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 #include "Extensions.h"
18 
19 #include "Debug.h"
20 #include "Properties.h"
21 #include "utils/StringUtils.h"
22 
23 #include <cutils/compiler.h>
24 
25 #include <GLES2/gl2.h>
26 #include <GLES2/gl2ext.h>
27 
28 #include <utils/Log.h>
29 
30 namespace android {
31 namespace uirenderer {
32 
Extensions()33 Extensions::Extensions() {
34     const char* version = (const char*) glGetString(GL_VERSION);
35 
36     // Section 6.1.5 of the OpenGL ES specification indicates the GL version
37     // string strictly follows this format:
38     //
39     // OpenGL<space>ES<space><version number><space><vendor-specific information>
40     //
41     // In addition section 6.1.5 describes the version number thusly:
42     //
43     // "The version number is either of the form major number.minor number or
44     // major number.minor number.release number, where the numbers all have one
45     // or more digits. The release number and vendor specific information are
46     // optional."
47 
48     if (sscanf(version, "OpenGL ES %d.%d", &mVersionMajor, &mVersionMinor) != 2) {
49         // If we cannot parse the version number, assume OpenGL ES 2.0
50         mVersionMajor = 2;
51         mVersionMinor = 0;
52     }
53 
54     auto extensions = StringUtils::split((const char*) glGetString(GL_EXTENSIONS));
55     mHasNPot = extensions.has("GL_OES_texture_npot");
56     mHasFramebufferFetch = extensions.has("GL_NV_shader_framebuffer_fetch");
57     mHasDiscardFramebuffer = extensions.has("GL_EXT_discard_framebuffer");
58     mHasDebugMarker = extensions.has("GL_EXT_debug_marker");
59     mHas1BitStencil = extensions.has("GL_OES_stencil1");
60     mHas4BitStencil = extensions.has("GL_OES_stencil4");
61     mHasUnpackSubImage = extensions.has("GL_EXT_unpack_subimage");
62 
63     mHasSRGB = mVersionMajor >= 3 || extensions.has("GL_EXT_sRGB");
64     mHasSRGBWriteControl = extensions.has("GL_EXT_sRGB_write_control");
65 
66 #ifdef ANDROID_ENABLE_LINEAR_BLENDING
67     // If linear blending is enabled, the device must have (ES3.0 or EXT_sRGB)
68     // and EXT_sRGB_write_control
69     LOG_ALWAYS_FATAL_IF(!mHasSRGB, "Linear blending requires ES 3.0 or EXT_sRGB");
70     LOG_ALWAYS_FATAL_IF(!mHasSRGBWriteControl, "Linear blending requires EXT_sRGB_write_control");
71 
72     mHasLinearBlending = true;
73 #else
74     mHasLinearBlending = false;
75 #endif
76 }
77 
78 }; // namespace uirenderer
79 }; // namespace android
80