From 6e5dc2b8a6dd6a14b7c8ea14826ae52cd731ef1a Mon Sep 17 00:00:00 2001
From: Beyley Cardellio <ep1cm1n10n123@gmail.com>
Date: Fri, 3 Jul 2026 21:28:38 -0700
Subject: [PATCH] t/constellation: Add debug flag to check if certain LEDs are
 neighbours

This helps debug issues with the LED search model, to see if some otherwise plausibly inclusive LEDs are not considered neighbours by the search model generation.

Signed-off-by: Beyley Cardellio <ep1cm1n10n123@gmail.com>
Part-of: <https://gitlab.freedesktop.org/monado/monado/-/merge_requests/2909>
---
 .../tracking/constellation/led_search_model.c | 53 +++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/src/xrt/tracking/constellation/led_search_model.c b/src/xrt/tracking/constellation/led_search_model.c
index d3d6e94c7..e0debe438 100644
--- a/src/xrt/tracking/constellation/led_search_model.c
+++ b/src/xrt/tracking/constellation/led_search_model.c
@@ -11,6 +11,8 @@
 
 #include "math/m_api.h"
 
+#include "util/u_logging.h"
+
 #include "led_search_model.h"
 
 
@@ -18,7 +20,11 @@
  * 1 to use orthographic projected (undistorted) 2D distance
  * with the anchor LED is forward-facing */
 #define PROJECTED_DISTANCE 0
+
+// @note: These should never be set to 1 when upstreamed!
 #define DUMP_FULL_DEBUG 0
+// Check if some combo of LEDs are neighbours of each other.
+#define CHECK_NEIGHBOURS 0
 
 struct led_candidate_sort_entry
 {
@@ -180,6 +186,53 @@ t_constellation_search_model_new(t_constellation_device_id_t device_id,
 		m->points[i] = t_constellation_search_led_candidate_new(led_model->leds + i, led_model);
 	}
 
+#if CHECK_NEIGHBOURS
+	{
+		const t_constellation_led_id_it target_ids[] = {6, 0, 1, 2};
+		const int num_targets = 4;
+
+		for (int ti = 0; ti < num_targets; ti++) {
+			t_constellation_led_id_it anchor_id = target_ids[ti];
+			struct t_constellation_search_led_candidate *anchor_c = NULL;
+
+			for (size_t i = 0; i < led_model->led_count; i++) {
+				if (led_model->leds[i].id == anchor_id) {
+					anchor_c = m->points[i];
+					break;
+				}
+			}
+
+			if (!anchor_c) {
+				U_LOG_D("[combo-check] LED %u not found in model", anchor_id);
+				continue;
+			}
+
+			U_LOG_D("[combo-check] LED %u has %u neighbours:", anchor_id, anchor_c->num_neighbours);
+			for (int j = 0; j < num_targets; j++) {
+				if (target_ids[j] == anchor_id) {
+					continue;
+				}
+				bool found = false;
+				int depth = -1;
+				for (uint8_t k = 0; k < anchor_c->num_neighbours; k++) {
+					if (anchor_c->neighbours[k]->id == target_ids[j]) {
+						found = true;
+						depth = k + 1;
+						break;
+					}
+				}
+				if (found) {
+					U_LOG_D("[combo-check]   -> LED %u found at neighbour depth %d", target_ids[j],
+					        depth);
+				} else {
+					U_LOG_D("[combo-check]   -> LED %u NOT in neighbour list (angle-filtered out?)",
+					        target_ids[j]);
+				}
+			}
+		}
+	}
+#endif
+
 	return m;
 }
 
-- 
2.54.0