text/v2: define different key types for StdFace and GoTextFaceSource

text/v2/glyph.go

@@ -18,8 +18,6 @@ import (
 	"math"
 	"sync"
 
-	"golang.org/x/image/math/fixed"
-
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/internal/hook"
 )
@@ -39,27 +37,17 @@ func init() {
 	})
 }
 
-type glyphImageCacheKey struct {
-	// id is rune for StdFace, and GID for GoTextFace.
-	id uint32
-
-	xoffset fixed.Int26_6
-	yoffset fixed.Int26_6
-
-	variations string
-}
-
 type glyphImageCacheEntry struct {
 	image *ebiten.Image
 	atime int64
 }
 
-type glyphImageCache struct {
-	cache map[glyphImageCacheKey]*glyphImageCacheEntry
+type glyphImageCache[Key comparable] struct {
+	cache map[Key]*glyphImageCacheEntry
 	m     sync.Mutex
 }
 
-func (g *glyphImageCache) getOrCreate(face Face, key glyphImageCacheKey, create func() *ebiten.Image) *ebiten.Image {
+func (g *glyphImageCache[Key]) getOrCreate(face Face, key Key, create func() *ebiten.Image) *ebiten.Image {
 	g.m.Lock()
 	defer g.m.Unlock()
 
@@ -70,7 +58,7 @@ func (g *glyphImageCache) getOrCreate(face Face, key glyphImageCacheKey, create
 	}
 
 	if g.cache == nil {
-		g.cache = map[glyphImageCacheKey]*glyphImageCacheEntry{}
+		g.cache = map[Key]*glyphImageCacheEntry{}
 	}
 
 	img := create()

text/v2/gotext.go

@@ -329,8 +329,8 @@ func (g *GoTextFace) glyphImage(glyph glyph, origin fixed.Point26_6) (*ebiten.Im
 		X: (origin.X + b.Min.X) & ((1 << 6) - 1),
 		Y: (origin.Y + b.Min.Y) & ((1 << 6) - 1),
 	}
-	key := glyphImageCacheKey{
-		id:         uint32(glyph.shapingGlyph.GlyphID),
+	key := goTextGlyphImageCacheKey{
+		gid:        glyph.shapingGlyph.GlyphID,
 		xoffset:    subpixelOffset.X,
 		yoffset:    subpixelOffset.Y,
 		variations: g.ensureVariationsString(),

text/v2/gotextfacesource.go

@@ -52,12 +52,19 @@ type goTextOutputCacheValue struct {
 	atime  int64
 }
 
+type goTextGlyphImageCacheKey struct {
+	gid        api.GID
+	xoffset    fixed.Int26_6
+	yoffset    fixed.Int26_6
+	variations string
+}
+
 // GoTextFaceSource is a source of a GoTextFace. This can be shared by multiple GoTextFace objects.
 type GoTextFaceSource struct {
 	f font.Face
 
 	outputCache     map[goTextOutputCacheKey]*goTextOutputCacheValue
-	glyphImageCache map[float64]*glyphImageCache
+	glyphImageCache map[float64]*glyphImageCache[goTextGlyphImageCacheKey]
 
 	addr *GoTextFaceSource
 
@@ -224,12 +231,12 @@ 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 {
+func (g *GoTextFaceSource) getOrCreateGlyphImage(goTextFace *GoTextFace, key goTextGlyphImageCacheKey, create func() *ebiten.Image) *ebiten.Image {
 	if g.glyphImageCache == nil {
-		g.glyphImageCache = map[float64]*glyphImageCache{}
+		g.glyphImageCache = map[float64]*glyphImageCache[goTextGlyphImageCacheKey]{}
 	}
 	if _, ok := g.glyphImageCache[goTextFace.Size]; !ok {
-		g.glyphImageCache[goTextFace.Size] = &glyphImageCache{}
+		g.glyphImageCache[goTextFace.Size] = &glyphImageCache[goTextGlyphImageCacheKey]{}
 	}
 	return g.glyphImageCache[goTextFace.Size].getOrCreate(goTextFace, key, create)
 }

text/v2/std.go

@@ -26,13 +26,20 @@ import (
 
 var _ Face = (*StdFace)(nil)
 
+type stdFaceGlyphImageCacheKey struct {
+	rune    rune
+	xoffset fixed.Int26_6
+
+	// yoffset is always the same if the rune is the same, so this doesn't have to be a key.
+}
+
 // StdFace is a Face implementation for a semi-standard font.Face (golang.org/x/image/font).
 // StdFace is useful to transit from existing codebase with text v1, or to use some bitmap fonts defined as font.Face.
 // StdFace must not be copied by value.
 type StdFace struct {
 	f *faceWithCache
 
-	glyphImageCache glyphImageCache
+	glyphImageCache glyphImageCache[stdFaceGlyphImageCacheKey]
 
 	addr *StdFace
 }
@@ -121,10 +128,9 @@ func (s *StdFace) glyphImage(r rune, origin fixed.Point26_6) (*ebiten.Image, int
 		X: (origin.X + b.Min.X) & ((1 << 6) - 1),
 		Y: (origin.Y + b.Min.Y) & ((1 << 6) - 1),
 	}
-	key := glyphImageCacheKey{
-		id:      uint32(r),
+	key := stdFaceGlyphImageCacheKey{
+		rune:    r,
 		xoffset: subpixelOffset.X,
-		// yoffset is always the same if the rune is the same, so this doesn't have to be a key.
 	}
 	img := s.glyphImageCache.getOrCreate(s, key, func() *ebiten.Image {
 		return s.glyphImageImpl(r, subpixelOffset, b)