adding more nodes

backend/nodes/extend_pad.py

@@ -0,0 +1,64 @@
+"""Extend / pad — add borders to a field with various fill methods."""
+
+from __future__ import annotations
+
+import numpy as np
+
+from backend.node_registry import register_node
+from backend.data_types import DataField
+
+
+@register_node(display_name="Extend / Pad")
+class ExtendPad:
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "field": ("DATA_FIELD",),
+                "top": ("INT", {"default": 0, "min": 0, "max": 1024, "step": 1}),
+                "bottom": ("INT", {"default": 0, "min": 0, "max": 1024, "step": 1}),
+                "left": ("INT", {"default": 0, "min": 0, "max": 1024, "step": 1}),
+                "right": ("INT", {"default": 0, "min": 0, "max": 1024, "step": 1}),
+                "method": (["mean", "edge", "mirror", "periodic", "zero"],
+                           {"default": "mirror"}),
+            }
+        }
+
+    OUTPUTS = (
+        ('DATA_FIELD', 'padded'),
+    )
+    FUNCTION = "process"
+
+    DESCRIPTION = (
+        "Add borders to a field with configurable padding method. "
+        "Mirror and periodic modes avoid edge discontinuities for FFT. "
+    )
+
+    def process(self, field: DataField, top: int, bottom: int,
+                left: int, right: int, method: str) -> tuple:
+        data = np.asarray(field.data, dtype=np.float64)
+
+        mode_map = {
+            "mean": "constant",
+            "edge": "edge",
+            "mirror": "reflect",
+            "periodic": "wrap",
+            "zero": "constant",
+        }
+        np_mode = mode_map.get(method, "constant")
+
+        kwargs = {}
+        if method == "mean":
+            kwargs["constant_values"] = data.mean()
+        elif method == "zero":
+            kwargs["constant_values"] = 0.0
+
+        result = np.pad(data, ((top, bottom), (left, right)), mode=np_mode, **kwargs)
+
+        new_xreal = result.shape[1] * field.dx
+        new_yreal = result.shape[0] * field.dy
+        new_xoff = field.xoff - left * field.dx
+        new_yoff = field.yoff - top * field.dy
+
+        return (field.replace(data=result, xreal=new_xreal, yreal=new_yreal,
+                              xoff=new_xoff, yoff=new_yoff),)