dv_save.c

一个c语言写做的编译器的源码

/*@A (C) 1992 Allen I. Holub                                                */
#include <stdio.h>
#include <stdlib.h>
#include "video.h"
#include <tools/termlib.h>

SBUF *dv_save( l, r, t, b )
int l, r, t, b;
{
    /* Save all characters and attributes in indicated region. Return a
     * pointer to a save buffer. The cursor is not modified. Note that the
     * save buffer can be allocated from the far heap, but the SBUF itself is
     * not. See also, dv_restore() and dv_freesbuf();
     */

    int		ysize, xsize, x, y ;
    IMAGEP	p;
    SBUF	*sbuf;

    xsize = (r - l) + 1;
    ysize = (b - t) + 1;

    if( !(sbuf = (SBUF *) malloc(sizeof(SBUF)) ))
    {
	fprintf(stderr, "Internal error (dv_save): No memory for SBUF.");
	exit( 1 );
    }
    if( !(p = (IMAGEP) IMALLOC(xsize * ysize * sizeof(WORD))))
    {
	fprintf(stderr, "Internal error (dv_save): No memory for image");
	exit( 2 );
    }

    sbuf->left   = l;
    sbuf->right  = r;
    sbuf->top    = t;
    sbuf->bottom = b;
    sbuf->image  = p;

    for( y = 0; y < ysize ; ++y )
	for( x = 0; x < xsize ; ++x )
    	    *p++ = VSCREEN[ y + t ][ x + l ];

    return sbuf;
}