refactor: biome build (#5)

* refactor: rename Biome to BiomeType

* feat: add biome builder

src/gameplay/builders/forest_builder.cpp

@@ -0,0 +1,72 @@
+#include "Cubed/gameplay/builders/forest_builder.hpp"
+
+#include "Cubed/gameplay/chunk.hpp"
+#include "Cubed/gameplay/chunk_generator.hpp"
+#include "Cubed/gameplay/tree.hpp"
+namespace Cubed {
+ForestBuilder::ForestBuilder(ChunkGenerator& chunk_generator)
+    : m_chunk_generator(chunk_generator) {}
+
+void ForestBuilder::build_biome() {
+    BiomeBuilder::build_bottom();
+    build_blocks();
+};
+
+void ForestBuilder::build_blocks() {
+    auto& m_chunk = m_chunk_generator.chunk();
+    auto& m_blocks = m_chunk.blocks();
+    auto& m_heightmap = m_chunk.heightmap();
+    for (int x = 0; x < CHUCK_SIZE; x++) {
+        for (int z = 0; z < CHUCK_SIZE; z++) {
+            int height = static_cast<int>(m_heightmap[x][z]);
+            for (int y = 5; y < height - 5; y++) {
+                m_blocks[Chunk::get_index(x, y, z)] = 3;
+            }
+            for (int y = height - 5; y < height; y++) {
+                m_blocks[Chunk::get_index(x, y, z)] = 2;
+            }
+            m_blocks[Chunk::get_index(x, height, z)] = 1;
+        }
+    }
+}
+
+void ForestBuilder::build_vegetation() {
+    auto& m_chunk = m_chunk_generator.chunk();
+    auto& m_heightmap = m_chunk.heightmap();
+    auto& m_random = m_chunk_generator.random();
+    std::array<int, SIZE_X> x_arr;
+    std::iota(x_arr.begin(), x_arr.end(), 0);
+    std::shuffle(x_arr.begin(), x_arr.end(), m_random.engine());
+    std::array<int, SIZE_Z> z_arr;
+    std::iota(z_arr.begin(), z_arr.end(), 0);
+    std::shuffle(z_arr.begin(), z_arr.end(), m_random.engine());
+    for (auto x : x_arr) {
+        for (auto z : z_arr) {
+            int y = static_cast<int>(m_heightmap[x][z]);
+            if (m_random.random_bool(forest_params().tree_frequency) &&
+                y >= SEA_LEVEL) {
+                build_tree(m_chunk, {x, y, z});
+            }
+        }
+    }
+    auto& m_blocks = m_chunk.blocks();
+    if (m_chunk_generator.neighbor_river()) {
+        for (int x = 0; x < SIZE_X; x++) {
+            for (int z = 0; z < SIZE_Z; z++) {
+                int height = static_cast<int>(m_heightmap[x][z]);
+                if (height >= SEA_LEVEL) {
+                    continue;
+                }
+                for (int y = height + 1; y < SEA_LEVEL; y++) {
+                    m_blocks[Chunk::get_index(x, y, z)] = 7;
+                }
+            }
+        }
+    }
+}
+
+ChunkGenerator& ForestBuilder::get_chunk_generator() {
+    return m_chunk_generator;
+};
+
+} // namespace Cubed