refactor: prevent desert from generation adjacent to mountain in biome generation

include/Cubed/config.hpp

@@ -4,13 +4,13 @@ constexpr int MAX_BLOCK_NUM = 5;
 constexpr int MAX_UI_NUM = 1;
 
 constexpr int CHUCK_SIZE = 16;
-constexpr int DISTANCE = 16;
+constexpr int DISTANCE = 24;
 constexpr int MAX_BLOCK_STATUS = 1;
 constexpr int MAX_CHARACTER = 128;
 constexpr float NORMAL_FOV = 70.0f;
 
 constexpr int MAX_BIOME_SUM = 4;
-constexpr float BIOME_NOISE_FREQUENCY = 0.005f;
+constexpr float BIOME_NOISE_FREQUENCY = 0.003f;
 
 constexpr float VERTICES_POS[6][6][3] = {
         // ===== front (z = +1) =====

include/Cubed/gameplay/chunk_status.hpp

@@ -1,4 +1,5 @@
 #pragma once
+#include <cmath>
 #include <array>
 #include <functional>
 #include <string>
@@ -29,6 +30,11 @@ struct ChunkPos {
     };
 };
 
+constexpr float PLAIN_FREQ = 0.5f;
+constexpr float FOREST_FREQ = 1.0f;
+constexpr float DESERT_FREQ = 1.0f;
+constexpr float MOUNTAIN_FREQ = 2.0f;
+
 enum class Biome {
     PLAIN = 0,
     FOREST,
@@ -62,9 +68,20 @@ constexpr inline std::string get_biome_str(Biome biome) {
 };
 
 inline Biome get_biome_from_noise(float temp, float humid) {
-    if (temp < 0.5f && humid < 0.5f) return Biome::MOUNTAIN;
+    auto weight = [](float t, float h, float ct, float ch) -> float {
-    if (temp < 0.5f && humid >= 0.5f) return Biome::PLAIN;
+            float dt = t - ct;
-    if (temp >= 0.5f && humid < 0.5f) return Biome::DESERT;
+            float dh = h - ch;
+            float dist = std::sqrt(dt*dt + dh*dh);
+            return std::max(0.0f, 0.5f - dist); 
+        };
+    float w_m = weight(temp, humid, 0.25f, 0.15f);
+    float w_p = weight(temp, humid, 0.50f, 0.40f);
+    float w_d = weight(temp, humid, 0.75f, 0.15f);
+    float w_f = weight(temp, humid, 0.75f, 0.75f);
+    w_m = pow(w_m, 8); w_p = pow(w_p, 8); w_d = pow(w_d, 8); w_f = pow(w_f, 8);
+    if (w_m >= w_p && w_m >= w_d && w_m >= w_f) return Biome::MOUNTAIN;
+    if (w_p >= w_m && w_p >= w_d && w_p >= w_f) return Biome::PLAIN;
+    if (w_d >= w_m && w_d >= w_p && w_d >= w_f) return Biome::DESERT;
     return Biome::FOREST;
 }
 
@@ -72,13 +89,13 @@ inline std::array<float, 3> get_noise_frequencies_for_biome(Biome biome) {
     using enum Biome;
     switch (biome) {
         case PLAIN:
-            return {0.003f, 0.008f, 0.018f};
+            return {0.003f, 0.010f, 0.020f};
         case FOREST:
             return {0.004f, 0.012f, 0.022f};
         case DESERT:
-            return {0.003f, 0.008f, 0.018f};
+            return {0.003f, 0.010f, 0.020f};
         case MOUNTAIN:
-            return {0.006f, 0.015f, 0.03f};
+            return {0.006f, 0.015f, 0.030f};
     }
     Logger::warn("Unknown Biome");
     return {0.003f, 0.015f, 0.06f};
@@ -88,11 +105,11 @@ inline BiomeHeightRange get_biome_height_range(Biome biome) {
     using enum Biome;
     switch (biome) {
         case PLAIN:
-            return {62, 4};
+            return {62, 8};
         case FOREST:
-            return {64, 8};
+            return {64, 12};
         case DESERT:
-            return {61, 8};
+            return {61, 12};
         case MOUNTAIN:
             return {70, 70};
     }

include/Cubed/tools/math_tools.hpp

@@ -2,5 +2,5 @@
 #include <glm/glm.hpp>
 namespace Math {
     void extract_frustum_planes(const glm::mat4& mvp_matrix, std::vector<glm::vec4>& planes);
-    int get_interpolated_height(float world_x, float world_z, float biome_noise, float temp, float humid);
+    int get_interpolated_height(float world_x, float world_z, float temp, float humid);
 }

src/gameplay/chunk.cpp

@@ -281,15 +281,9 @@ void Chunk::resolve_blocks() {
             float world_x = static_cast<float>(x + m_chunk_pos.x * CHUCK_SIZE);
             float world_z = static_cast<float>(z + m_chunk_pos.z * CHUCK_SIZE);
 
-            float biome_noise = PerlinNoise::noise(
-                world_x * BIOME_NOISE_FREQUENCY, 
-                0.5f, 
-                world_z * BIOME_NOISE_FREQUENCY
-            );
-
             float temp  = PerlinNoise::noise(world_x * BIOME_NOISE_FREQUENCY, 0.0f, world_z * BIOME_NOISE_FREQUENCY);
             float humid = PerlinNoise::noise(world_x * BIOME_NOISE_FREQUENCY, 1.0f, world_z * BIOME_NOISE_FREQUENCY);
-            int height = Math::get_interpolated_height(world_x, world_z, biome_noise, temp, humid);
+            int height = Math::get_interpolated_height(world_x, world_z, temp, humid);
             auto biome = get_biome_from_noise(temp, humid);
             for (int y = 5; y < height - 5; y++) {
                 m_blocks[get_index(x, y, z)] = 3;

src/tools/math_tools.cpp

@@ -34,8 +34,7 @@ namespace Math {
         }
     }
 
-    int get_interpolated_height(float world_x, float world_z, float biome_noise, float temp, float humid) {
+    int get_interpolated_height(float world_x, float world_z, float temp, float humid) {
-        
         
         auto weight = [](float t, float h, float ct, float ch) -> float {
             float dt = t - ct;
@@ -44,16 +43,16 @@ namespace Math {
             return std::max(0.0f, 0.5f - dist); 
         };
 
-        float w_mountain = weight(temp, humid, 0.25f, 0.25f);
+        float w_mountain = weight(temp, humid, 0.25f, 0.15f);
-        float w_plain    = weight(temp, humid, 0.25f, 0.75f);
+        float w_plain    = weight(temp, humid, 0.50f, 0.40f);
-        float w_desert   = weight(temp, humid, 0.75f, 0.25f);
+        float w_desert   = weight(temp, humid, 0.75f, 0.15f);
         float w_forest   = weight(temp, humid, 0.75f, 0.75f);
         // adjust transitions between chunks
         float pow_n = 8.0f; // the larger n is, the purer the biome
-        w_mountain = std::pow(w_mountain, pow_n);
+        w_mountain = std::pow(w_mountain, pow_n) * MOUNTAIN_FREQ;
-        w_plain    = std::pow(w_plain,    pow_n);
+        w_plain    = std::pow(w_plain,    pow_n) * PLAIN_FREQ;
-        w_desert   = std::pow(w_desert,   pow_n);
+        w_desert   = std::pow(w_desert,   pow_n) * DESERT_FREQ;
-        w_forest   = std::pow(w_forest,   pow_n);
+        w_forest   = std::pow(w_forest,   pow_n) * FOREST_FREQ;
 
         float total = w_mountain + w_plain + w_desert + w_forest;
         w_mountain /= total; w_plain /= total; w_desert /= total; w_forest /= total;