image/font: expose caret slope
Change-Id: I775224dd3fc7e5b6c2fc5c4a7d3db83bb36d047d
Reviewed-on: https://go-review.googlesource.com/136255
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Nigel Tao <nigeltao@golang.org>
diff --git a/font/basicfont/basicfont.go b/font/basicfont/basicfont.go
index acd1179..1550381 100644
--- a/font/basicfont/basicfont.go
+++ b/font/basicfont/basicfont.go
@@ -77,11 +77,12 @@
func (f *Face) Metrics() font.Metrics {
return font.Metrics{
- Height: fixed.I(f.Height),
- Ascent: fixed.I(f.Ascent),
- Descent: fixed.I(f.Descent),
- XHeight: fixed.I(f.Ascent),
- CapHeight: fixed.I(f.Ascent),
+ Height: fixed.I(f.Height),
+ Ascent: fixed.I(f.Ascent),
+ Descent: fixed.I(f.Descent),
+ XHeight: fixed.I(f.Ascent),
+ CapHeight: fixed.I(f.Ascent),
+ CaretSlope: image.Point{X: 0, Y: 1},
}
}
diff --git a/font/basicfont/basicfont_test.go b/font/basicfont/basicfont_test.go
index f3409d7..43cf635 100644
--- a/font/basicfont/basicfont_test.go
+++ b/font/basicfont/basicfont_test.go
@@ -5,13 +5,14 @@
package basicfont
import (
+ "image"
"testing"
"golang.org/x/image/font"
)
func TestMetrics(t *testing.T) {
- want := font.Metrics{Height: 832, Ascent: 704, Descent: 128, XHeight: 704, CapHeight: 704}
+ want := font.Metrics{Height: 832, Ascent: 704, Descent: 128, XHeight: 704, CapHeight: 704, CaretSlope: image.Point{X: 0, Y: 1}}
if got := Face7x13.Metrics(); got != want {
t.Errorf("Face7x13: Metrics: got %v want %v", got, want)
}
diff --git a/font/font.go b/font/font.go
index 56a3310..4d9d63c 100644
--- a/font/font.go
+++ b/font/font.go
@@ -94,6 +94,10 @@
// CapHeight is the distance from the top of uppercase letters to the
// baseline.
CapHeight fixed.Int26_6
+
+ // CaretSlope is the slope of a caret as a vector with the Y axis pointing up.
+ // The slope {0, 1} is the vertical caret.
+ CaretSlope image.Point
}
// Drawer draws text on a destination image.
diff --git a/font/opentype/face_test.go b/font/opentype/face_test.go
index 8389bd8..c8b7054 100644
--- a/font/opentype/face_test.go
+++ b/font/opentype/face_test.go
@@ -5,6 +5,7 @@
package opentype
import (
+ "image"
"testing"
"golang.org/x/image/font"
@@ -82,7 +83,8 @@
}
func TestFaceMetrics(t *testing.T) {
- want := font.Metrics{Height: 888, Ascent: 726, Descent: 162, XHeight: 407, CapHeight: 555}
+ want := font.Metrics{Height: 888, Ascent: 726, Descent: 162, XHeight: 407, CapHeight: 555,
+ CaretSlope: image.Point{X: 0, Y: 1}}
got := regular.Metrics()
if got != want {
t.Fatalf("metrics failed. got=%#v. want=%#v", got, want)
diff --git a/font/plan9font/plan9font.go b/font/plan9font/plan9font.go
index 82cd882..96d6944 100644
--- a/font/plan9font/plan9font.go
+++ b/font/plan9font/plan9font.go
@@ -67,11 +67,12 @@
// The same applies to CapHeight, using the uppercase 'H'.
hbounds, _, _ := f.GlyphBounds('H')
return font.Metrics{
- Height: fixed.I(f.height),
- Ascent: fixed.I(f.ascent),
- Descent: fixed.I(f.height - f.ascent),
- XHeight: -xbounds.Min.Y,
- CapHeight: -hbounds.Min.Y,
+ Height: fixed.I(f.height),
+ Ascent: fixed.I(f.ascent),
+ Descent: fixed.I(f.height - f.ascent),
+ XHeight: -xbounds.Min.Y,
+ CapHeight: -hbounds.Min.Y,
+ CaretSlope: image.Point{X: 0, Y: 1},
}
}
@@ -153,11 +154,12 @@
xbounds, _, _ := f.GlyphBounds('x')
hbounds, _, _ := f.GlyphBounds('H')
return font.Metrics{
- Height: fixed.I(f.height),
- Ascent: fixed.I(f.ascent),
- Descent: fixed.I(f.height - f.ascent),
- XHeight: -xbounds.Min.Y,
- CapHeight: -hbounds.Min.Y,
+ Height: fixed.I(f.height),
+ Ascent: fixed.I(f.ascent),
+ Descent: fixed.I(f.height - f.ascent),
+ XHeight: -xbounds.Min.Y,
+ CapHeight: -hbounds.Min.Y,
+ CaretSlope: image.Point{X: 0, Y: 1},
}
}
diff --git a/font/plan9font/plan9font_test.go b/font/plan9font/plan9font_test.go
index 04a701d..573f63b 100644
--- a/font/plan9font/plan9font_test.go
+++ b/font/plan9font/plan9font_test.go
@@ -5,6 +5,7 @@
package plan9font
import (
+ "image"
"io/ioutil"
"path"
"path/filepath"
@@ -25,7 +26,8 @@
if err != nil {
t.Fatal(err)
}
- want := font.Metrics{Height: 832, Ascent: 704, Descent: 128, XHeight: 704, CapHeight: 704}
+ want := font.Metrics{Height: 832, Ascent: 704, Descent: 128, XHeight: 704, CapHeight: 704,
+ CaretSlope: image.Point{X: 0, Y: 1}}
if got := face.Metrics(); got != want {
t.Errorf("unicode.7x13.font: Metrics: got %v, want %v", got, want)
}
diff --git a/font/sfnt/sfnt.go b/font/sfnt/sfnt.go
index 3f952e9..0b46d0a 100644
--- a/font/sfnt/sfnt.go
+++ b/font/sfnt/sfnt.go
@@ -21,6 +21,7 @@
import (
"errors"
+ "image"
"io"
"golang.org/x/image/font"
@@ -579,6 +580,7 @@
lineGap int32
numHMetrics int32
postTableVersion uint32
+ slope [2]int32
unitsPerEm Units
xHeight int32
}
@@ -627,7 +629,7 @@
if err != nil {
return err
}
- buf, ascent, descent, lineGap, numHMetrics, err := f.parseHhea(buf, numGlyphs)
+ buf, ascent, descent, lineGap, run, rise, numHMetrics, err := f.parseHhea(buf, numGlyphs)
if err != nil {
return err
}
@@ -658,6 +660,7 @@
f.cached.lineGap = lineGap
f.cached.numHMetrics = numHMetrics
f.cached.postTableVersion = postTableVersion
+ f.cached.slope = [2]int32{run, rise}
f.cached.unitsPerEm = unitsPerEm
f.cached.xHeight = xHeight
@@ -853,32 +856,40 @@
return buf, bounds, indexToLocFormat, unitsPerEm, nil
}
-func (f *Font) parseHhea(buf []byte, numGlyphs int32) (buf1 []byte, ascent, descent, lineGap, numHMetrics int32, err error) {
+func (f *Font) parseHhea(buf []byte, numGlyphs int32) (buf1 []byte, ascent, descent, lineGap, run, rise, numHMetrics int32, err error) {
// https://www.microsoft.com/typography/OTSPEC/hhea.htm
if f.hhea.length != 36 {
- return nil, 0, 0, 0, 0, errInvalidHheaTable
+ return nil, 0, 0, 0, 0, 0, 0, errInvalidHheaTable
}
u, err := f.src.u16(buf, f.hhea, 34)
if err != nil {
- return nil, 0, 0, 0, 0, err
+ return nil, 0, 0, 0, 0, 0, 0, err
}
if int32(u) > numGlyphs || u == 0 {
- return nil, 0, 0, 0, 0, errInvalidHheaTable
+ return nil, 0, 0, 0, 0, 0, 0, errInvalidHheaTable
}
a, err := f.src.u16(buf, f.hhea, 4)
if err != nil {
- return nil, 0, 0, 0, 0, err
+ return nil, 0, 0, 0, 0, 0, 0, err
}
d, err := f.src.u16(buf, f.hhea, 6)
if err != nil {
- return nil, 0, 0, 0, 0, err
+ return nil, 0, 0, 0, 0, 0, 0, err
}
l, err := f.src.u16(buf, f.hhea, 8)
if err != nil {
- return nil, 0, 0, 0, 0, err
+ return nil, 0, 0, 0, 0, 0, 0, err
}
- return buf, int32(int16(a)), int32(int16(d)), int32(int16(l)), int32(u), nil
+ ru, err := f.src.u16(buf, f.hhea, 20)
+ if err != nil {
+ return nil, 0, 0, 0, 0, 0, 0, err
+ }
+ ri, err := f.src.u16(buf, f.hhea, 18)
+ if err != nil {
+ return nil, 0, 0, 0, 0, 0, 0, err
+ }
+ return buf, int32(int16(a)), int32(int16(d)), int32(int16(l)), int32(int16(ru)), int32(int16(ri)), int32(u), nil
}
func (f *Font) parseHmtx(buf []byte, numGlyphs, numHMetrics int32) (buf1 []byte, err error) {
@@ -1384,11 +1395,12 @@
// Metrics returns the metrics of this font.
func (f *Font) Metrics(b *Buffer, ppem fixed.Int26_6, h font.Hinting) (font.Metrics, error) {
m := font.Metrics{
- Height: scale(fixed.Int26_6(f.cached.ascent-f.cached.descent+f.cached.lineGap)*ppem, f.cached.unitsPerEm),
- Ascent: +scale(fixed.Int26_6(f.cached.ascent)*ppem, f.cached.unitsPerEm),
- Descent: -scale(fixed.Int26_6(f.cached.descent)*ppem, f.cached.unitsPerEm),
- XHeight: scale(fixed.Int26_6(f.cached.xHeight)*ppem, f.cached.unitsPerEm),
- CapHeight: scale(fixed.Int26_6(f.cached.capHeight)*ppem, f.cached.unitsPerEm),
+ Height: scale(fixed.Int26_6(f.cached.ascent-f.cached.descent+f.cached.lineGap)*ppem, f.cached.unitsPerEm),
+ Ascent: +scale(fixed.Int26_6(f.cached.ascent)*ppem, f.cached.unitsPerEm),
+ Descent: -scale(fixed.Int26_6(f.cached.descent)*ppem, f.cached.unitsPerEm),
+ XHeight: scale(fixed.Int26_6(f.cached.xHeight)*ppem, f.cached.unitsPerEm),
+ CapHeight: scale(fixed.Int26_6(f.cached.capHeight)*ppem, f.cached.unitsPerEm),
+ CaretSlope: image.Point{X: int(f.cached.slope[0]), Y: int(f.cached.slope[1])},
}
if h == font.HintingFull {
// Quantize up to a whole pixel.
diff --git a/font/sfnt/sfnt_test.go b/font/sfnt/sfnt_test.go
index f5ddd2b..f91f3a1 100644
--- a/font/sfnt/sfnt_test.go
+++ b/font/sfnt/sfnt_test.go
@@ -7,6 +7,7 @@
import (
"bytes"
"fmt"
+ "image"
"io/ioutil"
"path/filepath"
"testing"
@@ -223,9 +224,11 @@
font []byte
want font.Metrics
}{
- "goregular": {goregular.TTF, font.Metrics{Height: 2367, Ascent: 1935, Descent: 432, XHeight: 1086, CapHeight: 1480}},
+ "goregular": {goregular.TTF, font.Metrics{Height: 2367, Ascent: 1935, Descent: 432, XHeight: 1086, CapHeight: 1480,
+ CaretSlope: image.Point{X: 0, Y: 1}}},
// cmapTest.ttf has a non-zero lineGap.
- "cmapTest": {cmapFont, font.Metrics{Height: 1549, Ascent: 1365, Descent: 0, XHeight: 800, CapHeight: 800}},
+ "cmapTest": {cmapFont, font.Metrics{Height: 1549, Ascent: 1365, Descent: 0, XHeight: 800, CapHeight: 800,
+ CaretSlope: image.Point{X: 20, Y: 100}}},
}
var b Buffer
for name, tc := range testCases {
