toaruos/apps/font-server.c

/* vim: tabstop=4 shiftwidth=4 noexpandtab
 * This file is part of ToaruOS and is released under the terms
 * of the NCSA / University of Illinois License - see LICENSE.md
 * Copyright (C) 2018 K. Lange
 *
 * font-server - Provides shared-memory fonts.
 *
 * This is an implementation of the shared memory font server
 * from Yutani in ToaruOS 1.2.x. It allows applications to
 * make use of the Freetype font rendering backend by providing
 * a common set of font files.
 */
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <unistd.h>
#include <sys/shm.h>

#if 0
#include <toaru/trace.h>
#define TRACE_APP_NAME "font-server"
#else
#define TRACE(...)
#endif

#define FONT_PATH "/usr/share/fonts/"
#define FONT(a,b) {a, FONT_PATH b}

struct font_def {
	char * identifier;
	char * path;
};

static struct font_def fonts[] = {
	FONT("sans-serif",            "DejaVuSans.ttf"),
	FONT("sans-serif.bold",       "DejaVuSans-Bold.ttf"),
	FONT("sans-serif.italic",     "DejaVuSans-Oblique.ttf"),
	FONT("sans-serif.bolditalic", "DejaVuSans-BoldOblique.ttf"),
	FONT("monospace",             "DejaVuSansMono.ttf"),
	FONT("monospace.bold",        "DejaVuSansMono-Bold.ttf"),
	FONT("monospace.italic",      "DejaVuSansMono-Oblique.ttf"),
	FONT("monospace.bolditalic",  "DejaVuSansMono-BoldOblique.ttf"),
	{NULL, NULL}
};

/**
 * Preload a font into the font cache.
 */
static char * precache_shmfont(char * ident, char * name) {
	FILE * f = fopen(name, "r");
	if (!f) return NULL;
	size_t s = 0;
	fseek(f, 0, SEEK_END);
	s = ftell(f);
	fseek(f, 0, SEEK_SET);

	size_t shm_size = s;
	char * font = shm_obtain(ident, &shm_size);
	assert((shm_size >= s) && "shm_obtain returned too little memory to load a font into!");

	fread(font, s, 1, f);

	fclose(f);
	return font;
}

/**
 * Load all of the fonts into the cache.
 */
static void load_fonts(char * server) {
	int i = 0;
	while (fonts[i].identifier) {
		char tmp[100];
		sprintf(tmp, "sys.%s.fonts.%s", server, fonts[i].identifier);
		TRACE("Loading font %s -> %s", fonts[i].path, tmp);
		if (!precache_shmfont(tmp, fonts[i].path)) {
			TRACE("  ... failed.");
		}
		++i;
	}
}

int main(int argc, char * argv[]) {

	/* Daemonize */
	if (!fork()) {
		load_fonts("fonts");

		while (1) {
			usleep(100000);
		}

		return 0;
	}

	return 0;
}