// Vytvoril (C)Cyril Höschl 
// Copyright 1997, Vsechna prava vyhrazena
// Zadna cast tohoto zdrojoveho kodu nesmi byt zkopirovana, modifikovana 
// nebo kdekoliv publikovana bez pisemneho svoleni Autora!
// 
// Tento zdrojovy kod slouzi ciste a jen k ucelu prohlizeni algoritmu zde pouzitych, 
// ktere vytvoril Cyril Hoschl a ktere nesmi byt nikde pouzity bez jeho pisemneho svoleni!

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <dos.h>
#include <math.h>
#define PI 3.14159265358979
#define POZOROVATEL 20
#define ROZHLED 150
#define DOHLED 50
#define POLEX 128
#define POLEY 128
#define NAKLON 0.01

int nacti_paletu(char *soubor)
{
 FILE *stream;
 char paleta[768];
 stream = fopen(soubor, "rb");
 fread(paleta, 768, 1, stream);
 fclose(stream);
 unsigned int seg, off;
 struct REGPACK reg;
 reg.r_ax = 0x1012;
 reg.r_bx = 0;
 reg.r_cx = 256;
 reg.r_es = FP_SEG(paleta);
 reg.r_dx = FP_OFF(paleta);
 intr(0x10, &reg);
 return 0;
}


void put(char *co, char *kam, int x, int y)
{
 asm {
      push ds
      lds si,co
      les di,kam
      mov dx,y
      mov bx,x
     }
znovu:
asm {
     mov cx,bx
     rep movsb
     add di,320
     sub di,bx
     dec dx
     jnz znovu
     pop ds
    }
}

int ConvPal(int brv)
{
 int barva;
 if (brv > 63) barva = 63; else
 if (brv < 0) barva = 0; else barva = brv;
 return barva;
}

int Norm(int uhel)
{
 if (uhel > 359) return(uhel-360);
 if (uhel < 0) return(uhel+360);
 return(uhel);
}

void OtocOsy(float *x, float *y, int uhel)
{
 *x += sin(uhel / 180.0 * PI);
 *y += cos(uhel / 180.0 * PI);
}

int main(void)
{
   FILE *stream;
   int x, y, u=135, v=0;//, Plus = 0, Vyska = 0;
   unsigned char *pole;
   char *kam;
   char *TabulkaX, *TabulkaY;
//   int i, uhel, delka;
   int i, uhel, delka, Zbuffer = 0, vyska = 0, barva;
   float StredX = 50, StredY = 90, o = 1;
//   char MazaciPole[64*ROZHLED];
   pole = (char*) malloc(POLEX*POLEY);
   stream = fopen("voxel.grf", "rb");
   fread(pole, POLEX*POLEY, 1, stream);
   fclose(stream);

   asm {
	mov ax, 0x13
	int 0x10
       }
    //Zde je nutne pred init pal. nanest na port 0x3c8 hodnotu 0, aby
    //se skala barev nacetla na 0-64 a ne treba na 0-55

    outp(0x3c8, 0);
   //Modra
   for (i = 0; i < 64; i++)
    {
     outp(0x3c9, 0);
     outp(0x3c9, 0);
     outp(0x3c9, i/4);
    }
   //Zelena
   for (i = 0; i < 64; i++)
    {
     outp(0x3c9, 0);
     outp(0x3c9, i/4);
     outp(0x3c9, 16-i/4);
    }
   //Bila
   for (i = 0; i < 64; i++)
    {
     outp(0x3c9, i);
     outp(0x3c9, 16+i/1.333);
     outp(0x3c9, i);
    }
//   for (i = 0; i < 64*ROZHLED; i++) MazaciPole[i] = 0;
//   nacti_paletu("voxel.pal");
   kam = (char*) MK_FP(0xA000, 0);
   put(pole, kam, POLEX, POLEY);
   TabulkaX = (char*) malloc(360*DOHLED);
   TabulkaY = (char*) malloc(360*DOHLED);

   kam = (char*) MK_FP(0xA000, 0);
   for (delka = POZOROVATEL; delka < POZOROVATEL+DOHLED; delka++)
   for (uhel = 0; uhel < 360; uhel++)
   {
    x = sin(uhel / 180.0 * PI) * delka;
    y = cos(uhel / 180.0 * PI) * delka;
    TabulkaX[uhel + (delka-POZOROVATEL) * 360] = x;
    TabulkaY[uhel + (delka-POZOROVATEL) * 360] = y;
   }

   do
   {
   switch(getch())
   {
    case 'w': StredX += sin((u+ROZHLED/2) / 180.0 * PI);
	      StredY += cos((u+ROZHLED/2) / 180.0 * PI);
	      break;
    case 's': StredX -= sin((u+ROZHLED/2) / 180.0 * PI);
	      StredY -= cos((u+ROZHLED/2) / 180.0 * PI);
	      break;
    case 'z': StredX -= sin((u-90+ROZHLED/2) / 180.0 * PI);
	      StredY -= cos((u-90+ROZHLED/2) / 180.0 * PI);
	      break;
    case 'x': StredX += sin((u-90+ROZHLED/2) / 180.0 * PI);
	      StredY += cos((u-90+ROZHLED/2) / 180.0 * PI);
	      break;
    case 'a': u++; break;
    case 'd': u--; break;
    case 'r': o+=NAKLON; break;
    case 'f': o-=NAKLON; break;
//    case 't': v++; break;
//    case 'g': v--; break;
    case 27: return 0;
   }

      kam = (char *) MK_FP(0xA000, 0);
      put(pole, kam, POLEX, POLEY);
      if (u < 0) u = 359;
      if (u > 359) u = 0;
      if (StredX < 0) StredX = POLEX - 1;
      if (StredX >= POLEX) StredX = 0;
      if (StredY < 0) StredY = POLEY - 1;
      if (StredY >= POLEY) StredY = 0;
   for (uhel = u; uhel < u+ROZHLED; uhel ++)
   {
     v = pole[(TabulkaX[Norm(uhel)]+(int)StredX) + (TabulkaY[Norm(uhel)]+(int)StredY) * POLEY];
     Zbuffer = 0;
     for (delka = 0; delka < DOHLED; delka++)
     {
      x = TabulkaX[Norm(uhel) + delka * 360];
      y = TabulkaY[Norm(uhel) + delka * 360];

      if (x > POLEX-StredX-1) x -= POLEX;
      if (x < 0-StredX) x += POLEX;
      if (y > POLEY-StredY-1) y -= POLEY;
      if (y < 0-StredY) y += POLEY;
      barva = pole[(x+(int)StredX) + (y+(int)StredY) * POLEX]-v;

      if (uhel == u || uhel == u+ROZHLED-1 || delka == 49 || delka == 0)
      {
       kam = (char*) MK_FP(0xA000, ((x+(int)StredX) + (y+(int)StredY) * 320));
       *kam = 255;
      }
      vyska = (POZOROVATEL*barva)/((delka+POZOROVATEL)*o);
      if (vyska > Zbuffer)
	 {
	  for (i = 200 - vyska; i < 200-Zbuffer; i++)
	      {
	       kam = (char *) MK_FP(0xA000, (300-uhel+u) + i*320);
	       *kam = barva+v;
	      }
	  Zbuffer = vyska;
	 }
     }
	  for (i = 50; i < 200-Zbuffer; i++)
	      {
	       kam = (char *) MK_FP(0xA000, (300-uhel+u) + i*320);
	       *kam = 50-i/4;
	      }
//	  getch();

   }
   } while (3==3);
   getch();
   free(pole);
   free(TabulkaX);
   free(TabulkaY);
   return 0;
}