examples/2048: use text/v2

Also, this changes fixes a bug in (*text/v2.GoTextFace).Metrics.

Updates #2454

examples/2048/2048/tile.go

@@ -15,6 +15,7 @@
 package twenty48
 
 import (
+	"bytes"
 	"errors"
 	"image/color"
 	"log"
@@ -22,51 +23,21 @@ import (
 	"sort"
 	"strconv"
 
-	"golang.org/x/image/font"
-	"golang.org/x/image/font/opentype"
-
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/examples/resources/fonts"
-	"github.com/hajimehoshi/ebiten/v2/text"
+	"github.com/hajimehoshi/ebiten/v2/text/v2"
 )
 
 var (
-	mplusSmallFont  font.Face
-	mplusNormalFont font.Face
-	mplusBigFont    font.Face
+	mplusFaceSource *text.GoTextFaceSource
 )
 
 func init() {
-	tt, err := opentype.Parse(fonts.MPlus1pRegular_ttf)
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	const dpi = 72
-	mplusSmallFont, err = opentype.NewFace(tt, &opentype.FaceOptions{
-		Size:    24,
-		DPI:     dpi,
-		Hinting: font.HintingVertical,
-	})
-	if err != nil {
-		log.Fatal(err)
-	}
-	mplusNormalFont, err = opentype.NewFace(tt, &opentype.FaceOptions{
-		Size:    32,
-		DPI:     dpi,
-		Hinting: font.HintingVertical,
-	})
-	if err != nil {
-		log.Fatal(err)
-	}
-	mplusBigFont, err = opentype.NewFace(tt, &opentype.FaceOptions{
-		Size:    48,
-		DPI:     dpi,
-		Hinting: font.HintingVertical,
-	})
+	s, err := text.NewGoTextFaceSource(bytes.NewReader(fonts.MPlus1pRegular_ttf))
 	if err != nil {
 		log.Fatal(err)
 	}
+	mplusFaceSource = s
 }
 
 // TileData represents a tile information like a value and a position.
@@ -387,17 +358,21 @@ func (t *Tile) Draw(boardImage *ebiten.Image) {
 	boardImage.DrawImage(tileImage, op)
 	str := strconv.Itoa(v)
 
-	f := mplusBigFont
+	sizeInPoints := 48.0
 	switch {
 	case 3 < len(str):
-		f = mplusSmallFont
+		sizeInPoints = 24
 	case 2 < len(str):
-		f = mplusNormalFont
+		sizeInPoints = 32
 	}
 
-	w := font.MeasureString(f, str).Floor()
-	h := (f.Metrics().Ascent + f.Metrics().Descent).Floor()
-	x += (tileSize - w) / 2
-	y += (tileSize-h)/2 + f.Metrics().Ascent.Floor()
-	text.Draw(boardImage, str, f, x, y, tileColor(v))
+	textOp := &text.DrawOptions{}
+	textOp.GeoM.Translate(float64(x)+float64(tileSize)/2, float64(y)+float64(tileSize)/2)
+	textOp.ColorScale.ScaleWithColor(tileColor(v))
+	textOp.PrimaryAlign = text.AlignCenter
+	textOp.SecondaryAlign = text.AlignCenter
+	text.Draw(boardImage, str, &text.GoTextFace{
+		Source:       mplusFaceSource,
+		SizeInPoints: sizeInPoints,
+	}, textOp)
 }

text/v2/gotext.go

@@ -179,7 +179,21 @@ func MustParseTag(str string) Tag {
 
 // Metrics implements Face.
 func (g *GoTextFace) Metrics() Metrics {
-	return g.Source.Metrics()
+	scale := float64(g.SizeInPoints) / float64(g.Source.f.Font.Upem())
+
+	var m Metrics
+	if h, ok := g.Source.f.FontHExtents(); ok {
+		m.Height = float64(h.Ascender-h.Descender+h.LineGap) * scale
+		m.HAscent = float64(h.Ascender) * scale
+		m.HDescent = float64(-h.Descender) * scale
+	}
+	if v, ok := g.Source.f.FontVExtents(); ok {
+		m.Width = float64(v.Ascender-v.Descender+v.LineGap) * scale
+		m.VAscent = float64(v.Ascender) * scale
+		m.VDescent = float64(-v.Descender) * scale
+	}
+
+	return m
 }
 
 // UnsafeInternal implements Face.

text/v2/gotextfacesource.go

@@ -128,25 +128,6 @@ func finalizeGoTextFaceSource(source *GoTextFaceSource) {
 	})
 }
 
-// Metrics returns the font's metrics.
-func (g *GoTextFaceSource) Metrics() Metrics {
-	upem := float64(g.f.Font.Upem())
-
-	var m Metrics
-	if h, ok := g.f.FontHExtents(); ok {
-		m.Height = float64(h.Ascender-h.Descender+h.LineGap) / upem
-		m.HAscent = float64(h.Ascender) / upem
-		m.HDescent = float64(-h.Descender) / upem
-	}
-	if v, ok := g.f.FontVExtents(); ok {
-		m.Width = float64(v.Ascender-v.Descender+v.LineGap) / upem
-		m.VAscent = float64(v.Ascender) / upem
-		m.VDescent = float64(-v.Descender) / upem
-	}
-
-	return m
-}
-
 func (g *GoTextFaceSource) shape(text string, face *GoTextFace) (shaping.Output, []glyph) {
 	g.m.Lock()
 	defer g.m.Unlock()