Add SlotAttachmentPlaceholder expression.

spine-ts/spine-construct3/src/aces.json

@@ -715,6 +715,18 @@
           }
         ]
       },
+      {
+        "id": "slot-attachment-placeholder",
+        "expressionName": "SlotAttachmentPlaceholder",
+        "highlight": false,
+        "returnType": "string",
+        "params": [
+          {
+            "id": "slot-name",
+            "type": "string"
+          }
+        ]
+      },
       {
         "id": "bone-x",
         "expressionName": "BoneX",

spine-ts/spine-construct3/src/c3runtime/expressions.ts

@@ -27,6 +27,7 @@
  * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *****************************************************************************/
 
+import type { Attachment, Skin } from "@esotericsoftware/spine-construct3-lib";
 import type { SDKInstanceClass as SpineC3Instance } from "./instance";
 
 const C3 = globalThis.C3;
@@ -34,13 +35,35 @@ const C3 = globalThis.C3;
 C3.Plugins.EsotericSoftware_SpineConstruct3.Exps =
 {
 	SlotAttachment (this: SpineC3Instance, slotName: string) {
-		if (!this.skeleton) return "";
-		const slot = this.skeleton.findSlot(slotName);
+		const { skeleton } = this;
+		if (!skeleton) return "";
+		const slot = skeleton.findSlot(slotName);
 		if (!slot) return "";
 		const attachment = slot.pose.getAttachment();
 		return attachment ? attachment.name : "";
 	},
 
+	SlotAttachmentPlaceholder (this: SpineC3Instance, slotName: string) {
+		const { skeleton } = this;
+		if (!skeleton) return "";
+		const slot = skeleton.findSlot(slotName);
+		if (!slot) return "";
+		const attachment = slot.pose.getAttachment();
+		if (!attachment) return "";
+		const slotIndex = slot.data.index;
+		const skin = skeleton.skin;
+		if (skin) {
+			const name = findPlaceholderName(skin, slotIndex, attachment);
+			if (name) return name;
+		}
+		const defaultSkin = skeleton.data.defaultSkin;
+		if (defaultSkin) {
+			const name = findPlaceholderName(defaultSkin, slotIndex, attachment);
+			if (name) return name;
+		}
+		return attachment.name;
+	},
+
 	BoneX (this: SpineC3Instance, boneName: string) {
 		return this.getBoneX(boneName);
 	},
@@ -116,3 +139,12 @@ C3.Plugins.EsotericSoftware_SpineConstruct3.Exps =
 		return this.getBounds().height;
 	}
 };
+
+function findPlaceholderName (skin: Skin, slotIndex: number, attachment: Attachment): string | null {
+	const dictionary = skin.attachments[slotIndex];
+	if (!dictionary) return null;
+	for (const name in dictionary) {
+		if (dictionary[name] === attachment) return name;
+	}
+	return null;
+}

spine-ts/spine-construct3/src/lang/en-US.json

@@ -811,6 +811,16 @@
               }
             }
           },
+          "slot-attachment-placeholder": {
+            "description": "Get the skin placeholder name of the attachment on a slot, or the attachment name if using the default skin. Returns empty string if no attachment.",
+            "translated-name": "SlotAttachmentPlaceholder",
+            "params": {
+              "slot-name": {
+                "name": "Slot name",
+                "desc": "Name of the slot"
+              }
+            }
+          },
           "bone-x": {
             "description": "Get the world X position of a bone.",
             "translated-name": "BoneX",

spine-ts/spine-construct3/src/lang/zh-CN.json

@@ -811,6 +811,16 @@
               }
             }
           },
+          "slot-attachment-placeholder": {
+            "description": "获取插槽上附件的皮肤占位符名称，如果使用默认皮肤则返回附件名称。如果没有附件则返回空字符串。",
+            "translated-name": "SlotAttachmentPlaceholder",
+            "params": {
+              "slot-name": {
+                "name": "插槽名称",
+                "desc": "插槽的名称"
+              }
+            }
+          },
           "bone-x": {
             "description": "获取骨骼的世界X位置。",
             "translated-name": "BoneX",