1/* 2 * Copyright (C) 2013 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#ifndef ANDROID_HWUI_QUERY_H 18#define ANDROID_HWUI_QUERY_H 19 20#include <GLES3/gl3.h> 21 22#include "Extensions.h" 23 24namespace android { 25namespace uirenderer { 26 27/** 28 * A Query instance can be used to perform occlusion queries. If the device 29 * does not support occlusion queries, the result of a query will always be 30 * 0 and the result will always be marked available. 31 * 32 * To run an occlusion query successfully, you must start end end the query: 33 * 34 * Query query; 35 * query.begin(); 36 * // execute OpenGL calls 37 * query.end(); 38 * GLuint result = query.getResult(); 39 */ 40class Query { 41public: 42 /** 43 * Possible query targets. 44 */ 45 enum Target { 46 /** 47 * Indicates if any sample passed the depth & stencil tests. 48 */ 49 kTargetSamples = GL_ANY_SAMPLES_PASSED, 50 /** 51 * Indicates if any sample passed the depth & stencil tests. 52 * The implementation may choose to use a less precise version 53 * of the test, potentially resulting in false positives. 54 */ 55 kTargetConservativeSamples = GL_ANY_SAMPLES_PASSED_CONSERVATIVE, 56 }; 57 58 /** 59 * Creates a new query with the specified target. The default 60 * target is kTargetSamples (of GL_ANY_SAMPLES_PASSED in OpenGL.) 61 */ 62 Query(Target target = kTargetSamples): mActive(false), mTarget(target), 63 mCanQuery(Extensions::getInstance().hasOcclusionQueries()), 64 mQuery(0) { 65 } 66 67 ~Query() { 68 if (mQuery) { 69 glDeleteQueries(1, &mQuery); 70 } 71 } 72 73 /** 74 * Begins the query. If the query has already begun or if the device 75 * does not support occlusion queries, calling this method as no effect. 76 * After calling this method successfully, the query is marked active. 77 */ 78 void begin() { 79 if (!mActive && mCanQuery) { 80 if (!mQuery) { 81 glGenQueries(1, &mQuery); 82 } 83 84 glBeginQuery(mTarget, mQuery); 85 mActive = true; 86 } 87 } 88 89 /** 90 * Ends the query. If the query has already begun or if the device 91 * does not support occlusion queries, calling this method as no effect. 92 * After calling this method successfully, the query is marked inactive. 93 */ 94 void end() { 95 if (mQuery && mActive) { 96 glEndQuery(mTarget); 97 mActive = false; 98 } 99 } 100 101 /** 102 * Returns true if the query is active, false otherwise. 103 */ 104 bool isActive() { 105 return mActive; 106 } 107 108 /** 109 * Returns true if the result of the query is available, 110 * false otherwise. Calling getResult() before the result 111 * is available may result in the calling thread being blocked. 112 * If the device does not support queries, this method always 113 * returns true. 114 */ 115 bool isResultAvailable() { 116 if (!mQuery) return true; 117 118 GLuint result; 119 glGetQueryObjectuiv(mQuery, GL_QUERY_RESULT_AVAILABLE, &result); 120 return result == GL_TRUE; 121 } 122 123 /** 124 * Returns the result of the query. If the device does not 125 * support queries this method will return 0. 126 * 127 * Calling this method implicitely calls end() if the query 128 * is currently active. 129 */ 130 GLuint getResult() { 131 if (!mQuery) return 0; 132 133 end(); 134 135 GLuint result; 136 glGetQueryObjectuiv(mQuery, GL_QUERY_RESULT, &result); 137 return result; 138 } 139 140 141private: 142 bool mActive; 143 GLenum mTarget; 144 bool mCanQuery; 145 GLuint mQuery; 146 147}; // class Query 148 149}; // namespace uirenderer 150}; // namespace android 151 152#endif // ANDROID_HWUI_QUERY_H 153