/*
 * intro.c
 *
 * FRACTINT intro screen (authors & credits)
 *
 *
 */

#include <time.h>

  /* see Fractint.c for a description of the "include"  hierarchy */
#include "port.h"
#include "prototyp.h"
#include "helpdefs.h"
#include "drivers.h"

/* stuff from fractint */

#ifdef XFRACT
extern int slowdisplay;
#endif

void intro(void)
{
	/* following overlayed data safe if "putstrings" are resident */
#ifdef XFRACT
	static char PRESS_ENTER[] = {"Press ENTER for main menu, Shift-1 for help."};
#else
	static char PRESS_ENTER[] = {"Press ENTER for main menu, F1 for help."};
#endif
	int       toprow, botrow, i, j, delaymax;
	char      oldchar;
	int       authors[100];              /* this should be enough for awhile */
	char *credits;
	char *screen_text;
	int       oldlookatmouse;
	int       oldhelpmode;

	timer_start -= clock_ticks();                /* "time out" during help */
	oldlookatmouse = lookatmouse;
	oldhelpmode = helpmode;
	lookatmouse = 0;                     /* de-activate full mouse checking */

	/* TODO: allocate real memory, not reuse shared segment */
	screen_text = extraseg;

	i = 32767 + read_help_topic(INTRO_AUTHORS, 0, 32767, screen_text);
	screen_text[i++] = '\0';
	credits = screen_text + i;
	i = 32767 + read_help_topic(INTRO_CREDITS, 0, 32767, credits);
	credits[i++] = '\0';

	j = 0;
	authors[j] = 0;              /* find the start of each credit-line */
	for (i = 0; credits[i] != 0; i++)
		if (credits[i] == 10)
			authors[++j] = i+1;
	authors[j+1] = i;

	helptitle();
#define END_MAIN_AUTHOR 5
	toprow = END_MAIN_AUTHOR+1;
#ifndef XFRACT
	botrow = 21;
#else
	botrow = 20;
	putstringcenter(21,0,80,C_TITLE,
	"Unix/X port of fractint by Ken Shirriff");
#endif
	putstringcenter(1,0,80,C_TITLE, PRESS_ENTER);
	driver_put_string(2,0,C_CONTRIB,screen_text);
	driver_set_attr(2,0,C_AUTHDIV1,80);
	driver_set_attr(END_MAIN_AUTHOR,0,C_AUTHDIV1,80);
	driver_set_attr(22,0,C_AUTHDIV2,80);
	driver_set_attr(3,0,C_PRIMARY,80*(END_MAIN_AUTHOR-3));
	driver_set_attr(23,0,C_TITLE_LOW,160);
	for (i = 3; i < END_MAIN_AUTHOR; ++i)
		driver_set_attr(i,21,C_CONTRIB,58);
	driver_set_attr(toprow,0,C_CONTRIB,(21-END_MAIN_AUTHOR)*80);
	i = botrow - toprow;
	srand((unsigned int)clock_ticks());
	j = rand()%(j-(botrow-toprow)); /* first to use */
	i = j+botrow-toprow; /* last to use */
	oldchar = credits[authors[i+1]];
	credits[authors[i+1]] = 0;
	driver_put_string(toprow,0,C_CONTRIB,credits+authors[j]);
	credits[authors[i+1]] = oldchar;
	delaymax = 10;
	driver_hide_text_cursor();
	helpmode = HELPMENU;
	while (! driver_key_pressed())
    {
#ifdef XFRACT
		if (slowdisplay) delaymax *= 15;
#endif
		for (j = 0; j < delaymax && !(driver_key_pressed()); j++)
			driver_delay(100);
		if (driver_key_pressed() == FIK_SPACE)
        {      /* spacebar pauses */
			driver_get_key();
			driver_wait_key_pressed(0);
			if (driver_key_pressed() == FIK_SPACE)
				driver_get_key();
        }
		delaymax = 15;
		driver_scroll_up(toprow, botrow);
		i++;
		if (credits[authors[i]] == 0)
			i = 0;
		oldchar = credits[authors[i+1]];
		credits[authors[i+1]] = 0;
		driver_put_string(botrow,0,C_CONTRIB,&credits[authors[i]]);
		driver_set_attr(botrow,0,C_CONTRIB,80);
		credits[authors[i+1]] = oldchar;
		driver_hide_text_cursor(); /* turn it off */
    }

	lookatmouse = oldlookatmouse;                /* restore the mouse-checking */
	helpmode = oldhelpmode;
	return;
}