Debug: Add debug zoning overlays for water regions

src/console_cmds.cpp

@@ -3342,6 +3342,7 @@ DEF_CONSOLE_CMD(ConMiscDebug)
 		IConsoleHelp("  8: MDF_ZONING_RS_ANIMATED_TILE");
 		IConsoleHelp(" 10: MDF_NEWGRF_SG_SAVE_RAW");
 		IConsoleHelp(" 20: MDF_SPECIAL_CMDS");
+		IConsoleHelp(" 40: MDF_ZONING_RS_WATER_REGION");
 		return true;
 	}
 

src/debug_settings.h

@@ -52,6 +52,7 @@ enum MiscDebugFlags {
 	MDF_ZONING_RS_ANIMATED_TILE,
 	MDF_NEWGRF_SG_SAVE_RAW,
 	MDF_SPECIAL_CMDS,
+	MDF_ZONING_RS_WATER_REGION,
 };
 extern uint32_t _misc_debug_flags;
 

src/pathfinder/water_regions.cpp

@@ -399,3 +399,43 @@ void InitializeWaterRegions()
 		}
 	}
 }
+
+uint GetWaterRegionTileDebugColourIndex(TileIndex tile)
+{
+	const uint32_t sub_x = TileX(tile) & WATER_REGION_EDGE_MASK;
+	const uint32_t sub_y = TileY(tile) & WATER_REGION_EDGE_MASK;
+
+	auto get_edge_distance = [&](uint32_t sub) -> uint32_t {
+		if (sub > WATER_REGION_EDGE_LENGTH / 2) sub = WATER_REGION_EDGE_MASK - sub;
+		return sub;
+	};
+	uint32_t mode = std::min(get_edge_distance(sub_x), get_edge_distance(sub_y));
+
+	switch (mode) {
+		case 0: {
+			const WaterRegion &wr = _water_regions[GetWaterRegionIndex(tile)];
+			if (!wr.IsInitialized()) return 1;
+
+			return 2 + wr.NumberOfPatches();
+		}
+
+		case 1: {
+			const WaterRegion &wr = _water_regions[GetWaterRegionIndex(tile)];
+			if (!wr.IsInitialized()) return 0;
+
+			if (wr.CountPatchLabelOccurence(1) == WATER_REGION_NUMBER_OF_TILES) return 2;
+
+			return 0;
+		}
+
+		case 2: {
+			const WaterRegion &wr = _water_regions[GetWaterRegionIndex(tile)];
+			if (wr.IsInitialized() && wr.HasCrossRegionAqueducts()) return 9;
+
+			return 0;
+		}
+
+		default:
+			return 0;
+	}
+}

src/zoning_cmd.cpp

@@ -287,6 +287,15 @@ SpriteID TileZoneCheckTraceRestrictEvaluation(TileIndex tile, Owner owner)
 	if (unlikely(HasBit(_misc_debug_flags, MDF_ZONING_RS_ANIMATED_TILE)) && _animated_tiles.find(tile) != _animated_tiles.end()) {
 		return SPR_ZONING_INNER_HIGHLIGHT_YELLOW;
 	}
+	if (unlikely(HasBit(_misc_debug_flags, MDF_ZONING_RS_WATER_REGION))) {
+		extern uint GetWaterRegionTileDebugColourIndex(TileIndex tile);
+		uint colour_index = GetWaterRegionTileDebugColourIndex(tile);
+		if (colour_index == 0) {
+			return ZONING_INVALID_SPRITE_ID;
+		} else {
+			return std::min<SpriteID>(SPR_ZONING_INNER_HIGHLIGHT_RED + colour_index - 1, SPR_ZONING_INNER_HIGHLIGHT_YELLOW);
+		}
+	}
 
 	return ZONING_INVALID_SPRITE_ID;
 }