#include "world.h"
#include "bettola/game/chunk.h"
#include "bettola/noise/fast_noise_lite.h"

World::World(void) {
  m_noise.SetNoiseType(FastNoiseLite::NoiseType_Perlin);
  m_noise.SetFrequency(0.02f);
}

BettolaLib::Game::Chunk& World::get_chunk(int x, int z) {
  ChunkPos pos = {x, z};
  auto it = m_chunks.find(pos);
  if(it != m_chunks.end()) {
    return it->second;
  }

  /* If chunk doesn't exist, generate it. */
  BettolaLib::Game::Chunk& new_chunk = m_chunks[pos];
  _generate_chunk(new_chunk, x, z);
  return new_chunk;
}

void World::_generate_chunk(BettolaLib::Game::Chunk& chunk, int chunk_x, int chunk_z) {
  for(int z = 0; z < BettolaLib::Game::CHUNK_HEIGHT; ++z) {
    for(int x = 0; x < BettolaLib::Game::CHUNK_WIDTH; ++x) {
      /* Calculate world coordinates. */
      float world_x = (float)(chunk_x * (BettolaLib::Game::CHUNK_WIDTH  - 1) + x);
      float world_z = (float)(chunk_z * (BettolaLib::Game::CHUNK_HEIGHT - 1) + z);

      /* generate noise value. */
      chunk.heightmap[z * BettolaLib::Game::CHUNK_WIDTH + x] = m_noise.GetNoise(world_x, world_z);
    }
  }
}