_graphgetmem

User hook into graphics memory allocation.

Defined in header <graphics.h>

Syntax

#include <graphics.h>
void far * far _graphgetmem (unsigned size);

Portability

Remarks

Routines in the graphics library (not the user program) normally call

must declare it exactly as shown in the declaration). The default version of this routine merely calls malloc.

Return value

None.

See also

• _graphfreemem
• initgraph
• setgraphbufsize

Example

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <alloc.h>
int main (void)
 {
   /* request  autodetection */
   int gdriver  = DETECT, gmode, errorcode, midx, midy;

   /* clear the  text screen */
   clrscr 0 ;
   printf ("Press any key to initialize graphics mode:");
   getchO  ;
   clrscr 0 ;

   /* initialize graphics  and local variables */
   initgraph (&gdriver, &gmode, "") ;

   /* read result  of initialization */
   errorcode = graphresult ();
   if  (errorcode != grOk) {  /.* an error occurred */
      printf ("Graphics error: %s\n", grapherrormsg(errorcode));
      printf ("Press any key to halt:");
      getchO  ;
      exit(l);                /* terminate with an error code */
   }
   midx = getmaxxO   / 2;
   midy = getmaxy () / 2;

   /* display a message  */
   settextjustify (CENTER_TEXT, CENTER_TEXT);
   outtextxy (midx, midy, "Press any key to exit graphics mode:")

   /* clean up */
   getchO ;
   closegraphO  ;
   return 0;
}
/* called by the graphics kernel  to allocate memory */
void far * far _graphgetmem (unsigned size) {
   printf ("_graphgetmem called to allocate %d bytes.\n", size);
   printf ("hit any key:");
   getchO;
   printf ("\n");

   /* allocate memory from  far heap */
   return farmalloc(size) ;
}
/* called by the graphics kernel to  free memory */
void far _graphfreemem(void  far *ptr, unsigned size) {
   printf ("_graphfreemem called to free %d bytes.\n", size)
   printf ("hit any key:");
   getchO ;
printf ("\n");

/* free ptr from far heap */
farfree(ptr);

Differences from modern implementations

Nothing recorded yet.

Modern references

• Microsoft C runtime (search)

These are search links, not yet checked by hand.

Stable link: /3.1/graphics.h/_graphgetmem/ · short form /3.1/_graphgetmem/