1 /* 2 * Copyright (C) 2012 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_STENCIL_H 18 #define ANDROID_HWUI_STENCIL_H 19 20 #ifndef LOG_TAG 21 #define LOG_TAG "OpenGLRenderer" 22 #endif 23 24 #include <cutils/compiler.h> 25 26 namespace android { 27 namespace uirenderer { 28 29 /////////////////////////////////////////////////////////////////////////////// 30 // Stencil buffer management 31 /////////////////////////////////////////////////////////////////////////////// 32 33 class ANDROID_API Stencil { 34 public: 35 Stencil(); 36 37 /** 38 * Returns the desired size for the stencil buffer. If the returned value 39 * is 0, then no stencil buffer is required. 40 */ 41 ANDROID_API static uint32_t getStencilSize(); 42 43 /** 44 * Clears the stencil buffer. 45 */ 46 void clear(); 47 48 /** 49 * Enables stencil test. When the stencil test is enabled the stencil 50 * buffer is not written into. 51 */ 52 void enableTest(); 53 54 /** 55 * Enables stencil write. When stencil write is enabled, the stencil 56 * test always succeeds and the value 0x1 is written in the stencil 57 * buffer for each fragment. 58 */ 59 void enableWrite(); 60 61 /** 62 * The test passes only when equal to the specified value. 63 */ 64 void enableDebugTest(GLint value, bool greater = false); 65 66 /** 67 * Used for debugging. The stencil test always passes and increments. 68 */ 69 void enableDebugWrite(); 70 71 /** 72 * Disables stencil test and write. 73 */ 74 void disable(); 75 76 /** 77 * Indicates whether either test or write is enabled. 78 */ isEnabled()79 bool isEnabled() { 80 return mState != kDisabled; 81 } 82 83 private: 84 void enable(); 85 86 enum StencilState { 87 kDisabled, 88 kTest, 89 kWrite 90 }; 91 92 StencilState mState; 93 94 }; // class Stencil 95 96 }; // namespace uirenderer 97 }; // namespace android 98 99 #endif // ANDROID_HWUI_STENCIL_H 100