Category : C Source Code
Archive   : WTWG12B.ZIP
Filename : WSAVE.C

/* wsave
*
* wsave text/graphics in current window frame,
* move it to 'wheap' storage, store address of the saved text in winsave
* if out of memory store NULL to winsave.
*
*/


#include "wscreen.h"
#include "wsys.h"




void wsave ( void )
{
int extra, extra2; /* need extra lines for borders ? */



/* text_mode screen pointers */
unsigned char far *line_ptr;

/* pointers to screen save area */
WHEAP *hptr;
unsigned char far *area;


int l, t, r, b; /* co-ords inlcuding window frame */

int movenum;

unsigned long int nbytes;


struct _CHATTR /* 2 byte char/attr */
{
unsigned char c;
unsigned char a;
};
typedef struct _CHATTR far *CHATTR; /* far pointer to a pair */


#ifndef __TURBOC__
/* Microsoft C needs an 'intermediary' ptr to handle syntax correctly.
*/
void far *msc_ptr;
#endif /* Microsoft 'idiot' fix */

#ifndef TEXTONLY
unsigned int hn; /* hercules bank offsets */
int color; /* EGA color bit mask */
int t_save; /* save top row # for each color */

/* graphics mode screen pointers */
unsigned char far *base, far *base_save;
#endif





/* if there is going to be a border
* then the area to save has to be larger than the text window
* (border occupies 1 line extra in each direction)
*/
extra = (w0-> winbox ) ? 1 : 0;
extra2 = 2*extra;

l = ( (w0->winleft) -extra );
t = ( (w0->wintop) -extra );
r = (l+(w0->winxmax) +extra2 );
b = (t+(w0->winymax) +extra2 );


/* number of characters in the window
*/
movenum = r-l+1; /* one text row */
nbytes = movenum*(b-t+1);




if ( wmode == 'T' )
{

/* number of bytes to allocate
* multiply by 2 (= text+attributes)
*/
hptr = wheap_alloc ( 2*nbytes, WIN_HP_PRIORITY, NULL );

w0->winsave = hptr;

if (hptr == NULL)
{
return;
}

area = wheap_access ( hptr, 0 );

movenum *= 2; /* char and attr */


for ( line_ptr = wpage_ram + 2*80*( t ) + 2*( l );
t<=b;
++t, line_ptr += 2*80
)
{
/* move one line per pass thru this loop
* loop limit is one char beyond end of line
*/
farmemcpy ( area, line_ptr, movenum );
area += movenum;
}

}

#ifndef TEXTONLY
else
{
/* graphics mode save
*
* Note that r and b point to the last line INCLUSIVE
* so loops need to go up to and include.
*/

/* convert single chars (=1 byte in text mode)
* to blocks of pixels in graphics mode
*/
nbytes *= (wpxchar/8) * wpychar;


if (wmonitor != 'H')
{
/* EGA and VGA -- 4 colors */
nbytes *= 4;
}



if ( nbytes >= WHEAP_MAX )
{
/* too large to save...
* convert window to WSAVE2NULL
*/
w0->winsave = NULL;
return;
}

hptr = wheap_alloc ( nbytes, WIN_HP_PRIORITY, NULL );

w0-> winsave = hptr;

if ( hptr == NULL )
{
return;
}

area = wheap_access ( hptr, 0 );


/* convert top and bottom counters
* to pixel co-ords only for counting rows
*/
t *= wpychar;
b = (b+1) * wpychar; /* includes last pixel row */


/* number of bytes in each row of pixels
*/
movenum = r-l+1;



/* get image */

switch ( wmonitor )
{
case ( 'H'):
/* NOTE addressing hercules graphics ram:
* l, t are 'text-mode' addresses.
* 720 pixels/row, wpxchar pixels per 'x' incr
* so 1st factor = wxabsmax = chars per row
* divide wpychar by 4(=# herc banks) =
* gives #of sets of banks (4 pxl rows each)
* wpxchar/8 =1 always, included for clarity.
*
* because charsizes are mults of 4,
* whbank starts at 0;
*
* also note that l and t have been converted
* from character rows to pixel rows
* so don't need wpychar.
* however, r & l still count text cols, not pxl
*/
base = wpage_ram
+ ( (720/wpxchar)*(t/4) ) + l;


for ( hn = 0; t < b; ++t, hn += 0x2000 )
{
/* loop iterates once per row

*/
if ( hn == 0x8000 )
{
/* finished one set of 4 banks,
* move up to next tier.
*/
hn = 0;
base += 90;
}
#ifdef __TURBOC__
/* much easier to move all the data in TurboC
*/
farmemcpy ( area, base+hn, movenum );
#else
/* Microsoft C preprocessor generates wrong code
* in small model.
*/
msc_ptr = base+hn;

farmemcpy ( area, msc_ptr, movenum );
#endif /* Microsoft vs Turbo C */

area += movenum; /* move ptr to target dn one row */
}
break; /* end hercules mode */

case ( 'E' ):
case ( 'V' ):
EGA_OUT (1, EGA_ENABLE );
/* how to put point = EGA_OUT(3, putmode)*/
/* 0x18 = XOR 0x10 = OR 0x08 = AND */


/*
* note that t, b have been converted to pixel rows
* rather than char rows.
* however, r&l still count text columns,
* not pixel columns
*/
base_save =
base = wpage_ram + ( wegarowsize * t ) + l;

t_save = t;

/* default for most graphics drivers is to leave
* write mode = 0 and EGA output enabled.
* so you don't need these, but in future, ...
* EGA_OUT ( 1, EGA_ENABLE ), EGA_OUT ( 5, 0 );
*
*/

for ( color = 0; color < 4; ++color )
{
/* becuase the size of the save area is <64k
* (imposed above), the pointers are
* always correctly normalized
* If larger save areas are desired,
* renormalize (area) for each new color
* which will suffice even for super VGA
* (800*600 = 60k per color)
*/
base = base_save;
t = t_save;

EGA_OUT (4, color);

for ( ; /* loop once per row */
t < b;
++t, base += 640/wpxchar )
{
farmemcpy ( area, base, movenum );
area += movenum;
} /* end for each rows */

}/* end loop for each color */

/* reset EGA */
EGA_OUT (0,0); /* BLACK */
EGA_OUT (8, 0xff); /* all bits */


break;
} /* end switch (wgdriver) */


/* end of get image in graphics mode */

}

#endif /* ifdef TEXTONLY - end of graphics mode save to RAM */

wheap_deaccess ( hptr, 1 );

return;
}

/*-------------------------end of wsave---------------------------*/