Fix json animation for single animation

scripts/components.js

@@ -302,7 +302,7 @@ SpriteAnim.aseprite = function(path) {
   function aseframeset2anim(frameset, meta) {
     var anim = {};
     anim.frames = [];
-    anim.path = path.dir() + "/" + meta.image;
+    anim.path = path.folder() + meta.image;
     var dim = meta.size;
 
     var ase_make_frame = function(ase_frame) {
@@ -329,6 +329,10 @@ SpriteAnim.aseprite = function(path) {
   var anims = {};
   var frames = Array.isArray(data.frames) ? data.frames : Object.values(data.frames);
   var f = 0;
+  if (data.meta.frameTags.length === 0) {
+    anims[0] = aseframeset2anim(frames, data.meta);
+    return anims;
+  }
   for (var tag of data.meta.frameTags) {
     anims[tag.name] = aseframeset2anim(frames.slice(tag.from, tag.to+1), data.meta);
     anims[f] = anims[tag.name];

scripts/engine.js

@@ -15,6 +15,14 @@ Object.defineProperty(String.prototype, 'dir', {
   }
 });
 
+Object.defineProperty(String.prototype, 'folder', {
+  value: function() {
+    var dir = this.dir();
+    if (!dir) return "";
+    else return dir + "/";
+  }
+});
+
 globalThis.Resources = {};
 
 Resources.replpath = function(str, path)

source/engine/jsffi.c

@@ -365,6 +365,7 @@ JSValue vecarr2js(HMM_Vec2 *points, int n) {
 
 int js_print_exception(JSValue v)
 {
+  if (!js) return 0;
 #ifndef NDEBUG
   if (!JS_IsException(v))
     return 0;