/***********************************************************************/
/* This program demonstrates how to use BIOS calls for programming the */
/* Atari Portfolio in graphics mode. The program should be compiled    */
/* with Turbo C 1.0                                                    */
/* Simple 3D engine implementation by RayeR (C) 2000                   */
/***********************************************************************/
// budem prekladat pro portfolio ?
//#define PORTFOLIO

#include <conio.h>
#include <stdlib.h>
#include <dos.h>

typedef unsigned char Byte;

#define GFX 0x04      // videomody
#define TXT 0x07
#define XRES 240
#define YRES 64
#define VRAMSIZE 1920
#define MIDX (XRES/2)
#define MIDY (YRES/2)
#define FP 10         // fixed point 6:10
#define FPR 6         // na kolik bitu bude platny sin/cos
#define FPPI (8-FPR)
#define XOFFSET (-20) // doladeni polohy 2D obrazu
#define YOFFSET (-3)  // doladeni polohy 2D obrazu

/* camera position */
#define CX 20
#define CY -2
#define CZ 80

/* krychle - 8 vertexu, 12 faces   */
#define VNUM 8
#define FNUM 12
#define HEDGE (19<<FP)

int i,j,l;
#ifndef PORTFOLIO
Byte far *vram=MK_FP(0xB800,0); /* pointer do VRAM */
#else
Byte far *vram=MK_FP(0xB000,0); /* pointer do VRAM */
#endif
int  v[VNUM][3];  /* 3D vertexy */
Byte f[FNUM][3];  /* fejsy */
Byte p[VNUM][2];  /* 2D transformovane body */
Byte sintbl[91]={ /* predpocitana tabulka sinus */
		0,
		4,
		8,
		13,
		17,
		22,
		26,
		31,
		35,
		40,
		44,
		48,
		53,
		57,
		61,
		66,
		70,
		74,
		79,
		83,
		87,
		91,
		95,
		100,
		104,
		108,
		112,
		116,
		120,
		124,
		127,
		131,
		135,
		139,
		143,
		146,
		150,
		154,
		157,
		161,
		164,
		167,
		171,
		174,
		177,
		181,
		184,
		187,
		190,
		193,
		196,
		198,
		201,
		204,
		207,
		209,
		212,
		214,
		217,
		219,
		221,
		223,
		226,
		228,
		230,
		232,
		233,
		235,
		237,
		238,
		240,
		242,
		243,
		244,
		246,
		247,
		248,
		249,
		250,
		251,
		252,
		252,
		253,
		254,
		254,
		255,
		255,
		255,
		255,
		255,
		255
		};

void pfdelay(unsigned int bogoloops) /* 1s = asi 27000 loopu */
{
  unsigned int i;
  for (i=0; i<bogoloops; i++);
}

void setmode(Byte mode) /* set mode GFX/TXT */
{
  union REGS regs;
  regs.h.ah = 0;
  regs.h.al = mode;
  int86(0x10, &regs, &regs);
}

void cls(Byte pattern)
{
  register int i;
  for (i=0; i<VRAMSIZE; i++)
    vram[i]=pattern;
}

#ifndef PORTFOLIO
void putpix(Byte x, Byte y, Byte color) // prez BIOS - desne pomaly
{
  union REGS regs;
  regs.h.ah = 0x0c;
  regs.h.al = color;
  regs.h.bh = 0;
  regs.x.cx = x;
  regs.x.dx = y;
  int86(0x10, &regs, &regs);
}
#else
void putpix(Byte x, Byte y, Byte color) /* putpixel prez porty 0/1 */
{
  register int offset=x+y*XRES;
  int bytenum=offset%8;
  int ofs=offset>>3;
  vram[ofs]=vram[ofs]|(0x80>>bytenum);
}
#endif

/*Byte getpix(Byte x, Byte y) // get pixel color 0/1
{
  union REGS regs;
  regs.h.ah = 0x0d;
  regs.h.bh = 0;
  regs.x.cx = x;
  regs.x.dx = y;
  int86(0x10, &regs, &regs);
  return(regs.h.al);
} */

void refresh(void) /* zkopiruje VRAM na displej (do kontroleru HD) */
{
  asm {
    cld
    push ax
    push cx
    push dx
    push bx
    push si
    push di
    push ds
    mov  si,0
    mov  ax,0b000h
    mov  ds,ax
    mov  di,64
    }
   refresh_2:
  asm {
    mov  cx,30
    mov  bx,si
    mov  al,0ah
    mov  dx,8011h
    cli
    out  dx,al
    mov  al,bl
    mov  dx,8010h
    out  dx,al
    sti
    mov  al,0bh
    mov  dx,8011h
    cli
    out  dx,al
    mov  dx,8010h
    mov  al,bh
    and  al,7
    out  dx,al
    sti
    }
   refresh_1:
  asm {
    lodsb
    ror  al,1
    mov  ah,al
    and  ah,136
    ror  al,1
    ror  al,1
    mov  bl,al
    and  bl,68
    or   ah,bl
    ror  al,1
    ror  al,1
    mov  bl,al
    and  bl,34
    or   ah,bl
    ror  al,1
    ror  al,1
    and  al,17
    or   al,ah
    mov  ah,al
    inc  dx
    mov  al,0ch
    cli
    out  dx,al
    mov  al,ah
    mov  dx,8010h
    out  dx,al
    sti
    loop refresh_1
    dec  di
    jnz  refresh_2
    pop  ds
    pop  di
    pop  si
    pop  bx
    pop  dx
    pop  cx
    pop  ax
  }
}

void line(Byte x1, Byte y1, Byte x2, Byte y2, Byte color) /* line */
{
  int x, y, d, a, b;
  int dx_diag, dy_diag;
  int dx_nondiag, dy_nondiag;
  int diag_inc, nondiag_inc;
  int i, swap;

  x = x1;
  y = y1;
  a = x2-x1;
  b = y2-y1;
  if (a<0) {
      a       = -a;
      dx_diag = -1;
  } else
      dx_diag = 1;
  if (b<0) {
      b       = -b;
      dy_diag = -1;
  } else
      dy_diag = 1;
  if (a<b) {
      swap       = a;
      a          = b;
      b          = swap;
      dx_nondiag = 0;
      dy_nondiag = dy_diag;
  } else {
      dx_nondiag = dx_diag;
      dy_nondiag = 0;
  }
  d           = b+b-a;
  nondiag_inc = b+b;
  diag_inc    = b+b-a-a;

  for(i=0; i<=a; i++) {
      putpix(x, y, color);
      if (d<0) {
	  x = x+dx_nondiag;
	  y = y+dy_nondiag;
	  d = d+nondiag_inc;
      } else {
	  x = x+dx_diag;
	  y = y+dy_diag;
	  d = d+diag_inc;
      }
  }
}

#define triangle(x1,y1,x2,y2,x3,y3,color) {line(x1,y1,x2,y2,color); line(x2,y2,x3,y3,color); line(x3,y3,x1,y1,color);}

void transform(void)
{
  Byte i;
  long zdivider;
  for (i=0; i<VNUM; i++)
    {
    zdivider=((v[i][2]>>FP)+CZ);
    p[i][0]=(int)( CZ*((v[i][0]>>FP)+CX)/zdivider+MIDX)+XOFFSET;
    p[i][1]=(int)(-CZ*((v[i][1]>>FP)+CY)/zdivider+MIDY)+YOFFSET;
    }
}

void render(Byte color)
{
  Byte i;
  for (i=0; i<FNUM; i++)
    triangle(p[f[i][0]][0],p[f[i][0]][1], p[f[i][1]][0],p[f[i][1]][1], p[f[i][2]][0],p[f[i][2]][1], color)
}

/*void move(int xo, int yo, int zo)
{
  Byte i;
  for (i=0; i<VNUM; i++)
    {
    v[i][0]+=xo<<FP;
    v[i][1]+=yo<<FP;
    v[i][2]+=zo<<FP;
    }
} */

/*void scale(int xm, int ym , int zm)
{
  int i;
  for (i=0; i<VNUM; i++)
    {
    if (xm>0)
      v[i][0]=v[i][0]<<xm;
    else
      v[i][0]=v[i][0]>>-xm;
    if (ym>0)
      v[i][1]=v[i][1]<<ym;
    else
      v[i][1]=v[i][1]>>-ym;
    if (zm>0)
      v[i][2]=v[i][2]<<zm;
    else
      v[i][2]=v[i][2]>>-zm;
    }
} */

void iscale(int xm, int ym , int zm)
{
  int i;
  for (i=0; i<VNUM; i++)
    {
    if (v[i][0]>0)
      v[i][0]+=xm;
    else
      if (v[i][0]<0)
	v[i][0]-=xm;
    if (v[i][1]>0)
      v[i][1]+=ym;
    else
      if (v[i][1]<0)
	v[i][1]-=ym;
    if (v[i][2]>0)
      v[i][2]+=zm;
    else
      if (v[i][2]<0)
	v[i][2]-=zm;
    }
}

int isin(char x)
{
  if (x>0)
    return(sintbl[x]>>FPPI);
  else
    return(-sintbl[-x]>>FPPI);
}

int icos(char x)
{
  if (x>0)
    return(sintbl[90-x]>>FPPI);
  else
    return(sintbl[90+x]>>FPPI);
}

void rotatex(Byte alfa)
{
  int i,temp;
  for (i=0; i<VNUM; i++)
    {
    temp=(v[i][2]>>FPR)*icos(alfa)-(v[i][1]>>FPR)*isin(alfa);
    v[i][1]=(v[i][2]>>FPR)*isin(alfa)+(v[i][1]>>FPR)*icos(alfa);
    v[i][2]=temp;
    }
}

void rotatey(Byte alfa)
{
  int i,temp;
  for (i=0; i<VNUM; i++)
    {
    temp=(v[i][0]>>FPR)*icos(alfa)-(v[i][2]>>FPR)*isin(alfa);
    v[i][2]=(v[i][0]>>FPR)*isin(alfa)+(v[i][2]>>FPR)*icos(alfa);
    v[i][0]=temp;
    }
}

void rotatez(Byte alfa)
{
  int i,temp;
  for (i=0; i<VNUM; i++)
    {
    temp=(v[i][0]>>FPR)*icos(alfa)-(v[i][1]>>FPR)*isin(alfa);
    v[i][1]=(v[i][0]>>FPR)*isin(alfa)+(v[i][1]>>FPR)*icos(alfa);
    v[i][0]=temp;
    }
}

void makebox(void)
{
  v[0][0]=-HEDGE;
  v[0][1]=HEDGE;
  v[0][2]=HEDGE;
  v[1][0]=HEDGE;
  v[1][1]=HEDGE;
  v[1][2]=HEDGE;
  v[2][0]=HEDGE;
  v[2][1]=-HEDGE;
  v[2][2]=HEDGE;
  v[3][0]=-HEDGE;
  v[3][1]=-HEDGE;
  v[3][2]=HEDGE;
  v[4][0]=-HEDGE;
  v[4][1]=HEDGE;
  v[4][2]=-HEDGE;
  v[5][0]=HEDGE;
  v[5][1]=HEDGE;
  v[5][2]=-HEDGE;
  v[6][0]=HEDGE;
  v[6][1]=-HEDGE;
  v[6][2]=-HEDGE;
  v[7][0]=-HEDGE;
  v[7][1]=-HEDGE;
  v[7][2]=-HEDGE;
}

main()
{
/* definice faces krychle */
  f[0][0]=0;
  f[0][1]=3;
  f[0][2]=2;
  f[1][0]=0;
  f[1][1]=1;
  f[1][2]=2;
  f[2][0]=1;
  f[2][1]=5;
  f[2][2]=6;
  f[3][0]=1;
  f[3][1]=2;
  f[3][2]=6;
  f[4][0]=0;
  f[4][1]=4;
  f[4][2]=7;
  f[5][0]=0;
  f[5][1]=3;
  f[5][2]=7;
  f[6][0]=4;
  f[6][1]=5;
  f[6][2]=6;
  f[7][0]=4;
  f[7][1]=7;
  f[7][2]=6;
  f[8][0]=0;
  f[8][1]=1;
  f[8][2]=5;
  f[9][0]=0;
  f[9][1]=4;
  f[9][2]=5;
  f[10][0]=3;
  f[10][1]=2;
  f[10][2]=6;
  f[11][0]=3;
  f[11][1]=7;
  f[11][2]=6;

  makebox();
  setmode(GFX);
  j=0;
  while (!kbhit())
    {
    for (i=0; i<16; i++)
      {
      rotatey(6);
      iscale(220,0,220); // korekce XZ chyby rotace
      transform();
      #ifndef PORTFOLIO
	setmode(GFX); // jako cls
	line(0,0,XRES-1,0,1);
	line(XRES-1,0,XRES-1,YRES-1,1);
	line(XRES-1,YRES-1,0,YRES-1,1);
	line(0,YRES-1,0,0,1);
      #else
	cls(0);
      #endif
      render(1);
      refresh();
      printf("Diz iz da Reel Hardk0re!");
      #ifndef PORTFOLIO
	delay(20);
      #else
	pfdelay(1000);
      #endif
      }
    makebox();
    j++;
    if ((j%4)==0)
      j=0;
    for (l=0; l<j; l++)
      rotatey(89);
    }

  setmode(TXT);
  return(0);
}