1 files changed, 78 insertions, 0 deletions
diff --git a/source/blender/gpu/opengl/gl_query.cc b/source/blender/gpu/opengl/gl_query.cc
new file mode 100644
index 00000000000..6da5cacfcb2
--- /dev/null
+++ b/source/blender/gpu/opengl/gl_query.cc
@@ -0,0 +1,78 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Copyright 2020, Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup gpu
+ */
+
+#include "gl_query.hh"
+
+namespace blender::gpu {
+
+#define QUERY_CHUNCK_LEN 256
+
+GLQueryPool::~GLQueryPool()
+{
+  glDeleteQueries(query_ids_.size(), query_ids_.data());
+}
+
+void GLQueryPool::init(GPUQueryType type)
+{
+  BLI_assert(initialized_ == false);
+  initialized_ = true;
+  type_ = type;
+  gl_type_ = to_gl(type);
+  query_issued_ = 0;
+}
+
+#if 0 /* TODO to avoid realloc of permanent query pool. */
+void GLQueryPool::reset(GPUQueryType type)
+{
+  initialized_ = false;
+}
+#endif
+
+void GLQueryPool::begin_query(void)
+{
+  /* TODO add assert about expected usage. */
+  while (query_issued_ >= query_ids_.size()) {
+    int64_t prev_size = query_ids_.size();
+    query_ids_.resize(prev_size + QUERY_CHUNCK_LEN);
+    glGenQueries(QUERY_CHUNCK_LEN, &query_ids_[prev_size]);
+  }
+  glBeginQuery(gl_type_, query_ids_[query_issued_++]);
+}
+
+void GLQueryPool::end_query(void)
+{
+  /* TODO add assert about expected usage. */
+  glEndQuery(gl_type_);
+}
+
+void GLQueryPool::get_occlusion_result(MutableSpan<uint32_t> r_values)
+{
+  BLI_assert(r_values.size() == query_issued_);
+
+  for (int i = 0; i < query_issued_; i++) {
+    /* Note: This is a sync point. */
+    glGetQueryObjectuiv(query_ids_[i], GL_QUERY_RESULT, &r_values[i]);
+  }
+}
+
+}  // namespace blender::gpu