blob: d25ad514e8924b34f4dbd02c910fd3d04619a768 [file] [log] [blame]
/*
* 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.
*/
#include "renderstate/Stencil.h"
#include "Caches.h"
#include "Debug.h"
#include "Extensions.h"
#include "Properties.h"
#include <GLES2/gl2ext.h>
namespace android {
namespace uirenderer {
#if DEBUG_STENCIL
#define STENCIL_WRITE_VALUE 0xff
#define STENCIL_MASK_VALUE 0xff
#else
#define STENCIL_WRITE_VALUE 0x1
#define STENCIL_MASK_VALUE 0x1
#endif
uint8_t Stencil::getStencilSize() {
return STENCIL_BUFFER_SIZE;
}
/**
* This method will return either GL_STENCIL_INDEX4_OES if supported,
* GL_STENCIL_INDEX8 if not.
*
* Layers can't use a single bit stencil because multi-rect ClipArea needs a high enough
* stencil resolution to represent the summation of multiple intersecting rect geometries.
*/
GLenum Stencil::getLayerStencilFormat() {
#if !DEBUG_STENCIL
const Extensions& extensions = Caches::getInstance().extensions();
if (extensions.has4BitStencil()) {
return GL_STENCIL_INDEX4_OES;
}
#endif
return GL_STENCIL_INDEX8;
}
void Stencil::clear() {
glStencilMask(0xff);
glClearStencil(0);
glClear(GL_STENCIL_BUFFER_BIT);
if (mState == StencilState::Test) {
// reset to test state, with immutable stencil
glStencilMask(0);
}
}
void Stencil::enableTest(int incrementThreshold) {
if (mState != StencilState::Test) {
enable();
if (incrementThreshold > 0) {
glStencilFunc(GL_EQUAL, incrementThreshold, 0xff);
} else {
glStencilFunc(GL_EQUAL, STENCIL_WRITE_VALUE, STENCIL_MASK_VALUE);
}
// We only want to test, let's keep everything
glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
glStencilMask(0);
mState = StencilState::Test;
}
}
void Stencil::enableWrite(int incrementThreshold) {
if (mState != StencilState::Write) {
enable();
if (incrementThreshold > 0) {
glStencilFunc(GL_ALWAYS, 1, 0xff);
// The test always passes so the first two values are meaningless
glStencilOp(GL_INCR, GL_INCR, GL_INCR);
} else {
glStencilFunc(GL_ALWAYS, STENCIL_WRITE_VALUE, STENCIL_MASK_VALUE);
// The test always passes so the first two values are meaningless
glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
}
glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
glStencilMask(0xff);
mState = StencilState::Write;
}
}
void Stencil::enableDebugTest(GLint value, bool greater) {
enable();
glStencilFunc(greater ? GL_LESS : GL_EQUAL, value, 0xffffffff);
// We only want to test, let's keep everything
glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
mState = StencilState::Test;
glStencilMask(0);
}
void Stencil::enableDebugWrite() {
enable();
glStencilFunc(GL_ALWAYS, 0x1, 0xffffffff);
// The test always passes so the first two values are meaningless
glStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
mState = StencilState::Write;
glStencilMask(0xff);
}
void Stencil::enable() {
if (mState == StencilState::Disabled) {
glEnable(GL_STENCIL_TEST);
}
}
void Stencil::disable() {
if (mState != StencilState::Disabled) {
glDisable(GL_STENCIL_TEST);
mState = StencilState::Disabled;
}
}
void Stencil::dump() {
ALOGD("Stencil: state %d", mState);
}
}; // namespace uirenderer
}; // namespace android