Using ANGLE for Windows and using the OpenGLES2.0 API

Submitted by prabindh on Fri, 01/15/2016 - 20:40 / /

Introduction
ANGLE (Almost Native Graphics Layer Engine) is a software wrapper, that provides a Khronos certified OpenGLES2.0 implementation on Windows platforms. This is a good tool to understand how 3D Graphics APIs work internally. Qt5 also uses ANGLE internally on windows builds, to be able to run the SceneGraph framework using OpenGLES2.0 across all platforms, including windows, in all versions from Qt5.1, Qt5.2 and further.
Note: For a quick way to use EGL and develop OpenGLES2 natively on Windows using your favorite tools, refer to the article - http://gpupowered.org/node/33
Note: This article is for using and building the ANGLE project source files directly from Google repository. With NuGet packaging, Microsoft provides its own source patches for building ANGLE projects for Windows10/Phone platforms. But note that this method needs the latest VIsual Studio tools (Visual studio 2015).

Need
Microsoft does not provide a native OpenGLES2.0 API on its platforms. The OpenGL version available by default on Windows is outdated. Hence ANGLE was created to satisfy the needs from browser vendors, applications, and various content providers to be able to run same content on mobile platforms, and Windows. However, by last quarter of 2013, Microsoft released its own WebGL implementation running in IE11, which indicates that internally there exists an OpenGLES2.0 like implementation on Windows (WebGL very closely resembles OpenGLES2.0). It remains to be seen how/if Microsoft will provide its own implementation along with its platforms.

ANGLE is not a pure software renderer for OpenGL ES2.0 API, and therefore is unlike Mesa. To be reasonably fast, it uses the underlying DirectX API on Windows itself, to render using OpenGLES2.0. Hence ANGLE can be considered an API translator, that runs on native Graphics HW accelerated API on Windows.

Obtaining the code
To get the code, git can be used, as below. Note that ANGLE is a part of Chromium repository at this time (2014).
git clone https://chromium.googlesource.com/angle/angle

Code organisation
ANGLE is written in c++, and there are 4 main sub projects in ANGLE. These are listed below:

libEGL

libGLESv2

preprocessor

translator The libEGL.lib, and libGLESv2.lib are linked in every application, just like regular OpenGL ES2 builds. The preprocessor and translator library outputs, are a part of libGLESv2.lib itself, and are used for Shader source compilation.

Building
There are 2 solution (.sln) files provided for building on Windows platforms. These are

angle/src/ANGLE.sln

angle/samples/samples.sln These need to be built, in the same order as above. When using Visual Studio 2012 for Desktop, the below additional steps are needed:

Add the below path to the "Include Directories" option for both projects (under C/C++ properties), and also separately for libGLESv2.rc file (note that this is not a C/C++ file)

C:\Program Files (x86)\Windows Kits\8.0\Include\um;C:\Program Files (x86)\Windows Kits\8.0\Include\shared



 Build logs


Below is the build log for the core ANGLE solution.




1>------ Build started: Project: translator, Configuration: Debug Win32 ------

2>------ Build started: Project: preprocessor, Configuration: Debug Win32 ------

2>  Tokenizer.cpp
1>  VersionGLSL.cpp
2>  Token.cpp
1>  ArrayBoundsClamper.cpp
2>  Preprocessor.cpp
1>  RestrictVertexShaderTiming.cpp
2>  MacroExpander.cpp
1>  RestrictFragmentShaderTiming.cpp
2>  Macro.cpp
2>  Lexer.cpp
2>  Input.cpp
1>  DependencyGraphTraverse.cpp
2>  ExpressionParser.cpp
2>  DirectiveParser.cpp
1>  DependencyGraphOutput.cpp
2>  DirectiveHandlerBase.cpp
1>  DependencyGraphBuilder.cpp
2>  DiagnosticsBase.cpp
1>  DependencyGraph.cpp
2>  Generating Code...
2>  preprocessor.vcxproj -> D:\angle\src\Debug\preprocessor.lib
1>  glslang_tab.cpp
1>  glslang_lex.cpp
1>  VariablePacker.cpp
1>  VariableInfo.cpp
1>  ValidateLimitations.cpp
1>  util.cpp
1>  Uniform.cpp
1>  UnfoldShortCircuitAST.cpp
1>  UnfoldShortCircuit.cpp
1>  TranslatorHLSL.cpp
1>  TranslatorGLSL.cpp
1>  TranslatorESSL.cpp
1>  Generating Code...
1>  Compiling...
1>  SymbolTable.cpp
1>  ShaderLang.cpp
1>  SearchSymbol.cpp
1>  RemoveTree.cpp
1>  QualifierAlive.cpp
1>  PoolAlloc.cpp
1>  ParseContext.cpp
1>  parseConst.cpp
1>  OutputHLSL.cpp
1>  OutputGLSLBase.cpp
1>  OutputGLSL.cpp
1>  OutputESSL.cpp
1>  ossource_win.cpp
1>  MapLongVariableNames.cpp
1>  IntermTraverse.cpp
1>  intermOut.cpp
1>  Intermediate.cpp
1>  InitializeParseContext.cpp
1>  InitializeGLPosition.cpp
1>  InitializeDll.cpp
1>  Generating Code...
1>  Compiling...
1>  Initialize.cpp
1>  InfoSink.cpp
1>  ForLoopUnroll.cpp
1>  DirectiveHandler.cpp
1>  Diagnostics.cpp
1>  DetectDiscontinuity.cpp
1>  DetectCallDepth.cpp
1>  debug.cpp
1>  Compiler.cpp
1>  CodeGen.cpp
1>  BuiltInFunctionEmulator.cpp
1>  Generating Code...
1>  translator.vcxproj -> D:\angle\src\Debug\translator.lib


3>------ Build started: Project: libGLESv2, Configuration: Debug Win32 ------

3>  precompiled.cpp
3>  event_tracer.cpp
3>  debug.cpp
3>  MurmurHash3.cpp
3>  Generating Code...
3>  utilities.cpp
3>  Uniform.cpp
3>  Texture.cpp
3>  Shader.cpp
3>  ResourceManager.cpp
3>  VertexDeclarationCache.cpp
3>  VertexDataManager.cpp
3>  VertexBuffer9.cpp
3>  VertexBuffer11.cpp
3>  VertexBuffer.cpp
3>  TextureStorage9.cpp
3>  TextureStorage11.cpp
3>  TextureStorage.cpp
3>  SwapChain9.cpp
3>  SwapChain11.cpp
3>  ShaderExecutable9.cpp
3>  ShaderExecutable11.cpp
3>  RenderStateCache.cpp
3>  RenderTarget9.cpp
3>  RenderTarget11.cpp
3>  Generating Code...
3>  Compiling...
3>  renderer9_utils.cpp
3>  Renderer9.cpp
3>  renderer11_utils.cpp
3>  Renderer11.cpp
3>  Renderer.cpp
3>  Query9.cpp
3>  Query11.cpp
3>  InputLayoutCache.cpp
3>  IndexRangeCache.cpp
3>  Image11.cpp
3>  ImageSSE2.cpp
3>  IndexDataManager.cpp
3>  IndexBuffer9.cpp
3>  IndexBuffer11.cpp
3>  IndexBuffer.cpp
3>  Image9.cpp
3>  Image.cpp
3>  BufferStorage9.cpp
3>  BufferStorage11.cpp
3>  BufferStorage.cpp
3>  Generating Code...
3>  Compiling...
3>  Fence9.cpp
3>  Fence11.cpp
3>  Blit.cpp
3>  Renderbuffer.cpp
3>  RefCountObject.cpp
3>  Query.cpp
3>  ProgramBinary.cpp
3>  Program.cpp
3>  main.cpp
3>  libGLESv2.cpp
3>  HandleAllocator.cpp
3>  Framebuffer.cpp
3>  Float16ToFloat32.cpp
3>  Fence.cpp
3>  Context.cpp
3>  Buffer.cpp
3>  Generating Code...

3>MurmurHash3.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification

3>     Creating library D:\angle\src\Debug\libGLESv2.lib and object D:\angle\src\Debug\libGLESv2.exp

3>  libGLESv2.vcxproj -> D:\angle\src\Debug\libGLESv2.dll
3>  A subdirectory or file D:\angle\src\libGLESv2\..\..\lib\Debug\ already exists.

3>          1 file(s) copied.

3>          1 file(s) copied.

4>------ Build started: Project: libEGL, Configuration: Debug Win32 ------

4>  Surface.cpp
4>  main.cpp
4>  libEGL.cpp
4>  Display.cpp
4>  debug.cpp
4>  Config.cpp
4>  Generating Code...
4>Config.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
4>     Creating library D:\angle\src\Debug\libEGL.lib and object D:\angle\src\Debug\libEGL.exp
4>  libEGL.vcxproj -> D:\angle\src\Debug\libEGL.dll
4>  A subdirectory or file D:\angle\src\libEGL\..\..\lib\Debug\ already exists.

4>          1 file(s) copied.
4>          1 file(s) copied.
========== Build: 4 succeeded, 0 failed, 0 up-to-date, 0 skipped ==========





Below is the log for the samples solution.


1>------ Build started: Project: preprocessor, Configuration: Debug Win32 ------
2>------ Build started: Project: translator, Configuration: Debug Win32 ------
1>  Tokenizer.cpp
2>  VersionGLSL.cpp
1>  Token.cpp
2>  ArrayBoundsClamper.cpp
1>  Preprocessor.cpp
2>  RestrictVertexShaderTiming.cpp
1>  MacroExpander.cpp
2>  RestrictFragmentShaderTiming.cpp
1>  Macro.cpp
1>  Lexer.cpp
1>  Input.cpp
1>  ExpressionParser.cpp
2>  DependencyGraphTraverse.cpp
1>  DirectiveParser.cpp
2>  DependencyGraphOutput.cpp
1>  DirectiveHandlerBase.cpp
2>  DependencyGraphBuilder.cpp
1>  DiagnosticsBase.cpp
1>  Generating Code...
2>  DependencyGraph.cpp
1>  preprocessor.vcxproj -> D:\angle\samples\Debug\preprocessor.lib
2>  glslang_tab.cpp
2>  glslang_lex.cpp
2>  VariablePacker.cpp
2>  VariableInfo.cpp
2>  ValidateLimitations.cpp
2>  util.cpp
2>  Uniform.cpp
2>  UnfoldShortCircuitAST.cpp
2>  UnfoldShortCircuit.cpp
2>  TranslatorHLSL.cpp
2>  TranslatorGLSL.cpp
2>  TranslatorESSL.cpp
2>  Generating Code...
2>  Compiling...
2>  SymbolTable.cpp
2>  ShaderLang.cpp
2>  SearchSymbol.cpp
2>  RemoveTree.cpp
2>  QualifierAlive.cpp
2>  PoolAlloc.cpp
2>  ParseContext.cpp
2>  parseConst.cpp
2>  OutputHLSL.cpp
2>  OutputGLSLBase.cpp
2>  OutputGLSL.cpp
2>  OutputESSL.cpp
2>  ossource_win.cpp
2>  MapLongVariableNames.cpp
2>  IntermTraverse.cpp
2>  intermOut.cpp
2>  Intermediate.cpp
2>  InitializeParseContext.cpp
2>  InitializeGLPosition.cpp
2>  InitializeDll.cpp
2>  Generating Code...
2>  Compiling...
2>  Initialize.cpp
2>  InfoSink.cpp
2>  ForLoopUnroll.cpp
2>  DirectiveHandler.cpp
2>  Diagnostics.cpp
2>  DetectDiscontinuity.cpp
2>  DetectCallDepth.cpp
2>  debug.cpp
2>  Compiler.cpp
2>  CodeGen.cpp
2>  BuiltInFunctionEmulator.cpp
2>  Generating Code...
2>  translator.vcxproj -> D:\angle\samples\Debug\translator.lib

3>------ Build started: Project: libGLESv2, Configuration: Debug Win32 ------
4>------ Build started: Project: essl_to_hlsl, Configuration: Debug Win32 ------
4>  translator.cpp
3>  precompiled.cpp
4>  debug.cpp
4>  Generating Code...
4>debug.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
3>  event_tracer.cpp
3>  debug.cpp
4>  essl_to_hlsl.vcxproj -> D:\angle\samples\Debug\essl_to_hlsl.exe
3>  MurmurHash3.cpp
3>  Generating Code...
3>  utilities.cpp
3>  Uniform.cpp
3>  Texture.cpp
3>  Shader.cpp
3>  ResourceManager.cpp
3>  VertexDeclarationCache.cpp
3>  VertexDataManager.cpp
3>  VertexBuffer9.cpp
3>  VertexBuffer11.cpp
3>  VertexBuffer.cpp
3>  TextureStorage9.cpp
3>  TextureStorage11.cpp
3>  TextureStorage.cpp
3>  SwapChain9.cpp
3>  SwapChain11.cpp
3>  ShaderExecutable9.cpp
3>  ShaderExecutable11.cpp
3>  RenderStateCache.cpp
3>  RenderTarget9.cpp
3>  RenderTarget11.cpp
3>  Generating Code...
3>  Compiling...
3>  renderer9_utils.cpp
3>  Renderer9.cpp
3>  renderer11_utils.cpp
3>  Renderer11.cpp
3>  Renderer.cpp
3>  Query9.cpp
3>  Query11.cpp
3>  InputLayoutCache.cpp
3>  IndexRangeCache.cpp
3>  Image11.cpp
3>  ImageSSE2.cpp
3>  IndexDataManager.cpp
3>  IndexBuffer9.cpp
3>  IndexBuffer11.cpp
3>  IndexBuffer.cpp
3>  Image9.cpp
3>  Image.cpp
3>  BufferStorage9.cpp
3>  BufferStorage11.cpp
3>  BufferStorage.cpp
3>  Generating Code...
3>  Compiling...
3>  Fence9.cpp
3>  Fence11.cpp
3>  Blit.cpp
3>  Renderbuffer.cpp
3>  RefCountObject.cpp
3>  Query.cpp
3>  ProgramBinary.cpp
3>  Program.cpp
3>  main.cpp
3>  libGLESv2.cpp
3>  HandleAllocator.cpp
3>  Framebuffer.cpp
3>  Float16ToFloat32.cpp
3>  Fence.cpp
3>  Context.cpp
3>  Buffer.cpp
3>  Generating Code...
3>MurmurHash3.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
3>     Creating library D:\angle\samples\Debug\libGLESv2.lib and object D:\angle\samples\Debug\libGLESv2.exp

3>  libGLESv2.vcxproj -> D:\angle\samples\Debug\libGLESv2.dll

3>  A subdirectory or file D:\angle\src\libGLESv2\..\..\lib\Debug\ already exists.
3>          1 file(s) copied.
3>          1 file(s) copied.
5>------ Build started: Project: libEGL, Configuration: Debug Win32 ------
5>  Surface.cpp
5>  main.cpp
5>  libEGL.cpp
5>  Display.cpp
5>  debug.cpp
5>  Config.cpp
5>  Generating Code...
5>Config.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
5>     Creating library D:\angle\samples\Debug\libEGL.lib and object D:\angle\samples\Debug\libEGL.exp

5>  libEGL.vcxproj -> D:\angle\samples\Debug\libEGL.dll

5>  A subdirectory or file D:\angle\src\libEGL\..\..\lib\Debug\ already exists.
5>          1 file(s) copied.
5>          1 file(s) copied.
6>------ Build started: Project: esUtil, Configuration: Debug Win32 ------
6>  esUtil.c
6>  esTransform.c
6>  esShapes.c
6>  esShader.c
6>  esUtil_win32.c
6>  esUtil_TGA.c
6>  Generating Code...
6>libGLESv2.lib(libGLESv2.dll) : warning LNK4006: __NULL_IMPORT_DESCRIPTOR already defined in libEGL.lib(libEGL.dll); second definition ignored
6>libGLESv2.lib(libGLESv2.dll) : warning LNK4221: This object file does not define any previously undefined public symbols, so it will not be used by any link operation that consumes this library
6>  esUtil.vcxproj -> D:\angle\samples\Debug\esUtil.lib
7>------ Build started: Project: Hello_Triangle, Configuration: Debug Win32 ------
8>------ Build started: Project: MipMap2D, Configuration: Debug Win32 ------
9>------ Build started: Project: MultiTexture, Configuration: Debug Win32 ------
10>------ Build started: Project: ParticleSystem, Configuration: Debug Win32 ------
9>  MultiTexture.c
8>  MipMap2D.c
7>  Hello_Triangle.c
10>  ParticleSystem.c
9>MultiTexture.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
8>MipMap2D.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
7>Hello_Triangle.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
10>ParticleSystem.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
9>  MultiTexture.vcxproj -> D:\angle\samples\Debug\MultiTexture.exe
7>  Hello_Triangle.vcxproj -> D:\angle\samples\Debug\Hello_Triangle.exe
8>  MipMap2D.vcxproj -> D:\angle\samples\Debug\MipMap2D.exe
9>  0 File(s) copied
9>  0 File(s) copied
11>------ Build started: Project: Simple_Texture2D, Configuration: Debug Win32 ------
11>  Simple_Texture2D.c
10>  ParticleSystem.vcxproj -> D:\angle\samples\Debug\ParticleSystem.exe
12>------ Build started: Project: Simple_TextureCubemap, Configuration: Debug Win32 ------
12>  Simple_TextureCubemap.c
10>  0 File(s) copied
13>------ Build started: Project: Simple_VertexShader, Configuration: Debug Win32 ------
14>------ Build started: Project: Stencil_Test, Configuration: Debug Win32 ------
13>  Simple_VertexShader.c
14>  Stencil_Test.c
11>Simple_Texture2D.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
12>Simple_TextureCubemap.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
14>Stencil_Test.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
13>Simple_VertexShader.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
11>  Simple_Texture2D.vcxproj -> D:\angle\samples\Debug\Simple_Texture2D.exe
15>------ Build started: Project: TextureWrap, Configuration: Debug Win32 ------
15>  TextureWrap.c
12>  Simple_TextureCubemap.vcxproj -> D:\angle\samples\Debug\Simple_TextureCubemap.exe
13>  Simple_VertexShader.vcxproj -> D:\angle\samples\Debug\Simple_VertexShader.exe
14>  Stencil_Test.vcxproj -> D:\angle\samples\Debug\Stencil_Test.exe
16>------ Build started: Project: PostSubBuffer, Configuration: Debug Win32 ------
17>------ Build started: Project: Simple_Instancing, Configuration: Debug Win32 ------
18>------ Build started: Project: MultipleRenderTargets, Configuration: Debug Win32 ------
16>  PostSubBuffer.c
17>  Simple_Instancing.c
18>  MultipleRenderTargets.c
15>TextureWrap.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
16>PostSubBuffer.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
18>MultipleRenderTargets.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
17>Simple_Instancing.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
15>  TextureWrap.vcxproj -> D:\angle\samples\Debug\TextureWrap.exe
17>  Simple_Instancing.vcxproj -> D:\angle\samples\Debug\Simple_Instancing.exe
16>  PostSubBuffer.vcxproj -> D:\angle\samples\Debug\PostSubBuffer.exe
18>  MultipleRenderTargets.vcxproj -> D:\angle\samples\Debug\MultipleRenderTargets.exe
========== Build: 18 succeeded, 0 failed, 0 up-to-date, 0 skipped ==========




 After this step, all ANGLE sample projects can be run from Visual Studio itself. For example, "Hello Triangle" will show a red triangle with black background.



References:


Since the original article written in 2013, an introduction to ANGLE from Shannon Woods available below:


https://docs.google.com/presentation/d/1vN_KTFDaKjFlIgx1vM3ZFA4Rkf723onAAhIfKR7kmgA/edit?pli=1#slide=id.gda2d11de0_0_58


-Prabindh Sundareson, 2015