Build a simple animation viewer

internal/assetstore/ani.go

@@ -0,0 +1,78 @@
+package assetstore
+
+import (
+	"code.ur.gs/lupine/ordoor/internal/idx"
+)
+
+type Animation struct {
+	Frames []*Sprite
+}
+
+func (a *AssetStore) AnimationsIndex() (*idx.Idx, error) {
+	if a.idx != nil {
+		return a.idx, nil
+	}
+
+	filename, err := a.lookup("WarHammer", "idx", "Idx")
+	if err != nil {
+		return nil, err
+	}
+
+	idx, err := idx.Load(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	a.idx = idx
+	return idx, nil
+}
+
+func (a *AssetStore) AnimationsObject() (*Object, error) {
+	if a.aniObj != nil {
+		return a.aniObj, nil
+	}
+
+	filename, err := a.lookup("WarHammer", "ani", "Anim")
+	if err != nil {
+		return nil, err
+	}
+
+	obj, err := a.ObjectByPath(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	a.aniObj = obj
+	return obj, nil
+}
+
+func (a *AssetStore) Animation(groupIdx, recIdx int) (*Animation, error) {
+	idx, err := a.AnimationsIndex()
+	if err != nil {
+		return nil, err
+	}
+
+	obj, err := a.AnimationsObject()
+	if err != nil {
+		return nil, err
+	}
+
+	group := idx.Groups[groupIdx]
+	if group.Spec.Count == 0 {
+		return &Animation{}, nil
+	}
+
+	//	rec := group.Records[recIdx]
+	det := group.Details[recIdx]
+
+	first := int(group.Spec.SpriteIdx) + int(det.FirstSprite)
+	last := int(group.Spec.SpriteIdx) + int(det.LastSprite)
+	count := last - first + 1
+
+	sprites, err := obj.Sprites(first, count)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Animation{Frames: sprites}, nil
+}