/* Peek 1.0
 *
 * June 10th, 1997.  August 26th, 1997
 * (C)opyright 1997 by Kelvin Sherlock
 *
 * Displays the SHR screen until return is pressed.
 *
 */


#include <stdio.h>
#include <signal.h>
#include <gno/gno.h>
#include <setjmp.h>

#pragma lint -1

/*
 * So I don't have to include <quickdraw.h> || <event.h>
 *
 */
extern pascal void GrafOff(void) inline(0x0B04,dispatcher);
extern pascal void GrafOn(void) inline(0x0A04,dispatcher);
extern pascal Word FlushEvents(Word, Word) inline(0x1506,dispatcher);



/*
 * Prototyped functions
 *
 */

int GrafStatus(void);
int needsgno(void);
void SigHandler(int,int);
void Version (char *);
void Usage (char *);

/*
 * Globals
 *
 */

jmp_buf buffer;

int main(int argc, char **argv){
 int i;
 int flush;
 int c;


	flush=0;

	if (argc>1)
	{
		if (*argv[1]!='-')
		{
			Usage(*argv);
			return(1);
		}
		switch (argv[1][1])
		{
			case 'V':Version(*argv);
				return(0);
			case 'h':Usage(*argv);
				return(0);
			case 'f':flush++;
				break;
			default:Usage(*argv);
				return(1);
		}
	}



	/*
	If the hires screen is active, just quit
	*/
	if ( GrafStatus() )
        	return (2);



	if ( needsgno() )
		for(i=1;i<25;i++)
			signal(i,  SigHandler);

	GrafOn();
        if (setjmp(buffer));
        else
	        /*
                 * While waiting for a character, the process will be
                 * blocked, which means ~0 cpu time spent on it
                 */
		while (fgetc(stdin)!='\n');	/* slurp all the chars */
	GrafOff();

	if (flush && needsgno())
		FlushEvents(0xffff,0);

	return (0);
}

/* GrafStatus()
 * Inputs:  none
 * Outputs: returns boolean true if the SHR
 *          screen is active
 */

/*
int GrafStatus(void){
	return ( *(char *)0xe0c029 & 0x80 );
}
*/

asm int GrafStatus(void){
	sep #0x20
        lda 0xE0C029
        rep #0x20
	and #0x0080
        rtl
}


/*
 * Signal Handler.  transfers control to past the
 * getchar() call
 *
 */
#pragma databank 1
void SigHandler(int sig, int code){
        longjmp(buffer,1);
}
#pragma databank 0


void Usage(char *fname)
{
	fprintf(stdout,"\n%s -f -h -V\n",fname);
	fputs("Display the SHR screen\n",stdout);
	fputs("-f\tFlush All Events\n",stdout);
	fputs("-h\tshow help and exit\n",stdout);
	fputs("-V\tShow version information and exit\n",stdout);
}

void Version(char *fname)
{
	fprintf(stdout,"\n%s version 1.0 by Kelvin Sherlock\n\n",fname);
	fputs("\tThis program contains material from the ORCA/C\n",stdout);
	fputs("\tRuntime Libraries, copyright 1987-1996\n",stdout);
	fputs("\tby Byte Works, Inc. Used with permission.\n",stdout);
}