From 82a6f7e9fd1d8f9701ad79eb785643e84ca0c64a Mon Sep 17 00:00:00 2001
From: Victor Giers <mail@victorgiers.com>
Date: Mon, 18 May 2026 16:09:00 +0200
Subject: [PATCH] auto-git:  [add]
 src/commands/set-custom-material-texture-command.ts

---
 .../set-custom-material-texture-command.ts    | 99 +++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100644 src/commands/set-custom-material-texture-command.ts

diff --git a/src/commands/set-custom-material-texture-command.ts b/src/commands/set-custom-material-texture-command.ts
new file mode 100644
index 00000000..d44e3089
--- /dev/null
+++ b/src/commands/set-custom-material-texture-command.ts
@@ -0,0 +1,99 @@
+import { createOpaqueId } from "../core/ids";
+import type { ProjectDocument } from "../document/scene-document";
+import {
+  cloneMaterialDef,
+  type CustomMaterialDef,
+  type MaterialTextureSlot
+} from "../materials/starter-material-library";
+import {
+  cloneProjectAssetRecord,
+  type ImageAssetRecord
+} from "../assets/project-assets";
+
+import type { EditorCommand } from "./command";
+
+interface SetCustomMaterialTextureCommandOptions {
+  materialId: string;
+  slot: MaterialTextureSlot;
+  assetId: string | null;
+  asset?: ImageAssetRecord;
+  label?: string;
+}
+
+export function createSetCustomMaterialTextureCommand(
+  options: SetCustomMaterialTextureCommandOptions
+): EditorCommand {
+  let previousProjectDocument: ProjectDocument | null = null;
+
+  return {
+    id: createOpaqueId("command"),
+    label: options.label ?? "Set custom material texture",
+    execute(context) {
+      const currentProjectDocument = context.getProjectDocument();
+      const currentMaterial =
+        currentProjectDocument.materials[options.materialId];
+
+      if (currentMaterial === undefined) {
+        throw new Error(`Material ${options.materialId} does not exist.`);
+      }
+
+      if (currentMaterial.kind !== "custom") {
+        throw new Error("Starter materials are read-only.");
+      }
+
+      if (options.asset !== undefined && options.asset.id !== options.assetId) {
+        throw new Error("Imported material texture asset id must match assetId.");
+      }
+
+      const existingAsset =
+        options.assetId === null
+          ? null
+          : (options.asset ?? currentProjectDocument.assets[options.assetId]);
+
+      if (existingAsset !== null) {
+        if (existingAsset === undefined) {
+          throw new Error(`Asset ${options.assetId} does not exist.`);
+        }
+
+        if (existingAsset.kind !== "image") {
+          throw new Error("Material texture slots require image assets.");
+        }
+      }
+
+      if (previousProjectDocument === null) {
+        previousProjectDocument = currentProjectDocument;
+      }
+
+      const nextMaterial: CustomMaterialDef = {
+        ...currentMaterial,
+        textures: {
+          ...currentMaterial.textures,
+          [options.slot]:
+            options.assetId === null ? null : { assetId: options.assetId }
+        }
+      };
+
+      context.setProjectDocument({
+        ...currentProjectDocument,
+        assets:
+          options.asset === undefined
+            ? currentProjectDocument.assets
+            : {
+                ...currentProjectDocument.assets,
+                [options.asset.id]: cloneProjectAssetRecord(options.asset)
+              },
+        materials: {
+          ...currentProjectDocument.materials,
+          [options.materialId]: cloneMaterialDef(nextMaterial)
+        }
+      });
+    },
+    undo(context) {
+      if (previousProjectDocument === null) {
+        return;
+      }
+
+      context.setProjectDocument(previousProjectDocument);
+    }
+  };
+}