text/v2: add (*GoTextFaceSource).Metadata

Updates #2454

text/v2/gotextfacesource.go

@@ -22,6 +22,8 @@ import (
 	"github.com/go-text/typesetting/font"
 	"github.com/go-text/typesetting/language"
 	"github.com/go-text/typesetting/opentype/api"
+	ofont "github.com/go-text/typesetting/opentype/api/font"
+	"github.com/go-text/typesetting/opentype/loader"
 	"github.com/go-text/typesetting/shaping"
 	"golang.org/x/image/math/fixed"
 
@@ -61,7 +63,8 @@ type goTextGlyphImageCacheKey struct {
 
 // GoTextFaceSource is a source of a GoTextFace. This can be shared by multiple GoTextFace objects.
 type GoTextFaceSource struct {
-	f font.Face
+	f        font.Face
+	metadata Metadata
 
 	outputCache     map[goTextOutputCacheKey]*goTextOutputCacheValue
 	glyphImageCache map[float64]*glyphImageCache[goTextGlyphImageCacheKey]
@@ -96,15 +99,22 @@ func NewGoTextFaceSource(source io.ReadSeeker) (*GoTextFaceSource, error) {
 		return nil, err
 	}
 
-	f, err := font.ParseTTF(src)
+	l, err := loader.NewLoader(src)
+	if err != nil {
+		return nil, err
+	}
+
+	ft, err := ofont.NewFont(l)
 	if err != nil {
 		return nil, err
 	}
 
 	s := &GoTextFaceSource{
-		f: f,
+		f: &ofont.Face{Font: ft},
 	}
 	s.addr = s
+	s.metadata = metadataFromLoader(l)
+
 	return s, nil
 }
 
@@ -115,17 +125,22 @@ func NewGoTextFaceSourcesFromCollection(source io.ReadSeeker) ([]*GoTextFaceSour
 		return nil, err
 	}
 
-	fs, err := font.ParseTTC(src)
+	ls, err := loader.NewLoaders(src)
 	if err != nil {
 		return nil, err
 	}
 
-	sources := make([]*GoTextFaceSource, len(fs))
+	sources := make([]*GoTextFaceSource, len(ls))
-	for i, f := range fs {
+	for i, l := range ls {
+		ft, err := ofont.NewFont(l)
+		if err != nil {
+			return nil, err
+		}
 		s := &GoTextFaceSource{
-			f: f,
+			f: &ofont.Face{Font: ft},
 		}
 		s.addr = s
+		s.metadata = metadataFromLoader(l)
 		sources[i] = s
 	}
 	return sources, nil
@@ -137,6 +152,11 @@ func (g *GoTextFaceSource) copyCheck() {
 	}
 }
 
+// Metadata returns its metadata.
+func (g *GoTextFaceSource) Metadata() Metadata {
+	return g.metadata
+}
+
 func (g *GoTextFaceSource) shape(text string, face *GoTextFace) (shaping.Output, []glyph) {
 	g.copyCheck()
 

text/v2/metadata.go

@@ -0,0 +1,72 @@
+// Copyright 2023 The Ebitengine Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package text
+
+import (
+	"github.com/go-text/typesetting/opentype/api/metadata"
+	"github.com/go-text/typesetting/opentype/loader"
+)
+
+// Metadata represents a font face's metadata.
+type Metadata struct {
+	Family    string
+	Style     Style
+	Weight    Weight
+	Stretch   Stretch
+	Monospace bool
+}
+
+func metadataFromLoader(l *loader.Loader) Metadata {
+	d := metadata.Metadata(l)
+	return Metadata{
+		Family:    d.Family,
+		Monospace: d.IsMonospace,
+	}
+}
+
+type Style uint8
+
+const (
+	StyleNormal Style = Style(metadata.StyleNormal)
+	StyleItalic Style = Style(metadata.StyleItalic)
+)
+
+type Weight float32
+
+const (
+	WeightThin       Weight = Weight(metadata.WeightThin)
+	WeightExtraLight Weight = Weight(metadata.WeightExtraLight)
+	WeightLight      Weight = Weight(metadata.WeightLight)
+	WeightNormal     Weight = Weight(metadata.WeightNormal)
+	WeightMedium     Weight = Weight(metadata.WeightMedium)
+	WeightSemibold   Weight = Weight(metadata.WeightSemibold)
+	WeightBold       Weight = Weight(metadata.WeightBold)
+	WeightExtraBold  Weight = Weight(metadata.WeightExtraBold)
+	WeightBlack      Weight = Weight(metadata.WeightBlack)
+)
+
+type Stretch float32
+
+const (
+	StretchUltraCondensed Stretch = Stretch(metadata.StretchUltraCondensed)
+	StretchExtraCondensed Stretch = Stretch(metadata.StretchExtraCondensed)
+	StretchCondensed      Stretch = Stretch(metadata.StretchCondensed)
+	StretchSemiCondensed  Stretch = Stretch(metadata.StretchSemiCondensed)
+	StretchNormal         Stretch = Stretch(metadata.StretchNormal)
+	StretchSemiExpanded   Stretch = Stretch(metadata.StretchSemiExpanded)
+	StretchExpanded       Stretch = Stretch(metadata.StretchExpanded)
+	StretchExtraExpanded  Stretch = Stretch(metadata.StretchExtraExpanded)
+	StretchUltraExpanded  Stretch = Stretch(metadata.StretchUltraExpanded)
+)