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 #include "Debug.h"
18 #include "Extensions.h"
19 #include "Properties.h"
20 #include "Stencil.h"
21
22 #include <GLES2/gl2ext.h>
23
24 namespace android {
25 namespace uirenderer {
26
27 #if DEBUG_STENCIL
28 #define STENCIL_WRITE_VALUE 0xff
29 #define STENCIL_MASK_VALUE 0xff
30 #else
31 #define STENCIL_WRITE_VALUE 0x1
32 #define STENCIL_MASK_VALUE 0x1
33 #endif
34
Stencil()35 Stencil::Stencil(): mState(kDisabled) {
36 }
37
getStencilSize()38 uint8_t Stencil::getStencilSize() {
39 return STENCIL_BUFFER_SIZE;
40 }
41
getSmallestStencilFormat()42 GLenum Stencil::getSmallestStencilFormat() {
43 #if !DEBUG_STENCIL
44 const Extensions& extensions = Extensions::getInstance();
45 if (extensions.has1BitStencil()) {
46 return GL_STENCIL_INDEX1_OES;
47 } else if (extensions.has4BitStencil()) {
48 return GL_STENCIL_INDEX4_OES;
49 }
50 #endif
51 return GL_STENCIL_INDEX8;
52 }
53
clear()54 void Stencil::clear() {
55 glClearStencil(0);
56 glClear(GL_STENCIL_BUFFER_BIT);
57 }
58
enableTest()59 void Stencil::enableTest() {
60 if (mState != kTest) {
61 enable();
62 glStencilFunc(GL_EQUAL, STENCIL_WRITE_VALUE, STENCIL_MASK_VALUE);
63 // We only want to test, let's keep everything
64 glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
65 glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
66 mState = kTest;
67 }
68 }
69
enableWrite()70 void Stencil::enableWrite() {
71 if (mState != kWrite) {
72 enable();
73 glStencilFunc(GL_ALWAYS, STENCIL_WRITE_VALUE, STENCIL_MASK_VALUE);
74 // The test always passes so the first two values are meaningless
75 glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
76 glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
77 mState = kWrite;
78 }
79 }
80
enableDebugTest(GLint value,bool greater)81 void Stencil::enableDebugTest(GLint value, bool greater) {
82 enable();
83 glStencilFunc(greater ? GL_LESS : GL_EQUAL, value, 0xffffffff);
84 // We only want to test, let's keep everything
85 glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
86 mState = kTest;
87 }
88
enableDebugWrite()89 void Stencil::enableDebugWrite() {
90 if (mState != kWrite) {
91 enable();
92 glStencilFunc(GL_ALWAYS, 0x1, 0xffffffff);
93 // The test always passes so the first two values are meaningless
94 glStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
95 glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
96 mState = kWrite;
97 }
98 }
99
enable()100 void Stencil::enable() {
101 if (mState == kDisabled) {
102 glEnable(GL_STENCIL_TEST);
103 }
104 }
105
disable()106 void Stencil::disable() {
107 if (mState != kDisabled) {
108 glDisable(GL_STENCIL_TEST);
109 mState = kDisabled;
110 }
111 }
112
113 }; // namespace uirenderer
114 }; // namespace android
115