uHex Code

/*
 * This file is part of the uHex project.
 * Copyright (C) 2013 Mateusz Viste
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */


#include <dos.h>   /* provides int86() along with the union REGS type */
#include <stdio.h> /* this one contains the NULL definition */
#include "io.h"    /* include self headers for control */

/* gets cursor's position and size */
void cursor_getprops(int *x, int *y, int *start, int *end) {
  union REGS regs;
  regs.h.ah = 3; /* get cursor position and shape */
  regs.h.bh = 0; /* page number (pretty much always 0) */
  int86(0x10, &regs, &regs);
  if (x != NULL) *x = regs.h.dl; /* column */
  if (y != NULL) *y = regs.h.dh; /* row */
  if (start != NULL) *start = regs.h.ch; /* start scan line */
  if (end != NULL) *end = regs.h.cl; /* end scan line */
}


void cursor_set(int startscanline, int endscanline) {
  union REGS regs;
  regs.h.ah = 0x01;
  regs.h.ch = startscanline;
  regs.h.cl = endscanline;
  int86(0x10, &regs, &regs);
}


/* gets file's attributes, and return them. returns -1 on error */
/* int getattrib(char *file) {
  union REGS regs;
  union SREGS sregs;
  regs.h.ah = 0x43; */ /* get file's attribs */
  /*regs.h.al = 0x00; *//* must be zero before the call */
 /* sregs.ds = (unsigned int) (file >> 16); */   /* segment of the pointer to ASCIZ filename */
 /* regs.x.dx = (unsigned int) (file & 0xFFFF); */ /* offset of the pointer to ASCIZ filename */
 /* int86x(0x21, &regs, &regs, &sregs); */
  /* CF clear if successful, set on error (AX = error code: 01h, 02h, 03h, 05h) */
 /* if (regs.x.cflag != 0) return(-1); */
  /* return the result */
 /* return(regs.h.al);
} */


void locate(int row, int column) {
  union REGS regs;
  regs.h.ah = 0x02;
  regs.h.bh = 0;
  regs.h.dh = row;
  regs.h.dl = column;
  int86(0x10, &regs, &regs);
}


void printchar(char c, int attr) {
  union REGS regs;
  regs.h.ah = 0x09; /* Write char and attribute */
  regs.h.al = c;
  regs.h.bh = 0;    /* display page */
  regs.h.bl = attr;
  regs.x.cx = 1;    /* write it 1 time */
  int86(0x10, &regs, &regs);
}


void readchar(char *c, int *attr) {
  union REGS regs;
  regs.h.ah = 0x08; /* Read character and attribute at cursor position */
  regs.h.bh = 0;    /* display page */
  int86(0x10, &regs, &regs);
  if (c != NULL) *c = regs.h.al;
  if (attr != NULL) *attr = regs.h.ah;
}


/* waits for a keypress and return it. Returns 0 for extended keystroke, then
   function must be called again to return scan code. */
int getkey() {
  union REGS regs;
  regs.h.ah = 0x08;  
  int86(0x21, &regs, &regs);
  return(regs.h.al);
}


void cls(int termwidth, int termheight, int colattr) {
  union REGS regs;
  regs.x.ax = 0x0600;  /* Scroll window up - entire window */
  regs.x.bx = (colattr << 8); /* Attribute to write */
  regs.x.cx = 0x0000;  /* Upper left */
  regs.x.dx = ((termheight - 1) << 8) | (termwidth - 1); /* Lower right */
  int86(0x10, &regs, &regs);
  locate(0,0);
}


void getcurvideomode(int *termwidth, int *termheight, int *colorflag) {
  union REGS regs;
  *termheight = peekb(0x40, 0x84) + 1;
  *termwidth = peek(0x40, 0x4A);
  if (*termwidth < 20) *termwidth = 25; /* some pre-EGA adapters don't return the height. Assume 25 then. */
  regs.h.ah = 0x0F;  /* get current video mode */
  int86(0x10, &regs, &regs);
  if ((regs.h.al == 0) || (regs.h.al == 2) || (regs.h.al == 7)) { /* detect mono modes */
      *colorflag = 0;
    } else { /* else we are in color */
      *colorflag = 1;
  }
}