VGA.C

// vga.c
// vga device driver

// This source code REALLY needs to be cleaned up. A lot.

#include <dpmi.h>
#include <sys\nearptr.h>
#include <stdio.h>
#include <strings.h>
#include "control.h"
#include "render.h"
#include "timer.h"

#include "engine.h" // for valloc()

unsigned char pal[768];
unsigned char pal2[768];
extern char waitvrt,*speech,fade,cancelfade,*strbuf;

char *fnt,*fnt2,*tbox,*n;
short int x1=17,y1=17;

__dpmi_regs regs;
unsigned char *screen;
unsigned char *virscr;

wait()
{
  while (inportb(0x3DA) & 8) {}
  while (!(inportb(0x3DA) & 8)) {}
}

set_palette(unsigned char *pall)
{ unsigned int i;

  if (waitvrt) wait();
  outportb(0x03c8, 0);
  for (i=0; i<768; i++)
      outportb(0x03c9, pall[i]);
}

get_palette()
{ unsigned int i;

  outportb(0x03c7, 0);
  for (i=0; i<768; i++)
      pal[i]=inportb(0x03c9);
}

set_intensity(unsigned int n)
  { int i;
    for (i=767; i>=0; --i)
      pal2[i] = (pal[i] * n) >> 6;
    set_palette(pal2);
  }

initvga()
{ memset(&regs, 0, sizeof regs);
  regs.x.ax=0x13;

  PreCalc_TransparencyFields();

  __dpmi_int(0x10, &regs);
  virscr=valloc(90000,"virscr");
  n=valloc(256,"initvga:n");
  //memset(virscr, 0, 81664);
  //memset(n, 0, 256);
  __djgpp_nearptr_enable();
  screen=0xa0000 + __djgpp_conventional_base;
}

closevga()
{ __djgpp_nearptr_disable();
  regs.x.ax = 0x0003;
  __dpmi_int(0x10, &regs);
}

quick_killgfx()
{ regs.x.ax=0x03;
  __dpmi_int(0x10, &regs);
}

quick_restoregfx()
{ regs.x.ax=0x013;
  __dpmi_int(0x10, &regs);
}

vgadump()
{
  if (waitvrt) wait();
  asm("movl _virscr, %%esi              \n\t"
      "addl $5648, %%esi                \n\t"
      "movl _screen, %%edi              \n\t"
      "movl $200, %%eax                 \n\t"
"lineloop:                              \n\t"
      "movl $80, %%ecx                  \n\t"
      "rep                              \n\t"
      "movsl                            \n\t"
      "addl $32, %%esi                  \n\t"
      "decl %%eax                       \n\t"
      "jnz lineloop                     \n\t"
      :
      :
      : "esi", "edi", "cc", "eax", "ecx");
}

setpixel(int x, int y, char c)
{  asm ("movl %1, %%eax                 \n\t"
        "imul $352, %%eax               \n\t"
        "addl %0, %%eax                 \n\t"
        "addl _virscr, %%eax            \n\t"
        "movl %%eax, %%edi              \n\t"
        "movb %2, %%al                  \n\t"
        "stosb                          \n\t"
        :
        :"m" (x), "m" (y), "m" (c)
        : "eax","edi","cc" );
}

vline(int x, int y, int y2, char c)
{ int i;

  for (i=0; i<(y2-y); i++)
      setpixel(x,(y+i),c);

}

hline(int x, int y, int x2, char c)
{  asm ("movl %2, %%ecx                 \n\t"
        "subl %0, %%ecx                 \n\t"
        "movl %1, %%eax                 \n\t"
        "imul $352, %%eax               \n\t"
        "addl %0, %%eax                 \n\t"
        "addl _virscr, %%eax            \n\t"
        "movl %%eax, %%edi              \n\t"
        "movb %3, %%al                  \n\t"
        "repz                           \n\t"
        "stosb                          \n\t"
        :
        : "m" (x), "m" (y), "m" (x2), "m" (c)
        : "eax","edi","ecx","cc" );
}

box(int x, int y, int x2, int y2, char color)
{ int i;

  if (x2<x) { i=x2; x2=x; x=i; }
  if (y2<y) { i=y2; y2=y; y=i; }

  for (i=0; i<=(y2-y); i++)
    { hline(x,(y+i),x2+1,color); }
}

/*
copytile(int x, int y, char *spr)
{ asm("movl $16, %%edx                  \n\t"
      "movl %2, %%esi                   \n\t"
      "movl %1, %%edi                   \n\t"
      "imul $352, %%edi                 \n\t"
      "addl %0, %%edi                   \n\t"
      "addl _virscr, %%edi              \n\t"
"ctl0:                                  \n\t"
      "movsl                            \n\t"
      "movsl                            \n\t"
      "movsl                            \n\t"
      "movsl                            \n\t"
      "addl $336, %%edi                 \n\t"
      "decl %%edx                       \n\t"
      "jnz ctl0                         \n\t"
      :
      : "m" (x), "m" (y), "m" (spr)
      : "edx","esi","edi","cc" );
}
*/

copytile(int x, int y, char *spr)
{
  asm("movl $16, %%ecx                  \n\t"
      "movl %2, %%esi                   \n\t"
      "movl %1, %%edi                   \n\t"
      "imul $352, %%edi                 \n\t"
      "addl %0, %%edi                   \n\t"
      "addl _virscr, %%edi              \n\t"
" ctl0:                                 \n\t"
      "movl (%%edi), %%eax              \n\t"
      "andl $0, %%eax                   \n\t"
      "orl  (%%esi), %%eax              \n\t"
      "movl %%eax, (%%edi)              \n\t"
      "movl 4(%%edi), %%eax             \n\t"
      "andl $0, %%eax                   \n\t"
      "orl  4(%%esi), %%eax             \n\t"
      "movl %%eax, 4(%%edi)             \n\t"
      "movl 8(%%edi), %%eax             \n\t"
      "andl $0, %%eax                   \n\t"
      "orl  8(%%esi), %%eax             \n\t"
      "movl %%eax, 8(%%edi)             \n\t"
      "movl 12(%%edi), %%eax            \n\t"
      "andl $0, %%eax                   \n\t"
      "orl  12(%%esi), %%eax            \n\t"
      "movl %%eax, 12(%%edi)            \n\t"
      "addl $16, %%esi                  \n\t"
      "addl $352, %%edi                 \n\t"
      "decl %%ecx                       \n\t"
      "jnz ctl0                         \n\t"
      :
      : "m" (x), "m" (y), "m" (spr)
      : "eax","ecx","esi","edi","cc" );
}

copysprite(int x, int y, int width, int height, char *spr)
{ asm("movl %3, %%edx                   \n\t"
      "movl %4, %%esi                   \n\t"
"csl0:                                  \n\t"
      "movl %1, %%eax                   \n\t"
      "imul $352, %%eax                 \n\t"
      "addl %0, %%eax                   \n\t"
      "addl _virscr, %%eax              \n\t"
      "movl %%eax, %%edi                \n\t"
      "movl %2, %%ecx                   \n\t"
      "shrl $1, %%ecx                   \n\t"
      "jnc csl1                         \n\t"
      "movsb                            \n\t"
"csl1:                                  \n\t"
      "repz                             \n\t"
      "movsw                            \n\t"
      "incl %1                          \n\t"
      "decl %%edx                       \n\t"
      "jnz csl0                         \n\t"
      :
      : "m" (x), "m" (y), "m" (width), "m" (height), "m" (spr)
      : "eax","edx","esi","edi","ecx","cc" );
}

grabregion(int x, int y, int width, int height, char *spr)
{ asm("movl %3, %%edx                   \n\t"
      "movl %4, %%edi                   \n\t"
"grl0:                                  \n\t"
      "movl %1, %%eax                   \n\t"
      "imul $352, %%eax                 \n\t"
      "addl %0, %%eax                   \n\t"
      "addl _virscr, %%eax              \n\t"
      "movl %%eax, %%esi                \n\t"
      "movl %2, %%ecx                   \n\t"
      "shrl $1, %%ecx                   \n\t"
      "jnc grl1                         \n\t"
      "movsb                            \n\t"
"grl1:                                  \n\t"
      "repz                             \n\t"
      "movsw                            \n\t"
      "incl %1                          \n\t"
      "decl %%edx                       \n\t"
      "jnz grl0                         \n\t"
      :
      : "m" (x), "m" (y), "m" (width), "m" (height), "m" (spr)
      : "eax","edx","esi","edi","ecx","cc" );
}

tcopytile(int x, int y, char *spr, char *matte)
{
  asm("movl $16, %%ecx                  \n\t"
      "movl %2, %%esi                   \n\t"
      "movl %1, %%edi                   \n\t"
      "imul $352, %%edi                 \n\t"
      "addl %0, %%edi                   \n\t"
      "addl _virscr, %%edi              \n\t"
      "movl %3, %%edx                   \n\t"
"tctl0:                                 \n\t"
      "movl (%%edi), %%eax              \n\t"
      "andl (%%edx), %%eax              \n\t"
      "orl  (%%esi), %%eax              \n\t"
      "movl %%eax, (%%edi)              \n\t"
      "movl 4(%%edi), %%eax             \n\t"
      "andl 4(%%edx), %%eax             \n\t"
      "orl  4(%%esi), %%eax             \n\t"
      "movl %%eax, 4(%%edi)             \n\t"
      "movl 8(%%edi), %%eax             \n\t"
      "andl 8(%%edx), %%eax             \n\t"
      "orl  8(%%esi), %%eax             \n\t"
      "movl %%eax, 8(%%edi)             \n\t"
      "movl 12(%%edi), %%eax            \n\t"
      "andl 12(%%edx), %%eax            \n\t"
      "orl  12(%%esi), %%eax            \n\t"
      "movl %%eax, 12(%%edi)            \n\t"
      "addl $16, %%esi                  \n\t"
      "addl $352, %%edi                 \n\t"
      "addl $16, %%edx                  \n\t"
      "decl %%ecx                       \n\t"
      "jnz tctl0                        \n\t"
      :
      : "m" (x), "m" (y), "m" (spr), "m" (matte)
      : "eax","ecx","edx","esi","edi","cc" );
}

tcopysprite(int x, int y, int width, int height, char *spr)
{ asm("movl %3, %%ecx                   \n\t"
      "movl %4, %%esi                   \n\t"
"tcsl0:                                 \n\t"
      "movl %1, %%eax                   \n\t"
      "imul $352, %%eax                 \n\t"
      "addl %0, %%eax                   \n\t"
      "addl _virscr, %%eax              \n\t"
      "movl %%eax, %%edi                \n\t"
      "movl %2, %%edx                   \n\t"
"drawloop:                              \n\t"
      "lodsb                            \n\t"
      "orb %%al, %%al                   \n\t"
      "jz nodraw                        \n\t"
      "stosb                            \n\t"
      "decl %%edx                       \n\t"
      "jz endline                       \n\t"
      "jmp drawloop                     \n\t"
"nodraw:                                \n\t"
      "incl %%edi                       \n\t"
      "decl %%edx                       \n\t"
      "jnz drawloop                     \n\t"
"endline:                               \n\t"
      "incl %1                          \n\t"
      "decl %%ecx                       \n\t"
      "jnz tcsl0                        \n\t"
      :
      : "m" (x), "m" (y), "m" (width), "m" (height), "m" (spr)
      : "eax","edx","esi","edi","ecx","cc" );
}

fin()
{ int i;

  if (!fade) return;
  if (cancelfade) { cancelfade--; return; }

  timer_count=0;
inloop:
  i=(timer_count*64)/30;
  set_intensity(i);
  if (timer_count<30) goto inloop;
  set_intensity(63);
}

fout()
{ int i;

   if (!fade) return;
   if (cancelfade) { cancelfade--; return; }

   timer_count=0;
outloop:
   i=(timer_count*64)/30; i=64-i;
   set_intensity(i);
   if (timer_count<30) goto outloop;
   set_intensity(0);
}

// Tranparency routines

unsigned char vergepal[768];          // VERGE main palette
unsigned char menuxlatbl[256];        // Menu transparencyfield (blue)
unsigned char greyxlatbl[256];        // Grey transparencyfield
unsigned char scrnxlatbl[256];        // screen transparencyfield
unsigned char *transparencytbl;       // full transparency table (64k)

unsigned char match(char r, char g, char b)
{ int vr, vg, vb, tab, tabpt, i, thistab;
  // This routine provides the color matching to the VERGE palette.

  tab=255;
  tabpt=1;

  for (i=1; i<255; i++)
      { vr=vergepal[i*3];
        vg=vergepal[(i*3)+1];
        vb=vergepal[(i*3)+2];

        thistab=abs(vr-r);
        thistab+=abs(vg-g);
        thistab+=abs(vb-b);
        if (thistab<tab) { tab=thistab;
                           tabpt=i; }
      }

  return tabpt;
}

BuildTable(char r, char g, char b, char *dest)
{ int i;
  unsigned char wr,wg,wb;

  for (i=0; i<256; i++)
      { wr=vergepal[(i*3)];             // set wr,wg,wb with source colors
        wg=vergepal[(i*3)+1];
        wb=vergepal[(i*3)+2];

        wr=(wr+r)/2;                    // average values to compute final RGB
        wg=(wg+g)/2;
        wb=(wb+b)/2;

        dest[i]=match(wr,wg,wb);        // find closest match
      }
}

ColorScale(char *dest,int st,int fn,int inv)
{ int i, intensity;

  for (i=0; i<256; i++)
  {
    intensity=vergepal[(i*3)];
    intensity+=vergepal[(i*3)+1];
    intensity+=vergepal[(i*3)+2];
    intensity=intensity*(fn-st)/192;
    if (inv) dest[i]=fn-intensity;
    else dest[i]=st+intensity;
  }
}

PreCalc_TransparencyFields()
{ FILE *f;
  int i;

  // First read the VERGE palette from verge.pal

  f=fopen("VERGE.PAL","rb");
  fread(&vergepal, 1, 768, f);
  fclose(f);
  transparencytbl=valloc(65536,"transparencytbl");

  // Precompute some common translation tables.

  ColorScale(&menuxlatbl,141,159,1);
  ColorScale(&greyxlatbl,0,31,0);

  // Load in the 64k bitmap-on-bitmap transparency table (precomputed)

  f=fopen("TRANS.TBL","rb");
  fread(transparencytbl, 1, 65535, f);
  fclose(f);
}
/*
ColorField(int x1, int y1, int x2, int y2, unsigned char *colortbl)
{ int j,i;
  unsigned char c;

  for (j=y1; j<y2; j++)
      for (i=x1; i<x2; i++)
          { c=virscr[(j*352)+i];
            virscr[(j*352)+i]=colortbl[c];
          }
}
*/
ColorField(int x, int y, int x2, int y2, unsigned char *tbl)
{
 asm( "movl %3, %%edx                   \n\t"
      "subl %1, %%edx                   \n\t"   // get height
      "movl %4, %%esi                   \n\t"
"acf0:                                  \n\t"
      "movl %1, %%edi                   \n\t"
      "imul $352, %%edi                 \n\t"
      "addl %0, %%edi                   \n\t"
      "addl _virscr, %%edi              \n\t"
      "movl %2, %%ecx                   \n\t"
      "subl %0, %%ecx                   \n\t"  // get width
"acf1:                                  \n\t"
      "movl $0, %%eax                   \n\t"
      "movb (%%edi), %%al               \n\t"
      "addl %%esi, %%eax                \n\t"
      "movb (%%eax), %%bl               \n\t"
      "movb %%bl, (%%edi)               \n\t"
      "incl %%edi                       \n\t"
      "decl %%ecx                       \n\t"
      "jnz acf1                         \n\t"
      "incl %1                          \n\t"
      "decl %%edx                       \n\t"
      "jnz acf0                         \n\t"
      :
      : "m" (x), "m" (y), "m" (x2), "m" (y2), "m" (tbl)
      : "eax","ebx","ecx","edx","esi","edi","cc" );
}

Tcopysprite(int x1, int y1, int width, int height, unsigned char *src)
{ unsigned int j,i,jz,iz;
  unsigned char c,d;

  for (j=0; j<height; j++)
      for (i=0; i<width; i++)
          { jz=j+y1;
            iz=i+x1;
            c=virscr[(jz*352)+iz];
            d=src[(j*width)+i];
            if (d) virscr[(jz*352)+iz]=transparencytbl[(d*256)+c];
          }
}

_Tcopysprite(int x1, int y1, int width, int height, unsigned char *src)
{ unsigned int j,i,jz,iz;
  unsigned char c,d;

  for (j=0; j<height; j++)
      for (i=0; i<width; i++)
          { jz=j+y1;
            iz=i+x1;
            c=virscr[(jz*352)+iz];
            d=src[(j*width)+i];
            if (d) virscr[(jz*352)+iz]=transparencytbl[(c*256)+d];
          }
}

// Font routines

unsigned char oc=31;

LoadFont()
{ FILE *f;

  fnt=valloc(6000,"fnt");
  fnt2=valloc(14000,"fnt2");
  tbox=valloc(30000,"tbox");
  if (!(f=fopen("SMALL.FNT","rb"))) err("FATAL ERROR: Could not open SMALL.FNT.");
  fread(fnt, 63, 95, f);
  fclose(f);
  if (!(f=fopen("MAIN.FNT","rb"))) err("FATAL ERROR: Could not open MAIN.FNT.");
  fread(fnt2, 144, 95, f);
  fclose(f);
  if (!(f=fopen("BOX.RAW","rb"))) err("FATAL ERROR: Could not open BOX.RAW.");
  fread(tbox, 320, 66, f);
  fclose(f);
}

pchar(int x, int y, char c)
{ char *img;

  if ((c<32) || (c>126)) return;
  img=fnt+((c-32)*63);
  if ((c==103) || (c==106) || (c==112) || (c==113) || (c==121))
     tcopysprite(x,y+2,7,9,img);
  else tcopysprite(x,y,7,9,img);
}

VCpchar(int x, int y, char c)
{ char *img;

  if ((c<32) || (c>126)) return;
  img=fnt+((c-32)*63);
  if ((c==103) || (c==106) || (c==112) || (c==113) || (c==121))
     VCtcopysprite(x,y+2,7,9,img);
  else VCtcopysprite(x,y,7,9,img);
}

bigpchar(int x, int y, char c)
{ char *img;

  if ((c<32) || (c>126)) return;
  img=fnt2+((c-32)*144);
  if ((c==103) || (c==106) || (c==112) || (c==113) || (c==121))
     tcopysprite(x,y+2,9,16,img);
  else tcopysprite(x,y,9,16,img);
}

gotoxy(int x, int y)
{ x1=x;
  y1=y;
}

printstring(char *str)
{ int i;
  char c;

  i=0;
  if (!str[0]) return;

mainloop:
  c=str[i];
  pchar(x1,y1,c);
  x1=x1+8;
  i++;
  if (str[i]!=0) goto mainloop;
}

VCprintstring(int xx, int yy, char *str)
{ int i;
  char c;

  i=0;
  if (!str[0]) return;

mainloop:
  c=str[i];
  VCpchar(xx,yy,c);
  xx=xx+8;
  i++;
  if (str[i]!=0) goto mainloop;
}

bigprintstring(char *str)
{ int i;
  char c;

  i=0;
  if (!str[0]) return;

mainloop:
  c=str[i];
  bigpchar(x1,y1,c);
  x1=x1+10;
  i++;
  if (str[i]!=0) goto mainloop;
}

putbox()
{
  ColorField(18,151,334,213,&menuxlatbl);
  tcopysprite(16,149,320,66,tbox);

//  border(18,149,333,213);
}

dec_to_asciiz(int num, char *buf)
{  asm ("movl $10, %%ebx              \n\t"
        "movl %0, %%eax               \n\t"
        "movl %1, %%edi               \n\t"
        "xor %%ecx, %%ecx             \n\t"
"dtal0:                               \n\t"
        "xor %%edx, %%edx             \n\t"
        "div %%ebx                    \n\t"
        "pushw %%dx                   \n\t"
        "incl %%ecx                   \n\t"
        "orl %%eax, %%eax             \n\t"
        "jnz dtal0                    \n\t"
"dtal1:                               \n\t"
        "popw %%ax                    \n\t"
        "addb $48, %%al               \n\t"
        "stosb                        \n\t"
        "loop dtal1                   \n\t"
        "xor %%al, %%al               \n\t"
        "stosb                        \n\t"
        :
        : "m" (num), "m" (buf)
        : "eax","ebx","edi","ecx","cc" );
}

textwindow(char portrait, char *str1, char *str2, char *str3)
{
 tcopysprite(20,114,32,32,speech+(portrait*1024));
 putbox();
 gotoxy(25,155);
 bigprintstring(str1);
 gotoxy(25,174);
 bigprintstring(str2);
 gotoxy(25,193);
 bigprintstring(str3);
}

fontcolor(unsigned char c)
{ int i;
  char *ptr;

  ptr=fnt;
  for (i=0; i<5985; i++)
      { if (*ptr==oc) *ptr=c;
        ptr++; }
  oc=c;
}