4-5.c

本书是单片机系列教材

/*4-5.c*/
#include<stdio.h>
#include<conio.h>
#include<alloc.h>
#include<graphics.h>
void save_restore_screen(char *buf);
int maxx,maxy;
int main(void)
{
int gdriver=DETECT,gmode,errorcode;
char *ptr;
initgraph(&gdriver,&gmode," ");
/*在屏幕上画一个图形*/
 setcolor(YELLOW);
 circle(50,50,30);
 getch();
save_restore_screen(ptr); /*保存--恢复当前的屏幕*/
getch();
closegraph();
return 0;
}
void save_restore_screen(char *buf)
{
 unsigned size;
size=imagesize(0,0,100,100);
   if((buf=malloc(size))==NULL)
	{
	closegraph();
	printf("Not enough heap space in save_screen().\n");
	exit(1);
	}
getimage(0,0,100,100,buf);
  getch();
  cleardevice();
  getch();
  putimage(0,0,buf,COPY_PUT);
  free(buf);
}