#include <stdio.h>
#include <math.h>
#include <dos.h>
#include <graphics.h>

#define TAULUKOKO 199

void laske();
void haekuva(char *nimi);
void piirra(int kx,int ky,int kz);
int initmouse();
void putmouse(int, int);
void mouseposition(int *,int *);
int leftbutton();

int sinit[360],cosinit[360];
int taulu[TAULUKOKO+1][4];
int koko;
int k1,k2,xk,yk;

long int s,et1,et2;


main(int argc,char *argv[])
{
   int l,l2,a,b,g,x,y,vx,vy,lx,ly,ry,hy,EGA;

   if (argc<2) {
      printf("You should give the name of the picture, eg. 3D KUVA.DAT");
      exit(1);
   }
   if (initmouse()!=-1) {
      printf("Mouse not installed");
      exit(1);
   }
   printf("Loading picture data...\n");
   haekuva(argv[1]);
   detectgraph(&a,&b);
   if (a==3) EGA=1; else EGA=0;
   initgraph(&a,&b,'');
   laske();
   ry=getmaxy()+1;
   hy=getmaxy()/10+1;
   g=1;
   if (EGA) setactivepage(g);
   setcolor(getmaxcolor());
   initmouse();
   putmouse(xk,yk);
   x=0;
   y=0;
   do {
      vx=x;
      vy=y;
      mouseposition(&x,&y);
      if (vx!=x || vy!=y) {
         lx=x-320;
         if (lx<0) lx=lx+640;
         lx=lx*36/64;
         ly=y-yk;
         if (ly<0) ly=ly+ry;
         ly=ly*36/hy;
         cleardevice();
         piirra(ly,lx,0);
         if (EGA) setvisualpage(g);
         g=1-g;
         if (EGA) setactivepage(g);
      }
   } while (!leftbutton());
   closegraph();
}


void laske()
{
   int l;

   s=taulu[0][0];
   et1=taulu[0][1];
   et2=taulu[0][2];
   k1=getmaxy()*4/40+1;
   k2=getmaxx()*3/40+1;
   xk=getmaxx()/2+1;
   yk=getmaxy()/2+1;
   printf("Calculating sine and cosine...\n");
   for(l=0;l<360;l++) {
      sinit[l]=(int)(sin( (double)l/180*M_PI )*256);
      cosinit[l]=(int)(cos( (double)l/180*M_PI )*256);
   }
}


void piirra(int kx,int ky,int kz)
{
   int l;
   long int p,x1,y1,z1,x2,y2,z2;
   int x,y;
   int vx=0;
   int vy=0;

   for(l=1;l<koko;l++) {
      x1=taulu[l][1] << 8;
      y1=(taulu[l][2]*cosinit[kx])+(taulu[l][3]*sinit[kx]);
      z1=-(taulu[l][2]*sinit[kx])+(taulu[l][3]*cosinit[kx]);

      x2=(x1*cosinit[ky] >> 8)-(z1*sinit[ky] >> 8);
      z2=(x1*sinit[ky] >> 8)+(z1*cosinit[ky] >> 8);

      x1=(x2*cosinit[kz] >> 8)+(y1*sinit[kz] >> 8);
      y2=-(x2*sinit[kz] >> 8)+(y1*cosinit[kz] >> 8);

      p=(256*et1)/((z2 >> 8)+et1+et2);

      x=(x1*p) >> 8;
      y=((y2*k1/k2)*p) >> 8;

      x=(x*s >> 8)+xk;
      y=-(y*s >> 8)+yk;

      if (taulu[l][0]==0)
         line(vx,vy,x,y);
      vx=x;
      vy=y;

   }
}


void haekuva(char *nimi)
{
   int c;
   char lu[5];
   int l1,l2,cl;
   FILE *fp;

   fp=fopen(nimi,"r");
   if (fp==NULL) {
      printf("File %s didn't open properly. Execution halted.\n",nimi);
      exit(1);
   }
   l1=0;
   l2=0;
   while((c=getc(fp))!=EOF && l1<=TAULUKOKO) {
      if ((c>47 && c<58) || c==45) {
         cl=0;
         while((c>47 && c<58) || c==45) {
            lu[cl]=c;
            cl++;
            c=getc(fp);
         }
         lu[cl]=0;
         taulu[l1][l2]=atoi(lu);
         l2++;
         if (l2>3) {
            l1++;
            l2=0;
         }
      }
   }
   koko=l1;
   fclose(fp);
}


int initmouse()
{
   struct REGPACK regs;

   regs.r_ax=0;
   intr(51,&regs);
   return(regs.r_ax);
}


void mouseposition(int *x,int *y)
{
   struct REGPACK regs;

   regs.r_ax=3;
   intr(51,&regs);
   *x=regs.r_cx;
   *y=regs.r_dx;
}


int leftbutton()
{
   struct REGPACK regs;

   regs.r_ax=3;
   intr(51,&regs);
   return (regs.r_bx & 1);
}


void putmouse(int x,int y)
{
   struct REGPACK regs;

   regs.r_ax=4;
   regs.r_cx=x;
   regs.r_dx=y;
   intr(51,&regs);
}