, 8, y2, 1);
      bar19( x1, 89, 8, y3 , 0);
      i++;
   } while ( i<21 );
}

drawsample()
{
            GOTOXY(2,0);
            WAITVSYNC();
            WRITESTR(" sample ");WRITEINT(sap); WRITESTR(" -->  "); 
   bar19(0,16,257,80,CLEARCOLOR);
   i = 1;
   z3 = 1;
   do {
      j = i-1;
      x1 = sap +j;
      x2 = sap +i;
      BX = x1;
      y1 = bo[BX];
      BX = x2;
      y2 = bo[BX];
      y1 = y1/4; y1= y1+16;
      y2 = y2/4; y2= y2+16;
      line19(j,y1,i,y2 ,4);

      BX = x1;
      y1 = bo2[BX];
      BX = x2;
      y2 = bo2[BX];
      y1 = y1/4; y1= y1+16;
      y2 = y2/4; y2= y2+16;
      line19(j,y1,i,y2 ,6);
      i = i+1;
      if (i >=256) z3 = 0;
      if (sap >= MAXB) z3 = 0;
   } while (z3 == 1);
}

mousetest()
{
   SHOWMOUSE();
   do { 
      getmouse();
      x1 = x / 10;
      j = x1*2;
      x1 = x1 + 1;
      BX = j;
      y2 = v[BX];
     if (lastset == 1)  y2 = v1[BX];
     if (lastset == 2)  y2 = v2[BX];

      GOTOXY(35,2);
      WAITVSYNC();
      WRITEINT(y2); WRITESTR(" "); 
      GOTOXY(35,3);
      WRITEINT(x1); WRITESTR(" "); 
      GOTOXY(35,5);
      WRITEINT(sap); WRITESTR(" "); 


      GOTOXY(35,4);
      // WRITEINT(buttons); WRITESTR(" "); 
      // WRITEINT(int co); WRITESTR(" ");
      GOTOXY(0,0);
      WRITESTR(" Send  Reset First Second Prev Next Quit "); 
   //           0     1     2     3     4     5     6     7
      GETTEXTPOSITION(,0);
      
      if (buttons == 0) {
         if (oldbuttons == 1) {
            oldbuttons = 0;
            GOTOXY(35,2); WRITESTR("    "); 
            if (lastset == 1) {
               maxcomp = 256;
               make_sample(sammax);
               sap = 0;
               drawsample();
               maxcomp = MAXB;
            }
         }
      }
      if (buttons == 1) { 
         if ( y < 8) {
            x1 = x;
            x1 = x1 / 48;
      //      x1 = x1 / 6;
            choice = x1 + 1;
      //      WRITEINT(choice);   WRITESTR(" ");
         } else {
            if (oldbuttons == 0) {
            }
            dobars();  
            oldbuttons = 1;
         }
      };

      if (choice == 2) {
         choice = 0;
         i=0;
         do {
            j = i * 2;
            BX = j;
            v[BX] = 0;
            if (lastset == 1) v1[BX] = 0;
            if (lastset == 2) v2[BX] = 0;
            i++;
         } while ( i < 21 );
         setbars();
      }
      if (choice == 1) {
         choice = 0;
         make_sample(sammax);
         fillz80noprint(MAXB);
      }
      if (choice == 3) {
         choice = 0;
         i=0;
         do {
            j = i * 2;
            BX = j;
            // if (lastset == 2) v2[BX] = v[BX];
            v[BX] = v1[BX];
            i++;
         } while ( i < 21 );
         lastset = 1;
         setbars();
      }
      if (choice == 4) {
         choice = 0;
         i=0;
         do {
            j = i * 2;
            BX = j;
         //    if (lastset == 1) v1[BX] = v[BX];
            v[BX] = v2[BX];
            i++;
         } while ( i < 21 );
         lastset = 2;
         setbars();
      }
      if (choice == 5) {     // Prev
         choice = 0;
         sap = sap -256;
         if (sap < 0) sap =0;
         drawsample();
      }
      if (choice == 6) {     // Next
         choice = 0;
         sap = sap +256;
         if (sap >= MAXB) sap =MAXB-256;
         drawsample();
      }
      if (choice == 7) return();
   } while ( 1 );
   HIDEMOUSE();
}

dovideo()
{
   @ SETVIDEOMODE( vid_320x200_256 );    /* set video mode */
   IF( @ GETVIDEOMODE() != vid_320x200_256 )  /* check if mode setting worked */
       {WRITESTR("Unable to enter 320x200 256 colour video mode.");
       EXIT(-1);}
   clearscreen();
   WAITVSYNC();
}

initbars()
{
         i=0;
         do {
            j = i * 2;
            BX = j;
            v[BX] = 0;
            v1[BX] = 0;
            v2[BX] = 0;
            i++;
         } while ( i < 64 );
	lastset = 1;          // start with first
   sap = 0;
   maxcomp = MAXB;
}

int main()
{
   if (init() != 0) { WRITESTR("Error: couldn't allocate buffer"); EXIT(-1); };
   dovideo();
   clearm(MAXB);
   if (readsamples() == 0) {
      WRITESTR("#=");WRITEINT(sammax);
      initbars();
      mousetest();
   }
   OUTPORTB(1, , ,0x37A);
   EXIT(0);
}