cons.c - windows console helper

/********************************************************************
 ** cons.h - functions to handle console positioning and colors
 ********************************************************************/

#ifndef _CONS_H_
#define _CONS_H_    // avoid multiple inclusions

#ifndef BOOL
#include <windows.h>
#endif

// macro to calculate the high intensity color
#define HI_COLOR(x)         (8 + (x))

// default color (current)
#define COLOR_DEFAULT       -1

// base color codes
#define COLOR_BLACK          0
#define COLOR_BLUE           1
#define COLOR_GREEN          2
#define COLOR_CYAN           3
#define COLOR_RED            4
#define COLOR_MAGENTA        5
#define COLOR_BROWN          6
#define COLOR_LIGHTGRAY      7

// high intensity
#define COLOR_DARKGRAY       HI_COLOR(COLOR_BLACK)
#define COLOR_LIGHTBLUE      HI_COLOR(COLOR_BLUE)
#define COLOR_LIGHTGREEN     HI_COLOR(COLOR_GREEN)
#define COLOR_LIGHTCYAN      HI_COLOR(COLOR_CYAN)
#define COLOR_LIGHTRED       HI_COLOR(COLOR_RED)
#define COLOR_LIGHTMAGENTA   HI_COLOR(COLOR_MAGENTA)
#define COLOR_YELLOW         HI_COLOR(COLOR_BROWN)
#define COLOR_WHITE          HI_COLOR(COLOR_LIGHTGRAY)

// default FG/BG colors
#define COLOR_DEF_FG         COLOR_LIGHTGRAY
#define COLOR_DEF_BG         COLOR_BLACK


// prototypes
BOOL CON_init(BOOL bEnableANSI);                // initialize (opt: enable ANSI escape processing)
void CON_reset(BOOL bRestore);                  // reset (opt: restore color and position)
void CON_clear();                               // clear and position to 0/0
void CON_printat(int r, int c, char *fmt, ...); // formatted print at given row/col
void CON_showcursor(BOOL bYesNo);               // show or hide the cursor
void CON_getsize(int *nr, int *nc);             // get rows and columns
void CON_getpos(int *row, int *col);            // get cursor position
void CON_setpos(int row, int col);              // set cursor position
void CON_getcolor(int *fg, int *bg);            // get colors
void CON_setcolor(int fg, int bg);              // set colors
void CON_resetcolor();                          // reset colors to initial default

#endif


/********************************************************************
 ** cons.c - functions to handle console positioning and colors
 ********************************************************************/

// standard headers
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <memory.h>
#include <malloc.h>
#include <string.h>
#include <stdarg.h>

// windows stuff
#include <windows.h>

// our header
#include "cons.h"

// misc macros (see code)
#define MKCOLOR(fg, bg) (((bg & 0x0F) << 4) + (fg & 0x0F))
#define FGCOLOR(c)      (c % 0x10)
#define BGCOLOR(c)      (c / 0x10)

// internal functions
static void  CON_getinfo();

// internal workareas
static HANDLE                      hConsole = INVALID_HANDLE_VALUE;
static DWORD                       dwModeFlags;
static CONSOLE_SCREEN_BUFFER_INFO  csbi, csbi_bak;
static int                         rows, cols;
static int                         nrow, ncol;
static int                         fgcol, bgcol;

// initializes console
BOOL CON_init(BOOL bEnableANSI)
{
  DWORD   dwMode;
  size_t  bufsize;

  // setup
  hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
  if (INVALID_HANDLE_VALUE == hConsole) return(FALSE);
  if (!GetConsoleScreenBufferInfo(hConsole, &csbi)) return(FALSE);
  memcpy(&csbi_bak, &csbi, sizeof(CONSOLE_SCREEN_BUFFER_INFO));
  if (!GetConsoleMode(hConsole, &dwModeFlags)) return(FALSE);

  // initialize values (rows, cols, ...)
  CON_getinfo();

  if (bEnableANSI)
  {
    // enable ANSI (VT) escape sequences support
    dwMode = (dwModeFlags | ENABLE_VIRTUAL_TERMINAL_PROCESSING);
    if (!SetConsoleMode(hConsole, dwMode)) return(FALSE);
  }

  // all Ok
  return(TRUE);
}

// reset console, optionally reset color and position
void CON_reset(BOOL bRestore)
{
  if (INVALID_HANDLE_VALUE == hConsole) return;
  if (bRestore)
  {
    // restore colors and cursor position
    SetConsoleTextAttribute(hConsole, csbi_bak.wAttributes);
    //if (csbi_bak.dwCursorPosition.Y > 0) csbi_bak.dwCursorPosition.Y--;
    SetConsoleCursorPosition(hConsole, csbi_bak.dwCursorPosition);
  }
  // set back mode to original one (e.g. disable ANSI)
  SetConsoleMode(hConsole, dwModeFlags);
  hConsole = NULL;
}

// clear the console and position to upper left corner
void CON_clear()
{
  COORD coordScreen = {0, 0};
  DWORD cCharsWritten;
  DWORD dwConSize;

  if (INVALID_HANDLE_VALUE == hConsole) return;
  // update console infos (size color), wipe and position to 0/0
  CON_getinfo();
  dwConSize = csbi.dwSize.X * csbi.dwSize.Y;
  FillConsoleOutputCharacter(hConsole, (TCHAR)' ', dwConSize, coordScreen, &cCharsWritten);
  FillConsoleOutputAttribute(hConsole, csbi.wAttributes, dwConSize, coordScreen, &cCharsWritten);
  SetConsoleCursorPosition(hConsole, coordScreen);
}

// print formatted data at given position
void CON_printat(int r, int c, char *fmt, ...)
{
  va_list ap;

  CON_setpos(r, c);
  va_start(ap, fmt);
  vfprintf(stdout, fmt, ap);
  va_end(ap);
  fflush(stdout);
}

// number of rows and columns
void CON_getsize(int *nr, int *nc)
{
  CON_getinfo();
  *nr = rows;
  *nc = cols;
}

// set cursor position
void CON_setpos(int row, int col)
{
  COORD pos = {col, row};
  if (INVALID_HANDLE_VALUE == hConsole) return;
  SetConsoleCursorPosition(hConsole, pos);
}

// get current position
void CON_getpos(int *row, int *col)
{
  CON_getinfo();
  *row = nrow;
  *col = ncol;
}

// show/hide the cursor
void CON_showcursor(BOOL bYesNo)
{
  CONSOLE_CURSOR_INFO curs;

  if (INVALID_HANDLE_VALUE == hConsole) return;
  GetConsoleCursorInfo(hConsole, &curs);
  if (bYesNo) curs.bVisible = TRUE;
    else curs.bVisible = FALSE;
  SetConsoleCursorInfo(hConsole, &curs);
}

// get current colors
void CON_getcolor(int *fg, int *bg)
{
  CON_getinfo();
  *fg = fgcol;
  *bg = bgcol;
}

// set foreground and background colors
void CON_setcolor(int fg, int bg)
{
  int fcol=fg, bcol=bg;

  if (INVALID_HANDLE_VALUE == hConsole) return;
  if ((COLOR_DEFAULT == fg)||(COLOR_DEFAULT == bg)) CON_getinfo();
  if (COLOR_DEFAULT == fg) fcol=fgcol;
  if (COLOR_DEFAULT == bg) bcol=bgcol;
  SetConsoleTextAttribute(hConsole, MKCOLOR(fcol, bcol));
}

// set color back to initial (at "CON_init" time) color
void CON_resetcolor()
{
  if (INVALID_HANDLE_VALUE == hConsole) return;
  SetConsoleTextAttribute(hConsole, csbi_bak.wAttributes);
  CON_getinfo();
}

// refresh console informations this is needed in case the infos
// are changed extenally or true ANSI escapes or if the console
// window is resized by the user
static void CON_getinfo()
{
  if (!GetConsoleScreenBufferInfo(hConsole, &csbi)) return;
  rows = csbi.srWindow.Bottom - csbi.srWindow.Top + 1;
  cols = csbi.srWindow.Right - csbi.srWindow.Left + 1;
  nrow = csbi.dwCursorPosition.Y;
  ncol = csbi.dwCursorPosition.X;
  fgcol = FGCOLOR(csbi.wAttributes);
  bgcol = BGCOLOR(csbi.wAttributes);
}