dos_compilers/Microsoft QuickC v251/SAMPLES/TOOLS.C
2024-07-02 08:12:15 -07:00

100 lines
3.1 KiB
C

/* TOOLS - Module containing several general functions that can be used
* from any program. Include TOOLS.H to use.
*/
#include <conio.h>
#include <string.h>
#include <time.h>
#include <graph.h>
#include <bios.h>
#include "tools.h"
/* delay - Pauses for a specified number of microseconds. Used to slow
* life by delaying between generations.
*
* Params: wait - time in microseconds
*
* Return: None
*/
void delay( clock_t wait )
{
clock_t t1, t2;
if( !wait )
return;
t1 = wait + clock();
do
{
t2 = clock();
} while( t2 < t1 );
}
/* getkey - Gets a key from the keyboard. This routine distinguishes
* between ASCII keys and function or control keys with different shift
* states. It also accepts a flag to return immediately if no key is
* available.
*
* Params: waitflag - Code to indicate how to handle keyboard buffer:
* NO_WAIT Return 0 if no key in buffer, else return key
* WAIT Return first key if available, else wait for key
* CLEAR_WAIT Throw away any key in buffer and wait for new key
*
* Return: One of the following:
*
* Keytype High Byte Low Byte
* ------- --------- --------
* No key available (only with NO_WAIT) 0 0
* ASCII value 0 ASCII code
* Unshifted function or keypad 1 scan code
* Shifted function or keypad 2 scan code
* CTRL function or keypad 3 scan code
* ALT function or keypad 4 scan code
*
* Note: getkey cannot return codes for keys not recognized by BIOS
* int 16, such as the CTRL-UP or the 5 key on the numeric keypad.
*/
unsigned getkey( int waitflag )
{
unsigned inkey, shiftstate;
/* If CLEAR_WAIT, drain the keyboard buffer. */
if( waitflag == CLEAR_WAIT )
while( _bios_keybrd( _KEYBRD_READY ) )
_bios_keybrd( _KEYBRD_READ );
/* If NO_WAIT, return 0 if there is no key ready. */
if( !waitflag && !_bios_keybrd( _KEYBRD_READY ) )
return FALSE;
/* Get key code. */
inkey = _bios_keybrd( _KEYBRD_READ );
/* If low byte is not zero, it's an ASCII key. Check scan code to see
* if it's on the numeric keypad. If not, clear high byte and return.
*/
if( inkey & 0x00ff )
if( (inkey >> 8) < 69 )
return( inkey & 0x00ff );
/* For function keys and numeric keypad, put scan code in low byte
* and shift state codes in high byte.
*/
inkey >>= 8;
shiftstate = _bios_keybrd( _KEYBRD_SHIFTSTATUS ) & 0x000f;
switch( shiftstate )
{
case 0:
return( 0x0100 | inkey ); /* None (1) */
case 1:
case 2:
case 3:
return( 0x0200 | inkey ); /* Shift (2) */
case 4:
return( 0x0300 | inkey ); /* Control (3) */
case 8:
return( 0x0400 | inkey ); /* Alt (4) */
}
}