1 files changed, 115 insertions, 0 deletions
diff --git a/intern/gawain/src/gwn_buffer_id.cpp b/intern/gawain/src/gwn_buffer_id.cpp
new file mode 100644
index 00000000000..a93c3950d29
--- /dev/null
+++ b/intern/gawain/src/gwn_buffer_id.cpp
@@ -0,0 +1,115 @@
+
+// Gawain buffer IDs
+//
+// This code is part of the Gawain library, with modifications
+// specific to integration with Blender.
+//
+// Copyright 2016 Mike Erwin
+//
+// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of
+// the MPL was not distributed with this file, You can obtain one at https://mozilla.org/MPL/2.0/.#include "buffer_id.h"
+
+#include "gwn_buffer_id.h"
+#include <mutex>
+#include <vector>
+
+#define ORPHAN_DEBUG 0
+
+#if ORPHAN_DEBUG
+	#include <cstdio>
+#endif
+
+static std::vector<GLuint> orphaned_buffer_ids;
+static std::vector<GLuint> orphaned_vao_ids;
+
+static std::mutex orphan_mutex;
+
+extern "C" {
+extern int BLI_thread_is_main(void); // Blender-specific function
+}
+
+static bool thread_is_main()
+	{
+	// "main" here means the GL context's thread
+	return BLI_thread_is_main();
+	}
+
+GLuint GWN_buf_id_alloc()
+	{
+#if TRUST_NO_ONE
+	assert(thread_is_main());
+#endif
+
+	// delete orphaned IDs
+	orphan_mutex.lock();
+	if (!orphaned_buffer_ids.empty())
+		{
+		const auto orphaned_buffer_ct = (unsigned)orphaned_buffer_ids.size();
+#if ORPHAN_DEBUG
+		printf("deleting %u orphaned VBO%s\n", orphaned_buffer_ct, orphaned_buffer_ct == 1 ? "" : "s");
+#endif
+		glDeleteBuffers(orphaned_buffer_ct, orphaned_buffer_ids.data());
+		orphaned_buffer_ids.clear();
+		}
+	orphan_mutex.unlock();
+
+	GLuint new_buffer_id = 0;
+	glGenBuffers(1, &new_buffer_id);
+	return new_buffer_id;
+	}
+
+void GWN_buf_id_free(GLuint buffer_id)
+	{
+	if (thread_is_main())
+		glDeleteBuffers(1, &buffer_id);
+	else
+		{
+		// add this ID to the orphaned list
+		orphan_mutex.lock();
+#if ORPHAN_DEBUG
+		printf("orphaning VBO %u\n", buffer_id);
+#endif
+		orphaned_buffer_ids.emplace_back(buffer_id);
+		orphan_mutex.unlock();
+		}
+	}
+
+GLuint GWN_vao_alloc()
+	{
+#if TRUST_NO_ONE
+	assert(thread_is_main());
+#endif
+
+	// delete orphaned IDs
+	orphan_mutex.lock();
+	if (!orphaned_vao_ids.empty())
+		{
+		const auto orphaned_vao_ct = (unsigned)orphaned_vao_ids.size();
+#if ORPHAN_DEBUG
+		printf("deleting %u orphaned VAO%s\n", orphaned_vao_ct, orphaned_vao_ct == 1 ? "" : "s");
+#endif
+		glDeleteVertexArrays(orphaned_vao_ct, orphaned_vao_ids.data());
+		orphaned_vao_ids.clear();
+		}
+	orphan_mutex.unlock();
+
+	GLuint new_vao_id = 0;
+	glGenVertexArrays(1, &new_vao_id);
+	return new_vao_id;
+	}
+
+void GWN_vao_free(GLuint vao_id)
+	{
+	if (thread_is_main())
+		glDeleteVertexArrays(1, &vao_id);
+	else
+		{
+		// add this ID to the orphaned list
+		orphan_mutex.lock();
+#if ORPHAN_DEBUG
+		printf("orphaning VAO %u\n", vao_id);
+#endif
+		orphaned_vao_ids.emplace_back(vao_id);
+		orphan_mutex.unlock();
+		}
+	}