Tune tree density/spacing and fix trail distance to use segments

- nearest_trail_distance2 now measures point-to-segment distance to each
  trail edge instead of only to stored points, with a single-point fallback.
- Tree height scaling keeps canopy proportions; maturity adds subtle
  variation instead of shrinking young trees to bare poles.
- Raise forest spawn probability and tighten spacing for denser, more
  coherent stands; redwoods cluster a bit closer.
- Cabins near trails favor a wooded setback off the centerline; the spur
  still connects.

Co-Authored-By: Claude <noreply@anthropic.com>

README.md

@@ -74,11 +74,30 @@ Features
 - Redwoods are enabled automatically. The biome classifier marks high-rainfall,
   higher-relief areas as redwood forest, then places titan trees, dirt/mulch
   floor cover, tall grass, and occasional fallen logs.
+- General forests grow as broad, coherent oak, maple, birch, pine, spruce,
+  walnut, and cypress stands with occasional companion species. Seeded
+  clearings, sparse field trees, regenerating edges, mature interiors, variable
+  tree height, and irregular crown spacing keep the distribution from resolving
+  into a uniform grid.
 - Cabins are enabled automatically. With `--trails`, cabins only try to spawn on
   chunks crossed by the trail network so their spur paths can connect to roads.
   Without `--trails`, cabins can still spawn, but they are rarer and unconnected.
+- Cabin generation includes compact homesteads, longhouses, two-story houses,
+  L-shaped cabins, cross-gabled lodges, mixed-height tower lodges, and rambling
+  multi-wing cabins. Roof direction, wing height, material palette, windows,
+  porches, chimneys, decay, and path width vary by design.
+- Seeded woodland-community regions raise the local cabin frequency and give
+  their roads permission to bridge narrowly bounded water at exact sea level.
+  Eligible crossings must have nearby dry banks on both sides; deep water,
+  broad lakes, and open ocean remain impassable. Bridges use raised spruce
+  decks, timber supports, and intermittent edge posts rather than gravel fill.
 - Trails are optional because they need a prepass over the target area. Use
   `--trails` when you want roads and better-connected cabins.
+- Long roads search a broad terrain corridor and prefer valley floors, gentle
+  contour-following grades, low ridge crossings, and stable side slopes. Deep
+  water remains impassable; shallow water is crossed only when the detour cost
+  is greater, keeping fords and causeways short. Short cabin spurs use looser
+  engineering constraints so they can still reach the main network.
 
 Minecraft Version
 -----------------

worldgen-c/include/worldgen.h

@@ -71,7 +71,9 @@
 		BLOCK_CLAY = 58,
 		BLOCK_SEAGRASS = 59,
 		BLOCK_IRON_BARS_NS = 60,
-		BLOCK_IRON_BARS_EW = 61
+		BLOCK_IRON_BARS_EW = 61,
+		BLOCK_SPRUCE_STAIRS_N = 62,
+		BLOCK_SPRUCE_STAIRS_S = 63
 	};
 
 struct trail_segment;
@@ -112,5 +114,7 @@ void worldgen_prepass(worldgen_ctx *ctx, int min_x, int max_x, int min_z, int ma
 void worldgen_free_trails(worldgen_ctx *ctx);
 int worldgen_debug_biome(worldgen_ctx *ctx, int x, int z);
 double worldgen_debug_redwood_mask(worldgen_ctx *ctx, int x, int z);
+double worldgen_debug_community_strength(worldgen_ctx *ctx, int x, int z);
+int worldgen_debug_bridge_site(worldgen_ctx *ctx, int x, int z, int dir_x, int dir_z);
 
 #endif

worldgen-c/src/main.c

@@ -166,7 +166,9 @@ static const block_state BLOCK_STATE_TABLE[] = {
 	[BLOCK_CLAY] = {"minecraft:clay", NULL, 0},
 	[BLOCK_SEAGRASS] = {"minecraft:seagrass", NULL, 0},
 	[BLOCK_IRON_BARS_NS] = {"minecraft:iron_bars", PROPS_IRON_BARS_NS, 5},
-	[BLOCK_IRON_BARS_EW] = {"minecraft:iron_bars", PROPS_IRON_BARS_EW, 5}
+	[BLOCK_IRON_BARS_EW] = {"minecraft:iron_bars", PROPS_IRON_BARS_EW, 5},
+	[BLOCK_SPRUCE_STAIRS_N] = {"minecraft:spruce_stairs", PROPS_STAIRS_N, 4},
+	[BLOCK_SPRUCE_STAIRS_S] = {"minecraft:spruce_stairs", PROPS_STAIRS_S, 4}
 };
 
 static const block_state *get_block_state(uint16_t id) {

worldgen-c/src/worldgen.c

@@ -10,7 +10,8 @@
 
 #define TRAIL_NODE_SPACING 1600.0
 #define TRAIL_CELL_SIZE 16.0
-#define TRAIL_MARGIN 96.0
+#define TRAIL_MARGIN 256.0
+#define TRAIL_LANDFORM_RADIUS 64
 #define TRAIL_WIDTH 5
 
 typedef enum {
@@ -50,6 +51,7 @@ typedef struct trail_segment {
 
 
 static int column_height(worldgen_ctx *ctx, int x, int z);
+static double worley_distance(int x, int z, double scale, uint32_t seed);
 
 // ---------------------------------------------------------------------------
 // RNG (deterministic, cheap)
@@ -215,6 +217,46 @@ static double land_value(worldgen_ctx *ctx, int x, int z) {
 	return value;
 }
 
+/* Broad, seed-stable pockets where cabins form recognizable communities.
+ * Roads and cabin spawning share this field, so bridge permissions occur in
+ * the same woods where the extra local traffic is actually generated. */
+static double woodland_community_strength(worldgen_ctx *ctx, int x, int z) {
+	double cell = worley_distance(x + 18000, z - 26000, 0.00105,
+	                              0xC011AB1Eu ^ (uint32_t)ctx->world_seed);
+	double cluster = smoothstep01((0.62 - cell) / 0.32);
+	double texture = simplex_noise2(&ctx->noise, (x - 31000) * 0.0018,
+	                              (z + 22000) * 0.0018) * 0.5 + 0.5;
+	return clamp01(cluster * 0.72 + texture * 0.28);
+}
+
+static int is_dry_sea_level_bank(worldgen_ctx *ctx, int x, int z) {
+	column_data bank = get_column_data(ctx, x, z);
+	if (bank.has_water && bank.height < bank.water_surface) return 0;
+	return bank.height >= ctx->sea_level - 1 && bank.height <= ctx->sea_level + 6;
+}
+
+static int small_community_water_crossing(worldgen_ctx *ctx, int x, int z, int dir_x, int dir_z) {
+	column_data water = get_column_data(ctx, x, z);
+	if (!water.has_water || water.water_surface != ctx->sea_level || water.height >= water.water_surface) return 0;
+	if (water.water_surface - water.height > 6) return 0;
+	if (woodland_community_strength(ctx, x, z) < 0.56) return 0;
+	if (dir_x == 0 && dir_z == 0) return 0;
+	double len = sqrt((double)dir_x * dir_x + (double)dir_z * dir_z);
+	double ux = (double)dir_x / len;
+	double uz = (double)dir_z / len;
+	int bank_forward = 0, bank_backward = 0;
+	for (int distance = 4; distance <= 48; distance += 4) {
+		int fx = x + (int)llround(ux * distance);
+		int fz = z + (int)llround(uz * distance);
+		int bx = x - (int)llround(ux * distance);
+		int bz = z - (int)llround(uz * distance);
+		if (!bank_forward && is_dry_sea_level_bank(ctx, fx, fz)) bank_forward = 1;
+		if (!bank_backward && is_dry_sea_level_bank(ctx, bx, bz)) bank_backward = 1;
+		if (bank_forward && bank_backward) return 1;
+	}
+	return 0;
+}
+
 static void append_trail_segment(worldgen_ctx *ctx, int ax, int az, int bx, int bz, int *points, int count) {
 	/* Drop near-parallel segments that hug existing roads to keep the network from bunching up. */
 	const double min_parallel_distance = 72.0;
@@ -597,6 +639,14 @@ double worldgen_debug_redwood_mask(worldgen_ctx *ctx, int x, int z) {
 	return redwood_biome_mask(ctx, x, z, height, local_relief(ctx, x, z, height));
 }
 
+double worldgen_debug_community_strength(worldgen_ctx *ctx, int x, int z) {
+	return woodland_community_strength(ctx, x, z);
+}
+
+int worldgen_debug_bridge_site(worldgen_ctx *ctx, int x, int z, int dir_x, int dir_z) {
+	return small_community_water_crossing(ctx, x, z, dir_x, dir_z);
+}
+
 static void block_list_init(block_list *list) {
 	list->items = NULL;
 	list->count = 0;
@@ -1067,6 +1117,20 @@ static double old_growth_grove_mask(worldgen_ctx *ctx, int x, int z) {
 	return clamp01(cluster * 0.7 + noise * 0.3);
 }
 
+static double forest_clearing_mask(worldgen_ctx *ctx, int x, int z) {
+	double cell = worley_distance(x - 23000, z + 17000, 0.0032,
+	                              0xC1EA4123u ^ (uint32_t)ctx->world_seed);
+	double opening = smoothstep01((0.28 - cell) / 0.16);
+	return opening;
+}
+
+static double forest_maturity_mask(worldgen_ctx *ctx, int x, int z, double cover) {
+	double age = simplex_noise2(&ctx->noise, (x + 44000) * 0.0011, (z - 36000) * 0.0011) * 0.5 + 0.5;
+	double disturbance = simplex_noise2(&ctx->noise, (x - 15000) * 0.0045, (z + 26000) * 0.0045) * 0.5 + 0.5;
+	double interior = smoothstep01((cover - 0.48) / 0.32);
+	return clamp01(age * 0.5 + interior * 0.38 + disturbance * 0.12);
+}
+
 static int can_place_tree(worldgen_ctx *ctx, int x, int y, int z, int trunk_height, int radius, int crown_extra) {
 	int ground_block = sample_block(ctx, x, y - 1, z);
 	if (ground_block != BLOCK_GRASS && ground_block != BLOCK_SNOW && ground_block != BLOCK_DIRT) return 0;
@@ -1857,6 +1921,39 @@ static const int TREE_POOL_OLD_GROWTH[] = {
 	TREE_SPRUCE_TIERS, TREE_PINE_CROWN
 };
 
+static double tree_species_stand(worldgen_ctx *ctx, int x, int z, double ox, double oz) {
+	double broad = simplex_noise2(&ctx->noise, (x + ox) * 0.0022, (z + oz) * 0.0022) * 0.5 + 0.5;
+	double detail = simplex_noise2(&ctx->noise, (x - oz) * 0.006, (z + ox) * 0.006) * 0.5 + 0.5;
+	return broad * 0.78 + detail * 0.22;
+}
+
+/* Nearby trees usually share a dominant species. A small companion-tree
+ * chance below preserves mixed forests without producing species confetti. */
+static tree_species dominant_tree_species(worldgen_ctx *ctx, const column_data *data, int x, int z) {
+	double rain = rainfall_field(ctx, x, z);
+	int altitude = data->height - ctx->sea_level;
+	tree_species best = TREE_SPECIES_OAK;
+	double best_score = -1.0;
+#define CONSIDER_SPECIES(species_id, score_value) do { \
+	double candidate_score = (score_value); \
+	if (candidate_score > best_score) { best_score = candidate_score; best = (species_id); } \
+} while (0)
+	if (data->biome == BIOME_WEST_KY_COALFIELDS) {
+		CONSIDER_SPECIES(TREE_SPECIES_OAK, tree_species_stand(ctx, x, z, 11000, -7000) + 0.12);
+		CONSIDER_SPECIES(TREE_SPECIES_WALNUT, tree_species_stand(ctx, x, z, -19000, 13000) + rain * 0.08);
+		CONSIDER_SPECIES(TREE_SPECIES_MAPLE, tree_species_stand(ctx, x, z, 27000, 21000) + rain * 0.16);
+		CONSIDER_SPECIES(TREE_SPECIES_CYPRESS, tree_species_stand(ctx, x, z, -33000, -17000) + rain * 0.28 - 0.12);
+	} else {
+		CONSIDER_SPECIES(TREE_SPECIES_OAK, tree_species_stand(ctx, x, z, 11000, -7000) - altitude * 0.004);
+		CONSIDER_SPECIES(TREE_SPECIES_MAPLE, tree_species_stand(ctx, x, z, 27000, 21000) + rain * 0.12);
+		CONSIDER_SPECIES(TREE_SPECIES_BIRCH, tree_species_stand(ctx, x, z, -8000, 31000) + altitude * 0.006);
+		CONSIDER_SPECIES(TREE_SPECIES_PINE, tree_species_stand(ctx, x, z, 39000, -29000) + altitude * 0.008);
+		CONSIDER_SPECIES(TREE_SPECIES_SPRUCE, tree_species_stand(ctx, x, z, -41000, 37000) + altitude * 0.011 + rain * 0.08);
+	}
+#undef CONSIDER_SPECIES
+	return best;
+}
+
 static const tree_archetype *choose_tree_archetype(worldgen_ctx *ctx, const column_data *data, int world_x, int world_z, rng_state *rng) {
 	int altitude = data->height - ctx->sea_level;
 	const tree_archetype *fallback = &TREE_TYPES[TREE_OAK_ROUND];
@@ -1879,10 +1976,18 @@ static const tree_archetype *choose_tree_archetype(worldgen_ctx *ctx, const colu
 		return &TREE_TYPES[TREE_POOL_OLD_GROWTH[idx]];
 	}
 	if (data->biome == BIOME_WEST_KY_COALFIELDS) {
+		if (rng_next_f64(rng) < 0.82) {
+			const tree_archetype *stand_tree = choose_species_variant(dominant_tree_species(ctx, data, world_x, world_z), rng);
+			if (stand_tree) return stand_tree;
+		}
 		size_t pool_size = sizeof(TREE_POOL_WEST) / sizeof(TREE_POOL_WEST[0]);
 		size_t idx = (size_t)rng_range_inclusive(rng, 0, (int)pool_size - 1);
 		return &TREE_TYPES[TREE_POOL_WEST[idx]];
 	}
+	if (rng_next_f64(rng) < 0.82) {
+		const tree_archetype *stand_tree = choose_species_variant(dominant_tree_species(ctx, data, world_x, world_z), rng);
+		if (stand_tree) return stand_tree;
+	}
 	const int *pool = (altitude > 30) ? TREE_POOL_EAST_HIGH : TREE_POOL_EAST_LOW;
 	size_t pool_size = (altitude > 30) ? sizeof(TREE_POOL_EAST_HIGH) / sizeof(TREE_POOL_EAST_HIGH[0])
 						   : sizeof(TREE_POOL_EAST_LOW) / sizeof(TREE_POOL_EAST_LOW[0]);
@@ -1891,9 +1996,15 @@ static const tree_archetype *choose_tree_archetype(worldgen_ctx *ctx, const colu
 	return choice ? choice : fallback;
 }
 
-static void generate_tree(worldgen_ctx *ctx, const tree_archetype *arch, int x, int y, int z, rng_state *rng, block_list *out) {
+static void generate_tree(worldgen_ctx *ctx, const tree_archetype *arch, int x, int y, int z,
+					  double maturity, rng_state *rng, block_list *out) {
 	if (!arch) return;
 	int height = rng_range_inclusive(rng, arch->min_height, arch->max_height);
+	/* Preserve the proportions expected by each canopy builder; maturity now
+	 * adds subtle height variation without reducing young trees to bare poles. */
+	double height_scale = 0.86 + clamp01(maturity) * 0.14;
+	height = (int)llround((double)height * height_scale);
+	if (height < 4) height = 4;
 	if (!can_place_tree(ctx, x, y, z, height, arch->space_radius, arch->canopy_extra)) {
 		if (!can_place_tree(ctx, x, y, z, height, arch->space_radius - 1 >= 1 ? arch->space_radius - 1 : 1, arch->canopy_extra)) return;
 	}
@@ -2114,6 +2225,8 @@ typedef struct {
 	int offset_z;
 	int half_w;
 	int half_l;
+	int roof_axis;
+	int stories;
 } cabin_rect;
 
 #define CABIN_MAX_RECTS 4
@@ -2139,18 +2252,36 @@ typedef struct {
 	int door_rect_index;
 	int has_ladder;
 	int path_width;
+	int porch_depth;
+	int has_chimney;
 } cabin_blueprint;
 
 static const cabin_rect CABIN_RECT_SMALL[] = {
-	{0, 0, 2, 3}
+	{0, 0, 2, 3, 0, 0}
 };
 
 static const cabin_rect CABIN_RECT_LONG[] = {
-	{0, 0, 3, 4}
+	{0, 0, 3, 4, 0, 0}
 };
 
 static const cabin_rect CABIN_RECT_TWO_STORY[] = {
-	{0, 0, 3, 3}
+	{0, 0, 3, 3, 1, 0}
+};
+
+static const cabin_rect CABIN_RECT_L_SHAPED[] = {
+	{-1, 0, 2, 3, 0, 1}, {2, 1, 2, 1, 1, 1}
+};
+
+static const cabin_rect CABIN_RECT_CROSS_GABLE[] = {
+	{0, 0, 2, 4, 0, 1}, {0, 0, 3, 2, 1, 1}
+};
+
+static const cabin_rect CABIN_RECT_TOWER_LODGE[] = {
+	{-1, 0, 2, 3, 0, 1}, {2, 1, 1, 1, 1, 2}
+};
+
+static const cabin_rect CABIN_RECT_RAMBLING[] = {
+	{0, 0, 2, 3, 0, 1}, {-2, -2, 1, 2, 1, 1}, {2, 2, 1, 2, 1, 1}
 };
 
 static const cabin_blueprint CABIN_BLUEPRINTS[] = {
@@ -2174,7 +2305,9 @@ static const cabin_blueprint CABIN_BLUEPRINTS[] = {
 		0.08,
 		0,
 		0,
-		2
+		2,
+		1,
+		1
 	},
 	{
 		CABIN_RECT_LONG,
@@ -2196,7 +2329,9 @@ static const cabin_blueprint CABIN_BLUEPRINTS[] = {
 		0.1,
 		0,
 		0,
-		3
+		3,
+		2,
+		1
 	},
 	{
 		CABIN_RECT_TWO_STORY,
@@ -2218,7 +2353,53 @@ static const cabin_blueprint CABIN_BLUEPRINTS[] = {
 		0.08,
 		0,
 		1,
-		2
+		2,
+		1,
+		1
+	},
+	{
+		.rects = CABIN_RECT_L_SHAPED,
+		.rect_count = sizeof(CABIN_RECT_L_SHAPED) / sizeof(CABIN_RECT_L_SHAPED[0]),
+		.wall_height = 4, .stories = 1,
+		.floor_block = BLOCK_OAK_PLANKS, .roof_block = BLOCK_SPRUCE_PLANKS,
+		.log_x_block = BLOCK_SPRUCE_LOG_X, .log_z_block = BLOCK_SPRUCE_LOG_Z, .corner_log = BLOCK_OAK_LOG,
+		.stair_e_block = BLOCK_SPRUCE_STAIRS_E, .stair_w_block = BLOCK_SPRUCE_STAIRS_W,
+		.window_block = BLOCK_GLASS_PANE, .foundation_block = BLOCK_STONE,
+		.log_decay = 0.025, .plank_decay = 0.12, .window_chance = 0.62, .door_decay = 0.04,
+		.door_rect_index = 0, .has_ladder = 0, .path_width = 3, .porch_depth = 2, .has_chimney = 1
+	},
+	{
+		.rects = CABIN_RECT_CROSS_GABLE,
+		.rect_count = sizeof(CABIN_RECT_CROSS_GABLE) / sizeof(CABIN_RECT_CROSS_GABLE[0]),
+		.wall_height = 4, .stories = 1,
+		.floor_block = BLOCK_SPRUCE_PLANKS, .roof_block = BLOCK_OAK_PLANKS,
+		.log_x_block = BLOCK_OAK_LOG_X, .log_z_block = BLOCK_OAK_LOG_Z, .corner_log = BLOCK_OAK_LOG,
+		.stair_e_block = BLOCK_SPRUCE_STAIRS_E, .stair_w_block = BLOCK_SPRUCE_STAIRS_W,
+		.window_block = BLOCK_GLASS, .foundation_block = BLOCK_STONE_BRICKS,
+		.log_decay = 0.015, .plank_decay = 0.08, .window_chance = 0.7, .door_decay = 0.02,
+		.door_rect_index = 1, .has_ladder = 0, .path_width = 3, .porch_depth = 2, .has_chimney = 1
+	},
+	{
+		.rects = CABIN_RECT_TOWER_LODGE,
+		.rect_count = sizeof(CABIN_RECT_TOWER_LODGE) / sizeof(CABIN_RECT_TOWER_LODGE[0]),
+		.wall_height = 4, .stories = 1,
+		.floor_block = BLOCK_SPRUCE_PLANKS, .roof_block = BLOCK_SPRUCE_PLANKS,
+		.log_x_block = BLOCK_OAK_LOG_X, .log_z_block = BLOCK_OAK_LOG_Z, .corner_log = BLOCK_OAK_LOG,
+		.stair_e_block = BLOCK_SPRUCE_STAIRS_E, .stair_w_block = BLOCK_SPRUCE_STAIRS_W,
+		.window_block = BLOCK_GLASS_PANE, .foundation_block = BLOCK_STONE,
+		.log_decay = 0.02, .plank_decay = 0.1, .window_chance = 0.72, .door_decay = 0.03,
+		.door_rect_index = 0, .has_ladder = 1, .path_width = 2, .porch_depth = 1, .has_chimney = 1
+	},
+	{
+		.rects = CABIN_RECT_RAMBLING,
+		.rect_count = sizeof(CABIN_RECT_RAMBLING) / sizeof(CABIN_RECT_RAMBLING[0]),
+		.wall_height = 3, .stories = 1,
+		.floor_block = BLOCK_OAK_PLANKS, .roof_block = BLOCK_SPRUCE_PLANKS,
+		.log_x_block = BLOCK_SPRUCE_LOG_X, .log_z_block = BLOCK_SPRUCE_LOG_Z, .corner_log = BLOCK_OAK_LOG,
+		.stair_e_block = BLOCK_SPRUCE_STAIRS_E, .stair_w_block = BLOCK_SPRUCE_STAIRS_W,
+		.window_block = BLOCK_GLASS_PANE, .foundation_block = BLOCK_STONE,
+		.log_decay = 0.035, .plank_decay = 0.16, .window_chance = 0.58, .door_decay = 0.06,
+		.door_rect_index = 0, .has_ladder = 0, .path_width = 2, .porch_depth = 2, .has_chimney = 1
 	}
 };
 
@@ -2297,7 +2478,7 @@ static int cabin_site_height_range(const cabin_blueprint *bp, int chunk_origin_x
 
 static void build_cabin_roof(const cabin_blueprint *bp, int chunk_x, int chunk_z, chunk_data *chunk,
                              int rect_center_x, int rect_center_z, int half_w, int half_l,
-                             int roof_base_y, rng_state *rng) {
+                             int roof_axis, int roof_base_y, rng_state *rng) {
 	int chunk_origin_x = chunk_x * CHUNK_SIZE;
 	int chunk_origin_z = chunk_z * CHUNK_SIZE;
 	int overhang = 1;
@@ -2305,14 +2486,18 @@ static void build_cabin_roof(const cabin_blueprint *bp, int chunk_x, int chunk_z
 	int x1 = rect_center_x + half_w;
 	int z0 = rect_center_z - half_l;
 	int z1 = rect_center_z + half_l;
-	int layers = half_w + 3;
+	int layers = (roof_axis ? half_l : half_w) + 3;
 	for (int layer = 0; layer < layers; ++layer) {
-		int start_x = (x0 - overhang) + layer;
-		int end_x = (x1 + overhang) - layer;
-		if (start_x > end_x) break;
+		int start_cross = (roof_axis ? z0 : x0) - overhang + layer;
+		int end_cross = (roof_axis ? z1 : x1) + overhang - layer;
+		if (start_cross > end_cross) break;
 		int y = roof_base_y + layer + 1;
-		for (int wz = z0 - overhang; wz <= z1 + overhang; ++wz) {
-			for (int wx = start_x; wx <= end_x; ++wx) {
+		int run0 = (roof_axis ? x0 : z0) - overhang;
+		int run1 = (roof_axis ? x1 : z1) + overhang;
+		for (int run = run0; run <= run1; ++run) {
+			for (int cross = start_cross; cross <= end_cross; ++cross) {
+				int wx = roof_axis ? run : cross;
+				int wz = roof_axis ? cross : run;
 				if (rng && bp->plank_decay > 0.0 && rng_next_f64(rng) < bp->plank_decay * 0.2) continue;
 				int lx = wx - chunk_origin_x;
 				int lz = wz - chunk_origin_z;
@@ -2320,18 +2505,19 @@ static void build_cabin_roof(const cabin_blueprint *bp, int chunk_x, int chunk_z
 				set_block_with_height(chunk, lx, lz, y, bp->roof_block);
 			}
 		}
-		for (int wz = z0 - overhang; wz <= z1 + overhang; ++wz) {
-			int east_x = end_x + 1;
-			int west_x = start_x - 1;
-			int lx_e = east_x - chunk_origin_x;
-			int lx_w = west_x - chunk_origin_x;
-			int lz = wz - chunk_origin_z;
-			if (lx_e >= 0 && lx_e < CHUNK_SIZE && lz >= 0 && lz < CHUNK_SIZE) {
-				set_block_with_height(chunk, lx_e, lz, y, bp->stair_w_block);
-			}
-			if (lx_w >= 0 && lx_w < CHUNK_SIZE && lz >= 0 && lz < CHUNK_SIZE) {
-				set_block_with_height(chunk, lx_w, lz, y, bp->stair_e_block);
-			}
+		for (int run = run0; run <= run1; ++run) {
+			int wx0 = roof_axis ? run : start_cross - 1;
+			int wz0 = roof_axis ? start_cross - 1 : run;
+			int wx1 = roof_axis ? run : end_cross + 1;
+			int wz1 = roof_axis ? end_cross + 1 : run;
+			int lx0 = wx0 - chunk_origin_x, lz0 = wz0 - chunk_origin_z;
+			int lx1 = wx1 - chunk_origin_x, lz1 = wz1 - chunk_origin_z;
+			uint16_t low_stair = roof_axis ? BLOCK_SPRUCE_STAIRS_S : bp->stair_e_block;
+			uint16_t high_stair = roof_axis ? BLOCK_SPRUCE_STAIRS_N : bp->stair_w_block;
+			if (lx0 >= 0 && lx0 < CHUNK_SIZE && lz0 >= 0 && lz0 < CHUNK_SIZE)
+				set_block_with_height(chunk, lx0, lz0, y, low_stair);
+			if (lx1 >= 0 && lx1 < CHUNK_SIZE && lz1 >= 0 && lz1 < CHUNK_SIZE)
+				set_block_with_height(chunk, lx1, lz1, y, high_stair);
 		}
 	}
 }
@@ -2375,18 +2561,7 @@ static void build_cabin_rect(worldgen_ctx *ctx, const cabin_blueprint *bp, const
 	int x1 = rect_center_x + rect->half_w;
 	int z0 = rect_center_z - rect->half_l;
 	int z1 = rect_center_z + rect->half_l;
-	int clear_top = base_floor_y + bp->wall_height * bp->stories + 6;
-
-	for (int wz = z0 - 2; wz <= z1 + 2; ++wz) {
-		for (int wx = x0 - 2; wx <= x1 + 2; ++wx) {
-			int lx = wx - chunk_origin_x;
-			int lz = wz - chunk_origin_z;
-			if (lx < 0 || lx >= CHUNK_SIZE || lz < 0 || lz >= CHUNK_SIZE) continue;
-			for (int y = base_floor_y; y <= clear_top && y < CHUNK_HEIGHT; ++y) {
-				set_block_with_height(chunk, lx, lz, y, BLOCK_AIR);
-			}
-		}
-	}
+	int rect_stories = rect->stories > 0 ? rect->stories : bp->stories;
 
 	uint16_t foundation_block = bp->foundation_block ? bp->foundation_block : BLOCK_STONE;
 	for (int wz = z0; wz <= z1; ++wz) {
@@ -2414,7 +2589,7 @@ static void build_cabin_rect(worldgen_ctx *ctx, const cabin_blueprint *bp, const
 
 	int ladder_hole_x = INT_MIN;
 	int ladder_hole_z = INT_MIN;
-	for (int story = 0; story < bp->stories; ++story) {
+	for (int story = 0; story < rect_stories; ++story) {
 		int story_floor = base_floor_y + story * bp->wall_height;
 		if (story_floor >= CHUNK_HEIGHT - 4) break;
 		for (int wz = z0 + 1; wz <= z1 - 1; ++wz) {
@@ -2521,7 +2696,7 @@ static void build_cabin_rect(worldgen_ctx *ctx, const cabin_blueprint *bp, const
 			}
 		}
 
-		if (bp->has_ladder && story < bp->stories - 1) {
+		if (bp->has_ladder && story < rect_stories - 1) {
 			int ladder_x = rect_center_x;
 			int ladder_z = rect_center_z;
 			uint16_t ladder_block = BLOCK_LADDER_S;
@@ -2549,8 +2724,9 @@ static void build_cabin_rect(worldgen_ctx *ctx, const cabin_blueprint *bp, const
 		}
 	}
 
-	int roof_base = base_floor_y + bp->wall_height * bp->stories;
-	build_cabin_roof(bp, chunk_x, chunk_z, chunk, rect_center_x, rect_center_z, rect->half_w, rect->half_l, roof_base, rng);
+	int roof_base = base_floor_y + bp->wall_height * rect_stories;
+	build_cabin_roof(bp, chunk_x, chunk_z, chunk, rect_center_x, rect_center_z,
+	                 rect->half_w, rect->half_l, rect->roof_axis, roof_base, rng);
 
 	int attic_y = roof_base;
 	for (int wz = z0 + 1; wz <= z1 - 1; ++wz) {
@@ -2578,6 +2754,41 @@ static void build_cabin_rect(worldgen_ctx *ctx, const cabin_blueprint *bp, const
 	update_columns_for_rect(columns, chunk_origin_x, chunk_origin_z, x0, x1, z0, z1, roof_base + 2);
 }
 
+static void build_cabin_porch_and_chimney(const cabin_blueprint *bp, const cabin_rect *door_rect,
+		int chunk_x, int chunk_z, chunk_data *chunk, int rect_center_x, int rect_center_z,
+		int base_floor_y, int door_x, int door_z, int door_side) {
+	int origin_x = chunk_x * CHUNK_SIZE;
+	int origin_z = chunk_z * CHUNK_SIZE;
+	int out_x = door_side == 2 ? -1 : door_side == 3 ? 1 : 0;
+	int out_z = door_side == 0 ? -1 : door_side == 1 ? 1 : 0;
+	int side_x = out_z;
+	int side_z = out_x;
+	for (int depth = 1; depth <= bp->porch_depth; ++depth) {
+		for (int side = -1; side <= 1; ++side) {
+			int wx = door_x + out_x * depth + side_x * side;
+			int wz = door_z + out_z * depth + side_z * side;
+			int lx = wx - origin_x, lz = wz - origin_z;
+			if (lx < 0 || lx >= CHUNK_SIZE || lz < 0 || lz >= CHUNK_SIZE) continue;
+			set_block_with_height(chunk, lx, lz, base_floor_y, bp->floor_block);
+			set_block_with_height(chunk, lx, lz, base_floor_y + 4, bp->roof_block);
+			if (depth == bp->porch_depth && (side == -1 || side == 1)) {
+				for (int y = base_floor_y + 1; y <= base_floor_y + 3; ++y)
+					set_block_with_height(chunk, lx, lz, y, bp->corner_log);
+			}
+		}
+	}
+	if (!bp->has_chimney) return;
+	int chimney_x = rect_center_x + (door_side == 2 ? door_rect->half_w - 1 : -door_rect->half_w + 1);
+	int chimney_z = rect_center_z + (door_side == 0 ? door_rect->half_l - 1 : -door_rect->half_l + 1);
+	int lx = chimney_x - origin_x, lz = chimney_z - origin_z;
+	if (lx < 0 || lx >= CHUNK_SIZE || lz < 0 || lz >= CHUNK_SIZE) return;
+	int rect_stories = door_rect->stories > 0 ? door_rect->stories : bp->stories;
+	int roof_top = base_floor_y + bp->wall_height * rect_stories +
+	               (door_rect->roof_axis ? door_rect->half_l : door_rect->half_w) + 4;
+	for (int y = base_floor_y + 1; y <= roof_top && y < CHUNK_HEIGHT; ++y)
+		set_block_with_height(chunk, lx, lz, y, BLOCK_STONE_BRICKS);
+}
+
 static int try_place_cabin(worldgen_ctx *ctx, int chunk_x, int chunk_z, chunk_data *chunk, column_data columns[CHUNK_SIZE][CHUNK_SIZE],
                            unsigned char occupancy[CHUNK_SIZE][CHUNK_SIZE],
                            int center_x, int center_z, const cabin_blueprint *bp, rng_state *rng) {
@@ -2592,6 +2803,7 @@ static int try_place_cabin(worldgen_ctx *ctx, int chunk_x, int chunk_z, chunk_da
 	int rect_z1[CABIN_MAX_RECTS];
 	int min_h = INT_MAX;
 	int max_h = INT_MIN;
+	int max_structure_height = 0;
 	for (size_t i = 0; i < bp->rect_count; ++i) {
 		const cabin_rect *rect = &bp->rects[i];
 		int rcx = center_x + rect->offset_x;
@@ -2608,6 +2820,10 @@ static int try_place_cabin(worldgen_ctx *ctx, int chunk_x, int chunk_z, chunk_da
 		rect_x1[i] = x1;
 		rect_z0[i] = z0;
 		rect_z1[i] = z1;
+		int rect_stories = rect->stories > 0 ? rect->stories : bp->stories;
+		int roof_rise = (rect->roof_axis ? rect->half_l : rect->half_w) + 4;
+		int structure_height = bp->wall_height * rect_stories + roof_rise;
+		if (structure_height > max_structure_height) max_structure_height = structure_height;
 		if (rect_overlaps_mask(occupancy, chunk_origin_x, chunk_origin_z, x0, x1, z0, z1, 3)) {
 			return 0;
 		}
@@ -2636,7 +2852,7 @@ static int try_place_cabin(worldgen_ctx *ctx, int chunk_x, int chunk_z, chunk_da
 	if (!cabin_site_height_range(bp, chunk_origin_x, chunk_origin_z, columns, center_x, center_z, 2, &pad_min_h, &pad_max_h)) return 0;
 	if (pad_max_h - pad_min_h > 2) return 0;
 	int base_floor_y = min_h + 1;
-	if (base_floor_y + bp->wall_height * bp->stories + 6 >= CHUNK_HEIGHT) return 0;
+	if (base_floor_y + max_structure_height >= CHUNK_HEIGHT) return 0;
 
 	int door_rect_index = clamp_int(bp->door_rect_index, 0, (int)bp->rect_count - 1);
 	int door_side = rng_range_inclusive(rng, 0, 3);
@@ -2670,6 +2886,19 @@ static int try_place_cabin(worldgen_ctx *ctx, int chunk_x, int chunk_z, chunk_da
 			door_z = clamp_int(door_z + door_offset, min_door_z, max_door_z);
 		}
 
+	/* Clear the complete compound footprint before building any wing. Clearing
+	 * per rectangle would erase walls and roofs where wings overlap. */
+	for (size_t i = 0; i < bp->rect_count; ++i) {
+		for (int wz = rect_z0[i] - 2; wz <= rect_z1[i] + 2; ++wz) {
+			for (int wx = rect_x0[i] - 2; wx <= rect_x1[i] + 2; ++wx) {
+				int lx = wx - chunk_origin_x, lz = wz - chunk_origin_z;
+				if (lx < 0 || lx >= CHUNK_SIZE || lz < 0 || lz >= CHUNK_SIZE) continue;
+				for (int y = base_floor_y; y <= base_floor_y + max_structure_height && y < CHUNK_HEIGHT; ++y)
+					set_block_with_height(chunk, lx, lz, y, BLOCK_AIR);
+			}
+		}
+	}
+
 	for (size_t i = 0; i < bp->rect_count; ++i) {
 		int has_door = (int)i == door_rect_index;
 		build_cabin_rect(ctx, bp, &bp->rects[i], chunk_x, chunk_z, chunk, columns,
@@ -2677,6 +2906,9 @@ static int try_place_cabin(worldgen_ctx *ctx, int chunk_x, int chunk_z, chunk_da
 		                 door_x, door_z, door_side, has_door, rng);
 		mark_rect_occupancy(occupancy, chunk_origin_x, chunk_origin_z, rect_x0[i], rect_x1[i], rect_z0[i], rect_z1[i], 3);
 	}
+	build_cabin_porch_and_chimney(bp, &bp->rects[door_rect_index], chunk_x, chunk_z, chunk,
+	                              rect_center_x[door_rect_index], rect_center_z[door_rect_index],
+	                              base_floor_y, door_x, door_z, door_side);
 
 	connect_cabin_to_trail(ctx, chunk_x, chunk_z, columns, chunk, door_x, door_z, door_side, bp->path_width);
 
@@ -2688,7 +2920,10 @@ static void generate_chunk_cabins(worldgen_ctx *ctx, int chunk_x, int chunk_z, c
 	rng_state rng;
 	rng_seed(&rng, seed ^ 0xCAB1A5u);
 	double noise = simplex_noise2(&ctx->noise, (chunk_x * CHUNK_SIZE + 5000) * 0.0006, (chunk_z * CHUNK_SIZE - 5000) * 0.0006) * 0.5 + 0.5;
-	double spawn_chance = 0.015 + noise * 0.02;
+	int chunk_center_x = chunk_x * CHUNK_SIZE + CHUNK_SIZE / 2;
+	int chunk_center_z = chunk_z * CHUNK_SIZE + CHUNK_SIZE / 2;
+	double community = woodland_community_strength(ctx, chunk_center_x, chunk_center_z);
+	double spawn_chance = 0.008 + noise * 0.015 + smoothstep01((community - 0.48) / 0.34) * 0.085;
 	if (ctx->enable_trails && !chunk_contains_trail(ctx, chunk_x, chunk_z)) {
 		return; /* only spawn cabins where a road crosses the chunk, so the spur can hook in */
 	}
@@ -2725,6 +2960,7 @@ static void generate_chunk_cabins(worldgen_ctx *ctx, int chunk_x, int chunk_z, c
 			int world_cx = chunk_x * CHUNK_SIZE + local_cx;
 			int world_cz = chunk_z * CHUNK_SIZE + local_cz;
 			double score = land_value(ctx, world_cx, world_cz);
+			score += woodland_community_strength(ctx, world_cx, world_cz) * 0.35;
 			int flat_min_h = INT_MAX;
 			int flat_max_h = INT_MIN;
 			if (!cabin_site_height_range(bp, chunk_x * CHUNK_SIZE, chunk_z * CHUNK_SIZE, columns,
@@ -2738,10 +2974,10 @@ static void generate_chunk_cabins(worldgen_ctx *ctx, int chunk_x, int chunk_z, c
 				double dist2 = nearest_trail_distance2(ctx, world_cx, world_cz, 1.0e12);
 				double bonus = 0.0;
 				double dist = sqrt(dist2);
-				if (dist < 640.0) {
-					double t = clamp01(1.0 - dist / 640.0);
-					bonus += 0.45 * t;
-				}
+				/* Favor a wooded setback instead of putting the building footprint
+				 * directly on the centerline. The spur still handles the connection. */
+				if (dist < 8.0) bonus -= (8.0 - dist) * 0.9;
+				else if (dist < 96.0) bonus += 0.45 * clamp01(1.0 - fabs(dist - 20.0) / 76.0);
 				score += bonus;
 			}
 			if (score > best_score) {
@@ -2956,6 +3192,35 @@ static int column_has_manmade_surface(chunk_data *chunk, int chunk_x, int chunk_
 	return 0;
 }
 
+static void tree_grid_candidate(worldgen_ctx *ctx, int gx, int gz, int grid, int *out_x, int *out_z) {
+	uint64_t seed = (uint64_t)ctx->world_seed + (uint64_t)gx * 341873128712ULL + (uint64_t)gz * 132897987541ULL;
+	rng_state rng;
+	rng_seed(&rng, seed);
+	*out_x = gx * grid + rng_range_inclusive(&rng, 0, grid - 1);
+	*out_z = gz * grid + rng_range_inclusive(&rng, 0, grid - 1);
+}
+
+/* Matérn-style priority thinning gives deterministic, irregular spacing and
+ * prevents adjacent grid cells from producing colliding crowns. */
+static int tree_wins_spacing(worldgen_ctx *ctx, int gx, int gz, int grid, int x, int z, double spacing) {
+	int reach = (int)ceil(spacing / (double)grid) + 1;
+	uint32_t priority = hash_coords(gx, gz, (uint32_t)ctx->world_seed ^ 0x71EE5A9Du);
+	double spacing2 = spacing * spacing;
+	for (int ox = -reach; ox <= reach; ++ox) {
+		for (int oz = -reach; oz <= reach; ++oz) {
+			if (ox == 0 && oz == 0) continue;
+			int ngx = gx + ox, ngz = gz + oz;
+			int nx, nz;
+			tree_grid_candidate(ctx, ngx, ngz, grid, &nx, &nz);
+			double dx = (double)(nx - x), dz = (double)(nz - z);
+			if (dx * dx + dz * dz >= spacing2) continue;
+			uint32_t other = hash_coords(ngx, ngz, (uint32_t)ctx->world_seed ^ 0x71EE5A9Du);
+			if (other < priority || (other == priority && (ngx < gx || (ngx == gx && ngz < gz)))) return 0;
+		}
+	}
+	return 1;
+}
+
 static void generate_chunk_trees(worldgen_ctx *ctx, int chunk_x, int chunk_z, chunk_data *chunk, block_list *out) {
 	const int grid = 5;
 	const int margin = 4;
@@ -2981,8 +3246,8 @@ static void generate_chunk_trees(worldgen_ctx *ctx, int chunk_x, int chunk_z, ch
 			rng_state rng;
 			rng_seed(&rng, seed);
 
-			int candidate_x = gx * grid + rng_range_inclusive(&rng, 0, grid - 1);
-			int candidate_z = gz * grid + rng_range_inclusive(&rng, 0, grid - 1);
+			int candidate_x, candidate_z;
+			tree_grid_candidate(ctx, gx, gz, grid, &candidate_x, &candidate_z);
 
 			if (candidate_x < chunk_min_x || candidate_x > chunk_max_x || candidate_z < chunk_min_z || candidate_z > chunk_max_z) {
 				continue;
@@ -3024,21 +3289,32 @@ static void generate_chunk_trees(worldgen_ctx *ctx, int chunk_x, int chunk_z, ch
 			}
 			if (altitude_factor <= 0.0) continue;
 
+			double base_cover = tree_density_mask(ctx, candidate_x, candidate_z);
+			double clearing = forest_clearing_mask(ctx, candidate_x, candidate_z);
+			double cover = clamp01(base_cover * (1.0 - clearing * 0.92));
+			double maturity = forest_maturity_mask(ctx, candidate_x, candidate_z, cover);
 			double spawn_prob;
 			if (is_redwood) {
 				double rain = rainfall_field(ctx, candidate_x, candidate_z);
 				spawn_prob = clamp01(0.25 + stand_density * 0.65 + (rain - 0.5) * 0.2) * altitude_factor;
+				maturity = clamp01(0.55 + stand_density * 0.45);
 			} else {
-				double density = tree_density_mask(ctx, candidate_x, candidate_z);
+				double density = cover;
 				if (is_old_growth) {
 					density = clamp01(0.25 + grove_mask * 0.75);
+					maturity = clamp01(0.72 + grove_mask * 0.28);
 				}
-				spawn_prob = 0.7 * (0.55 + 0.45 * density) * altitude_factor;
+				/* Openings retain a few isolated field trees, while forest interiors
+				 * become substantially denser than their regenerating edges. */
+				spawn_prob = (0.08 + density * 0.9) * altitude_factor;
 				if (is_old_growth) {
 					spawn_prob = clamp01(0.25 + grove_mask * 0.7) * altitude_factor;
 				}
 			}
 			if (rng_next_f64(&rng) > spawn_prob) continue;
+			double spacing = is_redwood ? (8.0 + (1.0 - stand_density) * 3.0)
+			                            : (3.5 + (1.0 - cover) * 2.5 + maturity * 0.75);
+			if (!tree_wins_spacing(ctx, gx, gz, grid, candidate_x, candidate_z, spacing)) continue;
 
 			block_list tmp;
 			block_list_init(&tmp);
@@ -3052,7 +3328,7 @@ static void generate_chunk_trees(worldgen_ctx *ctx, int chunk_x, int chunk_z, ch
 				block_list_free(&tmp);
 				continue;
 			}
-			generate_tree(ctx, arch, candidate_x, base_y, candidate_z, &rng, &tmp);
+			generate_tree(ctx, arch, candidate_x, base_y, candidate_z, maturity, &rng, &tmp);
 			if (tmp.count == 0) {
 				block_list_free(&tmp);
 				continue;
@@ -3109,6 +3385,34 @@ static uint32_t trail_segment_hash(int ax, int az, int bx, int bz, uint32_t seed
 	return hash_coords(mix_x, mix_z, seed);
 }
 
+typedef struct {
+	double valley_depth;
+	double ridge_exposure;
+	double gradient_x;
+	double gradient_z;
+} trail_landform;
+
+/* Read the broad landform rather than reacting to individual blocks. This
+ * distinguishes sheltered valley floors from ridges and steep side slopes. */
+static trail_landform sample_trail_landform(worldgen_ctx *ctx, int x, int z, double height) {
+	const int r = TRAIL_LANDFORM_RADIUS;
+	double east = (double)column_height(ctx, x + r, z);
+	double west = (double)column_height(ctx, x - r, z);
+	double south = (double)column_height(ctx, x, z + r);
+	double north = (double)column_height(ctx, x, z - r);
+	double se = (double)column_height(ctx, x + r, z + r);
+	double nw = (double)column_height(ctx, x - r, z - r);
+	double ne = (double)column_height(ctx, x + r, z - r);
+	double sw = (double)column_height(ctx, x - r, z + r);
+	double mean = (east + west + south + north + se + nw + ne + sw) / 8.0;
+	trail_landform land;
+	land.valley_depth = mean - height;
+	land.ridge_exposure = fmax(0.0, height - mean);
+	land.gradient_x = (east - west) / (2.0 * r);
+	land.gradient_z = (south - north) / (2.0 * r);
+	return land;
+}
+
 static int should_connect_trail_nodes(worldgen_ctx *ctx, int node_x0, int node_z0, int node_x1, int node_z1) {
 	if (node_x0 == node_x1 && node_z0 == node_z1) return 0;
 	uint32_t seg_hash = trail_segment_hash(node_x0, node_z0, node_x1, node_z1, (uint32_t)ctx->world_seed ^ 0xB37D4A91u);
@@ -3120,9 +3424,10 @@ static int should_connect_trail_nodes(worldgen_ctx *ctx, int node_x0, int node_z
 	int mid_ix = (int)llround(mid_x);
 	int mid_iz = (int)llround(mid_z);
 	column_data mid_column = get_column_data(ctx, mid_ix, mid_iz);
-	double ridge_bias = clamp01((double)(mid_column.height - ctx->sea_level) / 40.0);
+	trail_landform midpoint_land = sample_trail_landform(ctx, mid_ix, mid_iz, (double)mid_column.height);
+	double valley_bias = clamp01((midpoint_land.valley_depth + 4.0) / 16.0);
 	if (mid_column.has_water && mid_column.height <= mid_column.water_surface) {
-		ridge_bias -= 0.35;
+		valley_bias -= 0.35;
 	}
 	double dir_x = bx - ax;
 	double dir_z = bz - az;
@@ -3167,7 +3472,7 @@ static int should_connect_trail_nodes(worldgen_ctx *ctx, int node_x0, int node_z
 		base += 0.07;
 	}
 	base += (alignment - 0.5) * 0.2;
-	base += (ridge_bias - 0.5) * 0.15;
+	base += (valley_bias - 0.5) * 0.15;
 	double texture = simplex_noise2(&ctx->noise, mid_x * 0.0012, mid_z * 0.0012) * 0.5 + 0.5;
 	base += (texture - 0.5) * 0.15;
 	if (base < 0.02) base = 0.02;
@@ -3279,11 +3584,15 @@ static double nearest_trail_distance2(worldgen_ctx *ctx, int x, int z, double fa
 	for (size_t i = 0; i < ctx->trail_segment_count; ++i) {
 		trail_segment *seg = &ctx->trail_segments[i];
 		if (!seg || seg->count < 1 || !seg->points) continue;
-		for (int p = 0; p < seg->count; ++p) {
-			int tx = seg->points[p * 2];
-			int tz = seg->points[p * 2 + 1];
-			double dx = (double)(tx - x);
-			double dz = (double)(tz - z);
+		for (int p = 0; p < seg->count - 1; ++p) {
+			double d2 = point_segment_distance2((double)x, (double)z,
+			                                    (double)seg->points[p * 2], (double)seg->points[p * 2 + 1],
+			                                    (double)seg->points[(p + 1) * 2], (double)seg->points[(p + 1) * 2 + 1]);
+			if (d2 < best) best = d2;
+		}
+		if (seg->count == 1) {
+			double dx = (double)(seg->points[0] - x);
+			double dz = (double)(seg->points[1] - z);
 			double d2 = dx * dx + dz * dz;
 			if (d2 < best) best = d2;
 		}
@@ -3321,6 +3630,12 @@ static int build_trail_path(worldgen_ctx *ctx, double ax, double az, double bx,
 	if (grid_w < 2) grid_w = 2;
 	if (grid_h < 2) grid_h = 2;
 	int total = grid_w * grid_h;
+	double route_dx = bx - ax;
+	double route_dz = bz - az;
+	double route_length = sqrt(route_dx * route_dx + route_dz * route_dz);
+	/* Long inter-settlement roads are engineered more conservatively than
+	 * short cabin spurs, which may accept steeper and more direct approaches. */
+	double road_scale = clamp01((route_length - 240.0) / 900.0);
 	double *heights = (double *)malloc((size_t)total * sizeof(double));
 	if (!heights) return 0;
 	for (int gz = 0; gz < grid_h; ++gz) {
@@ -3381,14 +3696,23 @@ static int build_trail_path(worldgen_ctx *ctx, double ax, double az, double bx,
 			int ni = nz * grid_w + nx;
 			if (used[ni]) continue;
 			double next_height = heights[ni];
-			double slope = fabs(next_height - current_height);
-			if (slope > 3.0) continue;
 			int wx = (int)llround(min_x + nx * TRAIL_CELL_SIZE);
 			int wz = (int)llround(min_z + nz * TRAIL_CELL_SIZE);
 			column_data cd = get_column_data(ctx, wx, wz);
+			double water_penalty = 0.0;
 			if (cd.has_water && next_height <= cd.water_surface) {
-				continue; /* trails should never be routed through water */
+				if (!small_community_water_crossing(ctx, wx, wz, neighbors[n][0], neighbors[n][1])) continue;
+				next_height = (double)cd.water_surface + 1.0;
+				water_penalty = 8.0; /* worthwhile only when it materially shortens a community road */
 			}
+			int current_wx = (int)llround(min_x + cx * TRAIL_CELL_SIZE);
+			int current_wz = (int)llround(min_z + cz * TRAIL_CELL_SIZE);
+			column_data current_cd = get_column_data(ctx, current_wx, current_wz);
+			if (current_cd.has_water && current_cd.height < current_cd.water_surface)
+				current_height = (double)current_cd.water_surface + 1.0;
+			double slope = fabs(next_height - current_height);
+			double max_step = 4.0 - road_scale;
+			if (slope > max_step) continue;
 			double tree_penalty = 0.0;
 			if (cd.biome == BIOME_REDWOOD_FOREST) {
 				double stand = redwood_tree_presence(ctx, wx, wz);
@@ -3396,7 +3720,20 @@ static int build_trail_path(worldgen_ctx *ctx, double ax, double az, double bx,
 				tree_penalty = stand;
 			}
 			double base_cost = (neighbors[n][0] == 0 || neighbors[n][1] == 0) ? 1.0 : 1.41421356237;
-			double cost = base_cost * (1.0 + slope * 6.0 + tree_penalty * 4.5) + tree_penalty * 6.5;
+			trail_landform land = sample_trail_landform(ctx, wx, wz, next_height);
+			double valley_bonus = clamp01(land.valley_depth / 18.0) * (0.4 + road_scale * 0.2);
+			double ridge_penalty = clamp01(land.ridge_exposure / 22.0) * (1.4 + road_scale * 1.8);
+			double move_x = (double)neighbors[n][0] / base_cost;
+			double move_z = (double)neighbors[n][1] / base_cost;
+			double contour_climb = fabs(move_x * land.gradient_x + move_z * land.gradient_z);
+			double cross_relief = fabs(-move_z * land.gradient_x + move_x * land.gradient_z) *
+			                      (2.0 * TRAIL_LANDFORM_RADIUS);
+			double contour_penalty = contour_climb * (5.0 + road_scale * 5.0);
+			double earthwork_penalty = clamp01((cross_relief - 10.0) / 28.0) * (0.8 + road_scale * 1.2);
+			double grade_penalty = slope * (5.5 + road_scale * 3.5);
+			double terrain_cost = 1.0 + grade_penalty + ridge_penalty + contour_penalty +
+			                      earthwork_penalty + tree_penalty * 4.5 + water_penalty;
+			double cost = base_cost * terrain_cost * (1.0 - valley_bonus) + tree_penalty * 6.5;
 			if (dist[current] + cost < dist[ni]) {
 				dist[ni] = dist[current] + cost;
 				prev[ni] = current;
@@ -3556,6 +3893,26 @@ static void place_trail_column(chunk_data *out, column_data columns[CHUNK_SIZE][
 	columns[local_x][local_z].height = target_height;
 }
 
+static void place_trail_bridge_column(chunk_data *out, column_data columns[CHUNK_SIZE][CHUNK_SIZE],
+		int chunk_x, int chunk_z, int world_x, int world_z, int deck_y, int railing) {
+	int lx = world_x - chunk_x * CHUNK_SIZE;
+	int lz = world_z - chunk_z * CHUNK_SIZE;
+	if (lx < 0 || lx >= CHUNK_SIZE || lz < 0 || lz >= CHUNK_SIZE) return;
+	if (deck_y < 2 || deck_y >= CHUNK_HEIGHT - 4) return;
+	for (int y = 1; y < CHUNK_HEIGHT; ++y)
+		if (is_cabin_structure_block(out->blocks[y][lx][lz])) return;
+	out->blocks[deck_y][lx][lz] = BLOCK_SPRUCE_PLANKS;
+	for (int y = deck_y + 1; y <= deck_y + 3; ++y) out->blocks[y][lx][lz] = BLOCK_AIR;
+	uint32_t support_hash = hash_coords(world_x, world_z, 0xB21D6E5u);
+	if ((support_hash % 5u) == 0u) {
+		int bed = columns[lx][lz].height;
+		for (int y = bed + 1; y < deck_y; ++y) out->blocks[y][lx][lz] = BLOCK_OAK_LOG;
+	}
+	if (railing && (support_hash % 3u) == 0u) out->blocks[deck_y + 1][lx][lz] = BLOCK_OAK_LOG;
+	columns[lx][lz].height = deck_y;
+	out->heightmap[lx][lz] = (uint16_t)(deck_y + (railing ? 1 : 0));
+}
+
 static void carve_trail_pad(worldgen_ctx *ctx, int chunk_x, int chunk_z, chunk_data *out, column_data columns[CHUNK_SIZE][CHUNK_SIZE], int center_x, int center_z, int radius, int target_height) {
 	if (radius < 1) radius = 1;
 	(void)ctx;
@@ -3565,6 +3922,8 @@ static void carve_trail_pad(worldgen_ctx *ctx, int chunk_x, int chunk_z, chunk_d
 			if (dx * dx + dz * dz > radius_sq) continue;
 			int wx = center_x + dx;
 			int wz = center_z + dz;
+			column_data data = get_column_data(ctx, wx, wz);
+			if (data.has_water && data.height < data.water_surface) continue;
 			place_trail_column(out, columns, chunk_x, chunk_z, wx, wz, target_height);
 		}
 	}
@@ -3596,7 +3955,8 @@ static void carve_trail_span(worldgen_ctx *ctx, int chunk_x, int chunk_z, chunk_
 		int wx = (int)llround(px);
 		int wz = (int)llround(pz);
 		column_data data = get_column_data(ctx, wx, wz);
-		int target = data.height;
+		int is_bridge = small_community_water_crossing(ctx, wx, wz, x1 - x0, z1 - z0);
+		int target = is_bridge ? data.water_surface + 1 : data.height;
 		if (last_height != INT32_MIN) {
 			double blended = carry_weight * (double)last_height + (1.0 - carry_weight) * (double)target;
 			target = (int)llround(blended);
@@ -3614,6 +3974,15 @@ static void carve_trail_span(worldgen_ctx *ctx, int chunk_x, int chunk_z, chunk_
 			double oz = pz + nz * w;
 			int fx = (int)llround(ox);
 			int fz = (int)llround(oz);
+			column_data cross_data = get_column_data(ctx, fx, fz);
+			if (cross_data.has_water && cross_data.height < cross_data.water_surface) {
+				if (small_community_water_crossing(ctx, fx, fz, x1 - x0, z1 - z0)) {
+					int edge = fabs(w) >= half_width - 0.55;
+					place_trail_bridge_column(out, columns, chunk_x, chunk_z, fx, fz,
+					                          cross_data.water_surface + 1, edge);
+				}
+				continue;
+			}
 			place_trail_column(out, columns, chunk_x, chunk_z, fx, fz, target);
 		}
 	}

worldgen-c/tools/worldgen_scan.c

@@ -10,6 +10,7 @@ static int is_cabin_block(uint16_t block) {
 	       block == BLOCK_OAK_LOG_X || block == BLOCK_OAK_LOG_Z ||
 	       block == BLOCK_SPRUCE_LOG_X || block == BLOCK_SPRUCE_LOG_Z ||
 	       block == BLOCK_GLASS_PANE || block == BLOCK_GLASS || block == BLOCK_SPRUCE_STAIRS_E || block == BLOCK_SPRUCE_STAIRS_W ||
+	       block == BLOCK_SPRUCE_STAIRS_N || block == BLOCK_SPRUCE_STAIRS_S ||
 	       block == BLOCK_LADDER_N || block == BLOCK_LADDER_S || block == BLOCK_LADDER_E || block == BLOCK_LADDER_W ||
 	       block == BLOCK_SPRUCE_DOOR_N_LOWER || block == BLOCK_SPRUCE_DOOR_N_UPPER ||
 	       block == BLOCK_SPRUCE_DOOR_S_LOWER || block == BLOCK_SPRUCE_DOOR_S_UPPER ||
@@ -78,6 +79,8 @@ int main(int argc, char **argv) {
 	long cabin_columns = 0;
 	long gravel_columns = 0;
 	long cabin_gravel_columns = 0;
+	long bridge_deck_columns = 0;
+	long eligible_bridge_columns = 0;
 	long tall_log_columns = 0;
 	long max_oak_log_run = 0;
 	long biome_columns[4] = {0, 0, 0, 0};
@@ -96,8 +99,11 @@ int main(int argc, char **argv) {
 					if (biome >= 0 && biome < 4) ++biome_columns[biome];
 					double redwood_mask = worldgen_debug_redwood_mask(&ctx, wx, wz);
 					if (redwood_mask > max_redwood_mask) max_redwood_mask = redwood_mask;
+					if (worldgen_debug_bridge_site(&ctx, wx, wz, 1, 0) ||
+					    worldgen_debug_bridge_site(&ctx, wx, wz, 0, 1)) ++eligible_bridge_columns;
 					int has_cabin = 0;
 					int has_gravel = 0;
+					int has_bridge_deck = 0;
 					int current_run = 0;
 					int best_run = 0;
 					for (int y = 1; y < CHUNK_HEIGHT; ++y) {
@@ -109,6 +115,8 @@ int main(int argc, char **argv) {
 						if (block == BLOCK_GRAVEL) {
 							has_gravel = 1;
 						}
+						if (block == BLOCK_SPRUCE_PLANKS && y > 1 && chunk.blocks[y - 1][lx][lz] == BLOCK_WATER)
+							has_bridge_deck = 1;
 						if (block == BLOCK_OAK_LOG) {
 							++current_run;
 							if (current_run > best_run) best_run = current_run;
@@ -120,6 +128,7 @@ int main(int argc, char **argv) {
 					if (best_run >= 40) ++tall_log_columns;
 					if (has_cabin) ++cabin_columns;
 					if (has_gravel) ++gravel_columns;
+					if (has_bridge_deck) ++bridge_deck_columns;
 					if (has_cabin && has_gravel) {
 						++cabin_gravel_columns;
 					}
@@ -133,6 +142,8 @@ int main(int argc, char **argv) {
 	printf("cabin_columns=%ld\n", cabin_columns);
 	printf("gravel_columns=%ld\n", gravel_columns);
 	printf("cabin_gravel_columns=%ld\n", cabin_gravel_columns);
+	printf("bridge_deck_columns=%ld\n", bridge_deck_columns);
+	printf("eligible_bridge_columns=%ld\n", eligible_bridge_columns);
 	printf("tall_oak_log_columns=%ld\n", tall_log_columns);
 	printf("max_oak_log_run=%ld\n", max_oak_log_run);
 	printf("biome_west_ky=%ld\n", biome_columns[0]);