src/libdraw/openfont.c

#include <u.h>
#include <libc.h>
#include <draw.h>

extern vlong _drawflength(int);
int _fontpipe(char*);

int
parsefontscale(char *name, char **base)
{
	char *p;
	int scale;
	
	p = name;
	scale = 0;
	while('0' <= *p && *p <= '9') {
		scale = scale*10 + *p - '0';
		p++;
	}
	if(*p == '*' && scale > 0)
		*base = p+1;
	else {
		*base = name;
		scale = 1;
	}
	return scale;
}	

Font*
openfont1(Display *d, char *name)
{
	Font *fnt;
	int fd, i, n, scale;
	char *buf, *nambuf, *fname, *freename;

	nambuf = 0;
	freename = nil;
	scale = parsefontscale(name, &fname);

	fd = open(fname, OREAD);
	if(fd < 0 && strncmp(fname, "/lib/font/bit/", 14) == 0){
		nambuf = smprint("#9/font/%s", fname+14);
		if(nambuf == nil)
			return 0;
		nambuf = unsharp(nambuf);
		if(nambuf == nil)
			return 0;
		if((fd = open(nambuf, OREAD)) < 0){
			free(nambuf);
			return 0;
		}
		fname = nambuf;
		if(scale > 1) {
			name = smprint("%d*%s", scale, fname);
			freename = name;
		} else {
			name = fname;
		}
	}
	if(fd >= 0)
		n = _drawflength(fd);
	if(fd < 0 && strncmp(fname, "/mnt/font/", 10) == 0) {
		fd = _fontpipe(fname+10);
		n = 8192;
	}
	if(fd < 0)
		return 0;

	buf = malloc(n+1);
	if(buf == 0){
		close(fd);
		free(nambuf);
		return 0;
	}
	i = readn(fd, buf, n);
	close(fd);
	if(i <= 0){
		free(buf);
		free(nambuf);
		return 0;
	}
	buf[i] = 0;
	fnt = buildfont(d, buf, name);
	free(buf);
	free(nambuf);
	free(freename);
	if(scale != 1) {
		fnt->scale = scale;
		fnt->height *= scale;
		fnt->ascent *= scale;
		fnt->width *= scale;
	}
	return fnt;
}

void
swapfont(Font *targ, Font **oldp, Font **newp)
{
	Font f, *old, *new;

	if(targ != *oldp)
		sysfatal("bad swapfont %p %p %p", targ, *oldp, *newp);
	
	old = *oldp;
	new = *newp;

	f.name = old->name;
	f.display = old->display;
	f.height = old->height;
	f.ascent = old->ascent;
	f.width = old->width;
	f.nsub = old->nsub;
	f.age = old->age;
	f.maxdepth = old->maxdepth;
	f.ncache = old->ncache;
	f.nsubf = old->nsubf;
	f.scale = old->scale;
	f.cache = old->cache;
	f.subf = old->subf;
	f.sub = old->sub;
	f.cacheimage = old->cacheimage;

	old->name = new->name;
	old->display = new->display;
	old->height = new->height;
	old->ascent = new->ascent;
	old->width = new->width;
	old->nsub = new->nsub;
	old->age = new->age;
	old->maxdepth = new->maxdepth;
	old->ncache = new->ncache;
	old->nsubf = new->nsubf;
	old->scale = new->scale;
	old->cache = new->cache;
	old->subf = new->subf;
	old->sub = new->sub;
	old->cacheimage = new->cacheimage;

	new->name = f.name;
	new->display = f.display;
	new->height = f.height;
	new->ascent = f.ascent;
	new->width = f.width;
	new->nsub = f.nsub;
	new->age = f.age;
	new->maxdepth = f.maxdepth;
	new->ncache = f.ncache;
	new->nsubf = f.nsubf;
	new->scale = f.scale;
	new->cache = f.cache;
	new->subf = f.subf;
	new->sub = f.sub;
	new->cacheimage = f.cacheimage;

	*oldp = new;
	*newp = old;
}

static char*
hidpiname(Font *f)
{
	char *p, *q;
	int size;
	
	// If font name has form x,y return y.
	p = strchr(f->namespec, ',');
	if(p != nil)
		return strdup(p+1);
	
	// If font name is /mnt/font/Name/Size/font, scale Size.
	if(strncmp(f->name, "/mnt/font/", 10) == 0) {
		p = strchr(f->name+10, '/');
		if(p == nil || *++p < '0' || *p > '9')
			goto scale;
		q = p;
		size = 0;
		while('0' <= *q && *q <= '9')
			size = size*10 + *q++ - '0';
		return smprint("%.*s%d%s", utfnlen(f->name, p-f->name), f->name, size*2, q);
	}		

	// Otherwise use pixel doubling.	
scale:
	return smprint("%d*%s", f->scale*2, f->name);
}

void
loadhidpi(Font *f)
{
	char *name;
	Font *fnew;

	if(f->hidpi == f)
		return;
	if(f->hidpi != nil) {
		swapfont(f, &f->lodpi, &f->hidpi);
		return;
	}
	
	name = hidpiname(f);
	fnew = openfont1(f->display, name);
	if(fnew == nil)
		return;
	f->hidpi = fnew;
	free(name);

	swapfont(f, &f->lodpi, &f->hidpi);
}

Font*
openfont(Display *d, char *name)
{
	Font *f;
	char *p;
	char *namespec;
	
	// If font name has form x,y use x for lodpi, y for hidpi.
	name = strdup(name);
	namespec = strdup(name);
	if((p = strchr(name, ',')) != nil)
		*p = '\0';

	f = openfont1(d, name);
	f->lodpi = f;
	f->namespec = namespec;
	
	/* add to display list for when dpi changes */
	/* d can be nil when invoked from mc. */
	if(d != nil) {
		f->ondisplaylist = 1;
		f->prev = d->lastfont;
		f->next = nil;
		if(f->prev)
			f->prev->next = f;
		else
			d->firstfont = f;
		d->lastfont = f;
	
		/* if this is a hi-dpi display, find hi-dpi version and swap */
		if(d->dpi >= DefaultDPI*3/2)
			loadhidpi(f);
	}
	
	free(name);

	return f;
}

int
_fontpipe(char *name)
{
	int p[2];
	char c;
	char buf[1024], *argv[10];
	int nbuf, pid;
	
	if(pipe(p) < 0)
		return -1;
	pid = rfork(RFNOWAIT|RFFDG|RFPROC);
	if(pid < 0) {
		close(p[0]);
		close(p[1]);
		return -1;
	}
	if(pid == 0) {
		close(p[0]);
		dup(p[1], 1);
		dup(p[1], 2);
		if(p[1] > 2)
			close(p[1]);
		argv[0] = "fontsrv";
		argv[1] = "-pp";
		argv[2] = name;
		argv[3] = nil;
		execvp("fontsrv", argv);
		print("exec fontsrv: %r\n");
		_exit(0);
	}
	close(p[1]);
	
	// success marked with leading \001.
	// otherwise an error happened.
	for(nbuf=0; nbuf<sizeof buf-1; nbuf++) {
		if(read(p[0], &c, 1) < 1 || c == '\n') {
			buf[nbuf] = '\0';
			werrstr(buf);
			close(p[0]);
			return -1;
		}
		if(c == '\001')
			break;
	}
	return p[0];
}