void ChunkManager::UpdateChunksThread() {
while (m_updateThreadActive) {
while (m_stepLockEnabled && m_updateStepLock) {
std::this_thread::sleep_for(std::chrono::milliseconds(100));
}
ChunkList updateList;
ChunkList rebuildList;
ChunkCoordKeyList addKeyList;
// STEP 1: PUT ALL CREATED CHUNKS IN `UPDATE LIST`
m_chunkMapMutex.lock();
std::map<ChunkCoordKey, Chunk*>::iterator it;
for (it = m_chunkMap.begin(); it != m_chunkMap.end(); ++it) {
Chunk* chunk = it->second;
if (!chunk->IsUnloading()) {
updateList.push_back(chunk);
}
}
m_chunkMapMutex.unlock();
// STEP 2: FIND CHUNKS TO ADD (OR UNLOAD IF THEY'RE TOO FAR)
int numAddedChunks = 0;
const int MAX_NUM_CHUNKS_ADD = 10;
std::sort(updateList.begin(), updateList.end(), Chunk::ClosestToCamera);
for (unsigned int i = 0; i < updateList.size(); ++i) {
Chunk* chunk = updateList[i];
if (chunk) {
glm::vec3 chunkCenter = chunk->GetCenter();
glm::vec3 cameraPos = m_renderer->GetCamera().GetPosition();
float cameraDistance = glm::length(chunkCenter - cameraPos);
if (cameraDistance > m_loadRadius) {
chunk->SetUnloading();
}
else if (numAddedChunks < MAX_NUM_CHUNKS_ADD) {
ChunkCoordKeyList missing = chunk->GetMissingNeighbors();
if (!chunk->IsEmpty()) {
for (ChunkCoordKey key : missing) {
if (std::find(addKeyList.begin(), addKeyList.end(), key) == addKeyList.end()) {
// Here we are calculating the distance of each
// neighbor chunk to decide if we should add it
glm::vec3 chunkCenter = Chunk::GetWorldCenter(key.x, key.y, key.z);
float cameraDistance = glm::length(chunkCenter - cameraPos);
if (cameraDistance <= m_loadRadius && key.y == 0) {
addKeyList.push_back(key);
++numAddedChunks;
}
}
}
}
}
}
}
updateList.clear();
// STEP 3: ADD CHUNKS
for (unsigned int i = 0; i < addKeyList.size(); ++i) {
ChunkCoordKey key = addKeyList[i];
CreateNewChunk(key.x, key.y, key.z);
}
addKeyList.clear();
// STEP 4: CHECK FOR REBUILD CHUNKS
m_chunkMapMutex.lock();
for (it = m_chunkMap.begin(); it != m_chunkMap.end(); ++it) {
Chunk* chunk = it->second;
if (!chunk->IsUnloading() && chunk->NeedsRebuild()) {
rebuildList.push_back(chunk);
}
}
m_chunkMapMutex.unlock();
// STEP 5: REBUILD CHUNKS
int numRebuildChunks = 0;
const int MAX_NUM_CHUNKS_REBUILD = 30;
for (unsigned int i = 0; i < rebuildList.size() && numRebuildChunks < MAX_NUM_CHUNKS_REBUILD; ++i) {
Chunk* chunk = rebuildList[i];
chunk->RebuildMesh();
++numRebuildChunks;
}
rebuildList.clear();
if (m_stepLockEnabled && !m_updateStepLock) {
m_updateStepLock = true;
}
std::this_thread::sleep_for(std::chrono::milliseconds(10));
}
m_updateThreadFinished = true;
}
