Use the common golang.org/x/exp/shiny/font.Hinting type.

example/freetype/main.go

@@ -23,6 +23,7 @@ import (
 	"os"
 
 	"github.com/golang/freetype"
+	"golang.org/x/exp/shiny/font"
 )
 
 var (
@@ -80,7 +81,7 @@ func main() {
 		log.Println(err)
 		return
 	}
-	font, err := freetype.ParseFont(fontBytes)
+	f, err := freetype.ParseFont(fontBytes)
 	if err != nil {
 		log.Println(err)
 		return
@@ -97,16 +98,16 @@ func main() {
 	draw.Draw(rgba, rgba.Bounds(), bg, image.ZP, draw.Src)
 	c := freetype.NewContext()
 	c.SetDPI(*dpi)
-	c.SetFont(font)
+	c.SetFont(f)
 	c.SetFontSize(*size)
 	c.SetClip(rgba.Bounds())
 	c.SetDst(rgba)
 	c.SetSrc(fg)
 	switch *hinting {
 	default:
-		c.SetHinting(freetype.NoHinting)
+		c.SetHinting(font.HintingNone)
 	case "full":
-		c.SetHinting(freetype.FullHinting)
+		c.SetHinting(font.HintingFull)
 	}
 
 	// Draw the guidelines.
@@ -127,13 +128,13 @@ func main() {
 	}
 
 	// Save that RGBA image to disk.
-	f, err := os.Create("out.png")
+	outFile, err := os.Create("out.png")
 	if err != nil {
 		log.Println(err)
 		os.Exit(1)
 	}
-	defer f.Close()
-	b := bufio.NewWriter(f)
+	defer outFile.Close()
+	b := bufio.NewWriter(outFile)
 	err = png.Encode(b, rgba)
 	if err != nil {
 		log.Println(err)

example/gamma/main.go

@@ -64,13 +64,13 @@ func main() {
 	}
 
 	// Save that RGBA image to disk.
-	f, err := os.Create("out.png")
+	outFile, err := os.Create("out.png")
 	if err != nil {
 		log.Println(err)
 		os.Exit(1)
 	}
-	defer f.Close()
-	b := bufio.NewWriter(f)
+	defer outFile.Close()
+	b := bufio.NewWriter(outFile)
 	err = png.Encode(b, rgba)
 	if err != nil {
 		log.Println(err)

example/raster/main.go

@@ -163,13 +163,13 @@ func main() {
 	showNodes(rgba, inside)
 
 	// Save that RGBA image to disk.
-	f, err := os.Create("out.png")
+	outFile, err := os.Create("out.png")
 	if err != nil {
 		log.Println(err)
 		os.Exit(1)
 	}
-	defer f.Close()
-	b := bufio.NewWriter(f)
+	defer outFile.Close()
+	b := bufio.NewWriter(outFile)
 	err = png.Encode(b, rgba)
 	if err != nil {
 		log.Println(err)

example/round/main.go

@@ -88,13 +88,13 @@ func main() {
 	}
 
 	// Save that RGBA image to disk.
-	f, err := os.Create("out.png")
+	outFile, err := os.Create("out.png")
 	if err != nil {
 		log.Println(err)
 		os.Exit(1)
 	}
-	defer f.Close()
-	b := bufio.NewWriter(f)
+	defer outFile.Close()
+	b := bufio.NewWriter(outFile)
 	err = png.Encode(b, m)
 	if err != nil {
 		log.Println(err)

example/truetype/main.go

@@ -17,6 +17,7 @@ import (
 	"log"
 
 	"github.com/golang/freetype/truetype"
+	"golang.org/x/exp/shiny/font"
 	"golang.org/x/image/math/fixed"
 )
 
@@ -52,21 +53,21 @@ func main() {
 		log.Println(err)
 		return
 	}
-	font, err := truetype.Parse(b)
+	f, err := truetype.Parse(b)
 	if err != nil {
 		log.Println(err)
 		return
 	}
-	fupe := fixed.Int26_6(font.FUnitsPerEm())
-	printBounds(font.Bounds(fupe))
+	fupe := fixed.Int26_6(f.FUnitsPerEm())
+	printBounds(f.Bounds(fupe))
 	fmt.Printf("FUnitsPerEm:%d\n\n", fupe)
 
 	c0, c1 := 'A', 'V'
 
-	i0 := font.Index(c0)
-	hm := font.HMetric(fupe, i0)
+	i0 := f.Index(c0)
+	hm := f.HMetric(fupe, i0)
 	g := truetype.NewGlyphBuf()
-	err = g.Load(font, fupe, i0, truetype.NoHinting)
+	err = g.Load(f, fupe, i0, font.HintingNone)
 	if err != nil {
 		log.Println(err)
 		return
@@ -74,6 +75,6 @@ func main() {
 	fmt.Printf("'%c' glyph\n", c0)
 	fmt.Printf("AdvanceWidth:%d LeftSideBearing:%d\n", hm.AdvanceWidth, hm.LeftSideBearing)
 	printGlyph(g)
-	i1 := font.Index(c1)
-	fmt.Printf("\n'%c', '%c' Kerning:%d\n", c0, c1, font.Kerning(fupe, i0, i1))
+	i1 := f.Index(c1)
+	fmt.Printf("\n'%c', '%c' Kerning:%d\n", c0, c1, f.Kerning(fupe, i0, i1))
 }

freetype.go

@@ -15,6 +15,7 @@ import (
 
 	"github.com/golang/freetype/raster"
 	"github.com/golang/freetype/truetype"
+	"golang.org/x/exp/shiny/font"
 	"golang.org/x/image/math/fixed"
 )
 
@@ -55,20 +56,10 @@ func Pt(x, y int) fixed.Point26_6 {
 	}
 }
 
-// Hinting is the policy for snapping a glyph's contours to pixel boundaries.
-type Hinting int32
-
-const (
-	// NoHinting means to not perform any hinting.
-	NoHinting = Hinting(truetype.NoHinting)
-	// FullHinting means to use the font's hinting instructions.
-	FullHinting = Hinting(truetype.FullHinting)
-)
-
 // A Context holds the state for drawing text in a given font and size.
 type Context struct {
 	r        *raster.Rasterizer
-	font     *truetype.Font
+	f        *truetype.Font
 	glyphBuf *truetype.GlyphBuf
 	// clip is the clip rectangle for drawing.
 	clip image.Rectangle
@@ -79,7 +70,7 @@ type Context struct {
 	// 26.6 fixed point units in 1 em. hinting is the hinting policy.
 	fontSize, dpi float64
 	scale         fixed.Int26_6
-	hinting       Hinting
+	hinting       font.Hinting
 	// cache is the glyph cache.
 	cache [nGlyphs * nXFractions * nYFractions]cacheEntry
 }
@@ -170,7 +161,7 @@ func (c *Context) drawContour(ps []truetype.Point, dx, dy fixed.Int26_6) {
 func (c *Context) rasterize(glyph truetype.Index, fx, fy fixed.Int26_6) (
 	fixed.Int26_6, *image.Alpha, image.Point, error) {
 
-	if err := c.glyphBuf.Load(c.font, c.scale, glyph, truetype.Hinting(c.hinting)); err != nil {
+	if err := c.glyphBuf.Load(c.f, c.scale, glyph, c.hinting); err != nil {
 		return 0, nil, image.Point{}, err
 	}
 	// Calculate the integer-pixel bounds for the glyph.
@@ -237,15 +228,15 @@ func (c *Context) glyph(glyph truetype.Index, p fixed.Point26_6) (
 //
 // p is a fixed.Point26_6 and can therefore represent sub-pixel positions.
 func (c *Context) DrawString(s string, p fixed.Point26_6) (fixed.Point26_6, error) {
-	if c.font == nil {
+	if c.f == nil {
 		return fixed.Point26_6{}, errors.New("freetype: DrawText called with a nil font")
 	}
 	prev, hasPrev := truetype.Index(0), false
 	for _, rune := range s {
-		index := c.font.Index(rune)
+		index := c.f.Index(rune)
 		if hasPrev {
-			kern := fixed.Int26_6(c.font.Kerning(c.scale, prev, index))
-			if c.hinting != NoHinting {
+			kern := fixed.Int26_6(c.f.Kerning(c.scale, prev, index))
+			if c.hinting != font.HintingNone {
 				kern = (kern + 32) &^ 63
 			}
 			p.X += kern
@@ -270,11 +261,11 @@ func (c *Context) DrawString(s string, p fixed.Point26_6) (fixed.Point26_6, erro
 // resolution and font metrics, and invalidates the glyph cache.
 func (c *Context) recalc() {
 	c.scale = fixed.Int26_6(c.fontSize * c.dpi * (64.0 / 72.0))
-	if c.font == nil {
+	if c.f == nil {
 		c.r.SetBounds(0, 0)
 	} else {
 		// Set the rasterizer's bounds to be big enough to handle the largest glyph.
-		b := c.font.Bounds(c.scale)
+		b := c.f.Bounds(c.scale)
 		xmin := +int(b.XMin) >> 6
 		ymin := -int(b.YMax) >> 6
 		xmax := +int(b.XMax+63) >> 6
@@ -296,11 +287,11 @@ func (c *Context) SetDPI(dpi float64) {
 }
 
 // SetFont sets the font used to draw text.
-func (c *Context) SetFont(font *truetype.Font) {
-	if c.font == font {
+func (c *Context) SetFont(f *truetype.Font) {
+	if c.f == f {
 		return
 	}
-	c.font = font
+	c.f = f
 	c.recalc()
 }
 
@@ -314,7 +305,7 @@ func (c *Context) SetFontSize(fontSize float64) {
 }
 
 // SetHinting sets the hinting policy.
-func (c *Context) SetHinting(hinting Hinting) {
+func (c *Context) SetHinting(hinting font.Hinting) {
 	c.hinting = hinting
 	for i := range c.cache {
 		c.cache[i] = cacheEntry{}

freetype_test.go

@@ -25,7 +25,7 @@ func BenchmarkDrawString(b *testing.B) {
 	if err != nil {
 		b.Fatal(err)
 	}
-	font, err := ParseFont(data)
+	f, err := ParseFont(data)
 	if err != nil {
 		b.Fatal(err)
 	}
@@ -37,7 +37,7 @@ func BenchmarkDrawString(b *testing.B) {
 	c.SetDst(dst)
 	c.SetClip(dst.Bounds())
 	c.SetSrc(image.Black)
-	c.SetFont(font)
+	c.SetFont(f)
 
 	var ms runtime.MemStats
 	runtime.ReadMemStats(&ms)

truetype/glyph.go

@@ -6,20 +6,11 @@
 package truetype
 
 import (
+	"golang.org/x/exp/shiny/font"
 	"golang.org/x/image/math/fixed"
 )
 
-// Hinting is the policy for snapping a glyph's contours to pixel boundaries.
-type Hinting uint32
-
-const (
-	// NoHinting means to not perform any hinting.
-	NoHinting Hinting = iota
-	// FullHinting means to use the font's hinting instructions.
-	FullHinting
-
-	// TODO: implement VerticalHinting.
-)
+// TODO: implement VerticalHinting.
 
 // A Point is a co-ordinate pair plus whether it is 'on' a contour or an 'off'
 // control point.
@@ -50,7 +41,7 @@ type GlyphBuf struct {
 
 	font    *Font
 	scale   fixed.Int26_6
-	hinting Hinting
+	hinting font.Hinting
 	hinter  hinter
 	// phantomPoints are the co-ordinates of the synthetic phantom points
 	// used for hinting and bounding box calculations.
@@ -91,7 +82,7 @@ const (
 // Load loads a glyph's contours from a Font, overwriting any previously loaded
 // contours for this GlyphBuf. scale is the number of 26.6 fixed point units in
 // 1 em, i is the glyph index, and h is the hinting policy.
-func (g *GlyphBuf) Load(f *Font, scale fixed.Int26_6, i Index, h Hinting) error {
+func (g *GlyphBuf) Load(f *Font, scale fixed.Int26_6, i Index, h font.Hinting) error {
 	g.Point = g.Point[:0]
 	g.Unhinted = g.Unhinted[:0]
 	g.InFontUnits = g.InFontUnits[:0]
@@ -103,7 +94,7 @@ func (g *GlyphBuf) Load(f *Font, scale fixed.Int26_6, i Index, h Hinting) error
 	g.phantomPoints = [4]Point{}
 	g.metricsSet = false
 
-	if h != NoHinting {
+	if h != font.HintingNone {
 		if err := g.hinter.init(f, scale); err != nil {
 			return err
 		}
@@ -115,7 +106,7 @@ func (g *GlyphBuf) Load(f *Font, scale fixed.Int26_6, i Index, h Hinting) error
 	// and should be cleaned up once we have all the testScaling tests passing,
 	// plus additional tests for Freetype-Go's bounding boxes matching C Freetype's.
 	pp1x := g.pp1x
-	if h != NoHinting {
+	if h != font.HintingNone {
 		pp1x = g.phantomPoints[0].X
 	}
 	if pp1x != 0 {
@@ -125,7 +116,7 @@ func (g *GlyphBuf) Load(f *Font, scale fixed.Int26_6, i Index, h Hinting) error
 	}
 
 	advanceWidth := g.phantomPoints[1].X - g.phantomPoints[0].X
-	if h != NoHinting {
+	if h != font.HintingNone {
 		if len(f.hdmx) >= 8 {
 			if n := u32(f.hdmx, 4); n > 3+uint32(i) {
 				for hdmx := f.hdmx[8:]; uint32(len(hdmx)) >= n; hdmx = hdmx[n:] {
@@ -167,7 +158,7 @@ func (g *GlyphBuf) Load(f *Font, scale fixed.Int26_6, i Index, h Hinting) error
 			}
 		}
 		// Snap the box to the grid, if hinting is on.
-		if h != NoHinting {
+		if h != font.HintingNone {
 			g.B.XMin &^= 63
 			g.B.YMin &^= 63
 			g.B.XMax += 63
@@ -237,7 +228,7 @@ func (g *GlyphBuf) load(recursion uint32, i Index, useMyMetrics bool) (err error
 		program := g.loadSimple(glyf, ne)
 		g.addPhantomsAndScale(np0, np0, true, true)
 		pp1x = g.Point[len(g.Point)-4].X
-		if g.hinting != NoHinting {
+		if g.hinting != font.HintingNone {
 			if len(program) != 0 {
 				err := g.hinter.run(
 					program,
@@ -443,7 +434,7 @@ func (g *GlyphBuf) loadCompound(recursion uint32, uhm HMetric, i Index,
 	}
 
 	instrLen := 0
-	if g.hinting != NoHinting && offset+2 <= len(glyf) {
+	if g.hinting != font.HintingNone && offset+2 <= len(glyf) {
 		instrLen = int(u16(glyf, offset))
 		offset += 2
 	}
@@ -491,7 +482,7 @@ func (g *GlyphBuf) addPhantomsAndScale(np0, np1 int, simple, adjust bool) {
 	// Add the four phantom points.
 	g.Point = append(g.Point, g.phantomPoints[:]...)
 	// Scale the points.
-	if simple && g.hinting != NoHinting {
+	if simple && g.hinting != font.HintingNone {
 		g.InFontUnits = append(g.InFontUnits, g.Point[np1:]...)
 	}
 	for i := np1; i < len(g.Point); i++ {
@@ -499,7 +490,7 @@ func (g *GlyphBuf) addPhantomsAndScale(np0, np1 int, simple, adjust bool) {
 		p.X = g.font.scale(g.scale * p.X)
 		p.Y = g.font.scale(g.scale * p.Y)
 	}
-	if g.hinting == NoHinting {
+	if g.hinting == font.HintingNone {
 		return
 	}
 	// Round the 1st phantom point to the grid, shifting all other points equally.

truetype/truetype_test.go

@@ -15,55 +15,56 @@ import (
 	"strings"
 	"testing"
 
+	"golang.org/x/exp/shiny/font"
 	"golang.org/x/image/math/fixed"
 )
 
-func parseTestdataFont(name string) (font *Font, testdataIsOptional bool, err error) {
+func parseTestdataFont(name string) (f *Font, testdataIsOptional bool, err error) {
 	b, err := ioutil.ReadFile(fmt.Sprintf("../testdata/%s.ttf", name))
 	if err != nil {
 		// The "x-foo" fonts are optional tests, as they are not checked
 		// in for copyright or file size reasons.
 		return nil, strings.HasPrefix(name, "x-"), fmt.Errorf("%s: ReadFile: %v", name, err)
 	}
-	font, err = Parse(b)
+	f, err = Parse(b)
 	if err != nil {
 		return nil, true, fmt.Errorf("%s: Parse: %v", name, err)
 	}
-	return font, false, nil
+	return f, false, nil
 }
 
 // TestParse tests that the luxisr.ttf metrics and glyphs are parsed correctly.
 // The numerical values can be manually verified by examining luxisr.ttx.
 func TestParse(t *testing.T) {
-	font, _, err := parseTestdataFont("luxisr")
+	f, _, err := parseTestdataFont("luxisr")
 	if err != nil {
 		t.Fatal(err)
 	}
-	if got, want := font.FUnitsPerEm(), int32(2048); got != want {
+	if got, want := f.FUnitsPerEm(), int32(2048); got != want {
 		t.Errorf("FUnitsPerEm: got %v, want %v", got, want)
 	}
-	fupe := fixed.Int26_6(font.FUnitsPerEm())
-	if got, want := font.Bounds(fupe), (Bounds{-441, -432, 2024, 2033}); got != want {
+	fupe := fixed.Int26_6(f.FUnitsPerEm())
+	if got, want := f.Bounds(fupe), (Bounds{-441, -432, 2024, 2033}); got != want {
 		t.Errorf("Bounds: got %v, want %v", got, want)
 	}
 
-	i0 := font.Index('A')
-	i1 := font.Index('V')
+	i0 := f.Index('A')
+	i1 := f.Index('V')
 	if i0 != 36 || i1 != 57 {
 		t.Fatalf("Index: i0, i1 = %d, %d, want 36, 57", i0, i1)
 	}
-	if got, want := font.HMetric(fupe, i0), (HMetric{1366, 19}); got != want {
+	if got, want := f.HMetric(fupe, i0), (HMetric{1366, 19}); got != want {
 		t.Errorf("HMetric: got %v, want %v", got, want)
 	}
-	if got, want := font.VMetric(fupe, i0), (VMetric{2465, 553}); got != want {
+	if got, want := f.VMetric(fupe, i0), (VMetric{2465, 553}); got != want {
 		t.Errorf("VMetric: got %v, want %v", got, want)
 	}
-	if got, want := font.Kerning(fupe, i0, i1), fixed.Int26_6(-144); got != want {
+	if got, want := f.Kerning(fupe, i0, i1), fixed.Int26_6(-144); got != want {
 		t.Errorf("Kerning: got %v, want %v", got, want)
 	}
 
 	g := NewGlyphBuf()
-	err = g.Load(font, fupe, i0, NoHinting)
+	err = g.Load(f, fupe, i0, font.HintingNone)
 	if err != nil {
 		t.Fatalf("Load: %v", err)
 	}
@@ -180,7 +181,7 @@ func TestIndex(t *testing.T) {
 		},
 	}
 	for name, wants := range testCases {
-		font, testdataIsOptional, err := parseTestdataFont(name)
+		f, testdataIsOptional, err := parseTestdataFont(name)
 		if err != nil {
 			if testdataIsOptional {
 				t.Log(err)
@@ -190,7 +191,7 @@ func TestIndex(t *testing.T) {
 			continue
 		}
 		for r, want := range wants {
-			if got := font.Index(r); got != want {
+			if got := f.Index(r); got != want {
 				t.Errorf("%s: Index of %q, aka %U: got %d, want %d", name, r, r, got, want)
 			}
 		}
@@ -268,9 +269,9 @@ var scalingTestCases = []struct {
 	{"x-times-new-roman", 13},
 }
 
-func testScaling(t *testing.T, h Hinting) {
+func testScaling(t *testing.T, h font.Hinting) {
 	for _, tc := range scalingTestCases {
-		font, testdataIsOptional, err := parseTestdataFont(tc.name)
+		f, testdataIsOptional, err := parseTestdataFont(tc.name)
 		if err != nil {
 			if testdataIsOptional {
 				t.Log(err)
@@ -280,19 +281,19 @@ func testScaling(t *testing.T, h Hinting) {
 			continue
 		}
 		hintingStr := "sans"
-		if h != NoHinting {
+		if h != font.HintingNone {
 			hintingStr = "with"
 		}
-		f, err := os.Open(fmt.Sprintf(
+		testFile, err := os.Open(fmt.Sprintf(
 			"../testdata/%s-%dpt-%s-hinting.txt", tc.name, tc.size, hintingStr))
 		if err != nil {
 			t.Errorf("%s: Open: %v", tc.name, err)
 			continue
 		}
-		defer f.Close()
+		defer testFile.Close()
 
 		wants := []scalingTestData{}
-		scanner := bufio.NewScanner(f)
+		scanner := bufio.NewScanner(testFile)
 		if scanner.Scan() {
 			major, minor, patch := 0, 0, 0
 			_, err := fmt.Sscanf(scanner.Text(), "freetype version %d.%d.%d", &major, &minor, &patch)
@@ -320,7 +321,7 @@ func testScaling(t *testing.T, h Hinting) {
 
 		glyphBuf := NewGlyphBuf()
 		for i, want := range wants {
-			if err = glyphBuf.Load(font, fixed.I(tc.size), Index(i), h); err != nil {
+			if err = glyphBuf.Load(f, fixed.I(tc.size), Index(i), h); err != nil {
 				t.Errorf("%s: glyph #%d: Load: %v", tc.name, i, err)
 				continue
 			}
@@ -359,10 +360,5 @@ func testScaling(t *testing.T, h Hinting) {
 	}
 }
 
-func TestScalingSansHinting(t *testing.T) {
-	testScaling(t, NoHinting)
-}
-
-func TestScalingWithHinting(t *testing.T) {
-	testScaling(t, FullHinting)
-}
+func TestScalingHintingNone(t *testing.T) { testScaling(t, font.HintingNone) }
+func TestScalingHintingFull(t *testing.T) { testScaling(t, font.HintingFull) }