void _TxtClear( short r1, short c1, short r2, short c2 )
/*======================================================
Clear an area of the screen in text mode. Can't use BIOS scroll
function when the active page is not equal to the visual page. */
{
short len;
short i;
unsigned short seg;
unsigned int offset;
short __far *p;
short blank;
if( _CurrState->vc.mode == _TEXTMONO ) {
seg = _MonoSeg;
offset = _MonoOff;
} else {
seg = _CgaSeg;
offset = _CgaOff;
}
offset += 2 * ( r1 * _CurrState->vc.numtextcols + c1 ) +
_CurrActivePage * *(short __far *)_BIOS_data( CRT_LEN );
len = c2 - c1 + 1;
blank = ( _CharAttr << 8 ) + ' ';
for( ; r1 <= r2; ++r1 ) {
p = MK_FP( seg, offset );
for( i = 0; i < len; ++i ) {
*p = blank;
++p;
}
offset += 2 * _CurrState->vc.numtextcols;
}
}
short _SetRows( short rows )
/*==========================
This function sets the number of text rows in the current mode. It only
affects the _VGA, _EGA, and _MCGA adapters. */
{
_ErrorStatus = _GROK;
_InitState(); // read the current machine state
if( _GrMode ) {
GrModeRows( rows );
} else {
TextModeRows( rows );
}
if( _ErrorStatus != _GROK ) {
return( 0 );
} else {
rows = *(char far *)_BIOS_data( ROWS ) + 1; // 0 for Hercules
if( rows == 1 ) rows = 25;
_CurrState->vc.numtextrows = rows;
if( !_GrMode ) {
_CalcNumPages(); // update the video configuration
}
_Tx_Row_Min = 0; // text window is now
_Tx_Col_Min = 0; // the full screen
_Tx_Row_Max = _CurrState->vc.numtextrows - 1;
_Tx_Col_Max = _CurrState->vc.numtextcols - 1;
_TextPos.row = 0; // set mode function
_TextPos.col = 0; // sets position to 0,0
_CurrVisualPage = 0;
_CurrActivePage = 0;
VideoInt( _BIOS_VIDEO_PAGE, 0, 0, 0 ); // set to page 0
return( _CurrState->vc.numtextrows );
}
}
_WCRTLINK short _WCI86FAR _CGRAPH _setactivepage( short pagenum )
/*================================================
This routine sets the active page for graphics output. */
{
short pos;
short prev;
_InitState();
if( _CurrState->vc.numvideopages == 1 ) {
if( pagenum != 0 ) {
_ErrorStatus = _GRINVALIDPARAMETER;
return( -1 );
} else {
return( 0 );
}
}
pagenum %= _CurrState->vc.numvideopages;
// #if defined( __386__ )
_CurrState->screen_seg = _CurrState->screen_seg_base;
_CurrState->screen_off = _CurrState->screen_off_base +
( ( _CurrState->page_size * pagenum ) << 4 );
// #else
// _CurrState->screen_seg = _CurrState->screen_seg_base +
// _CurrState->page_size * pagenum;
// _CurrState->screen_off = _CurrState->screen_off_base;
// #endif
pos = *(short __far *)_BIOS_data( CURSOR_POSN + 2 * pagenum );
_TextPos.row = pos >> 8; /* cursor position */
_TextPos.col = pos & 0xFF; /* on new page */
prev = _CurrActivePage;
_CurrActivePage = pagenum;
return( prev );
}
static void Load_MCGA( short rows, short font, short cursor )
/*===========================================================
This routines loads an alphanumeric font for the MCGA. */
{
VideoInt( _BIOS_VIDEO_PAGE, 0, 0, 0 ); // set active page to 0
VideoInt( _BIOS_SET_MODE + GetVideoMode(), 0, 0, 0 );
_fmemset( MK_FP( _EgaSeg, _EgaOff ), 0, 0x2000 ); // must do for MCGA 40 rows
VideoInt( font & 0xFF0F, 0, 0, 0 ); // load character set
VideoInt( 0x1103, 0, 0, 0 );
VideoInt( _BIOS_CURSOR_SIZE, 0, cursor, 0 ); // reset the cursor
outpw( 0x03D4, ( cursor & 0xFF00 ) + 0x09 ); // # double scan lines
*(char far *)_BIOS_data( ROWS ) = rows - 1; // # of rows
// # of vertical points per character
*(short far *)_BIOS_data( POINTS ) = 2 * ( cursor & 0xFF + 1 );
_GrCursor = 1; // cursor is on
}
static void Load_25( void )
/*===================
When we want to go back to a 25-row display, just do a set mode
and update a few variables. */
{
VideoInt( _BIOS_SET_MODE + GetVideoMode(), 0, 0, 0 );
*(char far *)_BIOS_data( INFO ) &= 0xFE; // cursor emulation off
VideoInt( _BIOS_CURSOR_SIZE, 0, 0x0607, 0 ); // reset the cursor
_GrCursor = 1; // cursor is on
}
static void Load_EGA( short rows, short font, short cursor )
/*==========================================================
This routines loads an alphanumeric font for the EGA. */
{
VideoInt( _BIOS_VIDEO_PAGE, 0, 0, 0 ); // set active page to 0
VideoInt( _BIOS_SET_MODE + GetVideoMode(), 0, 0, 0 );
VideoInt( font, 0, 0, 0 ); // load pointer to character set in block 0
if( rows == 43 ) { // cursor emulation
*(char far *)_BIOS_data( INFO ) |= 1; // 43 rows only
} else {
outpw( 0x03D4, 0x1414 ); // reset underline location to none
}
VideoInt( _BIOS_CURSOR_SIZE, 0, cursor, 0 ); // reset the cursor
_GrCursor = 1; // cursor is on
}
short _SetMode( short mode )
/*==========================
This function sets the video mode on IBM PC family. */
{
char __far *p;
if( _ValidMode( mode ) ) {
p = _BIOS_data( EQUIP_FLAGS ); // equipment flags
*p &= 0xCF; // remove previous settings
if( mode == 7 || mode == 15 ) {
*p |= 0x30; // monochrome
} else {
*p |= 0x20; // colour
}
if( _NoClear ) {
mode |= 0x80; // set high bit, screen won't be cleared
}
VideoInt( _BIOS_SET_MODE + mode, 0, 0, 0 );
}
return( GetVideoMode() );
}