From 2e2a18c0320ee98aca3737efe168ef45f63962a7 Mon Sep 17 00:00:00 2001
From: Jared-Shi <jared.zshi@gmail.com>
Date: Thu, 19 Mar 2026 16:39:02 -0400
Subject: [PATCH] Refactor render function for ViewportOverlayInterface

---
 freud/overlay_DiffractionPattern.py | 87 ++++++++++++++++-------------
 1 file changed, 48 insertions(+), 39 deletions(-)

diff --git a/freud/overlay_DiffractionPattern.py b/freud/overlay_DiffractionPattern.py
index 4b251c9..ce86201 100644
--- a/freud/overlay_DiffractionPattern.py
+++ b/freud/overlay_DiffractionPattern.py
@@ -1,47 +1,56 @@
+
+
 # Copyright (c) 2021 The Regents of the University of Michigan
 # All rights reserved.
 # This software is licensed under the BSD 3-Clause License.
 
 import PySide6.QtGui
-import rowan
+import numpy as np
 
+import rowan
 import freud
-import numpy as np
 
-print("Diffraction, freud version", freud.__version__)
-
-
-def render(
-    args,
-    grid_size=256,
-    output_size=256,
-    draw_x: float = 10,
-    draw_y: float = 10,
-    zoom: float = 1,
-):
-    pipeline = args.scene.selected_pipeline
-    if not pipeline:
-        return
-    data = pipeline.compute(args.frame)
-    view_orientation = rowan.from_matrix(args.viewport.viewMatrix[:, :3])
-    dp = freud.diffraction.DiffractionPattern(
-        grid_size=grid_size,
-        output_size=output_size,
-    )
-    dp.compute(
-        system=data,
-        view_orientation=view_orientation,
-        zoom=zoom,
-        peak_width=1,
-    )
-    buf = dp.to_image(cmap="afmhot", vmax=np.max(dp.diffraction))
-    width, height, bytes_per_pixel = buf.shape
-    img = PySide6.QtGui.QImage(
-        buf,
-        width,
-        height,
-        width * bytes_per_pixel,
-        PySide6.QtGui.QImage.Format_RGBA8888,
-    )
-    # Paint QImage onto viewport canvas
-    args.painter.drawImage(draw_x, draw_y, img)
+from ovito.vis import *
+from ovito.data import *
+
+class MyOverlay(ViewportOverlayInterface):
+
+    def render(
+        self,
+        canvas,
+        data,
+        pipeline,
+        frame,
+        grid_size=256,
+        output_size=256,
+        draw_x: float = 10,
+        draw_y: float = 10,
+        zoom: float = 1,
+        **kwargs,
+    ):
+
+        if not pipeline:
+            return
+        data = pipeline.compute(frame)
+        view_orientation = rowan.from_matrix(canvas.view_tm[:, :3])
+        dp = freud.diffraction.DiffractionPattern(
+            grid_size=grid_size,
+            output_size=output_size,
+        )
+        dp.compute(
+            system=data,
+            view_orientation=view_orientation,
+            zoom=zoom,
+            peak_width=1,
+        )
+        buf = dp.to_image(cmap="afmhot", vmax=np.max(dp.diffraction))
+        width, height, bytes_per_pixel = buf.shape
+        img = PySide6.QtGui.QImage(
+            buf,
+            width,
+            height,
+            width * bytes_per_pixel,
+            PySide6.QtGui.QImage.Format_RGBA8888,
+        )
+        # Paint QImage onto viewport canvas
+        canvas.drawImage(draw_x, draw_y, img)