update

backend/routed_layout_preview.py

@@ -0,0 +1,61 @@
+# -----------------------------------------------------------------------------
+# Description: Routed layout preview helpers that invoke the routing/build flow and return preview artifacts.
+# Inside functions: create_routed_layout_svg, layout_has_links
+# Developer : Qin Yue @ 2026
+# Organization : OptiHK Limited
+# -----------------------------------------------------------------------------
+import os
+import tempfile
+
+import yaml
+
+from router_dependency import require_router_stack
+
+
+def create_routed_layout_svg(
+    yaml_content: str,
+    output_path: str,
+    pdk_root: str,
+    project_dir: str,
+    technology_manifest_path: str = None,
+    prefer_full_gds: bool = False,
+) -> str:
+    """Create an SVG preview from routed GDS geometry generated by mxpic_router."""
+    require_router_stack(require_gdstk=True)
+    import gdstk
+
+    layout = yaml.safe_load(yaml_content) or {}
+    cell_name = str(layout.get("name") or "layout")
+    from mxpic_router import build_project_gds
+
+    os.makedirs(os.path.dirname(output_path), exist_ok=True)
+    # Build into a temporary GDS first, then convert the generated top cell into
+    # the SVG preview consumed by the canvas.
+    with tempfile.TemporaryDirectory(prefix="mxpic_routed_preview_") as temp_dir:
+        temp_gds = os.path.join(temp_dir, f"{cell_name}.gds")
+        build_project_gds(
+            project_dir=project_dir,
+            output_path=temp_gds,
+            pdk_root=pdk_root,
+            technology_manifest_path=technology_manifest_path,
+            prefer_full_gds=prefer_full_gds,
+            target_cell_name=cell_name,
+        )
+        library = gdstk.read_gds(temp_gds)
+        top_cells = library.top_level()
+        if not top_cells:
+            raise RuntimeError("Routed preview GDS has no top-level cell")
+        top_cells[0].write_svg(output_path)
+    return output_path
+
+
+def layout_has_links(yaml_content: str) -> bool:
+    """Detect whether a layout YAML document contains routed bundle links."""
+    layout = yaml.safe_load(yaml_content) or {}
+    # Any bundle link means preview generation must use the routed builder
+    # instead of simple component placement.
+    for bundle in (layout.get("bundles") or {}).values():
+        links = bundle.get("links") or []
+        if links:
+            return True
+    return False