Merge pull request #2 from CesiumGS/concurrency-changes

Concurrency changes in XAtlas

xatlas.cpp

@@ -3235,6 +3235,8 @@ class sync_unordered_map {
 	}
 };
 
+const uint64_t defaultConcurrency = std::thread::hardware_concurrency() <= 1 ? 1 : std::thread::hardware_concurrency() - 1;
+
 #if XA_MULTITHREADED
 class TaskScheduler
 {
@@ -3257,12 +3259,11 @@ class TaskScheduler
 
 		TaskGroup(const TaskGroup&) = default;
 	};
-
 public:
-	TaskScheduler() : m_shutdown(false)
+	TaskScheduler(uint64_t threadPoolSize = defaultConcurrency) : m_shutdown(false)
 	{
 		m_threadIndex = 0;
-		m_workers.resize(std::thread::hardware_concurrency() <= 1 ? 1 : std::thread::hardware_concurrency() - 1);
+		m_workers.resize(threadPoolSize);
 		for (uint64_t i = 0; i < m_workers.size(); i++) {
 			new (&m_workers[i]) Worker();
 			m_workers[i].wakeup = false;
@@ -8965,11 +8966,11 @@ struct Context
 	bool uvMeshChartsComputed = false;
 };
 
-Atlas *Create()
+Atlas *Create(uint64_t concurrency)
 {
 	Context *ctx = XA_NEW(internal::MemTag::Default, Context);
 	memset(&ctx->atlas, 0, sizeof(Atlas));
-	ctx->taskScheduler = XA_NEW(internal::MemTag::Default, internal::TaskScheduler);
+	ctx->taskScheduler = XA_NEW_ARGS(internal::MemTag::Default, internal::TaskScheduler, concurrency);
 	return &ctx->atlas;
 }
 

xatlas.h

@@ -96,8 +96,12 @@ struct Atlas
 	float texelsPerUnit; // Equal to PackOptions texelsPerUnit if texelsPerUnit > 0, otherwise an estimated value to match PackOptions resolution.
 };
 
+namespace internal {
+extern const uint64_t defaultConcurrency;
+}
+
 // Create an empty atlas.
-Atlas *Create();
+Atlas *Create(uint64_t concurrency = internal::defaultConcurrency);
 
 void Destroy(Atlas *atlas);
 
@@ -117,7 +121,7 @@ struct MeshDecl
 	const void *vertexNormalData = nullptr; // optional
 	const void *vertexUvData = nullptr; // optional. The input UVs are provided as a hint to the chart generator.
 	const void *indexData = nullptr; // optional
-	
+
 	// Optional. Must be indexCount / 3 in length.
 	// Don't atlas faces set to true. Ignored faces still exist in the output meshes, Vertex uv is set to (0, 0) and Vertex atlasIndex to -1.
 	const bool *faceIgnoreData = nullptr;