add flip node

backend/node_menu.py

@@ -39,6 +39,7 @@ MENU_LAYOUT: dict[str, list[str]] = {
         "ColormapAdjust",
         "CropResizeField",
         "RotateField",
+        "FlipField",
     ],
     "Filter": [
         "GaussianFilter",

backend/nodes/__init__.py

@@ -20,6 +20,7 @@ from backend.nodes import (
     colormap_adjust,
     crop_resize_field,
     rotate_field,
+    flip_field,
     # Level
     plane_level_field,
     poly_level_field,

backend/nodes/flip_field.py

@@ -0,0 +1,93 @@
+from __future__ import annotations
+
+from copy import deepcopy
+
+import numpy as np
+
+from backend.data_types import DataField
+from backend.node_registry import register_node
+
+
+@register_node(display_name="Flip")
+class FlipField:
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "field": ("DATA_FIELD",),
+                "axis": (["x", "y"], {"default": "x"}),
+            }
+        }
+
+    RETURN_TYPES = ("DATA_FIELD",)
+    RETURN_NAMES = ("field",)
+    FUNCTION = "process"
+
+    DESCRIPTION = (
+        "Reflect a DATA_FIELD across the X axis (top/bottom) or Y axis (left/right). "
+        "Physical extents are preserved, and stored markup overlays are mirrored with the data."
+    )
+
+    def process(self, field: DataField, axis: str) -> tuple:
+        axis_name = str(axis).strip().lower()
+        if axis_name == "x":
+            flipped = np.flipud(field.data).copy()
+        elif axis_name == "y":
+            flipped = np.fliplr(field.data).copy()
+        else:
+            raise ValueError(f"Unknown flip axis: {axis}")
+
+        return (
+            field.replace(
+                data=np.asarray(flipped, dtype=np.float64),
+                overlays=self._flip_overlays(field.overlays, axis_name),
+            ),
+        )
+
+    @classmethod
+    def _flip_overlays(cls, overlays: list[dict] | None, axis: str) -> list[dict]:
+        if not isinstance(overlays, list):
+            return []
+
+        flipped_overlays = []
+        for overlay in overlays:
+            if not isinstance(overlay, dict):
+                continue
+
+            next_overlay = deepcopy(overlay)
+            if str(next_overlay.get("kind", "")).strip().lower() == "markup":
+                next_overlay["shapes"] = [
+                    cls._flip_markup_shape(shape, axis)
+                    for shape in next_overlay.get("shapes", [])
+                    if isinstance(shape, dict)
+                ]
+            flipped_overlays.append(next_overlay)
+        return flipped_overlays
+
+    @staticmethod
+    def _flip_markup_shape(shape: dict, axis: str) -> dict:
+        flipped = deepcopy(shape)
+        kind = str(flipped.get("kind", "")).strip().lower()
+
+        try:
+            x1 = float(flipped.get("x1"))
+            y1 = float(flipped.get("y1"))
+            x2 = float(flipped.get("x2"))
+            y2 = float(flipped.get("y2"))
+        except (TypeError, ValueError):
+            return flipped
+
+        if axis == "x":
+            y1, y2 = 1.0 - y1, 1.0 - y2
+        else:
+            x1, x2 = 1.0 - x1, 1.0 - x2
+
+        if kind in {"rectangle", "circle"}:
+            x1, x2 = sorted((x1, x2))
+            y1, y2 = sorted((y1, y2))
+
+        flipped["x1"] = float(np.clip(x1, 0.0, 1.0))
+        flipped["y1"] = float(np.clip(y1, 0.0, 1.0))
+        flipped["x2"] = float(np.clip(x2, 0.0, 1.0))
+        flipped["y2"] = float(np.clip(y2, 0.0, 1.0))
+        return flipped