text/v2: let StdFace and GoTextFaceSource have their own glyph caches

text/v2/glyph.go

@@ -39,11 +39,6 @@ func init() {
 	})
 }
 
-type faceCacheKey struct {
-	id             uint64
-	goTextFaceSize float64
-}
-
 type glyphImageCacheKey struct {
 	// id is rune for StdFace, and GID for GoTextFace.
 	id uint32
@@ -60,28 +55,22 @@ type glyphImageCacheEntry struct {
 }
 
 type glyphImageCache struct {
-	cache map[faceCacheKey]map[glyphImageCacheKey]*glyphImageCacheEntry
+	cache map[glyphImageCacheKey]*glyphImageCacheEntry
 	m     sync.Mutex
 }
 
-var theGlyphImageCache glyphImageCache
-
 func (g *glyphImageCache) getOrCreate(face Face, key glyphImageCacheKey, create func() *ebiten.Image) *ebiten.Image {
 	g.m.Lock()
 	defer g.m.Unlock()
 
-	e, ok := g.cache[face.faceCacheKey()][key]
+	e, ok := g.cache[key]
 	if ok {
 		e.atime = now()
 		return e.image
 	}
 
 	if g.cache == nil {
-		g.cache = map[faceCacheKey]map[glyphImageCacheKey]*glyphImageCacheEntry{}
+		g.cache = map[glyphImageCacheKey]*glyphImageCacheEntry{}
-	}
-	faceCacheKey := face.faceCacheKey()
-	if g.cache[faceCacheKey] == nil {
-		g.cache[faceCacheKey] = map[glyphImageCacheKey]*glyphImageCacheEntry{}
 	}
 
 	img := create()
@@ -95,7 +84,7 @@ func (g *glyphImageCache) getOrCreate(face Face, key glyphImageCacheKey, create
 		// Keep this until the face is GCed.
 		e.atime = infTime
 	}
-	g.cache[faceCacheKey][key] = e
+	g.cache[key] = e
 
 	// Clean up old entries.
 
@@ -104,26 +93,15 @@ func (g *glyphImageCache) getOrCreate(face Face, key glyphImageCacheKey, create
 	// Even after cleaning up the cache, the number of glyphs might still exceed the soft limit, but
 	// this is fine.
 	cacheSoftLimit := 128 * glyphVariationCount(face)
-	if len(g.cache[faceCacheKey]) > cacheSoftLimit {
+	if len(g.cache) > cacheSoftLimit {
-		for key, e := range g.cache[faceCacheKey] {
+		for key, e := range g.cache {
 			// 60 is an arbitrary number.
 			if e.atime >= now()-60 {
 				continue
 			}
-			delete(g.cache[faceCacheKey], key)
+			delete(g.cache, key)
 		}
 	}
 
 	return img
 }
-
-func (g *glyphImageCache) clear(comp func(key faceCacheKey) bool) {
-	g.m.Lock()
-	defer g.m.Unlock()
-
-	for key := range g.cache {
-		if comp(key) {
-			delete(g.cache, key)
-		}
-	}
-}

text/v2/gotext.go

@@ -238,14 +238,6 @@ func (g *GoTextFace) ensureFeaturesString() string {
 	return g.featuresString
 }
 
-// faceCacheKey implements Face.
-func (g *GoTextFace) faceCacheKey() faceCacheKey {
-	return faceCacheKey{
-		id:             g.Source.id,
-		goTextFaceSize: g.Size,
-	}
-}
-
 func (g *GoTextFace) outputCacheKey(text string) goTextOutputCacheKey {
 	return goTextOutputCacheKey{
 		text:       text,
@@ -343,7 +335,7 @@ func (g *GoTextFace) glyphImage(glyph glyph, origin fixed.Point26_6) (*ebiten.Im
 		yoffset:    subpixelOffset.Y,
 		variations: g.ensureVariationsString(),
 	}
-	img := theGlyphImageCache.getOrCreate(g, key, func() *ebiten.Image {
+	img := g.Source.getOrCreateGlyphImage(g, key, func() *ebiten.Image {
 		return segmentsToImage(glyph.scaledSegments, subpixelOffset, b)
 	})
 

text/v2/gotextfacesource.go

@@ -17,7 +17,6 @@ package text
 import (
 	"bytes"
 	"io"
-	"runtime"
 	"sync"
 
 	"github.com/go-text/typesetting/font"
@@ -25,6 +24,8 @@ import (
 	"github.com/go-text/typesetting/opentype/api"
 	"github.com/go-text/typesetting/shaping"
 	"golang.org/x/image/math/fixed"
+
+	"github.com/hajimehoshi/ebiten/v2"
 )
 
 type goTextOutputCacheKey struct {
@@ -54,9 +55,9 @@ type goTextOutputCacheValue struct {
 // GoTextFaceSource is a source of a GoTextFace. This can be shared by multiple GoTextFace objects.
 type GoTextFaceSource struct {
 	f font.Face
-	id uint64
 
 	outputCache     map[goTextOutputCacheKey]*goTextOutputCacheValue
+	glyphImageCache map[float64]*glyphImageCache
 
 	addr *GoTextFaceSource
 
@@ -95,10 +96,8 @@ func NewGoTextFaceSource(source io.ReadSeeker) (*GoTextFaceSource, error) {
 
 	s := &GoTextFaceSource{
 		f: f,
-		id: nextUniqueID(),
 	}
 	s.addr = s
-	runtime.SetFinalizer(s, finalizeGoTextFaceSource)
 	return s, nil
 }
 
@@ -118,22 +117,13 @@ func NewGoTextFaceSourcesFromCollection(source io.ReadSeeker) ([]*GoTextFaceSour
 	for i, f := range fs {
 		s := &GoTextFaceSource{
 			f: f,
-			id: nextUniqueID(),
 		}
 		s.addr = s
-		runtime.SetFinalizer(s, finalizeGoTextFaceSource)
 		sources[i] = s
 	}
 	return sources, nil
 }
 
-func finalizeGoTextFaceSource(source *GoTextFaceSource) {
-	runtime.SetFinalizer(source, nil)
-	theGlyphImageCache.clear(func(key faceCacheKey) bool {
-		return key.id == source.id
-	})
-}
-
 func (g *GoTextFaceSource) copyCheck() {
 	if g.addr != g {
 		panic("text: illegal use of non-zero GoTextFaceSource copied by value")
@@ -233,3 +223,13 @@ func (g *GoTextFaceSource) shape(text string, face *GoTextFace) (shaping.Output,
 func (g *GoTextFaceSource) scale(size float64) float64 {
 	return size / float64(g.f.Upem())
 }
+
+func (g *GoTextFaceSource) getOrCreateGlyphImage(goTextFace *GoTextFace, key glyphImageCacheKey, create func() *ebiten.Image) *ebiten.Image {
+	if g.glyphImageCache == nil {
+		g.glyphImageCache = map[float64]*glyphImageCache{}
+	}
+	if _, ok := g.glyphImageCache[goTextFace.Size]; !ok {
+		g.glyphImageCache[goTextFace.Size] = &glyphImageCache{}
+	}
+	return g.glyphImageCache[goTextFace.Size].getOrCreate(goTextFace, key, create)
+}

text/v2/std.go

@@ -16,7 +16,6 @@ package text
 
 import (
 	"image"
-	"runtime"
 	"unicode/utf8"
 
 	"golang.org/x/image/font"
@@ -33,7 +32,7 @@ var _ Face = (*StdFace)(nil)
 type StdFace struct {
 	f *faceWithCache
 
-	id uint64
+	glyphImageCache glyphImageCache
 
 	addr *StdFace
 }
@@ -44,20 +43,11 @@ func NewStdFace(face font.Face) *StdFace {
 		f: &faceWithCache{
 			f: face,
 		},
-		id: nextUniqueID(),
 	}
 	s.addr = s
-	runtime.SetFinalizer(s, finalizeStdFace)
 	return s
 }
 
-func finalizeStdFace(face *StdFace) {
-	runtime.SetFinalizer(face, nil)
-	theGlyphImageCache.clear(func(key faceCacheKey) bool {
-		return key.id == face.id
-	})
-}
-
 func (s *StdFace) copyCheck() {
 	if s.addr != s {
 		panic("text: illegal use of non-zero StdFace copied by value")
@@ -82,13 +72,6 @@ func (s *StdFace) UnsafeInternal() any {
 	return s.f.f
 }
 
-// faceCacheKey implements Face.
-func (s *StdFace) faceCacheKey() faceCacheKey {
-	return faceCacheKey{
-		id: s.id,
-	}
-}
-
 // advance implements Face.
 func (s *StdFace) advance(text string) float64 {
 	return fixed26_6ToFloat64(font.MeasureString(s.f, text))
@@ -143,7 +126,7 @@ func (s *StdFace) glyphImage(r rune, origin fixed.Point26_6) (*ebiten.Image, int
 		xoffset: subpixelOffset.X,
 		// yoffset is always the same if the rune is the same, so this doesn't have to be a key.
 	}
-	img := theGlyphImageCache.getOrCreate(s, key, func() *ebiten.Image {
+	img := s.glyphImageCache.getOrCreate(s, key, func() *ebiten.Image {
 		return s.glyphImageImpl(r, subpixelOffset, b)
 	})
 	imgX := (origin.X + b.Min.X).Floor()

text/v2/text.go

@@ -20,7 +20,6 @@ package text
 import (
 	"math"
 	"strings"
-	"sync/atomic"
 
 	"golang.org/x/image/math/fixed"
 
@@ -37,8 +36,6 @@ type Face interface {
 	// This is unsafe since this might make internal cache states out of sync.
 	UnsafeInternal() any
 
-	faceCacheKey() faceCacheKey
-
 	advance(text string) float64
 
 	appendGlyphs(glyphs []Glyph, text string, indexOffset int, originX, originY float64) []Glyph
@@ -262,9 +259,3 @@ func CacheGlyphs(text string, face Face) {
 		}
 	}
 }
-
-var currentUniqueID uint64
-
-func nextUniqueID() uint64 {
-	return atomic.AddUint64(&currentUniqueID, 1)
-}