Fix editor preview for Spine models without attachments

corrupted/15_no_attachments.go

@@ -0,0 +1,9 @@
+embedded_components {
+  id: "corruption_case"
+  type: "spinemodel"
+  data: "spine_scene: \"/corrupted/_assets/cases/15_no_attachments/case.spinescene\"\n"
+  "default_animation: \"idle\"\n"
+  "skin: \"\"\n"
+  "material: \"/corrupted/_assets/shared/spine.material\"\n"
+  ""
+}

corrupted/README.md

@@ -24,6 +24,7 @@ atlas and exercises the intended attachment-loader failure.
 | `12_missing_deform_attachment.go` | Animation deform timeline references an absent attachment. | SkeletonBinary.c: attachment timeline lookup | Fatal 'Animation corrupted' resource error. |
 | `13_unknown_attachment_type.go` | Skin attachment has the unused type value 7. | SkeletonBinary.c: attachment switch default / readSkin NULL | Must not crash. Current runtime silently drops it and opens empty. |
 | `14_non_finite_transform.go` | Valid structure contains NaN as the root bone X position. | Operation path after a successful binary load | Must not crash while creating, updating, or previewing the skeleton. |
+| `15_no_attachments.go` | Valid binary with a slot but no attachments. | Editor render path with empty vertex and index buffers | Opens with an empty preview and updates without an error. |
 
 ## Known limits
 

corrupted/_assets/cases/15_no_attachments/case.spinescene

@@ -0,0 +1,2 @@
+spine_json: "/corrupted/_assets/cases/15_no_attachments/case.skel"
+atlas: "/corrupted/_assets/shared/test.atlas"

corrupted/_assets/tools/generate.py

@@ -435,6 +435,13 @@ def build_unknown_attachment_type() -> bytes:
     return writer.finish()
 
 
+def build_no_attachments() -> bytes:
+    writer = BinaryWriter()
+    write_skeleton_prefix(writer, [], None)
+    write_default_skin(writer, [], [])
+    return finish_skeleton(writer, animations=[("idle", write_empty_animation)])
+
+
 CASES = [
     Case(
         "00_valid_control",
@@ -556,6 +563,14 @@ def build_unknown_attachment_type() -> bytes:
         "idle",
         lambda: build_valid_control(bone_x=math.nan),
     ),
+    Case(
+        "15_no_attachments",
+        "Valid binary with a slot but no attachments.",
+        "Opens with an empty preview and updates without an error.",
+        "Editor render path with empty vertex and index buffers",
+        "idle",
+        build_no_attachments,
+    ),
 ]
 
 
@@ -712,7 +727,7 @@ def generated_files() -> dict[Path, bytes]:
         SHARED_ROOT / "spine.material": MATERIAL.encode(),
         SHARED_ROOT / "spine.vp": VERTEX_SHADER.encode(),
         SHARED_ROOT / "spine.fp": FRAGMENT_SHADER.encode(),
-        ASSETS_ROOT / "README.md": make_readme().encode(),
+        CORRUPTED_ROOT / "README.md": make_readme().encode(),
     }
 
     for case in CASES:
@@ -749,7 +764,7 @@ def check(files: dict[Path, bytes]) -> int:
         elif path.read_bytes() != expected:
             errors.append(f"out of date: {path.relative_to(CORRUPTED_ROOT)}")
 
-    expected_root_files = {f"{case.key}.go" for case in CASES}
+    expected_root_files = {"README.md"} | {f"{case.key}.go" for case in CASES}
     actual_root_files = {path.name for path in CORRUPTED_ROOT.iterdir() if path.is_file()}
     for unexpected in sorted(actual_root_files - expected_root_files):
         errors.append(f"unexpected root file: {unexpected}")

defold-spine/editor/src/spineext.clj

@@ -333,20 +333,20 @@
 
 
 (defn- render-group-transparent [^GL2 gl render-args override-shader group]
-  (let [renderable (:renderable group)
-        user-data (:user-data renderable)
-        gpu-texture (or (get user-data :gpu-texture) texture/white-pixel)
-        shader (or override-shader (:shader user-data))
-        vb (:vertex-buffer group)
-        ib (:index-buffer group)
-        draw-descs (:draw-descs group)
-        vertex-binding (vtx2/use-with ::spine-trans vb shader)
-        bindings (cond-> [shader gpu-texture vertex-binding]
-                   ib (conj ib))]
-    (gl/with-gl-bindings gl render-args bindings
-      (run! (fn [draw-desc]
-              (do-draw-desc! gl render-args shader renderable draw-desc))
-            draw-descs))))
+  (when-let [vb (:vertex-buffer group)]
+    (let [renderable (:renderable group)
+          user-data (:user-data renderable)
+          gpu-texture (or (get user-data :gpu-texture) texture/white-pixel)
+          shader (or override-shader (:shader user-data))
+          ib (:index-buffer group)
+          draw-descs (:draw-descs group)
+          vertex-binding (vtx2/use-with ::spine-trans vb shader)
+          bindings (cond-> [shader gpu-texture vertex-binding]
+                     ib (conj ib))]
+      (gl/with-gl-bindings gl render-args bindings
+        (run! (fn [draw-desc]
+                (do-draw-desc! gl render-args shader renderable draw-desc))
+              draw-descs)))))
 
 ;; When debugging render using REPL, don't forget to run (dev/clear-caches!)
 ;; Also, it's possible to switch render modes in the Debug Editor using Cmd+T