fontsrv: use CoreText API on OS X

This gets us font fallback for free and avoids use of a
deprecated API that might go away some day.

Change-Id: I4b9b1a1ce3e6d98bfb407e3baea13f4adfe2c26a
Reviewed-on: https://plan9port-review.googlesource.com/1160
Reviewed-by: Russ Cox <rsc@swtch.com>

5 files changed, 143 insertions, 106 deletions

diff --git a/src/cmd/fontsrv/a.h b/src/cmd/fontsrv/a.h
index ffe46ae6..67a7b365 100644
--- a/src/cmd/fontsrv/a.h
+++ b/src/cmd/fontsrv/a.h
@@ -11,6 +11,7 @@ struct XFont
 	int unit;
 	double height;
 	double originy;
+	void (*loadheight)(XFont*, int, int*, int*);
 
 	// fontconfig workarround, as FC_FULLNAME does not work for matching fonts.
 	char *fontfile;
@@ -19,7 +20,7 @@ struct XFont
 
 void	loadfonts(void);
 void	load(XFont*);
-Memsubfont*	mksubfont(char*, int, int, int, int);
+Memsubfont*	mksubfont(XFont*, char*, int, int, int, int);
 
 extern XFont *xfont;
 extern int nxfont;
diff --git a/src/cmd/fontsrv/main.c b/src/cmd/fontsrv/main.c
index 93eb39e2..5a43ef15 100644
--- a/src/cmd/fontsrv/main.c
+++ b/src/cmd/fontsrv/main.c
@@ -144,7 +144,7 @@ xwalk1(Fid *fid, char *name, Qid *qid)
 	switch(QTYPE(path)) {
 	default:
 	NotFound:
-		return "file not  found";
+		return "file not found";
 
 	case Qroot:
 		if(dotdot)
@@ -313,10 +313,18 @@ xread(Req *r)
 		fmtstrinit(&fmt);
 		f = &xfont[QFONT(path)];
 		load(f);
-		if(f->unit == 0)
+		if(f->unit == 0 && f->loadheight == nil) {
+			readstr(r, "font missing\n");
 			break;
-		height = f->height * (int)QSIZE(path)/f->unit + 0.99999999;
-		ascent = height - (int)(-f->originy * (int)QSIZE(path)/f->unit + 0.99999999);
+		}
+		height = 0;
+		ascent = 0;
+		if(f->unit > 0) {
+			height = f->height * (int)QSIZE(path)/f->unit + 0.99999999;
+			ascent = height - (int)(-f->originy * (int)QSIZE(path)/f->unit + 0.99999999);
+		}
+		if(f->loadheight != nil)
+			f->loadheight(f, QSIZE(path), &height, &ascent);
 		fmtprint(&fmt, "%11d %11d\n", height, ascent);
 		for(i=0; i<nelem(f->range); i++) {
 			if(f->range[i] == 0)
@@ -331,7 +339,7 @@ xread(Req *r)
 		f = &xfont[QFONT(path)];
 		load(f);
 		if(r->fid->aux == nil) {
-			r->fid->aux = mksubfont(f->name, QRANGE(path)<<8, (QRANGE(path)<<8)+0xFF, QSIZE(path), QANTIALIAS(path));
+			r->fid->aux = mksubfont(f, f->name, QRANGE(path)<<8, (QRANGE(path)<<8)+0xFF, QSIZE(path), QANTIALIAS(path));
 			if(r->fid->aux == nil) {
 				responderrstr(r);
 				return;
diff --git a/src/cmd/fontsrv/nowsys.c b/src/cmd/fontsrv/nowsys.c
index eb3b57a9..86610bd1 100644
--- a/src/cmd/fontsrv/nowsys.c
+++ b/src/cmd/fontsrv/nowsys.c
@@ -15,7 +15,7 @@ load(XFont *f)
 }
 
 Memsubfont*
-mksubfont(char *name, int lo, int hi, int size, int antialias)
+mksubfont(XFont *f, char *name, int lo, int hi, int size, int antialias)
 {
 	return nil;
 }
diff --git a/src/cmd/fontsrv/osx.c b/src/cmd/fontsrv/osx.c
index a35eb4a5..2c88fd55 100644
--- a/src/cmd/fontsrv/osx.c
+++ b/src/cmd/fontsrv/osx.c
@@ -15,7 +15,6 @@
 #include <memdraw.h>
 #include "a.h"
 
-
 extern void CGFontGetGlyphsForUnichars(CGFontRef, const UniChar[], const CGGlyph[], size_t);
 
 int
@@ -84,35 +83,73 @@ loadfonts(void)
 	}
 }
 
-CGRect
-subfontbbox(CGFontRef font, int lo, int hi)
+// Some representative text to try to discern line heights.
+static char *lines[] = {
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZ",
+	"abcdefghijklmnopqrstuvwxyz",
+	"g",
+	"ὕαλον ϕαγεῖν δύναμαι· τοῦτο οὔ με βλάπτει.",
+	"私はガラスを食べられます。それは私を傷つけません。",
+	"Aš galiu valgyti stiklą ir jis manęs nežeidžia",
+	"Môžem jesť sklo. Nezraní ma.",
+};
+
+static void
+fontheight(XFont *f, int size, int *height, int *ascent)
 {
-	int i, first;
+	int i;
+	CFStringRef s;
 	CGRect bbox;
+	CTFontRef font;
+	CTFontDescriptorRef desc;
+	CGContextRef ctxt;
+	CGColorSpaceRef color;
+
+	s = c2mac(f->name);
+	desc = CTFontDescriptorCreateWithNameAndSize(s, size);
+	CFRelease(s);
+	if(desc == nil)
+		return;
+	font = CTFontCreateWithFontDescriptor(desc, 0, nil);
+	CFRelease(desc);
+	if(font == nil)
+		return;
 
-	bbox.origin.x = 0;
-	bbox.origin.y = 0;
-	bbox.size.height = 0;
-	bbox.size.width = 0;
+	color = CGColorSpaceCreateWithName(kCGColorSpaceGenericGray);
+	ctxt = CGBitmapContextCreate(nil, 1, 1, 8, 1, color, kCGImageAlphaNone);
+	CGColorSpaceRelease(color);
+	CGContextSetTextPosition(ctxt, 0, 0);
 
-	first = 1;
-	for(i=lo; i<=hi; i++) {
-		UniChar u;
-		CGGlyph g;
+	for(i=0; i<nelem(lines); i++) {
+		CFStringRef keys[] = { kCTFontAttributeName };
+		CFTypeRef values[] = { font };
+		CFStringRef str;
+		CFDictionaryRef attrs;
+		CFAttributedStringRef attrString;
 		CGRect r;
+		CTLineRef line;
 
-		u = mapUnicode(i);
-		CGFontGetGlyphsForUnichars(font, &u, &g, 1);
-		if(g == 0 || !CGFontGetGlyphBBoxes(font, &g, 1, &r))
-			continue;
+ 		str = c2mac(lines[i]);
+ 		
+ 		// See https://developer.apple.com/library/ios/documentation/StringsTextFonts/Conceptual/CoreText_Programming/LayoutOperations/LayoutOperations.html#//apple_ref/doc/uid/TP40005533-CH12-SW2
+ 		attrs = CFDictionaryCreate(kCFAllocatorDefault, (const void**)&keys,
+			(const void**)&values, sizeof(keys) / sizeof(keys[0]),
+			&kCFTypeDictionaryKeyCallBacks,
+			&kCFTypeDictionaryValueCallBacks);
+		attrString = CFAttributedStringCreate(kCFAllocatorDefault, str, attrs);
+		CFRelease(str);
+		CFRelease(attrs);
 
+		line = CTLineCreateWithAttributedString(attrString);
+		r = CTLineGetImageBounds(line, ctxt);
 		r.size.width += r.origin.x;
 		r.size.height += r.origin.y;
-		if(first) {
+		CFRelease(line);
+		
+//	fprint(2, "%s: %g %g %g %g\n", lines[i], r.origin.x, r.origin.y, r.size.width, r.size.height);
+		
+		if(i == 0)
 			bbox = r;
-			first = 0;
-			continue;
-		}
 		if(bbox.origin.x > r.origin.x)
 			bbox.origin.x = r.origin.x;	
 		if(bbox.origin.y > r.origin.y)
@@ -122,79 +159,71 @@ subfontbbox(CGFontRef font, int lo, int hi)
 		if(bbox.size.height < r.size.height)
 			bbox.size.height = r.size.height;
 	}
-	
+
 	bbox.size.width -= bbox.origin.x;
 	bbox.size.height -= bbox.origin.y;
-	return bbox;
+
+	*height = bbox.size.height + 0.999999;
+	*ascent = *height - (-bbox.origin.y + 0.999999);
+		
+	CGContextRelease(ctxt);
+	CFRelease(font);
 }
 
 void
 load(XFont *f)
 {
-	int i, j;
-	CGFontRef font;
-	CFStringRef s;
-	UniChar u[256];
-	CGGlyph g[256];
-	CGRect bbox;
+	int i;
 
 	if(f->loaded)
 		return;
 	f->loaded = 1;
-	s = c2mac(f->name);
-	font = CGFontCreateWithFontName(s);
-	CFRelease(s);
-	if(font == nil)
-		return;
-	
-	// assume bbox gives latin1 is height/ascent for all
-	bbox = subfontbbox(font, 0x00, 0xff);
-	f->unit = CGFontGetUnitsPerEm(font);
-	f->height = bbox.size.height;
-	f->originy = bbox.origin.y;
-
-	// figure out where the letters are
-	for(i=0; i<0xffff; i+=0x100) {
-		for(j=0; j<0x100; j++) {
-			u[j] = mapUnicode(i+j);
-			g[j] = 0;
-		}
-		CGFontGetGlyphsForUnichars(font, u, g, 256);
-		for(j=0; j<0x100; j++) {
-			if(g[j] != 0) {
-				f->range[i>>8] = 1;
-				f->nrange++;
-				break;
-			}
-		}
+
+	// compute height and ascent for each size on demand
+	f->loadheight = fontheight;
+
+	// enable all Unicode ranges
+	for(i=0; i<nelem(f->range); i++) {
+		f->range[i] = 1;
+		f->nrange++;
 	}
-	CFRelease(font);
 }
 
 Memsubfont*
-mksubfont(char *name, int lo, int hi, int size, int antialias)
+mksubfont(XFont *f, char *name, int lo, int hi, int size, int antialias)
 {
 	CFStringRef s;
 	CGColorSpaceRef color;
 	CGContextRef ctxt;
-	CGFontRef font;
+	CTFontRef font;
+	CTFontDescriptorRef desc;
 	CGRect bbox;
 	Memimage *m, *mc, *m1;
 	int x, y, y0;
-	int i, unit;
+	int i, height, ascent;
 	Fontchar *fc, *fc0;
 	Memsubfont *sf;
+	CGFloat whitef[] = { 1.0, 1.0 };
+	CGColorRef white;
 
 	s = c2mac(name);
-	font = CGFontCreateWithFontName(s);
+	desc = CTFontDescriptorCreateWithNameAndSize(s, size);
 	CFRelease(s);
+	if(desc == nil)
+		return nil;
+	font = CTFontCreateWithFontDescriptor(desc, 0, nil);
+	CFRelease(desc);
 	if(font == nil)
 		return nil;
-	bbox = subfontbbox(font, lo, hi);
-	unit = CGFontGetUnitsPerEm(font);
-	x = (int)(bbox.size.width * size / unit + 0.99999999);
-	y = bbox.size.height * size/unit + 0.99999999;
-	y0 = (int)(-bbox.origin.y * size/unit + 0.99999999);
+	
+	
+	bbox = CTFontGetBoundingBox(font);
+	x = (int)(bbox.size.width + 0.99999999);
+
+	fontheight(f, size, &height, &ascent);
+	y = height;
+	y0 = height - ascent;
+
 	m = allocmemimage(Rect(0, 0, x*(hi+1-lo)+1, y+1), GREY8);
 	if(m == nil)
 		return nil;
@@ -217,6 +246,7 @@ mksubfont(char *name, int lo, int hi, int size, int antialias)
 	color = CGColorSpaceCreateWithName(kCGColorSpaceGenericGray);
 	ctxt = CGBitmapContextCreate(byteaddr(mc, mc->r.min), Dx(mc->r), Dy(mc->r), 8,
 		mc->width*sizeof(u32int), color, kCGImageAlphaNone);
+	white = CGColorCreate(color, whitef);
 	CGColorSpaceRelease(color);
 	if(ctxt == nil) {
 		freememimage(m);
@@ -226,46 +256,56 @@ mksubfont(char *name, int lo, int hi, int size, int antialias)
 		return nil;
 	}
 
-	CGContextSetFont(ctxt, font);
-	CGContextSetFontSize(ctxt, size);
 	CGContextSetAllowsAntialiasing(ctxt, antialias);
-	CGContextSetRGBFillColor(ctxt, 1, 1, 1, 1);
 	CGContextSetTextPosition(ctxt, 0, 0);	// XXX
 
 	x = 0;
 	for(i=lo; i<=hi; i++, fc++) {
-		UniChar u[2];
-		CGGlyph g[2];
-		CGRect r[2];
+		char buf[20];
+		CFStringRef str;
+		CFDictionaryRef attrs;
+		CFAttributedStringRef attrString;
+		CTLineRef line;
+		CGRect r;
 		CGPoint p1;
-		int n;
+		CFStringRef keys[] = { kCTFontAttributeName, kCTForegroundColorAttributeName };
+		CFTypeRef values[] = { font, white };
+
+		sprint(buf, "%C", (Rune)mapUnicode(i));
+ 		str = c2mac(buf);
+ 		
+ 		// See https://developer.apple.com/library/ios/documentation/StringsTextFonts/Conceptual/CoreText_Programming/LayoutOperations/LayoutOperations.html#//apple_ref/doc/uid/TP40005533-CH12-SW2
+ 		attrs = CFDictionaryCreate(kCFAllocatorDefault, (const void**)&keys,
+			(const void**)&values, sizeof(keys) / sizeof(keys[0]),
+			&kCFTypeDictionaryKeyCallBacks,
+			&kCFTypeDictionaryValueCallBacks);
+		attrString = CFAttributedStringCreate(kCFAllocatorDefault, str, attrs);
+		CFRelease(str);
+		CFRelease(attrs);
+
+		line = CTLineCreateWithAttributedString(attrString);
+		CGContextSetTextPosition(ctxt, 0, y0);
+		r = CTLineGetImageBounds(line, ctxt);
+		memfillcolor(mc, DBlack);
+		CTLineDraw(line, ctxt);		
+		CFRelease(line);
 
 		fc->x = x;
 		fc->top = 0;
 		fc->bottom = Dy(m->r);
 
-		n = 0;
-		u[n++] = mapUnicode(i);
-		if(0)	// debugging
-			u[n++] = '|';
-		g[0] = 0;
-		CGFontGetGlyphsForUnichars(font, u, g, n);
-		if(g[0] == 0 || !CGFontGetGlyphBBoxes(font, g, n, r)) {
-		None:
+//		fprint(2, "printed %#x: %g %g\n", mapUnicode(i), p1.x, p1.y);
+		p1 = CGContextGetTextPosition(ctxt);
+		if(p1.x <= 0 || mapUnicode(i) == 0xfffd) {
 			fc->width = 0;
 			fc->left = 0;
 			if(i == 0) {
-				drawpjw(m, fc, x, (int)(bbox.size.width * size / unit + 0.99999999), y, y - y0);
+				drawpjw(m, fc, x, (int)(bbox.size.width + 0.99999999), y, y - y0);
 				x += fc->width;
 			}	
 			continue;
 		}
-		memfillcolor(mc, DBlack);
-		CGContextSetTextPosition(ctxt, 0, y0);
-		CGContextShowGlyphs(ctxt, g, n);
-		p1 = CGContextGetTextPosition(ctxt);
-		if(p1.x <= 0)
-			goto None;
+
 		memimagedraw(m, Rect(x, 0, x + p1.x, y), mc, ZP, memopaque, ZP, S);
 		fc->width = p1.x;
 		fc->left = 0;
@@ -297,4 +337,3 @@ mksubfont(char *name, int lo, int hi, int size, int antialias)
 	
 	return sf;
 }
-
diff --git a/src/cmd/fontsrv/x11.c b/src/cmd/fontsrv/x11.c
index 43b013e3..c7acaeb9 100644
--- a/src/cmd/fontsrv/x11.c
+++ b/src/cmd/fontsrv/x11.c
@@ -102,7 +102,7 @@ load(XFont *f)
 }
 
 Memsubfont*
-mksubfont(char *name, int lo, int hi, int size, int antialias)
+mksubfont(XFont *xf, char *name, int lo, int hi, int size, int antialias)
 {
 	XFont *xf, *xfp, *xfe;
 	FT_Face face;
@@ -115,17 +115,6 @@ mksubfont(char *name, int lo, int hi, int size, int antialias)
 	Memsubfont *sf;
 	//Point rect_points[4];
 
-	xf = nil;
-	for(xfp=xfont, xfe=xfont+nxfont; xfp != xfe; xfp++) {
-		if(strcmp(xfp->name, name) == 0) {
-			xf = xfp;
-			break;
-		}
-	}
-
-	if(!xf)
-		return nil;
-
 	e = FT_New_Face(lib, xf->fontfile, xf->index, &face);
 
 	if(e){