aboutsummaryrefslogtreecommitdiff
path: root/vendor/golang.org/x/image/font/sfnt/sfnt_test.go
blob: 74de278dd844a61a268389ccfc91e35c464feb6f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package sfnt

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"path/filepath"
	"testing"

	"golang.org/x/image/font"
	"golang.org/x/image/font/gofont/gobold"
	"golang.org/x/image/font/gofont/gomono"
	"golang.org/x/image/font/gofont/goregular"
	"golang.org/x/image/math/fixed"
)

func pt(x, y fixed.Int26_6) fixed.Point26_6 {
	return fixed.Point26_6{X: x, Y: y}
}

func moveTo(xa, ya fixed.Int26_6) Segment {
	return Segment{
		Op:   SegmentOpMoveTo,
		Args: [3]fixed.Point26_6{pt(xa, ya)},
	}
}

func lineTo(xa, ya fixed.Int26_6) Segment {
	return Segment{
		Op:   SegmentOpLineTo,
		Args: [3]fixed.Point26_6{pt(xa, ya)},
	}
}

func quadTo(xa, ya, xb, yb fixed.Int26_6) Segment {
	return Segment{
		Op:   SegmentOpQuadTo,
		Args: [3]fixed.Point26_6{pt(xa, ya), pt(xb, yb)},
	}
}

func cubeTo(xa, ya, xb, yb, xc, yc fixed.Int26_6) Segment {
	return Segment{
		Op:   SegmentOpCubeTo,
		Args: [3]fixed.Point26_6{pt(xa, ya), pt(xb, yb), pt(xc, yc)},
	}
}

func translate(dx, dy fixed.Int26_6, s Segment) Segment {
	translateArgs(&s.Args, dx, dy)
	return s
}

func transform(txx, txy, tyx, tyy int16, dx, dy fixed.Int26_6, s Segment) Segment {
	transformArgs(&s.Args, txx, txy, tyx, tyy, dx, dy)
	return s
}

func checkSegmentsEqual(got, want []Segment) error {
	// Flip got's Y axis. The test cases' coordinates are given with the Y axis
	// increasing up, as that is what the ttx tool gives, and is the model for
	// the underlying font format. The Go API returns coordinates with the Y
	// axis increasing down, the same as the standard graphics libraries.
	for i := range got {
		for j := range got[i].Args {
			got[i].Args[j].Y *= -1
		}
	}

	if len(got) != len(want) {
		return fmt.Errorf("got %d elements, want %d\noverall:\ngot  %v\nwant %v",
			len(got), len(want), got, want)
	}
	for i, g := range got {
		if w := want[i]; g != w {
			return fmt.Errorf("element %d:\ngot  %v\nwant %v\noverall:\ngot  %v\nwant %v",
				i, g, w, got, want)
		}
	}

	// Check that every contour is closed.
	if len(got) == 0 {
		return nil
	}
	if got[0].Op != SegmentOpMoveTo {
		return fmt.Errorf("segments do not start with a moveTo")
	}
	var (
		first, last fixed.Point26_6
		firstI      int
	)
	checkClosed := func(lastI int) error {
		if first != last {
			return fmt.Errorf("segments[%d:%d] not closed:\nfirst %v\nlast  %v", firstI, lastI, first, last)
		}
		return nil
	}
	for i, g := range got {
		switch g.Op {
		case SegmentOpMoveTo:
			if i != 0 {
				if err := checkClosed(i); err != nil {
					return err
				}
			}
			firstI, first, last = i, g.Args[0], g.Args[0]
		case SegmentOpLineTo:
			last = g.Args[0]
		case SegmentOpQuadTo:
			last = g.Args[1]
		case SegmentOpCubeTo:
			last = g.Args[2]
		}
	}
	return checkClosed(len(got))
}

func TestTrueTypeParse(t *testing.T) {
	f, err := Parse(goregular.TTF)
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}
	testTrueType(t, f)
}

func TestTrueTypeParseReaderAt(t *testing.T) {
	f, err := ParseReaderAt(bytes.NewReader(goregular.TTF))
	if err != nil {
		t.Fatalf("ParseReaderAt: %v", err)
	}
	testTrueType(t, f)
}

func testTrueType(t *testing.T, f *Font) {
	if got, want := f.UnitsPerEm(), Units(2048); got != want {
		t.Errorf("UnitsPerEm: got %d, want %d", got, want)
	}
	// The exact number of glyphs in goregular.TTF can vary, and future
	// versions may add more glyphs, but https://blog.golang.org/go-fonts says
	// that "The WGL4 character set... [has] more than 650 characters in all.
	if got, want := f.NumGlyphs(), 650; got <= want {
		t.Errorf("NumGlyphs: got %d, want > %d", got, want)
	}
}

func fontData(name string) []byte {
	switch name {
	case "gobold":
		return gobold.TTF
	case "gomono":
		return gomono.TTF
	case "goregular":
		return goregular.TTF
	}
	panic("unreachable")
}

func TestBounds(t *testing.T) {
	testCases := map[string]fixed.Rectangle26_6{
		"gobold": {
			Min: fixed.Point26_6{
				X: -452,
				Y: -2193,
			},
			Max: fixed.Point26_6{
				X: 2190,
				Y: 432,
			},
		},
		"gomono": {
			Min: fixed.Point26_6{
				X: 0,
				Y: -2227,
			},
			Max: fixed.Point26_6{
				X: 1229,
				Y: 432,
			},
		},
		"goregular": {
			Min: fixed.Point26_6{
				X: -440,
				Y: -2118,
			},
			Max: fixed.Point26_6{
				X: 2160,
				Y: 543,
			},
		},
	}

	var b Buffer
	for name, want := range testCases {
		f, err := Parse(fontData(name))
		if err != nil {
			t.Errorf("Parse(%q): %v", name, err)
			continue
		}
		ppem := fixed.Int26_6(f.UnitsPerEm())

		got, err := f.Bounds(&b, ppem, font.HintingNone)
		if err != nil {
			t.Errorf("name=%q: Bounds: %v", name, err)
			continue
		}
		if got != want {
			t.Errorf("name=%q: Bounds: got %v, want %v", name, got, want)
			continue
		}
	}
}

func TestGlyphAdvance(t *testing.T) {
	testCases := map[string][]struct {
		r    rune
		want fixed.Int26_6
	}{
		"gobold": {
			{' ', 569},
			{'A', 1479},
			{'Á', 1479},
			{'Æ', 2048},
			{'i', 592},
			{'x', 1139},
		},
		"gomono": {
			{' ', 1229},
			{'A', 1229},
			{'Á', 1229},
			{'Æ', 1229},
			{'i', 1229},
			{'x', 1229},
		},
		"goregular": {
			{' ', 569},
			{'A', 1366},
			{'Á', 1366},
			{'Æ', 2048},
			{'i', 505},
			{'x', 1024},
		},
	}

	var b Buffer
	for name, testCases1 := range testCases {
		f, err := Parse(fontData(name))
		if err != nil {
			t.Errorf("Parse(%q): %v", name, err)
			continue
		}
		ppem := fixed.Int26_6(f.UnitsPerEm())

		for _, tc := range testCases1 {
			x, err := f.GlyphIndex(&b, tc.r)
			if err != nil {
				t.Errorf("name=%q, r=%q: GlyphIndex: %v", name, tc.r, err)
				continue
			}
			got, err := f.GlyphAdvance(&b, x, ppem, font.HintingNone)
			if err != nil {
				t.Errorf("name=%q, r=%q: GlyphAdvance: %v", name, tc.r, err)
				continue
			}
			if got != tc.want {
				t.Errorf("name=%q, r=%q: GlyphAdvance: got %d, want %d", name, tc.r, got, tc.want)
				continue
			}
		}
	}
}

func TestGoRegularGlyphIndex(t *testing.T) {
	f, err := Parse(goregular.TTF)
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}

	testCases := []struct {
		r    rune
		want GlyphIndex
	}{
		// Glyphs that aren't present in Go Regular.
		{'\u001f', 0}, // U+001F <control>
		{'\u0200', 0}, // U+0200 LATIN CAPITAL LETTER A WITH DOUBLE GRAVE
		{'\u2000', 0}, // U+2000 EN QUAD

		// The want values below can be verified by running the ttx tool on
		// Go-Regular.ttf.
		//
		// The actual values are ad hoc, and result from whatever tools the
		// Bigelow & Holmes type foundry used and the order in which they
		// crafted the glyphs. They may change over time as newer versions of
		// the font are released.

		{'\u0020', 3},  // U+0020 SPACE
		{'\u0021', 4},  // U+0021 EXCLAMATION MARK
		{'\u0022', 5},  // U+0022 QUOTATION MARK
		{'\u0023', 6},  // U+0023 NUMBER SIGN
		{'\u0024', 7},  // U+0024 DOLLAR SIGN
		{'\u0025', 8},  // U+0025 PERCENT SIGN
		{'\u0026', 9},  // U+0026 AMPERSAND
		{'\u0027', 10}, // U+0027 APOSTROPHE

		{'\u03bd', 396}, // U+03BD GREEK SMALL LETTER NU
		{'\u03be', 397}, // U+03BE GREEK SMALL LETTER XI
		{'\u03bf', 398}, // U+03BF GREEK SMALL LETTER OMICRON
		{'\u03c0', 399}, // U+03C0 GREEK SMALL LETTER PI
		{'\u03c1', 400}, // U+03C1 GREEK SMALL LETTER RHO
		{'\u03c2', 401}, // U+03C2 GREEK SMALL LETTER FINAL SIGMA
	}

	var b Buffer
	for _, tc := range testCases {
		got, err := f.GlyphIndex(&b, tc.r)
		if err != nil {
			t.Errorf("r=%q: %v", tc.r, err)
			continue
		}
		if got != tc.want {
			t.Errorf("r=%q: got %d, want %d", tc.r, got, tc.want)
			continue
		}
	}
}

func TestGlyphIndex(t *testing.T) {
	data, err := ioutil.ReadFile(filepath.FromSlash("../testdata/cmapTest.ttf"))
	if err != nil {
		t.Fatal(err)
	}

	for _, format := range []int{-1, 0, 4, 12} {
		testGlyphIndex(t, data, format)
	}
}

func testGlyphIndex(t *testing.T, data []byte, cmapFormat int) {
	if cmapFormat >= 0 {
		originalSupportedCmapFormat := supportedCmapFormat
		defer func() {
			supportedCmapFormat = originalSupportedCmapFormat
		}()
		supportedCmapFormat = func(format, pid, psid uint16) bool {
			return int(format) == cmapFormat && originalSupportedCmapFormat(format, pid, psid)
		}
	}

	f, err := Parse(data)
	if err != nil {
		t.Errorf("cmapFormat=%d: %v", cmapFormat, err)
		return
	}

	testCases := []struct {
		r    rune
		want GlyphIndex
	}{
		// Glyphs that aren't present in cmapTest.ttf.
		{'?', 0},
		{'\ufffd', 0},
		{'\U0001f4a9', 0},

		// For a .TTF file, FontForge maps:
		//	- ".notdef"          to glyph index 0.
		//	- ".null"            to glyph index 1.
		//	- "nonmarkingreturn" to glyph index 2.

		{'/', 0},
		{'0', 3},
		{'1', 4},
		{'2', 5},
		{'3', 0},

		{'@', 0},
		{'A', 6},
		{'B', 7},
		{'C', 0},

		{'`', 0},
		{'a', 8},
		{'b', 0},

		// Of the remaining runes, only U+00FF LATIN SMALL LETTER Y WITH
		// DIAERESIS is in both the Mac Roman encoding and the cmapTest.ttf
		// font file.
		{'\u00fe', 0},
		{'\u00ff', 9},
		{'\u0100', 10},
		{'\u0101', 11},
		{'\u0102', 0},

		{'\u4e2c', 0},
		{'\u4e2d', 12},
		{'\u4e2e', 0},

		{'\U0001f0a0', 0},
		{'\U0001f0a1', 13},
		{'\U0001f0a2', 0},

		{'\U0001f0b0', 0},
		{'\U0001f0b1', 14},
		{'\U0001f0b2', 15},
		{'\U0001f0b3', 0},
	}

	var b Buffer
	for _, tc := range testCases {
		want := tc.want
		switch {
		case cmapFormat == 0 && tc.r > '\u007f' && tc.r != '\u00ff':
			// cmap format 0, with the Macintosh Roman encoding, can only
			// represent a limited set of non-ASCII runes, e.g. U+00FF.
			want = 0
		case cmapFormat == 4 && tc.r > '\uffff':
			// cmap format 4 only supports the Basic Multilingual Plane (BMP).
			want = 0
		}

		got, err := f.GlyphIndex(&b, tc.r)
		if err != nil {
			t.Errorf("cmapFormat=%d, r=%q: %v", cmapFormat, tc.r, err)
			continue
		}
		if got != want {
			t.Errorf("cmapFormat=%d, r=%q: got %d, want %d", cmapFormat, tc.r, got, want)
			continue
		}
	}
}

func TestPostScriptSegments(t *testing.T) {
	// wants' vectors correspond 1-to-1 to what's in the CFFTest.sfd file,
	// although OpenType/CFF and FontForge's SFD have reversed orders.
	// https://fontforge.github.io/validation.html says that "All paths must be
	// drawn in a consistent direction. Clockwise for external paths,
	// anti-clockwise for internal paths. (Actually PostScript requires the
	// exact opposite, but FontForge reverses PostScript contours when it loads
	// them so that everything is consistant internally -- and reverses them
	// again when it saves them, of course)."
	//
	// The .notdef glyph isn't explicitly in the SFD file, but for some unknown
	// reason, FontForge generates it in the OpenType/CFF file.
	wants := [][]Segment{{
		// .notdef
		// - contour #0
		moveTo(50, 0),
		lineTo(450, 0),
		lineTo(450, 533),
		lineTo(50, 533),
		lineTo(50, 0),
		// - contour #1
		moveTo(100, 50),
		lineTo(100, 483),
		lineTo(400, 483),
		lineTo(400, 50),
		lineTo(100, 50),
	}, {
		// zero
		// - contour #0
		moveTo(300, 700),
		cubeTo(380, 700, 420, 580, 420, 500),
		cubeTo(420, 350, 390, 100, 300, 100),
		cubeTo(220, 100, 180, 220, 180, 300),
		cubeTo(180, 450, 210, 700, 300, 700),
		// - contour #1
		moveTo(300, 800),
		cubeTo(200, 800, 100, 580, 100, 400),
		cubeTo(100, 220, 200, 0, 300, 0),
		cubeTo(400, 0, 500, 220, 500, 400),
		cubeTo(500, 580, 400, 800, 300, 800),
	}, {
		// one
		// - contour #0
		moveTo(100, 0),
		lineTo(300, 0),
		lineTo(300, 800),
		lineTo(100, 800),
		lineTo(100, 0),
	}, {
		// Q
		// - contour #0
		moveTo(657, 237),
		lineTo(289, 387),
		lineTo(519, 615),
		lineTo(657, 237),
		// - contour #1
		moveTo(792, 169),
		cubeTo(867, 263, 926, 502, 791, 665),
		cubeTo(645, 840, 380, 831, 228, 673),
		cubeTo(71, 509, 110, 231, 242, 93),
		cubeTo(369, -39, 641, 18, 722, 93),
		lineTo(802, 3),
		lineTo(864, 83),
		lineTo(792, 169),
	}, {
		// uni4E2D
		// - contour #0
		moveTo(141, 520),
		lineTo(137, 356),
		lineTo(245, 400),
		lineTo(331, 26),
		lineTo(355, 414),
		lineTo(463, 434),
		lineTo(453, 620),
		lineTo(341, 592),
		lineTo(331, 758),
		lineTo(243, 752),
		lineTo(235, 562),
		lineTo(141, 520),
	}}

	testSegments(t, "CFFTest.otf", wants)
}

func TestTrueTypeSegments(t *testing.T) {
	// wants' vectors correspond 1-to-1 to what's in the glyfTest.sfd file,
	// although FontForge's SFD format stores quadratic Bézier curves as cubics
	// with duplicated off-curve points. quadTo(bx, by, cx, cy) is stored as
	// "bx by bx by cx cy".
	//
	// The .notdef, .null and nonmarkingreturn glyphs aren't explicitly in the
	// SFD file, but for some unknown reason, FontForge generates them in the
	// TrueType file.
	wants := [][]Segment{{
		// .notdef
		// - contour #0
		moveTo(68, 0),
		lineTo(68, 1365),
		lineTo(612, 1365),
		lineTo(612, 0),
		lineTo(68, 0),
		// - contour #1
		moveTo(136, 68),
		lineTo(544, 68),
		lineTo(544, 1297),
		lineTo(136, 1297),
		lineTo(136, 68),
	}, {
	// .null
	// Empty glyph.
	}, {
	// nonmarkingreturn
	// Empty glyph.
	}, {
		// zero
		// - contour #0
		moveTo(614, 1434),
		quadTo(369, 1434, 369, 614),
		quadTo(369, 471, 435, 338),
		quadTo(502, 205, 614, 205),
		quadTo(860, 205, 860, 1024),
		quadTo(860, 1167, 793, 1300),
		quadTo(727, 1434, 614, 1434),
		// - contour #1
		moveTo(614, 1638),
		quadTo(1024, 1638, 1024, 819),
		quadTo(1024, 0, 614, 0),
		quadTo(205, 0, 205, 819),
		quadTo(205, 1638, 614, 1638),
	}, {
		// one
		// - contour #0
		moveTo(205, 0),
		lineTo(205, 1638),
		lineTo(614, 1638),
		lineTo(614, 0),
		lineTo(205, 0),
	}, {
		// five
		// - contour #0
		moveTo(0, 0),
		lineTo(0, 100),
		lineTo(400, 100),
		lineTo(400, 0),
		lineTo(0, 0),
	}, {
		// six
		// - contour #0
		moveTo(0, 0),
		lineTo(0, 100),
		lineTo(400, 100),
		lineTo(400, 0),
		lineTo(0, 0),
		// - contour #1
		translate(111, 234, moveTo(205, 0)),
		translate(111, 234, lineTo(205, 1638)),
		translate(111, 234, lineTo(614, 1638)),
		translate(111, 234, lineTo(614, 0)),
		translate(111, 234, lineTo(205, 0)),
	}, {
		// seven
		// - contour #0
		moveTo(0, 0),
		lineTo(0, 100),
		lineTo(400, 100),
		lineTo(400, 0),
		lineTo(0, 0),
		// - contour #1
		transform(1<<13, 0, 0, 1<<13, 56, 117, moveTo(205, 0)),
		transform(1<<13, 0, 0, 1<<13, 56, 117, lineTo(205, 1638)),
		transform(1<<13, 0, 0, 1<<13, 56, 117, lineTo(614, 1638)),
		transform(1<<13, 0, 0, 1<<13, 56, 117, lineTo(614, 0)),
		transform(1<<13, 0, 0, 1<<13, 56, 117, lineTo(205, 0)),
	}, {
		// eight
		// - contour #0
		moveTo(0, 0),
		lineTo(0, 100),
		lineTo(400, 100),
		lineTo(400, 0),
		lineTo(0, 0),
		// - contour #1
		transform(3<<13, 0, 0, 1<<13, 56, 117, moveTo(205, 0)),
		transform(3<<13, 0, 0, 1<<13, 56, 117, lineTo(205, 1638)),
		transform(3<<13, 0, 0, 1<<13, 56, 117, lineTo(614, 1638)),
		transform(3<<13, 0, 0, 1<<13, 56, 117, lineTo(614, 0)),
		transform(3<<13, 0, 0, 1<<13, 56, 117, lineTo(205, 0)),
	}, {
		// nine
		// - contour #0
		moveTo(0, 0),
		lineTo(0, 100),
		lineTo(400, 100),
		lineTo(400, 0),
		lineTo(0, 0),
		// - contour #1
		transform(22381, 8192, 5996, 14188, 237, 258, moveTo(205, 0)),
		transform(22381, 8192, 5996, 14188, 237, 258, lineTo(205, 1638)),
		transform(22381, 8192, 5996, 14188, 237, 258, lineTo(614, 1638)),
		transform(22381, 8192, 5996, 14188, 237, 258, lineTo(614, 0)),
		transform(22381, 8192, 5996, 14188, 237, 258, lineTo(205, 0)),
	}}

	testSegments(t, "glyfTest.ttf", wants)
}

func testSegments(t *testing.T, filename string, wants [][]Segment) {
	data, err := ioutil.ReadFile(filepath.FromSlash("../testdata/" + filename))
	if err != nil {
		t.Fatalf("ReadFile: %v", err)
	}
	f, err := Parse(data)
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}
	ppem := fixed.Int26_6(f.UnitsPerEm())

	if ng := f.NumGlyphs(); ng != len(wants) {
		t.Fatalf("NumGlyphs: got %d, want %d", ng, len(wants))
	}
	var b Buffer
	for i, want := range wants {
		got, err := f.LoadGlyph(&b, GlyphIndex(i), ppem, nil)
		if err != nil {
			t.Errorf("i=%d: LoadGlyph: %v", i, err)
			continue
		}
		if err := checkSegmentsEqual(got, want); err != nil {
			t.Errorf("i=%d: %v", i, err)
			continue
		}
	}
	if _, err := f.LoadGlyph(nil, 0xffff, ppem, nil); err != ErrNotFound {
		t.Errorf("LoadGlyph(..., 0xffff, ...):\ngot  %v\nwant %v", err, ErrNotFound)
	}

	name, err := f.Name(nil, NameIDFamily)
	if err != nil {
		t.Errorf("Name: %v", err)
	} else if want := filename[:len(filename)-len(".ttf")]; name != want {
		t.Errorf("Name:\ngot  %q\nwant %q", name, want)
	}
}

func TestPPEM(t *testing.T) {
	data, err := ioutil.ReadFile(filepath.FromSlash("../testdata/glyfTest.ttf"))
	if err != nil {
		t.Fatalf("ReadFile: %v", err)
	}
	f, err := Parse(data)
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}
	var b Buffer
	x, err := f.GlyphIndex(&b, '1')
	if err != nil {
		t.Fatalf("GlyphIndex: %v", err)
	}
	if x == 0 {
		t.Fatalf("GlyphIndex: no glyph index found for the rune '1'")
	}

	testCases := []struct {
		ppem fixed.Int26_6
		want []Segment
	}{{
		ppem: fixed.Int26_6(12 << 6),
		want: []Segment{
			moveTo(77, 0),
			lineTo(77, 614),
			lineTo(230, 614),
			lineTo(230, 0),
			lineTo(77, 0),
		},
	}, {
		ppem: fixed.Int26_6(2048),
		want: []Segment{
			moveTo(205, 0),
			lineTo(205, 1638),
			lineTo(614, 1638),
			lineTo(614, 0),
			lineTo(205, 0),
		},
	}}

	for i, tc := range testCases {
		got, err := f.LoadGlyph(&b, x, tc.ppem, nil)
		if err != nil {
			t.Errorf("i=%d: LoadGlyph: %v", i, err)
			continue
		}
		if err := checkSegmentsEqual(got, tc.want); err != nil {
			t.Errorf("i=%d: %v", i, err)
			continue
		}
	}
}

func TestGlyphName(t *testing.T) {
	f, err := Parse(goregular.TTF)
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}

	testCases := []struct {
		r    rune
		want string
	}{
		{'\x00', "uni0000"},
		{'!', "exclam"},
		{'A', "A"},
		{'{', "braceleft"},
		{'\u00c4', "Adieresis"}, // U+00C4 LATIN CAPITAL LETTER A WITH DIAERESIS
		{'\u2020', "dagger"},    // U+2020 DAGGER
		{'\u2660', "spade"},     // U+2660 BLACK SPADE SUIT
		{'\uf800', "gopher"},    // U+F800 <Private Use>
		{'\ufffe', ".notdef"},   // Not in the Go Regular font, so GlyphIndex returns (0, nil).
	}

	var b Buffer
	for _, tc := range testCases {
		x, err := f.GlyphIndex(&b, tc.r)
		if err != nil {
			t.Errorf("r=%q: GlyphIndex: %v", tc.r, err)
			continue
		}
		got, err := f.GlyphName(&b, x)
		if err != nil {
			t.Errorf("r=%q: GlyphName: %v", tc.r, err)
			continue
		}
		if got != tc.want {
			t.Errorf("r=%q: got %q, want %q", tc.r, got, tc.want)
			continue
		}
	}
}

func TestBuiltInPostNames(t *testing.T) {
	testCases := []struct {
		x    GlyphIndex
		want string
	}{
		{0, ".notdef"},
		{1, ".null"},
		{2, "nonmarkingreturn"},
		{13, "asterisk"},
		{36, "A"},
		{93, "z"},
		{123, "ocircumflex"},
		{202, "Edieresis"},
		{255, "Ccaron"},
		{256, "ccaron"},
		{257, "dcroat"},
		{258, ""},
		{999, ""},
		{0xffff, ""},
	}

	for _, tc := range testCases {
		if tc.x >= numBuiltInPostNames {
			continue
		}
		i := builtInPostNamesOffsets[tc.x+0]
		j := builtInPostNamesOffsets[tc.x+1]
		got := builtInPostNamesData[i:j]
		if got != tc.want {
			t.Errorf("x=%d: got %q, want %q", tc.x, got, tc.want)
		}
	}
}