sdl_engine.c

/* sz81 Copyright (C) 2007-2011 Thunor <thunorsif@hotmail.com>
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* Includes */
#include "sdl_engine.h"
#include "w5100.h"
#include "zx81.h"
#ifndef Win32
#include <sys/ioctl.h>
#endif

/* Defines */

/* Emulator variables I require access to */
extern int zx80, ramsize;
extern int load_hook, save_hook;
extern int rwsz81mem;
extern void exitmem();
extern ZX81 zx81;

/* Variables */

char startdir[256];

runtimeoptions_ runtime_options[MAX_RUNTIME_OPTIONS];

/* Function prototypes */
void clean_up_before_exit(void);


/***************************************************************************
 * SDL Initialise                                                          *
 ***************************************************************************/
/* Since this is the first function the emulator calls prior to
 * sdl_com_line_process (which could exit) many things are done here.
 * Firstly some variables are initialised with defaults, SDL is initialised
 * and then a window manager icon is loaded and a title set if the platform
 * requires it.
 * 
 * On exit: returns TRUE on error
 *          else FALSE */

int sdl_init(void) {
	int count;
	#if defined(PLATFORM_GP2X)
	#elif defined(PLATFORM_ZAURUS)
	#else
		char filename[256];
	#endif
	
	/* Set-up a default video resolution depending on platform */
	#if defined(PLATFORM_GP2X)
		video.xres = 320; video.yres = 240; video.scale = 1;
		video.fullscreen = SDL_FULLSCREEN;
	#elif defined(PLATFORM_ZAURUS)
		video.xres = 640; video.yres = 480; video.scale = 2;
		video.fullscreen = SDL_FULLSCREEN;
	#else
		video.xres = 640; video.yres = 480; video.scale = 2;
		video.bigscreen = video.fullscreen = FALSE;
	#endif

	/* All SDL pointers are initialised to NULL here since we could
	 * exit prematurely and we don't want to cause seg faults by
	 * freeing nothing. As long as they are NULL everything is fine */
	sdl_emulator.timer_id = NULL;
	control_bar.scaled = NULL;
	vkeyb.zx80original = vkeyb.zx81original = vkeyb.scaled = NULL;
	sz81icons.original = sz81icons.scaled = NULL;
	zx80font.original = zx81font.original = zx82font.original = NULL;
	for (count = 0; count < MAX_FONTS; count++)
		zx80font.scaled[count] = zx81font.scaled[count] = 
			zx82font.scaled[count] = NULL;
	joystick = NULL;
	wm_icon = NULL;

	/* Initialise everything to a default here that could possibly be
	 * overridden by a command line option or from an rcfile */
	joystick_dead_zone = JOYSTICK_DEAD_ZONE;
	sdl_key_repeat.delay = KEY_REPEAT_DELAY;
	sdl_key_repeat.interval = KEY_REPEAT_INTERVAL;
	sdl_emulator.model = &zx80;		/* It's a lot easier to do this */
	sdl_emulator.m1not = 0;
#ifdef UDG_CHAR16
	sdl_emulator.wrx = HIRESDISABLED;
	sdl_emulator.chrgen = CHRGENCHR16;
#else
	sdl_emulator.wrx = HIRESWRX;
	sdl_emulator.chrgen = CHRGENSINCLAIR;
#endif
	sdl_emulator.frameskip = 1;		/* Equivalent to z81's scrn_freq=2 */
	sdl_emulator.ramsize = 16;		/* 16K is the default */
	sdl_emulator.invert = 0;		/* Off is the default */
	#if defined(PLATFORM_GP2X)
		sdl_sound.volume = 30;
	#else
		sdl_sound.volume = 64;
	#endif
	sdl_sound.device = DEVICE_NONE;
	sdl_sound.stereo = TRUE;
	sdl_sound.ay_unreal = FALSE;
	vkeyb.alpha = SDL_ALPHA_OPAQUE;
	vkeyb.autohide = FALSE;
	vkeyb.toggle_shift = FALSE;
	colours.colour_key = 0xff0080;
	colours.bmf_fg_default = 0xffffff;
	colours.emu_fg = 0x202018;
	colours.emu_bg = 0xf0f0e8;
	colours.hs_load_selected = 0x00ff00;
	colours.hs_load_pressed = 0xffc000;
	colours.hs_vkeyb_zx80_selected = 0x00ff00;
	colours.hs_vkeyb_zx80_pressed = 0xffff00;
	colours.hs_vkeyb_zx80_toggle_pressed = 0xff4000;
	colours.hs_vkeyb_zx81_selected = 0x00ff00;
	colours.hs_vkeyb_zx81_pressed = 0xffc000;
	colours.hs_vkeyb_zx81_toggle_pressed = 0xff4000;
	colours.hs_ctb_selected = 0x00ff00;
	colours.hs_ctb_pressed = 0xffc000;
	colours.hs_options_selected = 0x00ff00;
	colours.hs_options_pressed = 0xffc000;
	sdl_com_line.nxtlin = UNDEFINED;
	sdl_com_line.load_hook = UNDEFINED;
	sdl_com_line.save_hook = UNDEFINED;
	sdl_com_line.rsz81mem = UNDEFINED;
	sdl_com_line.wsz81mem = UNDEFINED;
	sdl_com_line.bigscreen = UNDEFINED;
	sdl_com_line.fullscreen = UNDEFINED;
	sdl_com_line.networking = UNDEFINED;
	sdl_com_line.scale = UNDEFINED;
	sdl_com_line.xres = UNDEFINED;
	sdl_com_line.yres = UNDEFINED;
	sdl_com_line.bdis = UNDEFINED;
	sdl_com_line.edis = UNDEFINED;
	sdl_com_line.filename[0] = 0;

	/* Initialise other things that need to be done before sdl_video_setmode */
	sdl_emulator.state = TRUE;
	sdl_emulator.speed = 20;		/* 1000ms/50Hz=20ms is the default */
	sdl_emulator.autoload = FALSE;
	sdl_emulator.paused = FALSE;
	sdl_sound.state = FALSE;
	video.redraw = TRUE;
	vkeyb.state = FALSE;
	ctrl_remapper.state = FALSE;
	joy_cfg.state = FALSE;
	rcfile.rewrite = FALSE;
	sdl_zx80rom.state = FALSE;
	sdl_zx81rom.state = FALSE;
	runtime_options[0].state = FALSE;
	runtime_options[0].text = runtime_options_text0;
	runtime_options[1].state = FALSE;
	runtime_options[1].text = runtime_options_text1;
	runtime_options[2].state = FALSE;
	runtime_options[2].text = runtime_options_text2;
	runtime_options[3].state = FALSE;
	runtime_options[3].text = runtime_options_text3;
	show_input_id = FALSE;
	current_input_id = UNDEFINED;
	strcpy(startdir, ""); getcwd(startdir, 256); startdir[255] = 0;
	load_file_dialog.state = FALSE;
	strcpy(load_file_dialog.dir, startdir);
	load_file_dialog.dirlist = NULL;
	strcpy(load_file_dialog.loaded, "");
	load_file_dialog.method = LOAD_FILE_METHOD_NONE;
	/* Populate the load file dialog's directory List */
	load_file_dialog_dirlist_populate(FALSE);
	save_state_dialog.state = FALSE;
	dialog.state = FALSE;
	dialog.flags = 0;
	dialog.title = "";	/* strlen doesn't like NULLs ;) */
	dialog.text[0] = NULL;

	/* Initialise SDL */
	if (SDL_Init(SDL_INIT_TIMER | SDL_INIT_AUDIO | SDL_INIT_VIDEO | SDL_INIT_JOYSTICK)) {
		fprintf(stderr, "%s: Cannot initialise SDL: %s", __func__,
			SDL_GetError());
		return TRUE;
	}

	atexit(clean_up_before_exit);

	/* Set WM icon and title if required for platform before
	 * setting a video mode as per SDL docs instructions */
	#if defined(PLATFORM_GP2X)
	#elif defined(PLATFORM_ZAURUS)
	#else
		strcpy(filename, PACKAGE_DATA_DIR);
		strcatdelimiter(filename);
		strcat(filename, IMG_WM_ICON);

		/* Load the bitmap */
		if ((wm_icon = SDL_LoadBMP(filename)) == NULL) {
			fprintf(stderr, "%s: Cannot load window manager icon %s: %s\n",
				__func__, filename, SDL_GetError ());
		} else {
			SDL_WM_SetIcon (wm_icon, NULL);
		}

		/* Set display window title */
		SDL_WM_SetCaption("sz81", "sz81");
	#endif

	/* Set-up the local data directory */
	local_data_dir_init();

	return FALSE;
}

/***************************************************************************
 * Process the Command Line Options                                        *
 ***************************************************************************/
/* On exit: returns TRUE on error
 *          else FALSE */

int sdl_com_line_process(int argc, char *argv[]) {
	int count;

#ifdef __amigaos4__
	if(argc == 0) amiga_read_tooltypes((struct WBStartup *)argv);
#endif

	if (argc > 1) {
		for (count = 1; count < argc; count++) {
			if (!strcmp (argv[count], "-N")) {
				sdl_com_line.nxtlin = FALSE;
			} else if (!strcmp (argv[count], "-L")) {
				sdl_com_line.load_hook = FALSE;
			} else if (!strcmp (argv[count], "-S")) {
				sdl_com_line.save_hook = FALSE;
			} else if (!strcmp (argv[count], "-R")) {
				sdl_com_line.rsz81mem = TRUE;
			} else if (!strcmp (argv[count], "-W")) {
				sdl_com_line.wsz81mem = TRUE;
			} else if (!strcmp (argv[count], "-b")) {
				sdl_com_line.bigscreen = TRUE;
			} else if (!strcmp (argv[count], "-f")) {
				sdl_com_line.fullscreen = TRUE;
#if defined(SIOCGIFHWADDR) || defined(Win32)
			} else if (!strcmp (argv[count], "-n")) {
				sdl_com_line.networking = TRUE;
#endif
			} else if (sscanf (argv[count], "-B%i",
				&sdl_com_line.bdis) == 1) {
			} else if (sscanf (argv[count], "-E%i",
				&sdl_com_line.edis) == 1) {
			} else if (sscanf (argv[count], "-%ix%i", 
				&sdl_com_line.xres, &sdl_com_line.yres) == 2) {
				/* The minimum xres was changed from 240 to 320; 240 is too small to see all pixels */
				if (sdl_com_line.xres < 320 || sdl_com_line.yres < 240) {
					fprintf (stdout, "Invalid resolution: a minimum of 320x240 is required.\n");
					return TRUE;
				}
			} else if (sdl_filetype_casecmp(argv[count], ".o") == 0 ||
				sdl_filetype_casecmp(argv[count], ".80") == 0 ||
				sdl_filetype_casecmp(argv[count], ".p") == 0 ||
				sdl_filetype_casecmp(argv[count], ".81") == 0) {
				strcpy(sdl_com_line.filename, argv[count]);
			} else {
				/*   1234567890123456789012345678901234567890 <- Formatting for small terminal. */
				fprintf (stdout,
					"z81 2.1 - copyright (C) 1994-2004 Ian Collier and Russell Marks.\n"
					"sz81 " VERSION " (unofficial, see NEWS) - copyright (C) 2007-2011 Thunor and Chris Young.\n\n"
					"usage: sz81 [-bfhnBENLSRW] [-XRESxYRES] [filename.{o|p|80|81}]\n\n"
					"  -b  use a big screen for display\n"
					"  -f  run the program fullscreen\n"
					"  -h  this usage help\n"
#if defined(SIOCGIFHWADDR) || defined(Win32)
					"  -n  enable networking\n"
#endif
					"  -Baddr beginning of region to disassemble\n"
					"  -Eaddr end of region to disassemble\n"
					"  -N  do not autorun (NXTLIN=0)\n"
					"  -L  disable LOAD hook\n"
					"  -S  disable SAVE hook\n"
					"  -R  enable reading from shared memory\n"
					"  -W  enable writing to shared memory\n"
					"  -XRESxYRES e.g. -800x600\n\n");
				return TRUE;
			}
		}
	}

	/* Process sz81's command line options */
	load_hook = sdl_com_line.load_hook;
	save_hook = sdl_com_line.save_hook;
	if (sdl_com_line.rsz81mem==TRUE) rwsz81mem = 1;
	else if (sdl_com_line.wsz81mem==TRUE) rwsz81mem = 2;
	else rwsz81mem = 0;
	video.bigscreen = sdl_com_line.bigscreen == UNDEFINED ? FALSE : sdl_com_line.bigscreen;
	if (video.bigscreen) { video.xres = 800; video.yres = 600; } /* re-init */
	if (sdl_com_line.fullscreen != UNDEFINED && sdl_com_line.fullscreen)
		video.fullscreen = SDL_FULLSCREEN;
	sdl_emulator.networking = sdl_com_line.networking==UNDEFINED ? FALSE : TRUE;
	if (sdl_com_line.xres != UNDEFINED) {
		/* Calculate the scale for the requested resolution */
		if (video.bigscreen) {
			if (sdl_com_line.xres / 400 > sdl_com_line.yres / 300) {
				sdl_com_line.scale = sdl_com_line.yres / 300;
			} else {
				sdl_com_line.scale = sdl_com_line.xres / 400;
			}
		} else {
			if (sdl_com_line.xres / 320 > sdl_com_line.yres / 240) {
				sdl_com_line.scale = sdl_com_line.yres / 240;
			} else {
				sdl_com_line.scale = sdl_com_line.xres / 320;
			}
		}
		video.scale = sdl_com_line.scale;
		video.xres = sdl_com_line.xres;
		video.yres = sdl_com_line.yres;
	}
	sdl_emulator.bdis = sdl_com_line.bdis;
	sdl_emulator.edis = sdl_com_line.edis == UNDEFINED ? sdl_com_line.bdis : sdl_com_line.edis;
	if (*sdl_com_line.filename) {
		/* sdl_load_file will detect this preset method when
		 * autoloading is triggered at the top of z80.c */
		load_file_dialog.method = LOAD_FILE_METHOD_AUTOLOAD;
		sdl_emulator.autoload = TRUE;
	}

	#ifdef SDL_DEBUG_COM_LINE
		printf("%s:\n", __func__);
		printf("  argc=%i\n", argc);
		for (count = 0; count < argc; count++) {
			printf("  %i: %s\n", count, argv[count]);
		}
		printf("  sdl_com_line.bigscreen=%i\n", sdl_com_line.bigscreen);
		printf("  sdl_com_line.fullscreen=%i\n", sdl_com_line.fullscreen);
		printf("  sdl_com_line.scale=%i\n", sdl_com_line.scale);
		printf("  sdl_com_line.xres=%i\n", sdl_com_line.xres);
		printf("  sdl_com_line.yres=%i\n", sdl_com_line.yres);
		printf("  sdl_com_line.filename=%s\n", sdl_com_line.filename);
	#endif

	return FALSE;
}

/***************************************************************************
 * Component Executive                                                     *
 ***************************************************************************/
/* This function monitors program component state changes and if something
 * needs to be done as a result of a state change then it is managed from
 * here to keep things organised and to cut down on code duplication */

void sdl_component_executive(void) {
	static int active_components = 0;
	static int ctrl_remapper_state = FALSE;
	static int sdl_emulator_model = 0;
	static int sdl_emulator_ramsize = 16;
	static int sdl_emulator_m1not = FALSE;
#ifdef UDG_CHAR16
	static int sdl_emulator_wrx = HIRESDISABLED;
	static int sdl_emulator_chrgen = CHRGENCHR16;
#else
	static int sdl_emulator_wrx = HIRESWRX;
	static int sdl_emulator_chrgen = CHRGENSINCLAIR;
#endif
	static int sdl_emulator_invert = 0;
	#ifdef OSS_SOUND_SUPPORT
		static int sdl_sound_device = 0;
		static int sdl_sound_stereo = 0;
	#endif
	static int vkeyb_alpha = SDL_ALPHA_OPAQUE;
	static int vkeyb_autohide = FALSE;
	static int vkeyb_toggle_shift = FALSE;
	int found = FALSE;
	int count;

	/* Monitor control remapper's state */ 
	if (ctrl_remapper_state != ctrl_remapper.state) {
		ctrl_remapper_state = ctrl_remapper.state;
		if (ctrl_remapper.state) {
			ctrl_remapper.master_interval = CTRL_REMAPPER_INTERVAL / 
				sdl_emulator.speed / (sdl_emulator.frameskip + 1);
			ctrl_remapper.interval = 0;
		}
	}
	/* Manage control remapper's interval decrementing and resetting */
	if (ctrl_remapper.state && --ctrl_remapper.interval <= 0)
		ctrl_remapper.interval = ctrl_remapper.master_interval;

	/* Monitor vkeyb autohide, toggle_shift and invert changes
	 * i.e. the control bar icons with images that require toggling */
	if (vkeyb_autohide != vkeyb.autohide || vkeyb_toggle_shift != vkeyb.toggle_shift ||
		sdl_emulator_invert != sdl_emulator.invert) {
		vkeyb_autohide = vkeyb.autohide;
		sdl_emulator_invert = sdl_emulator.invert;
		if (vkeyb_toggle_shift != vkeyb.toggle_shift) {
			vkeyb_toggle_shift = vkeyb.toggle_shift;
			hotspots_vkeyb_shift_init();
		}
		control_bar_init();
		video.redraw = TRUE;
	}

	/* Monitor vkeyb alpha changes */
	if (vkeyb_alpha != vkeyb.alpha) {
		vkeyb_alpha = vkeyb.alpha;
		vkeyb_alpha_apply();
		video.redraw = TRUE;
	}

	/* Monitor machine model changes i.e. ZX80/ZX81 switching */
	if (sdl_emulator_model != *sdl_emulator.model) {
		sdl_emulator_model = *sdl_emulator.model;
		/* Change the virtual keyboard */
		vkeyb_init();
		/* Repopulate the load file dialog's directory list */
		load_file_dialog_dirlist_populate(FALSE);
		/* Resize relevant hotspots */
		hotspots_resize(HS_GRP_VKEYB | HS_GRP_LDFILE);
		/* Reset the emulator */
#ifndef ZXMORE
		emulator_reset();
#endif
	}

	/* Monitor RAM size changes */
	if (sdl_emulator_ramsize != sdl_emulator.ramsize) {
		sdl_emulator_ramsize = sdl_emulator.ramsize;
		/* Reset the emulator */
		emulator_reset();
	}

	/* Monitor M1NOT changes */
	if (sdl_emulator_m1not != sdl_emulator.m1not) {
		sdl_emulator_m1not = sdl_emulator.m1not;
		/* Reset the emulator */
		emulator_reset();
	}

	/* Monitor WRX changes */
	if (sdl_emulator_wrx != sdl_emulator.wrx) {
		sdl_emulator_wrx = sdl_emulator.wrx;
		zx81.truehires = sdl_emulator.wrx;
		/* Reset the emulator */
//		emulator_reset();
	}

	/* Monitor character generator changes */
	if (sdl_emulator_chrgen != sdl_emulator.chrgen) {
		sdl_emulator_chrgen = sdl_emulator.chrgen;
		zx81.chrgen = sdl_emulator.chrgen;
		/* Reset the emulator */
//		emulator_reset();
	}

	#ifdef OSS_SOUND_SUPPORT
		/* Monitor sound device and stereo changes */
	        if (sdl_sound_device != sdl_sound.device || sdl_sound_stereo != sdl_sound.stereo || (sdl_sound_device == DEVICE_ZONX && sound_ay_unreal != sdl_sound.ay_unreal)) {
			sound_end();
			/* Update stereo regardless */
			sdl_sound_stereo = sdl_sound.stereo;
			/* Only restart the mainloop if either the sound device 
			 * has changed or stereo has changed for an AY device */
			if (sdl_sound_device != sdl_sound.device ||
				(sdl_sound_device == DEVICE_QUICKSILVA || sdl_sound_device == DEVICE_ZONX)) {
				sdl_sound_device = sdl_sound.device;
				switch (sdl_sound.device) {
					case DEVICE_NONE:
						sound = 0; sound_ay = 0; sound_vsync = 0;
						sound_ay_type = DEVICE_NONE;
						sound_stereo = sound_stereo_acb = 0;
						break;
					case DEVICE_QUICKSILVA:
						sound = 1; sound_ay = 1; sound_vsync = 0;
						sound_ay_type = DEVICE_QUICKSILVA;
						if (sdl_sound.stereo) {
							sound_stereo = sound_stereo_acb = 1;
						} else {
							sound_stereo = sound_stereo_acb = 0;
						}
						break;
					case DEVICE_ZONX:
						sound = 1; sound_ay = 1; sound_vsync = 0;
						sound_ay_type = DEVICE_ZONX;
						if (sdl_sound.stereo) {
							sound_stereo = sound_stereo_acb = 1;
						} else {
							sound_stereo = sound_stereo_acb = 0;
						}
						if (sdl_sound.ay_unreal) {
							sound_ay_unreal = 1;
						} else {
							sound_ay_unreal = 0;
						}
						break;
					case DEVICE_VSYNC:
						sound = 1; sound_ay = 0; sound_vsync = 1;
						sound_ay_type = DEVICE_NONE;
						sound_stereo = sound_stereo_acb = 0;
						break;
				}
				/* Reset the emulator */
				emulator_reset();
			}
		}
	#endif

	/* Monitor emulator's state */
	if ((active_components & COMP_EMU) != (sdl_emulator.state * COMP_EMU)) {
		if (!sdl_emulator.state && load_selector_state) load_selector_state = FALSE;
		found = TRUE;
	}

	/* Monitor load selector's state */
	if ((active_components & COMP_LOAD) != (load_selector_state * COMP_LOAD)) {
		if (load_selector_state && vkeyb.state) vkeyb.state = FALSE;
		found = TRUE;
	}

	/* Monitor load file dialog's state */
	if ((active_components & COMP_LDFILE) != (load_file_dialog.state * COMP_LDFILE)) {
		if (load_file_dialog.state && vkeyb.state) vkeyb.state = FALSE;
		if (load_file_dialog.state)
			/* Resize hotspots and scrollbar to match new text */
			hotspots_resize(HS_GRP_LDFILE);
		video.redraw = TRUE;
		found = TRUE;
	}

	/* Monitor save state dialog's state */
	if ((active_components & COMP_SSTATE) != (save_state_dialog.state * COMP_SSTATE)) {
		if (save_state_dialog.state && vkeyb.state) vkeyb.state = FALSE;
		found = TRUE;
	}

	/* Monitor runtime options' state */
	for (count = 0; count < MAX_RUNTIME_OPTIONS; count++) {
		if ((active_components & (COMP_RUNOPTS0 << count)) !=
			(runtime_options[count].state * (COMP_RUNOPTS0 << count))) {
			if ((runtime_options_which() < MAX_RUNTIME_OPTIONS)) {
				if (vkeyb.state) vkeyb.state = FALSE;
				/* Update the joycfg text */
				set_joy_cfg_text(0);
				/* It's a runopts page change so don't reset PgUp/PgDn
				 * (this requires that we don't reset any key repeat) */
				keyboard_buffer_reset(FALSE, SDLK_PAGEUP, SDLK_PAGEDOWN);
				/* Update hotspot states */
				hotspots_update();
			} else {
				/* It's a runopts exit so use the normal code below */
				video.redraw = TRUE;
				found = TRUE;
			}
			break;
		}
	}

	/* Monitor virtual keyboard's state */
	if ((active_components & COMP_VKEYB) != (vkeyb.state * COMP_VKEYB)) {
		if (!vkeyb.state) video.redraw = TRUE;
		found = TRUE;
	}

	/* Monitor dialog's state */
	if ((active_components & COMP_DIALOG) != (dialog.state * COMP_DIALOG)) {
		if (dialog.state)
			/* Resize hotspots to match new dialog */
			hotspots_resize(HS_GRP_DIALOG);
		video.redraw = TRUE;
		found = TRUE;
	}

	if (found) {
		keyboard_buffer_reset(FALSE, 0, 0);
		key_repeat_manager(KRM_FUNC_RELEASE, NULL, 0);
		/* Update hotspot states */
		hotspots_update();
	}

	/* Maintain a copy of current program component states  */
	active_components = 0;
	if (sdl_emulator.state) active_components |= COMP_EMU;
	if (load_selector_state) active_components |= COMP_LOAD;
	if (vkeyb.state) active_components |= COMP_VKEYB;
	if (runtime_options_which() < MAX_RUNTIME_OPTIONS)
		active_components |= COMP_RUNOPTS0 << runtime_options_which();
	if (load_file_dialog.state) active_components |= COMP_LDFILE;
	if (save_state_dialog.state) active_components |= COMP_SSTATE;
	if (dialog.state) active_components |= COMP_DIALOG;

}

/***************************************************************************
 * Get Active Component                                                    *
 ***************************************************************************/
/* This returns the main currently active component.
 * 
 * COMP_DIALOG will be active above another active component so this needs
 * to be detected first.
 * 
 * COMP_EMU is inactive when another fullscreen component is covering it but
 * not when the vkeyb or save state dialog is active, so COMP_EMU's state
 * should be detected last otherwise it can override something else */

int get_active_component(void) {
	int retval;

	if (dialog.state) {
		retval = COMP_DIALOG;
	} else if (runtime_options_which() < MAX_RUNTIME_OPTIONS) {
		retval = COMP_RUNOPTS0 << runtime_options_which();
	} else if (save_state_dialog.state) {
		retval = COMP_SSTATE;
	} else if (load_file_dialog.state) {
		retval = COMP_LDFILE;
	} else if (vkeyb.state) {
		retval = COMP_VKEYB;
	} else if (load_selector_state) {
		retval = COMP_LOAD;
	} else if (sdl_emulator.state) {
		retval = COMP_EMU;
	} else {
		retval = 0;
	}

	return retval;
}

/***************************************************************************
 * Runtime Options Which                                                   *
 ***************************************************************************/
/*  On exit: returns 0 to MAX_RUNTIME_OPTIONS-1 if one of the
 *               COMP_RUNOPTSx is active
 *           returns MAX_RUNTIME_OPTIONS if none of them are active */

int runtime_options_which(void) {
	int count;
	
	for (count = 0; count < MAX_RUNTIME_OPTIONS; count++)
		if (runtime_options[count].state) break;
	
	return count;
}

/***************************************************************************
 * Timer Initialise                                                        *
 ***************************************************************************/

void sdl_timer_init(void) {
	/* Create a 10ms timer */
	sdl_emulator.timer_id = SDL_AddTimer (10, emulator_timer, NULL);
}

/***************************************************************************
 * Emulator Timer                                                          *
 ***************************************************************************/

Uint32 emulator_timer(Uint32 interval, void *param) {
	static int intervals = 0;

	/* speed setting is partly done here, partly in sz81.c... */

	intervals++;
	if (intervals >= (sdl_emulator.speed > 20 ? sdl_emulator.speed : 20) / 10) {
		signal_int_flag = TRUE;
		intervals = 0;
	}
	
	return interval;
}

/***************************************************************************
 * Emulator Reset                                                          *
 ***************************************************************************/
/* The mainloop is restarted via this function */

void emulator_reset(void) {

        /* printf("Emulator reset...\n"); */

	/* Erase record of which program was last loaded/saved */
	strcpy(load_file_dialog.loaded, "");

	/* If the user paused the emulator then unpause it */
	if (sdl_emulator.paused) toggle_emulator_paused(TRUE);

	/* Restart mainloop on return */
	interrupted = INTERRUPT_EMULATOR_RESET;
}

/***************************************************************************
 * Emulator Hold                                                           *
 ***************************************************************************/
/* This will place the emulator into a holding position until the condition
 * changes or the user has initiated emulator exit.
 * 
 * On entry: int *condition points to the variable to monitor
 *  On exit: returns TRUE if emulator exit detected
 *           else FALSE */

int emulator_hold(int *condition) {
	int origcond = *condition;
	int retval = FALSE;

	do {
		/* This waits until it's time to process the next frame
		 * (signal_int_flag=1) */
		frame_pause();
		/* This calls update_scrn if the frame is to be rendered
		 * i.e. not skipped, calls check_events which then calls
		 * keyboard_update */
		do_interrupt();
		/* If the user initiates emulator exit then quit loop */
		if (interrupted == INTERRUPT_EMULATOR_EXIT) retval = TRUE;
	} while (origcond == *condition && !retval);

	return retval;
}

/***************************************************************************
 * Emulator Exit                                                           *
 ***************************************************************************/

void emulator_exit(void) {

        SDL_PauseAudio(1);

	/* If the rcfile is scheduled for writing then get user confirmation
	 * for writing to sz81rc so that they can choose to discard changes */
	if (rcfile.rewrite) {
		dialog.text[0] = "Write to";
		dialog.text[1] = RESOURCE_FILE "?";
		dialog.text[2] = NULL;	/* There MUST be a terminating NULL pointer */
		dialog.title = "Exit";
		dialog.flags = DIALOG_ICON_QUESTION |
			DIALOG_BUTTONS_YES_NO |
			DIALOG_DEFAULT_YES;
		dialog.state = TRUE;
		emulator_hold(&dialog.state);
		if (dialog.retval == SDLK_n) rcfile.rewrite = FALSE;
	}

	/* If runopts is active then restore variables else the rcfile might
	 * be flagged for saving and it'll erroneously save the previewed ones */
	if (get_active_component() & COMP_RUNOPTS_ALL)
		runopts_transit(TRANSIT_OUT);

	/* Exit mainloop on return */
	interrupted = INTERRUPT_EMULATOR_EXIT;
}

/***************************************************************************
 * Clean Up Before Exit                                                    *
 ***************************************************************************/

void clean_up_before_exit(void) {
	int count;

	if (load_file_dialog.dirlist) free(load_file_dialog.dirlist);

	#ifdef OSS_SOUND_SUPPORT
		sdl_sound_end();
	#endif

	if (sdl_emulator.timer_id) SDL_RemoveTimer (sdl_emulator.timer_id);

	if (rcfile.rewrite) rcfile_write();

	if (control_bar.scaled) SDL_FreeSurface(control_bar.scaled);
	if (vkeyb.zx80original) SDL_FreeSurface(vkeyb.zx80original);
	if (vkeyb.zx81original) SDL_FreeSurface(vkeyb.zx81original);
	if (vkeyb.scaled) SDL_FreeSurface(vkeyb.scaled);
	if (sz81icons.original) SDL_FreeSurface(sz81icons.original);
	if (sz81icons.scaled) SDL_FreeSurface(sz81icons.scaled);
	if (zx80font.original) SDL_FreeSurface(zx80font.original);
	if (zx81font.original) SDL_FreeSurface(zx81font.original);
	if (zx82font.original) SDL_FreeSurface(zx82font.original);
	for (count = 0; count < MAX_FONTS; count++) {
		if (zx80font.scaled[count]) SDL_FreeSurface(zx80font.scaled[count]);
		if (zx81font.scaled[count]) SDL_FreeSurface(zx81font.scaled[count]);
		if (zx82font.scaled[count]) SDL_FreeSurface(zx82font.scaled[count]);
	}

	#ifdef PLATFORM_GP2X
		#if defined(TOOLCHAIN_OPEN2X) || defined(TOOLCHAIN_OPENWIZ)
			if (joystick) SDL_JoystickClose(joystick);
		#endif
	#else
		if (joystick) SDL_JoystickClose(joystick);
	#endif

	if (wm_icon) SDL_FreeSurface(wm_icon);

	if (sdl_emulator.networking) w_exit();
	exitmem();

	SDL_Quit();

	#ifdef __amigaos4__
		amiga_close_libs();
	#endif
}