/*****************************************************************************
 *									     *
 *    Priklad pocitani stereogramu / An example of rendering sterograms      *
 *									     *
 *****************************************************************************/

/*		                TL Tomas Loun				     *
				    inf96
			     lount@risc.upol.cz
 *			http://www.inf.upol.cz/~lount			     */

#include <graphics.h>
#include <stdio.h>
#include <math.h>
#include <bios.h>
#include <stdlib.h>

#define PATSIZE	80
#define MAXX (640-PATSIZE)	// je treba zmenit pri jinem video modu nez
#define MAXY 480		// 640x480 (VGA)
#define DEEP PATSIZE/3		// hloubka obrazku
#define byte unsigned char
#define pi 3.1415926536

const byte MYCOLORS[]={0,1,11,5,13};
int gd = VGA, gm = VGAHI;
int x,y;
char      a;
unsigned int COPYSIZE=0;
void *data;

byte GetLevel(int ax, int ay)
{ float x,y;
 y=(float(ay)-(MAXY/2))/(MAXX/2)*3;
 x=(float(ax)-(MAXX/2))/(MAXX/2)*3;
 x*=x; y*=y;
 return cos(pi*sqrt(x+y))*127+128;
}

byte GetLevel2(int ax,int ay)
{ int x,y;
 x=ax/2; y=ay/2+1;
 return(x*x+x*y+y*y)/y;
}

void DrawLevelPic()
{
 for (int y=0; y<MAXY/4; y++)
   for (int x=0; x<MAXX/4; x++) putpixel(PATSIZE+x*4,y*4,GetLevel(x*4,y*4)/16);
}

void MakePattern()
{
 for (int y=0; y<MAXY; y++)
  for (int x=0; x<PATSIZE; x++) putpixel(x,y,MYCOLORS[random(5)]);
}

void DrawStereogram()
{ byte color;
  int XPos;
 for (int c=0; c<=MAXX/PATSIZE-(MAXX%PATSIZE==0); c++)
 {
  XPos=PATSIZE*c;
  if (XPos+2*PATSIZE<640) COPYSIZE=PATSIZE-1;
   else COPYSIZE=640-XPos-PATSIZE-1;
  getimage(XPos,0,XPos+COPYSIZE,MAXY-1,data);
  putimage(XPos+PATSIZE,0,data,COPY_PUT);
  for (y=0;y<MAXY;y++)
   for (x=0;x<PATSIZE;x++)
   {
    color=getpixel(XPos+x,y);
    putpixel(XPos+x+PATSIZE-(GetLevel(XPos+x,y)*DEEP)/256,y,color);
   }
 }
}

void main()
{
 initgraph(&gd,&gm,"D:\\BC\\BGI");
 data=malloc(imagesize(0,0,PATSIZE-1,MAXY-1));

 DrawLevelPic();		// Nakresli,jak bude stereogram vypadat
 MakePattern();			// Vygeneruj vzor pro pokryti
 DrawStereogram();		// Spocitej stereogram

 fflush(stdin);
 while (!(char)bioskey(0));
 free(data);
 closegraph();
}