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diff --git a/libs/hwui/Query.h b/libs/hwui/Query.h
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+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HWUI_QUERY_H
+#define ANDROID_HWUI_QUERY_H
+
+#include <GLES3/gl3.h>
+
+#include "Extensions.h"
+
+namespace android {
+namespace uirenderer {
+
+/**
+ * A Query instance can be used to perform occlusion queries. If the device
+ * does not support occlusion queries, the result of a query will always be
+ * 0 and the result will always be marked available.
+ *
+ * To run an occlusion query successfully, you must start end end the query:
+ *
+ * Query query;
+ * query.begin();
+ * // execute OpenGL calls
+ * query.end();
+ * GLuint result = query.getResult();
+ */
+class Query {
+public:
+    /**
+     * Possible query targets.
+     */
+    enum Target {
+        /**
+         * Indicates if any sample passed the depth & stencil tests.
+         */
+        kTargetSamples = GL_ANY_SAMPLES_PASSED,
+        /**
+         * Indicates if any sample passed the depth & stencil tests.
+         * The implementation may choose to use a less precise version
+         * of the test, potentially resulting in false positives.
+         */
+        kTargetConservativeSamples = GL_ANY_SAMPLES_PASSED_CONSERVATIVE,
+    };
+
+    /**
+     * Creates a new query with the specified target. The default
+     * target is kTargetSamples (of GL_ANY_SAMPLES_PASSED in OpenGL.)
+     */
+    Query(Target target = kTargetSamples): mActive(false), mTarget(target),
+            mCanQuery(Extensions::getInstance().hasOcclusionQueries()),
+            mQuery(0) {
+    }
+
+    ~Query() {
+        if (mQuery) {
+            glDeleteQueries(1, &mQuery);
+        }
+    }
+
+    /**
+     * Begins the query. If the query has already begun or if the device
+     * does not support occlusion queries, calling this method as no effect.
+     * After calling this method successfully, the query is marked active.
+     */
+    void begin() {
+        if (!mActive && mCanQuery) {
+            if (!mQuery) {
+                glGenQueries(1, &mQuery);
+            }
+
+            glBeginQuery(mTarget, mQuery);
+            mActive = true;
+        }
+    }
+
+    /**
+     * Ends the query. If the query has already begun or if the device
+     * does not support occlusion queries, calling this method as no effect.
+     * After calling this method successfully, the query is marked inactive.
+     */
+    void end() {
+        if (mQuery && mActive) {
+            glEndQuery(mTarget);
+            mActive = false;
+        }
+    }
+
+    /**
+     * Returns true if the query is active, false otherwise.
+     */
+    bool isActive() {
+        return mActive;
+    }
+
+    /**
+     * Returns true if the result of the query is available,
+     * false otherwise. Calling getResult() before the result
+     * is available may result in the calling thread being blocked.
+     * If the device does not support queries, this method always
+     * returns true.
+     */
+    bool isResultAvailable() {
+        if (!mQuery) return true;
+
+        GLuint result;
+        glGetQueryObjectuiv(mQuery, GL_QUERY_RESULT_AVAILABLE, &result);
+        return result == GL_TRUE;
+    }
+
+    /**
+     * Returns the result of the query. If the device does not
+     * support queries this method will return 0.
+     *
+     * Calling this method implicitely calls end() if the query
+     * is currently active.
+     */
+    GLuint getResult() {
+        if (!mQuery) return 0;
+
+        end();
+
+        GLuint result;
+        glGetQueryObjectuiv(mQuery, GL_QUERY_RESULT, &result);
+        return result;
+    }
+
+
+private:
+    bool mActive;
+    GLenum mTarget;
+    bool mCanQuery;
+    GLuint mQuery;
+
+}; // class Query
+
+}; // namespace uirenderer
+}; // namespace android
+
+#endif // ANDROID_HWUI_QUERY_H