fix: biome demo

Signed-off-by: szdytom <szdytom@qq.com>

tilemap/examples/biome_demo.cpp

@@ -38,11 +38,10 @@ void generate_bmp(const istd::TileMap &tilemap, const std::string &filename) {
 	// Generate tiles
 	for (int chunk_y = 0; chunk_y < chunks_per_side; ++chunk_y) {
 		for (int chunk_x = 0; chunk_x < chunks_per_side; ++chunk_x) {
-			const auto &chunk = tilemap.get_chunk(chunk_x, chunk_y);
-
 			for (int tile_y = 0; tile_y < tiles_per_chunk; ++tile_y) {
 				for (int tile_x = 0; tile_x < tiles_per_chunk; ++tile_x) {
-					const auto &tile = chunk.tiles[tile_x][tile_y];
+					istd::TilePos pos(chunk_x, chunk_y, tile_x, tile_y);
+					const auto &tile = tilemap.get_tile(pos);
 
 					int global_x = chunk_x * tiles_per_chunk + tile_x;
 					int global_y = chunk_y * tiles_per_chunk + tile_y;
@@ -134,7 +133,7 @@ void print_statistics(const istd::TileMap &tilemap) {
 
 int main(int argc, char *argv[]) {
 	// Parse command line arguments
-	if (argc < 3 || argc > 4) {
+	if (argc > 4) {
 		std::cerr << "Usage: " << argv[0]
 				  << " <seed> <output_file.bmp> [chunks_per_side]\n";
 		std::cerr << "  seed           - Random seed for generation\n";
@@ -145,8 +144,9 @@ int main(int argc, char *argv[]) {
 		return 1;
 	}
 
-	std::uint64_t seed = std::strtoull(argv[1], nullptr, 10);
-	std::string output_filename = argv[2];
+	std::uint64_t seed
+		= argc >= 2 ? std::strtoull(argv[1], nullptr, 10) : 541234;
+	std::string output_filename = argc >= 3 ? argv[2] : "output.bmp";
 	int chunks_per_side = 4; // Default value
 
 	// Parse optional chunks_per_side parameter
@@ -158,7 +158,7 @@ int main(int argc, char *argv[]) {
 		}
 		if (chunks_per_side > 20) {
 			std::cerr << "Warning: Large chunk counts may produce very large "
-			             "images\n";
+						 "images\n";
 		}
 	}
 
@@ -178,9 +178,6 @@ int main(int argc, char *argv[]) {
 	// Configure generation parameters
 	istd::GenerationConfig config;
 	config.seed = seed;
-	config.temperature_scale = 0.005;
-	config.humidity_scale = 0.007;
-	config.base_scale = 0.08;
 
 	// Generate the map
 	std::cout << "Generating terrain..." << std::endl;
@@ -194,4 +191,4 @@ int main(int argc, char *argv[]) {
 	print_statistics(tilemap);
 
 	return 0;
-}
+}

tilemap/include/biome.h

@@ -62,11 +62,9 @@ struct SubChunkPos {
 };
 
 // Get the starting tile coordinates for a sub-chunk
-constexpr std::pair<std::uint8_t, std::uint8_t> subchunk_to_tile_start(
+std::pair<std::uint8_t, std::uint8_t> subchunk_to_tile_start(
 	const SubChunkPos &pos
-) {
-	return {pos.sub_x * 16, pos.sub_y * 16};
-}
+);
 
 } // namespace istd
 

tilemap/src/biome.cpp

@@ -1,4 +1,5 @@
 #include "biome.h"
+#include "chunk.h"
 #include <algorithm>
 #include <array>
 #include <cmath>
@@ -115,4 +116,11 @@ BiomeType determine_biome(double temperature, double humidity) {
 	return static_cast<BiomeType>(index);
 }
 
+std::pair<std::uint8_t, std::uint8_t> subchunk_to_tile_start(
+	const SubChunkPos &pos
+) {
+	// Convert sub-chunk position to tile start coordinates
+	return {pos.sub_x * Chunk::subchunk_size, pos.sub_y * Chunk::subchunk_size};
+}
+
 } // namespace istd

tilemap/src/generation.cpp

@@ -37,15 +37,18 @@ void TerrainGenerator::generate_biomes(TileMap &tilemap) {
 		for (std::uint8_t chunk_x = 0; chunk_x < map_size; ++chunk_x) {
 			Chunk &chunk = tilemap.get_chunk(chunk_x, chunk_y);
 
-			for (std::uint8_t sub_y = 0; sub_y < 4; ++sub_y) {
-				for (std::uint8_t sub_x = 0; sub_x < 4; ++sub_x) {
+			for (std::uint8_t sub_y = 0; sub_y < Chunk::subchunk_count;
+			     ++sub_y) {
+				for (std::uint8_t sub_x = 0; sub_x < Chunk::subchunk_count;
+				     ++sub_x) {
 					// Calculate global position for this sub-chunk's center
-					double global_x = static_cast<double>(
-						chunk_x * Chunk::size + sub_x * 16 + 8
-					);
-					double global_y = static_cast<double>(
-						chunk_y * Chunk::size + sub_y * 16 + 8
-					);
+					auto [start_x, start_y]
+						= subchunk_to_tile_start(SubChunkPos(sub_x, sub_y));
+					double global_x = chunk_x * Chunk::size + start_x
+					                  + Chunk::subchunk_size / 2;
+
+					double global_y = chunk_y * Chunk::size + start_y
+					                  + Chunk::subchunk_size / 2;
 
 					// Get climate values
 					auto [temperature, humidity]
@@ -85,14 +88,13 @@ void TerrainGenerator::generate_subchunk(
 	auto [start_x, start_y] = subchunk_to_tile_start(sub_pos);
 
 	// Generate terrain for each tile in the 16x16 sub-chunk
-	for (std::uint8_t local_y = start_y; local_y < start_y + 16; ++local_y) {
-		for (std::uint8_t local_x = start_x; local_x < start_x + 16;
-		     ++local_x) {
+	for (std::uint8_t local_y = start_y;
+	     local_y < start_y + Chunk::subchunk_size; ++local_y) {
+		for (std::uint8_t local_x = start_x;
+		     local_x < start_x + Chunk::subchunk_size; ++local_x) {
 			// Calculate global coordinates
-			double global_x
-				= static_cast<double>(chunk_x * Chunk::size + local_x);
-			double global_y
-				= static_cast<double>(chunk_y * Chunk::size + local_y);
+			double global_x = chunk_x * Chunk::size + local_x;
+			double global_y = chunk_y * Chunk::size + local_y;
 
 			// Generate base terrain noise value using uniform distribution
 			double base_noise_value