src/world/Generator.cpp

   1 #include "Generator.hpp"
   2
   3 #include "BlockType.hpp"
   4 #include "BlockTypeRegistry.hpp"
   5 #include "Chunk.hpp"
   6 #include "../rand/OctaveNoise.hpp"
   7
   8 #include <glm/glm.hpp>
   9
  10
  11 namespace blank {
  12
  13 namespace {
  14
  15 struct Candidate {
  16         const BlockType *type;
  17         float threshold;
  18         Candidate(const BlockType *type, float threshold)
  19         : type(type), threshold(threshold) { }
  20 };
  21
  22 std::vector<Candidate> candidates;
  23
  24 }
  25
  26 Generator::Generator(const Config &config) noexcept
  27 : config(config)
  28 , types()
  29 , min_solidity(2.0f)
  30 , solidity_noise(config.seed ^ config.solidity.seed_mask)
  31 , humidity_noise(config.seed ^ config.humidity.seed_mask)
  32 , temperature_noise(config.seed ^ config.temperature.seed_mask)
  33 , richness_noise(config.seed ^ config.richness.seed_mask)
  34 , random_noise(config.seed ^ config.randomness.seed_mask) {
  35
  36 }
  37
  38 void Generator::LoadTypes(const BlockTypeRegistry &reg) {
  39         types.clear();
  40         min_solidity = 2.0f;
  41         for (const BlockType &type : reg) {
  42                 if (type.generate) {
  43                         types.push_back(&type);
  44                         if (type.min_solidity < min_solidity) {
  45                                 min_solidity = type.min_solidity;
  46                         }
  47                 }
  48         }
  49         candidates.reserve(types.size());
  50 }
  51
  52 void Generator::operator ()(Chunk &chunk) const noexcept {
  53         Chunk::Pos pos(chunk.Position());
  54         glm::vec3 coords(pos * Chunk::Extent());
  55         for (int z = 0; z < Chunk::depth; ++z) {
  56                 for (int y = 0; y < Chunk::height; ++y) {
  57                         for (int x = 0; x < Chunk::width; ++x) {
  58                                 Block::Pos block_pos(x, y, z);
  59                                 chunk.SetBlock(block_pos, Generate(coords + block_pos));
  60                         }
  61                 }
  62         }
  63         chunk.SetGenerated();
  64 }
  65
  66 Block Generator::Generate(const glm::vec3 &pos) const noexcept {
  67         float solidity = GetValue(solidity_noise, pos, config.solidity);
  68         if (solidity < min_solidity) {
  69                 return Block(0);
  70         }
  71         float humidity = GetValue(humidity_noise, pos, config.humidity);
  72         float temperature = GetValue(temperature_noise, pos, config.temperature);
  73         float richness = GetValue(richness_noise, pos, config.richness);
  74
  75         candidates.clear();
  76         float total = 0.0f;
  77         for (const BlockType *type : types) {
  78                 if (solidity < type->min_solidity || solidity > type->max_solidity) continue;
  79                 if (humidity < type->min_humidity || humidity > type->max_humidity) continue;
  80                 if (temperature < type->min_temperature || temperature > type->max_temperature) continue;
  81                 if (richness < type->min_richness || richness > type->max_richness) continue;
  82                 float solidity_match = 4.0f - ((solidity - type->mid_solidity) * (solidity - type->mid_solidity));
  83                 float humidity_match = 4.0f - ((humidity - type->mid_humidity) * (humidity - type->mid_humidity));
  84                 float temperature_match = 4.0f - ((temperature - type->mid_temperature) * (temperature - type->mid_temperature));
  85                 float richness_match = 4.0f - ((richness - type->mid_richness) * (richness - type->mid_richness));
  86                 float chance = (solidity_match + humidity_match + temperature_match + richness_match) * type->commonness;
  87                 total += chance;
  88                 candidates.emplace_back(type, total);
  89         }
  90         if (candidates.empty()) {
  91                 return Block(0);
  92         }
  93         float random = GetValue(random_noise, pos, config.randomness);
  94         if (random < 0.0f) random += 1.0f;
  95         float value = random * total;
  96         // TODO: change to binary search
  97         for (const Candidate &cand : candidates) {
  98                 if (value < cand.threshold) {
  99                         return Block(cand.type->id);
 100                 }
 101         }
 102         // theoretically, this should never happen
 103         return Block(candidates.back().type->id);
 104 }
 105
 106 float Generator::GetValue(
 107         const SimplexNoise &noise,
 108         const glm::vec3 &pos,
 109         const Config::NoiseParam &conf
 110 ) noexcept {
 111         return OctaveNoise(
 112                 noise,
 113                 pos,
 114                 conf.octaves,
 115                 conf.persistence,
 116                 conf.frequency,
 117                 conf.amplitude,
 118                 conf.growth
 119         );
 120 }
 121
 122 }