From b45b8e77f3a71eda16402778b98760235c977615 Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Wed, 10 Jan 2024 17:40:51 +0000
Subject: [PATCH] Add cache checking of water regions

---
 src/debug_desync.h               |  1 +
 src/openttd.cpp                  |  5 ++++
 src/pathfinder/water_regions.cpp | 49 ++++++++++++++++++++++++++++++++
 3 files changed, 55 insertions(+)

diff --git a/src/debug_desync.h b/src/debug_desync.h
index 4e6fdf9ce8..745e9ca5e9 100644
--- a/src/debug_desync.h
+++ b/src/debug_desync.h
@@ -16,6 +16,7 @@ enum CheckCachesFlags : uint32_t {
 	CHECK_CACHE_NONE               =       0,
 	CHECK_CACHE_GENERAL            = 1 <<  0,
 	CHECK_CACHE_INFRA_TOTALS       = 1 <<  1,
+	CHECK_CACHE_WATER_REGIONS      = 1 <<  2,
 	CHECK_CACHE_ALL                = UINT16_MAX,
 	CHECK_CACHE_EMIT_LOG           = 1 << 16,
 };
diff --git a/src/openttd.cpp b/src/openttd.cpp
index efa36b0716..70b79b3522 100644
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -2052,6 +2052,11 @@ void CheckCaches(bool force_check, std::function<void(const char *)> log, CheckC
 		}
 	}
 
+	if (flags & CHECK_CACHE_WATER_REGIONS) {
+		extern void WaterRegionCheckCaches(std::function<void(const char *)> log);
+		WaterRegionCheckCaches(log);
+	}
+
 	if ((flags & CHECK_CACHE_EMIT_LOG) && !saved_messages.empty()) {
 		InconsistencyExtraInfo info;
 		info.check_caches_result = std::move(saved_messages);
diff --git a/src/pathfinder/water_regions.cpp b/src/pathfinder/water_regions.cpp
index 47856f6fe8..b38e6c7b7d 100644
--- a/src/pathfinder/water_regions.cpp
+++ b/src/pathfinder/water_regions.cpp
@@ -260,6 +260,17 @@ public:
 	{
 		return this->wr.tile_patch_labels != nullptr;
 	}
+
+	TWaterRegionPatchLabelArray CopyPatchLabelArray() const
+	{
+		TWaterRegionPatchLabelArray out;
+		if (this->HasPatchStorage()) {
+			out = *this->wr.tile_patch_labels;
+		} else {
+			out.fill(this->NumberOfPatches() == 0 ? INVALID_WATER_REGION_PATCH : 1);
+		}
+		return out;
+	}
 };
 
 std::vector<WaterRegion> _water_regions;
@@ -472,3 +483,41 @@ uint GetWaterRegionTileDebugColourIndex(TileIndex tile)
 			return 0;
 	}
 }
+
+void WaterRegionCheckCaches(std::function<void(const char *)> log)
+{
+	char cclog_buffer[1024];
+#define CCLOG(...) { \
+	char *cc_log_pos = cclog_buffer + seprintf(cclog_buffer, lastof(cclog_buffer), "Region: %u x %u to %u x %u: ", \
+			x * WATER_REGION_EDGE_LENGTH, y * WATER_REGION_EDGE_LENGTH, (x * WATER_REGION_EDGE_LENGTH) + WATER_REGION_EDGE_MASK, (y * WATER_REGION_EDGE_LENGTH) + WATER_REGION_EDGE_MASK); \
+	seprintf(cc_log_pos, lastof(cclog_buffer), __VA_ARGS__); \
+	DEBUG(desync, 0, "%s", cclog_buffer); \
+	if (log) log(cclog_buffer); \
+}
+
+	const uint32_t size_x = GetWaterRegionMapSizeX();
+	const uint32_t size_y = GetWaterRegionMapSizeY();
+	for (uint32_t y = 0; y < size_y; y++) {
+		for (uint32_t x = 0; x < size_x; x++) {
+			WaterRegionReference wr = GetWaterRegionRef(x, y);
+			if (!wr.IsInitialized()) continue;
+
+			const bool old_has_cross_region_aqueducts = wr.HasCrossRegionAqueducts();
+			const int old_number_of_patches = wr.NumberOfPatches();
+			const TWaterRegionPatchLabelArray old_patch_labels = wr.CopyPatchLabelArray();
+
+			wr.ForceUpdate();
+
+			if (old_has_cross_region_aqueducts != wr.HasCrossRegionAqueducts()) {
+				CCLOG("Has cross region aqueducts mismatch: %u -> %u", old_has_cross_region_aqueducts, wr.HasCrossRegionAqueducts());
+			}
+			if (old_number_of_patches != wr.NumberOfPatches()) {
+				CCLOG("Number of patches mismatch: %u -> %u", old_number_of_patches, wr.NumberOfPatches());
+			}
+			if (old_patch_labels != wr.CopyPatchLabelArray()) {
+				CCLOG("Patch label mismatch");
+			}
+		}
+	}
+#undef CCLOG
+}