Fix replay 2D black canvas and journey UX clarity

Stored analysis overlays now use the decoded frame; latch resets and draw failures surface. Verified with bare-video, replay-wiring, visual_policy, and analysis-progress tests.

shared/src/orisys_app_shared/acquisition/arrows.py

@@ -280,6 +280,18 @@ def magnitude_to_ramp_index(
     return np.clip(scaled * 255.0, 0.0, 255.0).astype(np.uint8)
 
 
+def carry_frame_diagnostic(image: np.ndarray, diagnostic=None) -> np.ndarray:
+    """``image`` as a draw result that still carries ``frame_diagnostic``.
+
+    Used by :func:`draw_arrow_display` and by callers that must re-wrap after a
+    transform (orientation) that would otherwise drop the attribute. ``None`` means
+    the draw succeeded.
+    """
+    out = np.asarray(image).view(_DrawResult)
+    out.frame_diagnostic = diagnostic
+    return out
+
+
 def _flow_result(image: np.ndarray, diagnostic=None) -> np.ndarray:
     """``image`` as the result of :func:`draw_arrow_display`, carrying ``diagnostic``.
 
@@ -295,9 +307,7 @@ def _flow_result(image: np.ndarray, diagnostic=None) -> np.ndarray:
     panel's job is ``code -> localized text``; this module deliberately carries no locale
     string (see :data:`ARROW_RENDER_FAILED_MESSAGE`).
     """
-    out = image.view(_DrawResult)
-    out.frame_diagnostic = diagnostic
-    return out
+    return carry_frame_diagnostic(image, diagnostic)
 
 
 class _DrawResult(np.ndarray):

shared/src/orisys_app_shared/acquisition/image_backend.py

@@ -29,6 +29,7 @@ from typing import Any
 import numpy as np
 
 from orisys_app_shared.acquisition.arrows import (
+    carry_frame_diagnostic,
     depth_map_to_bgr,
     draw_arrow_display,
     flow_colormap,
@@ -451,21 +452,25 @@ def render_image(
         flow = frame.flow
         if sdk_result:
             flow = np.nan_to_num(np.asarray(flow, dtype=np.float64), nan=0.0)
-        return apply_orientation(
-            draw_arrow_display(
-                frame.image_bgr,
-                flow,
-                background="captured" if wanted == ARROW_STITCHED else "pure_color",
-                canvas_bgr=canvas_bgr,
-                draw_style=draw_style,
-                shared_painter=str(frame.source or "") in RESULT_SOURCES and not sdk_result,
-                valid_mask=frame.valid_mask,
-                domain_mask=domain_mask,
-                colormap=flow_colormap(theme),
-                policy=arrow_policy,
-            ),
-            turn,
+        drawn = draw_arrow_display(
+            frame.image_bgr,
+            flow,
+            background="captured" if wanted == ARROW_STITCHED else "pure_color",
+            canvas_bgr=canvas_bgr,
+            draw_style=draw_style,
+            shared_painter=str(frame.source or "") in RESULT_SOURCES and not sdk_result,
+            valid_mask=frame.valid_mask,
+            domain_mask=domain_mask,
+            colormap=flow_colormap(theme),
+            policy=arrow_policy,
         )
+        # Orientation may rebuild the array; keep the draw failure on the result so the
+        # panel can say so instead of showing a silent black canvas.
+        diagnostic = getattr(drawn, "frame_diagnostic", None)
+        oriented = apply_orientation(drawn, turn)
+        if diagnostic is None:
+            return oriented
+        return carry_frame_diagnostic(oriented, diagnostic)
     # ``recorded``: the frame is the picture, with nothing drawn over it — and the
     # camera's own orientation, which no domain convention applies to.
     return ensure_bgr(np.asarray(frame.image_bgr))

shared/src/orisys_app_shared/scene3d/visual_policy.py

@@ -248,6 +248,11 @@ def select_flow_samples(
     ) * margin
     dx = dx * scale
     dy = dy * scale
+    # Non-finite tips are discarded by ``valid`` below; zero them before the integer
+    # cast so numpy does not warn on every sparse recovered frame during replay.
+    finite_tip = np.isfinite(dx) & np.isfinite(dy)
+    dx = np.where(finite_tip, dx, 0.0)
+    dy = np.where(finite_tip, dy, 0.0)
     end_x = np.clip(np.round(cc + dx).astype(np.int32), 0, w - 1)
     end_y = np.clip(np.round(rr + dy).astype(np.int32), 0, h - 1)
 

shared/tests/test_visual_policy.py

@@ -145,3 +145,16 @@ def test_paint_domain_background_colours() -> None:
     )
     assert tuple(canvas[0, 0]) == (1, 2, 3)
     assert tuple(canvas[1, 1]) == (10, 20, 30)
+
+
+def test_select_flow_samples_screens_non_finite_tips() -> None:
+    """Sparse recovered fields put NaN off the recorded cells; cast must stay quiet."""
+    h, w = 30, 30
+    flow = np.full((h, w, 2), np.nan, dtype=np.float64)
+    flow[15, 15] = (0.5, 0.0)
+    policy = VisualPolicy(flow_on_px=0.4, flow_grid_spacing=10, flow_edge_margin=0)
+    with np.errstate(invalid="raise"):
+        samples = select_flow_samples(flow, None, policy)
+    pairs = set(zip(samples.rows.tolist(), samples.cols.tolist()))
+    assert (15, 15) in pairs
+    assert samples.active_count >= 1