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/*
* Copyright (C) 2012 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_STENCIL_H
#define ANDROID_HWUI_STENCIL_H
#include <GLES2/gl2.h>
#include <cutils/compiler.h>
namespace android {
namespace uirenderer {
///////////////////////////////////////////////////////////////////////////////
// Stencil buffer management
///////////////////////////////////////////////////////////////////////////////
class ANDROID_API Stencil {
public:
/**
* Returns the desired size for the stencil buffer. If the returned value
* is 0, then no stencil buffer is required.
*/
ANDROID_API static uint8_t getStencilSize();
static GLenum getLayerStencilFormat();
/**
* Clears the stencil buffer.
*/
void clear();
/**
* Enables stencil test. When the stencil test is enabled the stencil buffer is not written
* into. An increment threshold of zero causes the stencil to use a constant reference value
* and GL_EQUAL for the test. A non-zero increment threshold causes the stencil to use that
* value as the reference value and GL_EQUAL for the test.
*/
void enableTest(int incrementThreshold);
/**
* Enables stencil write. When stencil write is enabled, the stencil
* test always succeeds and the value 0x1 is written in the stencil
* buffer for each fragment. An increment threshold of zero causes the stencil to use a constant
* reference value and GL_EQUAL for the test. A non-zero increment threshold causes the stencil
* to use that value as the reference value and GL_EQUAL for the test.
*/
void enableWrite(int incrementThreshold);
/**
* The test passes only when equal to the specified value.
*/
void enableDebugTest(GLint value, bool greater = false);
/**
* Used for debugging. The stencil test always passes and increments.
*/
void enableDebugWrite();
/**
* Disables stencil test and write.
*/
void disable();
/**
* Indicates whether either test or write is enabled.
*/
bool isEnabled() {
return mState != StencilState::Disabled;
}
/**
* Indicates whether testing only is enabled.
*/
bool isTestEnabled() {
return mState == StencilState::Test;
}
bool isWriteEnabled() {
return mState == StencilState::Write;
}
void dump();
private:
enum class StencilState {
Disabled,
Test,
Write
};
void enable();
StencilState mState = StencilState::Disabled;
}; // class Stencil
}; // namespace uirenderer
}; // namespace android
#endif // ANDROID_HWUI_STENCIL_H