Get the initial copyright notice displaying

This is really awful, but it's nice to check it off.

internal/assetstore/assetstore.go

@@ -8,6 +8,8 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/hajimehoshi/ebiten"
+
 	"code.ur.gs/lupine/ordoor/internal/config"
 	"code.ur.gs/lupine/ordoor/internal/data"
 	"code.ur.gs/lupine/ordoor/internal/idx"
@@ -44,6 +46,7 @@ type AssetStore struct {
 	fonts     map[string]*Font
 	generic   *data.Generic
 	idx       *idx.Idx
+	images    map[string]*ebiten.Image
 	maps      map[string]*Map
 	menus     map[string]*Menu
 	objs      map[string]*Object
@@ -109,6 +112,7 @@ func (a *AssetStore) Refresh() error {
 	a.entries = newEntryMap
 	a.fonts = make(map[string]*Font)
 	a.idx = nil
+	a.images = make(map[string]*ebiten.Image)
 	a.maps = make(map[string]*Map)
 	a.menus = make(map[string]*Menu)
 	a.objs = make(map[string]*Object)

internal/assetstore/image.go

@@ -0,0 +1,42 @@
+package assetstore
+
+import (
+	"image"
+	"os"
+
+	"github.com/hajimehoshi/ebiten"
+	_ "github.com/samuel/go-pcx/pcx" // PCX support
+)
+
+func (a *AssetStore) Image(name string) (*ebiten.Image, error) {
+	name = canonical(name)
+	if img, ok := a.images[name]; ok {
+		return img, nil
+	}
+
+	// baps, ordoor, geas store .pcx files in Pic
+	// TODO: SL stores .bmp files in Res
+	filename, err := a.lookup(name, "pcx", "Pic")
+	if err != nil {
+		return nil, err
+	}
+
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	rawImg, _, err := image.Decode(f)
+	if err != nil {
+		return nil, err
+	}
+
+	img, err := ebiten.NewImageFromImage(rawImg, ebiten.FilterDefault)
+	if err != nil {
+		return nil, err
+	}
+
+	a.images[name] = img
+	return img, nil
+}