Make a start on font rendering

I was hopeful I could use ebiten/text, but font.Face doesn't seem set
up for fixed-colour fonts.

internal/assetstore/menu.go

@@ -8,8 +8,9 @@ import (
 
 type Menu struct {
 	assets *AssetStore
-	obj    *Object // TODO: handle multiple objects in the menu
-	raw    *menus.Menu
+	fonts  []*Font     // TODO: place the fonts directly into the relevant records
+	obj    *Object     // TODO: handle multiple objects in the menu
+	raw    *menus.Menu // TODO: remove raw
 
 	Name string
 }
@@ -19,6 +20,11 @@ func (m *Menu) Records() []*menus.Record {
 	return m.raw.Records
 }
 
+// FIXME: don't expose this
+func (m *Menu) Font(idx int) *Font {
+	return m.fonts[idx]
+}
+
 func (m *Menu) Images(start, count int) ([]*ebiten.Image, error) {
 	out := make([]*ebiten.Image, count)
 
@@ -70,6 +76,16 @@ func (a *AssetStore) Menu(name string) (*Menu, error) {
 		return nil, err
 	}
 
+	var fonts []*Font
+	for _, fontName := range raw.FontNames {
+		fnt, err := a.Font(fontName)
+		if err != nil {
+			return nil, err
+		}
+
+		fonts = append(fonts, fnt)
+	}
+
 	i18n, err := a.i18n()
 	if err != nil {
 		return nil, err
@@ -84,6 +100,7 @@ func (a *AssetStore) Menu(name string) (*Menu, error) {
 
 	menu := &Menu{
 		assets: a,
+		fonts:  fonts,
 		obj:    obj,
 		raw:    raw,
 		Name:   name,