A useful loadable/alternate font testing script.

Either run it with no options to demo all the loaded/built-in fonts, or:
load it with a path of some font files (e.g. ctrl/fonts/*.f16) and it'll
demo those font files.

exec/fonttest.js

+// $Id$
+
+var cterm = load({}, 'cterm_lib.js');
+var ansiterm = load({}, 'ansiterm_lib.js');
+load('sbbsdefs.js');
+
+var verbose = true;
+
+function printable(ch)
+{
+	switch(ascii(ch)) {
+		case '\x00':
+		case '\x07':
+		case '\b':
+		case '\t':
+		case '\r':
+		case '\n':
+		case '\f':
+		case '\x1b':
+			return '.';
+	}
+	return ch;
+}
+
+function demo_font(slot, blink)
+{
+	print('Enabled modes ' + cterm.query_mode());
+	var activated = cterm.activate_font(cterm.font_styles.blink, slot);
+	print("Activate font result: " + activated);
+	if(activated !== true)
+		return;
+	ansiterm.send('ext_mode', blink ? 'clear':'set', 'no_blink');
+	console.attributes = LIGHTGRAY|BLINK;
+	for(var ch = 0; ch < 255; ch++) {
+		if(verbose)
+			console.write(format("%02x%c ", ch, printable(ch)));
+		else
+			console.write(format("%c", printable(ch)));
+	}
+	console.crlf();
+	printf("\xc9\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xbb\r\n");
+	printf("\xba Hello, World! This is font %-3u \xba\r\n", slot);
+	printf("\xc8\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xcd\xbc\r\n");
+	printf("\1nNormal  High     Blink    High-blink\r\n");
+	printf("\1nExample \1hExample  \1n\1iExample  \1hExample\r\n");
+	console.crlf();
+	console.attributes = LIGHTGRAY;
+}
+
+function demo_files()
+{
+	var files = directory(argv[0]);
+	var filenum = 0;
+	var blink = false;
+	while(files.length && bbs.online) {
+		console.clear(WHITE);
+		printf("Font file: %s\1n\r\n\r\n", files[filenum]);
+		var f = new File(files[filenum]);
+		if(!f.open("rb")) {
+			alert("FAILURE opening " + f.name);
+			break;
+		}
+		var data = f.read();
+		f.close();
+		cterm.load_font(cterm.font_slot_last, data, /* force: */true);
+		demo_font(cterm.font_slot_last, blink);
+		console.mnemonics("Which, ~+, ~-, ~Blink-toggle, ~Verbosity-toggle, ~Delete, or ~Quit: ");
+		var which = console.getkeys('-+BQDV', files.length - 1);
+		switch(which) {
+			case 'Q':
+				exit();
+			case 'V':
+				verbose = !verbose;
+				break;
+			case 'B':
+				blink = !blink;
+				break;
+			case '+':
+				filenum++;
+				if(filenum >= files.length)
+					filenum = 0;
+				break;
+			case 'D':
+				file_remove(files[filenum]);
+				files.splice(filenum, 1);
+				// fall-through
+			case '-':
+				filenum--;
+				if(filenum < 0)
+					filenum = files.length - 1;
+				break;
+			default:
+				filenum = parseInt(which);
+				if(!filenum)
+					filenum = 0;
+				break;
+		}
+	}
+}
+
+function demo_slots()
+{
+	var slot = 0;
+	var blink = false;
+	while(bbs.online) {
+		console.clear(WHITE);
+		printf("Slot %d\1n\r\n\r\n", slot);
+		demo_font(slot, blink);
+		console.mnemonics("Which, ~+, ~-, ~Blink-toggle, ~Verbosity-toggle, or ~Quit: ");
+		var which = console.getkeys('-+QVB', cterm.font_slot_last);
+		switch(which) {
+			case 'Q':
+				exit();
+			case 'V':
+				verbose = !verbose;
+				break;
+			case 'B':
+				blink = !blink;
+				break;
+			case '+':
+				slot++;
+				if(slot > cterm.font_slot_last)
+					slot = 0;
+				break;
+			case '-':
+				slot--;
+				if(slot < 0)
+					slot = cterm.font_slot_last;
+				break;
+			default:
+				slot = parseInt(which);
+				if(!slot)
+					slot = 0;
+				break;
+		}
+	}
+}
+
+function main()
+{
+	ansiterm.send('ext_mode', 'save_all');
+	js.on_exit("ansiterm.send('ext_mode', 'restore_all')");
+
+	if(argc)
+		demo_files();
+	else
+		demo_slots();
+}
+
+main();
\ No newline at end of file