Quelle  Context.cpp   Sprache: C

//
// Copyright 2002 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//

// Context.cpp: Implements the gl::Context class, managing all GL state and performing
// rendering operations. It is the GLES2 specific implementation of EGLContext.
#include "libANGLE/Context.inl.h"

#include <stdarg.h>
#include <stdio.h>
#include <string.h>

#include <iterator>
#include <sstream>
#include <vector>

#include "common/PackedEnums.h"
#include "common/angle_version_info.h"
#include "common/matrix_utils.h"
#include "common/platform.h"
#include "common/system_utils.h"
#include "common/utilities.h"
#include "libANGLE/Buffer.h"
#include "libANGLE/Compiler.h"
#include "libANGLE/Display.h"
#include "libANGLE/Fence.h"
#include "libANGLE/FramebufferAttachment.h"
#include "libANGLE/MemoryObject.h"
#include "libANGLE/PixelLocalStorage.h"
#include "libANGLE/Program.h"
#include "libANGLE/ProgramPipeline.h"
#include "libANGLE/Query.h"
#include "libANGLE/Renderbuffer.h"
#include "libANGLE/ResourceManager.h"
#include "libANGLE/Sampler.h"
#include "libANGLE/Semaphore.h"
#include "libANGLE/Surface.h"
#include "libANGLE/Texture.h"
#include "libANGLE/TransformFeedback.h"
#include "libANGLE/VertexArray.h"
#include "libANGLE/capture/FrameCapture.h"
#include "libANGLE/capture/frame_capture_utils.h"
#include "libANGLE/formatutils.h"
#include "libANGLE/queryconversions.h"
#include "libANGLE/queryutils.h"
#include "libANGLE/renderer/DisplayImpl.h"
#include "libANGLE/renderer/Format.h"
#include "libANGLE/validationES.h"

#if defined(ANGLE_PLATFORM_APPLE)
#    include <dispatch/dispatch.h>
#    include "common/tls.h"
#endif

namespace gl
{
namespace
{

egl::ShareGroup *AllocateOrGetShareGroup(egl::Display *display, const gl::Context *shareContext)
{
    if (shareContext)
    {
        egl::ShareGroup *shareGroup = shareContext->getState().getShareGroup();
        shareGroup->addRef();
        return shareGroup;
    }
    else
    {
        return new egl::ShareGroup(display->getImplementation());
    }
}

template <typename T>
angle::Result GetQueryObjectParameter(const Context *context, Query *query, GLenum pname, T *params)
{
    if (!query)
    {
        // Some applications call into glGetQueryObjectuiv(...) prior to calling glBeginQuery(...)
        // This wouldn't be an issue since the validation layer will handle such a usecases but when
        // the app enables EGL_KHR_create_context_no_error extension, we skip the validation layer.
        switch (pname)
        {
            case GL_QUERY_RESULT_EXT:
                *params = 0;
                break;
            case GL_QUERY_RESULT_AVAILABLE_EXT:
                *params = GL_FALSE;
                break;
            default:
                UNREACHABLE();
                return angle::Result::Stop;
        }
        return angle::Result::Continue;
    }

    switch (pname)
    {
        case GL_QUERY_RESULT_EXT:
            return query->getResult(context, params);
        case GL_QUERY_RESULT_AVAILABLE_EXT:
        {
            bool available = false;
            if (context->isContextLost())
            {
                available = true;
            }
            else
            {
                ANGLE_TRY(query->isResultAvailable(context, &available));
            }
            *params = CastFromStateValue<T>(pname, static_cast<GLuint>(available));
            return angle::Result::Continue;
        }
        default:
            UNREACHABLE();
            return angle::Result::Stop;
    }
}

// Attribute map queries.
EGLint GetClientMajorVersion(const egl::AttributeMap &attribs)
{
    return static_cast<EGLint>(attribs.get(EGL_CONTEXT_CLIENT_VERSION, 1));
}

EGLint GetClientMinorVersion(const egl::AttributeMap &attribs)
{
    return static_cast<EGLint>(attribs.get(EGL_CONTEXT_MINOR_VERSION, 0));
}

bool GetBackwardCompatibleContext(const egl::AttributeMap &attribs)
{
    return attribs.get(EGL_CONTEXT_OPENGL_BACKWARDS_COMPATIBLE_ANGLE, EGL_TRUE) == EGL_TRUE;
}

bool GetWebGLContext(const egl::AttributeMap &attribs)
{
    return (attribs.get(EGL_CONTEXT_WEBGL_COMPATIBILITY_ANGLE, EGL_FALSE) == EGL_TRUE);
}

Version GetClientVersion(egl::Display *display,
                         const egl::AttributeMap &attribs,
                         const EGLenum clientType)
{
    Version requestedVersion =
        Version(GetClientMajorVersion(attribs), GetClientMinorVersion(attribs));
    if (GetBackwardCompatibleContext(attribs))
    {
        if (clientType == EGL_OPENGL_API)
        {
            Optional<gl::Version> maxSupportedDesktopVersion =
                display->getImplementation()->getMaxSupportedDesktopVersion();
            if (maxSupportedDesktopVersion.valid())
                return std::max(maxSupportedDesktopVersion.value(), requestedVersion);
            else
                return requestedVersion;
        }
        else if (requestedVersion.major == 1)
        {
            // If the user requests an ES1 context, we cannot return an ES 2+ context.
            return Version(1, 1);
        }
        else
        {
            // Always up the version to at least the max conformant version this display supports.
            // Only return a higher client version if requested.
            const Version conformantVersion = std::max(
                display->getImplementation()->getMaxConformantESVersion(), requestedVersion);
            // Limit the WebGL context to at most version 3.1
            const bool isWebGL = GetWebGLContext(attribs);
            return isWebGL ? std::min(conformantVersion, Version(3, 1)) : conformantVersion;
        }
    }
    else
    {
        return requestedVersion;
    }
}

EGLint GetProfileMask(const egl::AttributeMap &attribs)
{
    return attribs.getAsInt(EGL_CONTEXT_OPENGL_PROFILE_MASK, EGL_CONTEXT_OPENGL_CORE_PROFILE_BIT);
}

GLenum GetResetStrategy(const egl::AttributeMap &attribs)
{
    EGLAttrib resetStrategyExt =
        attribs.get(EGL_CONTEXT_OPENGL_RESET_NOTIFICATION_STRATEGY_EXT, EGL_NO_RESET_NOTIFICATION);
    EGLAttrib resetStrategyCore =
        attribs.get(EGL_CONTEXT_OPENGL_RESET_NOTIFICATION_STRATEGY, resetStrategyExt);

    switch (resetStrategyCore)
    {
        case EGL_NO_RESET_NOTIFICATION:
            return GL_NO_RESET_NOTIFICATION_EXT;
        case EGL_LOSE_CONTEXT_ON_RESET:
            return GL_LOSE_CONTEXT_ON_RESET_EXT;
        default:
            UNREACHABLE();
            return GL_NONE;
    }
}

bool GetRobustAccess(const egl::AttributeMap &attribs)
{
    EGLAttrib robustAccessExt  = attribs.get(EGL_CONTEXT_OPENGL_ROBUST_ACCESS_EXT, EGL_FALSE);
    EGLAttrib robustAccessCore = attribs.get(EGL_CONTEXT_OPENGL_ROBUST_ACCESS, robustAccessExt);

    bool attribRobustAccess = (robustAccessCore == EGL_TRUE);
    bool contextFlagsRobustAccess =
        ((attribs.get(EGL_CONTEXT_FLAGS_KHR, 0) & EGL_CONTEXT_OPENGL_ROBUST_ACCESS_BIT_KHR) != 0);

    return (attribRobustAccess || contextFlagsRobustAccess);
}

bool GetDebug(const egl::AttributeMap &attribs)
{
    return (attribs.get(EGL_CONTEXT_OPENGL_DEBUG, EGL_FALSE) == EGL_TRUE) ||
           ((attribs.get(EGL_CONTEXT_FLAGS_KHR, 0) & EGL_CONTEXT_OPENGL_DEBUG_BIT_KHR) != 0);
}

bool GetNoError(const egl::AttributeMap &attribs)
{
    return (attribs.get(EGL_CONTEXT_OPENGL_NO_ERROR_KHR, EGL_FALSE) == EGL_TRUE);
}

bool GetExtensionsEnabled(const egl::AttributeMap &attribs, bool webGLContext)
{
    // If the context is WebGL, extensions are disabled by default
    EGLAttrib defaultValue = webGLContext ? EGL_FALSE : EGL_TRUE;
    return (attribs.get(EGL_EXTENSIONS_ENABLED_ANGLE, defaultValue) == EGL_TRUE);
}

bool GetBindGeneratesResource(const egl::AttributeMap &attribs)
{
    return (attribs.get(EGL_CONTEXT_BIND_GENERATES_RESOURCE_CHROMIUM, EGL_TRUE) == EGL_TRUE);
}

bool GetClientArraysEnabled(const egl::AttributeMap &attribs)
{
    return (attribs.get(EGL_CONTEXT_CLIENT_ARRAYS_ENABLED_ANGLE, EGL_TRUE) == EGL_TRUE);
}

bool GetRobustResourceInit(egl::Display *display, const egl::AttributeMap &attribs)
{
    const angle::FrontendFeatures &frontendFeatures = display->getFrontendFeatures();
    return (frontendFeatures.forceRobustResourceInit.enabled ||
            attribs.get(EGL_ROBUST_RESOURCE_INITIALIZATION_ANGLE, EGL_FALSE) == EGL_TRUE);
}

EGLenum GetContextPriority(const egl::AttributeMap &attribs)
{
    return static_cast<EGLenum>(
        attribs.getAsInt(EGL_CONTEXT_PRIORITY_LEVEL_IMG, EGL_CONTEXT_PRIORITY_MEDIUM_IMG));
}

bool GetProtectedContent(const egl::AttributeMap &attribs)
{
    return static_cast<bool>(attribs.getAsInt(EGL_PROTECTED_CONTENT_EXT, EGL_FALSE));
}

std::string GetObjectLabelFromPointer(GLsizei length, const GLchar *label)
{
    std::string labelName;
    if (label != nullptr)
    {
        size_t labelLength = length < 0 ? strlen(label) : length;
        labelName          = std::string(label, labelLength);
    }
    return labelName;
}

void GetObjectLabelBase(const std::string &objectLabel,
                        GLsizei bufSize,
                        GLsizei *length,
                        GLchar *label)
{
    size_t writeLength = objectLabel.length();
    if (label != nullptr && bufSize > 0)
    {
        writeLength = std::min(static_cast<size_t>(bufSize) - 1, objectLabel.length());
        std::copy(objectLabel.begin(), objectLabel.begin() + writeLength, label);
        label[writeLength] = '\0';
    }

    if (length != nullptr)
    {
        *length = static_cast<GLsizei>(writeLength);
    }
}

enum SubjectIndexes : angle::SubjectIndex
{
    kTexture0SubjectIndex       = 0,
    kTextureMaxSubjectIndex     = kTexture0SubjectIndex + IMPLEMENTATION_MAX_ACTIVE_TEXTURES,
    kImage0SubjectIndex         = kTextureMaxSubjectIndex,
    kImageMaxSubjectIndex       = kImage0SubjectIndex + IMPLEMENTATION_MAX_IMAGE_UNITS,
    kUniformBuffer0SubjectIndex = kImageMaxSubjectIndex,
    kUniformBufferMaxSubjectIndex =
        kUniformBuffer0SubjectIndex + IMPLEMENTATION_MAX_UNIFORM_BUFFER_BINDINGS,
    kAtomicCounterBuffer0SubjectIndex = kUniformBufferMaxSubjectIndex,
    kAtomicCounterBufferMaxSubjectIndex =
        kAtomicCounterBuffer0SubjectIndex + IMPLEMENTATION_MAX_ATOMIC_COUNTER_BUFFER_BINDINGS,
    kShaderStorageBuffer0SubjectIndex = kAtomicCounterBufferMaxSubjectIndex,
    kShaderStorageBufferMaxSubjectIndex =
        kShaderStorageBuffer0SubjectIndex + IMPLEMENTATION_MAX_SHADER_STORAGE_BUFFER_BINDINGS,
    kSampler0SubjectIndex    = kShaderStorageBufferMaxSubjectIndex,
    kSamplerMaxSubjectIndex  = kSampler0SubjectIndex + IMPLEMENTATION_MAX_ACTIVE_TEXTURES,
    kVertexArraySubjectIndex = kSamplerMaxSubjectIndex,
    kReadFramebufferSubjectIndex,
    kDrawFramebufferSubjectIndex,
    kProgramPipelineSubjectIndex,
};

bool IsClearBufferEnabled(const FramebufferState &fbState, GLenum buffer, GLint drawbuffer)
{
    return buffer != GL_COLOR || fbState.getEnabledDrawBuffers()[drawbuffer];
}

bool IsEmptyScissor(const State &glState)
{
    if (!glState.isScissorTestEnabled())
    {
        return false;
    }

    const Extents &dimensions = glState.getDrawFramebuffer()->getExtents();
    Rectangle framebufferArea(0, 0, dimensions.width, dimensions.height);
    return !ClipRectangle(framebufferArea, glState.getScissor(), nullptr);
}

bool IsColorMaskedOut(const BlendStateExt &blendStateExt, const GLint drawbuffer)
{
    ASSERT(static_cast<size_t>(drawbuffer) < blendStateExt.getDrawBufferCount());
    return blendStateExt.getColorMaskIndexed(static_cast<size_t>(drawbuffer)) == 0;
}

bool GetIsExternal(const egl::AttributeMap &attribs)
{
    return (attribs.get(EGL_EXTERNAL_CONTEXT_ANGLE, EGL_FALSE) == EGL_TRUE);
}

bool GetSaveAndRestoreState(const egl::AttributeMap &attribs)
{
    return (attribs.get(EGL_EXTERNAL_CONTEXT_SAVE_STATE_ANGLE, EGL_FALSE) == EGL_TRUE);
}

void GetPerfMonitorString(const std::string &name,
                          GLsizei bufSize,
                          GLsizei *length,
                          GLchar *stringOut)
{
    GLsizei numCharsWritten = std::min(bufSize, static_cast<GLsizei>(name.size()));

    if (length)
    {
        if (bufSize == 0)
        {
            *length = static_cast<GLsizei>(name.size());
        }
        else
        {
            // Excludes null terminator.
            ASSERT(numCharsWritten > 0);
            *length = numCharsWritten - 1;
        }
    }

    if (stringOut)
    {
        memcpy(stringOut, name.c_str(), numCharsWritten);
    }
}

bool CanSupportAEP(const gl::Version &version, const gl::Extensions &extensions)
{
    // From the GL_ANDROID_extension_pack_es31a extension spec:
    // OpenGL ES 3.1 and GLSL ES 3.10 are required.
    // The following extensions are required:
    // * KHR_debug
    // * KHR_texture_compression_astc_ldr
    // * KHR_blend_equation_advanced
    // * OES_sample_shading
    // * OES_sample_variables
    // * OES_shader_image_atomic
    // * OES_shader_multisample_interpolation
    // * OES_texture_stencil8
    // * OES_texture_storage_multisample_2d_array
    // * EXT_copy_image
    // * EXT_draw_buffers_indexed
    // * EXT_geometry_shader
    // * EXT_gpu_shader5
    // * EXT_primitive_bounding_box
    // * EXT_shader_io_blocks
    // * EXT_tessellation_shader
    // * EXT_texture_border_clamp
    // * EXT_texture_buffer
    // * EXT_texture_cube_map_array
    // * EXT_texture_sRGB_decode
    return (version >= ES_3_1 && extensions.debugKHR && extensions.textureCompressionAstcLdrKHR &&
            extensions.blendEquationAdvancedKHR && extensions.sampleShadingOES &&
            extensions.sampleVariablesOES && extensions.shaderImageAtomicOES &&
            extensions.shaderMultisampleInterpolationOES && extensions.textureStencil8OES &&
            extensions.textureStorageMultisample2dArrayOES && extensions.copyImageEXT &&
            extensions.drawBuffersIndexedEXT && extensions.geometryShaderEXT &&
            extensions.gpuShader5EXT && extensions.primitiveBoundingBoxEXT &&
            extensions.shaderIoBlocksEXT && extensions.tessellationShaderEXT &&
            extensions.textureBorderClampEXT && extensions.textureBufferEXT &&
            extensions.textureCubeMapArrayEXT && extensions.textureSRGBDecodeEXT);
}
}  // anonymous namespace

#if defined(ANGLE_PLATFORM_APPLE)
// TODO(angleproject:6479): Due to a bug in Apple's dyld loader, `thread_local` will cause
// excessive memory use. Temporarily avoid it by using pthread's thread
// local storage instead.
static TLSIndex GetCurrentValidContextTLSIndex()
{
    static TLSIndex CurrentValidContextIndex = TLS_INVALID_INDEX;
    static dispatch_once_t once;
    dispatch_once(&once, ^{
      ASSERT(CurrentValidContextIndex == TLS_INVALID_INDEX);
      CurrentValidContextIndex = CreateTLSIndex(nullptr);
    });
    return CurrentValidContextIndex;
}
Context *GetCurrentValidContextTLS()
{
    TLSIndex CurrentValidContextIndex = GetCurrentValidContextTLSIndex();
    ASSERT(CurrentValidContextIndex != TLS_INVALID_INDEX);
    return static_cast<Context *>(GetTLSValue(CurrentValidContextIndex));
}
void SetCurrentValidContextTLS(Context *context)
{
    TLSIndex CurrentValidContextIndex = GetCurrentValidContextTLSIndex();
    ASSERT(CurrentValidContextIndex != TLS_INVALID_INDEX);
    SetTLSValue(CurrentValidContextIndex, context);
}
#else
thread_local Context *gCurrentValidContext = nullptr;
#endif

Context::Context(egl::Display *display,
                 const egl::Config *config,
                 const Context *shareContext,
                 TextureManager *shareTextures,
                 SemaphoreManager *shareSemaphores,
                 MemoryProgramCache *memoryProgramCache,
                 MemoryShaderCache *memoryShaderCache,
                 const EGLenum clientType,
                 const egl::AttributeMap &attribs,
                 const egl::DisplayExtensions &displayExtensions,
                 const egl::ClientExtensions &clientExtensions)
    : mState(shareContext ? &shareContext->mState : nullptr,
             AllocateOrGetShareGroup(display, shareContext),
             shareTextures,
             shareSemaphores,
             &mOverlay,
             clientType,
             GetClientVersion(display, attribs, clientType),
             GetProfileMask(attribs),
             GetDebug(attribs),
             GetBindGeneratesResource(attribs),
             GetClientArraysEnabled(attribs),
             GetRobustResourceInit(display, attribs),
             memoryProgramCache != nullptr,
             GetContextPriority(attribs),
             GetRobustAccess(attribs),
             GetProtectedContent(attribs)),
      mShared(shareContext != nullptr || shareTextures != nullptr || shareSemaphores != nullptr),
      mSkipValidation(GetNoError(attribs)),
      mDisplayTextureShareGroup(shareTextures != nullptr),
      mDisplaySemaphoreShareGroup(shareSemaphores != nullptr),
      mErrors(this),
      mImplementation(display->getImplementation()
                          ->createContext(mState, &mErrors, config, shareContext, attribs)),
      mLabel(nullptr),
      mCompiler(),
      mConfig(config),
      mHasBeenCurrent(false),
      mContextLost(false),
      mResetStatus(GraphicsResetStatus::NoError),
      mContextLostForced(false),
      mResetStrategy(GetResetStrategy(attribs)),
      mSurfacelessSupported(displayExtensions.surfacelessContext),
      mCurrentDrawSurface(static_cast<egl::Surface *>(EGL_NO_SURFACE)),
      mCurrentReadSurface(static_cast<egl::Surface *>(EGL_NO_SURFACE)),
      mDisplay(display),
      mWebGLContext(GetWebGLContext(attribs)),
      mBufferAccessValidationEnabled(false),
      mExtensionsEnabled(GetExtensionsEnabled(attribs, mWebGLContext)),
      mMemoryProgramCache(memoryProgramCache),
      mMemoryShaderCache(memoryShaderCache),
      mVertexArrayObserverBinding(this, kVertexArraySubjectIndex),
      mDrawFramebufferObserverBinding(this, kDrawFramebufferSubjectIndex),
      mReadFramebufferObserverBinding(this, kReadFramebufferSubjectIndex),
      mProgramPipelineObserverBinding(this, kProgramPipelineSubjectIndex),
      mSingleThreadPool(nullptr),
      mMultiThreadPool(nullptr),
      mFrameCapture(new angle::FrameCapture),
      mRefCount(0),
      mOverlay(mImplementation.get()),
      mIsExternal(GetIsExternal(attribs)),
      mSaveAndRestoreState(GetSaveAndRestoreState(attribs)),
      mIsDestroyed(false)
{
    for (angle::SubjectIndex uboIndex = kUniformBuffer0SubjectIndex;
         uboIndex < kUniformBufferMaxSubjectIndex; ++uboIndex)
    {
        mUniformBufferObserverBindings.emplace_back(this, uboIndex);
    }

    for (angle::SubjectIndex acbIndex = kAtomicCounterBuffer0SubjectIndex;
         acbIndex < kAtomicCounterBufferMaxSubjectIndex; ++acbIndex)
    {
        mAtomicCounterBufferObserverBindings.emplace_back(this, acbIndex);
    }

    for (angle::SubjectIndex ssboIndex = kShaderStorageBuffer0SubjectIndex;
         ssboIndex < kShaderStorageBufferMaxSubjectIndex; ++ssboIndex)
    {
        mShaderStorageBufferObserverBindings.emplace_back(this, ssboIndex);
    }

    for (angle::SubjectIndex samplerIndex = kSampler0SubjectIndex;
         samplerIndex < kSamplerMaxSubjectIndex; ++samplerIndex)
    {
        mSamplerObserverBindings.emplace_back(this, samplerIndex);
    }

    for (angle::SubjectIndex imageIndex = kImage0SubjectIndex; imageIndex < kImageMaxSubjectIndex;
         ++imageIndex)
    {
        mImageObserverBindings.emplace_back(this, imageIndex);
    }

    // Implementations now require the display to be set at context creation.
    ASSERT(mDisplay);
}

egl::Error Context::initialize()
{
    if (!mImplementation)
        return egl::Error(EGL_NOT_INITIALIZED, "native context creation failed");
    return egl::NoError();
}

void Context::initializeDefaultResources()
{
    mImplementation->setMemoryProgramCache(mMemoryProgramCache);

    initCaps();

    mState.initialize(this);

    mDefaultFramebuffer = std::make_unique<Framebuffer>(this, mImplementation.get());

    mFenceNVHandleAllocator.setBaseHandle(0);

    // [OpenGL ES 2.0.24] section 3.7 page 83:
    // In the initial state, TEXTURE_2D and TEXTURE_CUBE_MAP have two-dimensional
    // and cube map texture state vectors respectively associated with them.
    // In order that access to these initial textures not be lost, they are treated as texture
    // objects all of whose names are 0.

    Texture *zeroTexture2D = new Texture(mImplementation.get(), {0}, TextureType::_2D);
    mZeroTextures[TextureType::_2D].set(this, zeroTexture2D);

    Texture *zeroTextureCube = new Texture(mImplementation.get(), {0}, TextureType::CubeMap);
    mZeroTextures[TextureType::CubeMap].set(this, zeroTextureCube);

    if (getClientVersion() >= Version(3, 0) || mSupportedExtensions.texture3DOES)
    {
        Texture *zeroTexture3D = new Texture(mImplementation.get(), {0}, TextureType::_3D);
        mZeroTextures[TextureType::_3D].set(this, zeroTexture3D);
    }
    if (getClientVersion() >= Version(3, 0))
    {
        Texture *zeroTexture2DArray =
            new Texture(mImplementation.get(), {0}, TextureType::_2DArray);
        mZeroTextures[TextureType::_2DArray].set(this, zeroTexture2DArray);
    }
    if (getClientVersion() >= Version(3, 1) || mSupportedExtensions.textureMultisampleANGLE)
    {
        Texture *zeroTexture2DMultisample =
            new Texture(mImplementation.get(), {0}, TextureType::_2DMultisample);
        mZeroTextures[TextureType::_2DMultisample].set(this, zeroTexture2DMultisample);
    }
    if (getClientVersion() >= Version(3, 1))
    {
        Texture *zeroTexture2DMultisampleArray =
            new Texture(mImplementation.get(), {0}, TextureType::_2DMultisampleArray);
        mZeroTextures[TextureType::_2DMultisampleArray].set(this, zeroTexture2DMultisampleArray);

        for (int i = 0; i < mState.mCaps.maxAtomicCounterBufferBindings; i++)
        {
            bindBufferRange(BufferBinding::AtomicCounter, i, {0}, 0, 0);
        }

        for (int i = 0; i < mState.mCaps.maxShaderStorageBufferBindings; i++)
        {
            bindBufferRange(BufferBinding::ShaderStorage, i, {0}, 0, 0);
        }
    }

    if ((getClientType() != EGL_OPENGL_API && getClientVersion() >= Version(3, 2)) ||
        mSupportedExtensions.textureCubeMapArrayAny())
    {
        Texture *zeroTextureCubeMapArray =
            new Texture(mImplementation.get(), {0}, TextureType::CubeMapArray);
        mZeroTextures[TextureType::CubeMapArray].set(this, zeroTextureCubeMapArray);
    }

    if ((getClientType() != EGL_OPENGL_API && getClientVersion() >= Version(3, 2)) ||
        mSupportedExtensions.textureBufferAny())
    {
        Texture *zeroTextureBuffer = new Texture(mImplementation.get(), {0}, TextureType::Buffer);
        mZeroTextures[TextureType::Buffer].set(this, zeroTextureBuffer);
    }

    if (mSupportedExtensions.textureRectangleANGLE)
    {
        Texture *zeroTextureRectangle =
            new Texture(mImplementation.get(), {0}, TextureType::Rectangle);
        mZeroTextures[TextureType::Rectangle].set(this, zeroTextureRectangle);
    }

    if (mSupportedExtensions.EGLImageExternalOES ||
        mSupportedExtensions.EGLStreamConsumerExternalNV)
    {
        Texture *zeroTextureExternal =
            new Texture(mImplementation.get(), {0}, TextureType::External);
        mZeroTextures[TextureType::External].set(this, zeroTextureExternal);
    }

    // This may change native TEXTURE_2D, TEXTURE_EXTERNAL_OES and TEXTURE_RECTANGLE,
    // binding states. Ensure state manager is aware of this when binding
    // this texture type.
    if (mSupportedExtensions.videoTextureWEBGL)
    {
        Texture *zeroTextureVideoImage =
            new Texture(mImplementation.get(), {0}, TextureType::VideoImage);
        mZeroTextures[TextureType::VideoImage].set(this, zeroTextureVideoImage);
    }

    mState.initializeZeroTextures(this, mZeroTextures);

    ANGLE_CONTEXT_TRY(mImplementation->initialize());

    // Add context into the share group
    mState.getShareGroup()->addSharedContext(this);

    bindVertexArray({0});

    if (getClientVersion() >= Version(3, 0))
    {
        // [OpenGL ES 3.0.2] section 2.14.1 pg 85:
        // In the initial state, a default transform feedback object is bound and treated as
        // a transform feedback object with a name of zero. That object is bound any time
        // BindTransformFeedback is called with id of zero
        bindTransformFeedback(GL_TRANSFORM_FEEDBACK, {0});
    }

    for (auto type : angle::AllEnums<BufferBinding>())
    {
        bindBuffer(type, {0});
    }

    bindRenderbuffer(GL_RENDERBUFFER, {0});

    for (int i = 0; i < mState.mCaps.maxUniformBufferBindings; i++)
    {
        bindBufferRange(BufferBinding::Uniform, i, {0}, 0, -1);
    }

    // Initialize GLES1 renderer if appropriate.
    if (getClientVersion() < Version(2, 0))
    {
        mGLES1Renderer.reset(new GLES1Renderer());
    }

    // Initialize dirty bit masks
    mAllDirtyBits.set();

    mDrawDirtyObjects.set(State::DIRTY_OBJECT_ACTIVE_TEXTURES);
    mDrawDirtyObjects.set(State::DIRTY_OBJECT_DRAW_FRAMEBUFFER);
    mDrawDirtyObjects.set(State::DIRTY_OBJECT_VERTEX_ARRAY);
    mDrawDirtyObjects.set(State::DIRTY_OBJECT_TEXTURES);
    mDrawDirtyObjects.set(State::DIRTY_OBJECT_PROGRAM);
    mDrawDirtyObjects.set(State::DIRTY_OBJECT_PROGRAM_PIPELINE_OBJECT);
    mDrawDirtyObjects.set(State::DIRTY_OBJECT_SAMPLERS);
    mDrawDirtyObjects.set(State::DIRTY_OBJECT_IMAGES);

    mTexImageDirtyBits.set(State::DIRTY_BIT_UNPACK_STATE);
    mTexImageDirtyBits.set(State::DIRTY_BIT_UNPACK_BUFFER_BINDING);
    mTexImageDirtyBits.set(State::DIRTY_BIT_EXTENDED);
    // No dirty objects.

    // Readpixels uses the pack state and read FBO
    mReadPixelsDirtyBits.set(State::DIRTY_BIT_PACK_STATE);
    mReadPixelsDirtyBits.set(State::DIRTY_BIT_PACK_BUFFER_BINDING);
    mReadPixelsDirtyBits.set(State::DIRTY_BIT_READ_FRAMEBUFFER_BINDING);
    mReadPixelsDirtyObjects.set(State::DIRTY_OBJECT_READ_FRAMEBUFFER);

    mClearDirtyBits.set(State::DIRTY_BIT_RASTERIZER_DISCARD_ENABLED);
    mClearDirtyBits.set(State::DIRTY_BIT_SCISSOR_TEST_ENABLED);
    mClearDirtyBits.set(State::DIRTY_BIT_SCISSOR);
    mClearDirtyBits.set(State::DIRTY_BIT_VIEWPORT);
    mClearDirtyBits.set(State::DIRTY_BIT_CLEAR_COLOR);
    mClearDirtyBits.set(State::DIRTY_BIT_CLEAR_DEPTH);
    mClearDirtyBits.set(State::DIRTY_BIT_CLEAR_STENCIL);
    mClearDirtyBits.set(State::DIRTY_BIT_COLOR_MASK);
    mClearDirtyBits.set(State::DIRTY_BIT_DEPTH_MASK);
    mClearDirtyBits.set(State::DIRTY_BIT_STENCIL_WRITEMASK_FRONT);
    mClearDirtyBits.set(State::DIRTY_BIT_STENCIL_WRITEMASK_BACK);
    mClearDirtyBits.set(State::DIRTY_BIT_DRAW_FRAMEBUFFER_BINDING);
    mClearDirtyObjects.set(State::DIRTY_OBJECT_DRAW_FRAMEBUFFER);

    // We sync the draw Framebuffer manually in prepareForClear to allow the clear calls to do
    // more custom handling for robust resource init.

    mBlitDirtyBits.set(State::DIRTY_BIT_SCISSOR_TEST_ENABLED);
    mBlitDirtyBits.set(State::DIRTY_BIT_SCISSOR);
    mBlitDirtyBits.set(State::DIRTY_BIT_FRAMEBUFFER_SRGB_WRITE_CONTROL_MODE);
    mBlitDirtyBits.set(State::DIRTY_BIT_READ_FRAMEBUFFER_BINDING);
    mBlitDirtyBits.set(State::DIRTY_BIT_DRAW_FRAMEBUFFER_BINDING);
    mBlitDirtyObjects.set(State::DIRTY_OBJECT_READ_FRAMEBUFFER);
    mBlitDirtyObjects.set(State::DIRTY_OBJECT_DRAW_FRAMEBUFFER);

    mComputeDirtyBits.set(State::DIRTY_BIT_SHADER_STORAGE_BUFFER_BINDING);
    mComputeDirtyBits.set(State::DIRTY_BIT_UNIFORM_BUFFER_BINDINGS);
    mComputeDirtyBits.set(State::DIRTY_BIT_ATOMIC_COUNTER_BUFFER_BINDING);
    mComputeDirtyBits.set(State::DIRTY_BIT_PROGRAM_BINDING);
    mComputeDirtyBits.set(State::DIRTY_BIT_PROGRAM_EXECUTABLE);
    mComputeDirtyBits.set(State::DIRTY_BIT_TEXTURE_BINDINGS);
    mComputeDirtyBits.set(State::DIRTY_BIT_SAMPLER_BINDINGS);
    mComputeDirtyBits.set(State::DIRTY_BIT_IMAGE_BINDINGS);
    mComputeDirtyBits.set(State::DIRTY_BIT_DISPATCH_INDIRECT_BUFFER_BINDING);
    mComputeDirtyObjects.set(State::DIRTY_OBJECT_ACTIVE_TEXTURES);
    mComputeDirtyObjects.set(State::DIRTY_OBJECT_TEXTURES);
    mComputeDirtyObjects.set(State::DIRTY_OBJECT_PROGRAM);
    mComputeDirtyObjects.set(State::DIRTY_OBJECT_PROGRAM_PIPELINE_OBJECT);
    mComputeDirtyObjects.set(State::DIRTY_OBJECT_IMAGES);
    mComputeDirtyObjects.set(State::DIRTY_OBJECT_SAMPLERS);

    mCopyImageDirtyBits.set(State::DIRTY_BIT_READ_FRAMEBUFFER_BINDING);
    mCopyImageDirtyObjects.set(State::DIRTY_OBJECT_READ_FRAMEBUFFER);

    mReadInvalidateDirtyBits.set(State::DIRTY_BIT_READ_FRAMEBUFFER_BINDING);
    mDrawInvalidateDirtyBits.set(State::DIRTY_BIT_DRAW_FRAMEBUFFER_BINDING);

    mOverlay.init();
}

egl::Error Context::onDestroy(const egl::Display *display)
{
    if (!mHasBeenCurrent)
    {
        // The context is never current, so default resources are not allocated.
        return egl::NoError();
    }

    // eglDestoryContext() must have been called for this Context and there must not be any Threads
    // that still have it current.
    ASSERT(mIsDestroyed == true && mRefCount == 0);

    // Dump frame capture if enabled.
    getShareGroup()->getFrameCaptureShared()->onDestroyContext(this);

    // Remove context from the capture share group
    getShareGroup()->removeSharedContext(this);

    if (mGLES1Renderer)
    {
        mGLES1Renderer->onDestroy(this, &mState);
    }

    ANGLE_TRY(unMakeCurrent(display));

    mDefaultFramebuffer->onDestroy(this);
    mDefaultFramebuffer.reset();

    for (auto fence : mFenceNVMap)
    {
        if (fence.second)
        {
            fence.second->onDestroy(this);
        }
        SafeDelete(fence.second);
    }
    mFenceNVMap.clear();

    for (auto query : mQueryMap)
    {
        if (query.second != nullptr)
        {
            query.second->release(this);
        }
    }
    mQueryMap.clear();

    for (auto vertexArray : mVertexArrayMap)
    {
        if (vertexArray.second)
        {
            vertexArray.second->onDestroy(this);
        }
    }
    mVertexArrayMap.clear();

    for (auto transformFeedback : mTransformFeedbackMap)
    {
        if (transformFeedback.second != nullptr)
        {
            transformFeedback.second->release(this);
        }
    }
    mTransformFeedbackMap.clear();

    for (BindingPointer<Texture> &zeroTexture : mZeroTextures)
    {
        if (zeroTexture.get() != nullptr)
        {
            zeroTexture.set(this, nullptr);
        }
    }

    releaseShaderCompiler();

    mState.reset(this);

    mState.mBufferManager->release(this);
    // mProgramPipelineManager must be before mShaderProgramManager to give each
    // PPO the chance to release any references they have to the Programs that
    // are bound to them before the Programs are released()'ed.
    mState.mProgramPipelineManager->release(this);
    mState.mShaderProgramManager->release(this);
    mState.mTextureManager->release(this);
    mState.mRenderbufferManager->release(this);
    mState.mSamplerManager->release(this);
    mState.mSyncManager->release(this);
    mState.mFramebufferManager->release(this);
    mState.mMemoryObjectManager->release(this);
    mState.mSemaphoreManager->release(this);

    mSingleThreadPool.reset();
    mMultiThreadPool.reset();

    mImplementation->onDestroy(this);

    // Backend requires implementation to be destroyed first to close down all the objects
    mState.mShareGroup->release(display);

    mOverlay.destroy(this);

    return egl::NoError();
}

Context::~Context() {}

void Context::setLabel(EGLLabelKHR label)
{
    mLabel = label;
}

EGLLabelKHR Context::getLabel() const
{
    return mLabel;
}

egl::Error Context::makeCurrent(egl::Display *display,
                                egl::Surface *drawSurface,
                                egl::Surface *readSurface)
{
    mDisplay = display;

    if (!mHasBeenCurrent)
    {
        initializeDefaultResources();
        initRendererString();
        initVersionStrings();
        initExtensionStrings();

        int width  = 0;
        int height = 0;
        if (drawSurface != nullptr)
        {
            width  = drawSurface->getWidth();
            height = drawSurface->getHeight();
        }

        mState.setViewportParams(0, 0, width, height);
        mState.setScissorParams(0, 0, width, height);

        mHasBeenCurrent = true;
    }

    ANGLE_TRY(unsetDefaultFramebuffer());

    getShareGroup()->getFrameCaptureShared()->onMakeCurrent(this, drawSurface);

    // TODO(jmadill): Rework this when we support ContextImpl
    mState.setAllDirtyBits();
    mState.setAllDirtyObjects();

    ANGLE_TRY(setDefaultFramebuffer(drawSurface, readSurface));

    // Notify the renderer of a context switch.
    angle::Result implResult = mImplementation->onMakeCurrent(this);

    // If the implementation fails onMakeCurrent, unset the default framebuffer.
    if (implResult != angle::Result::Continue)
    {
        ANGLE_TRY(unsetDefaultFramebuffer());
        return angle::ResultToEGL(implResult);
    }

    return egl::NoError();
}

egl::Error Context::unMakeCurrent(const egl::Display *display)
{
    ANGLE_TRY(angle::ResultToEGL(mImplementation->onUnMakeCurrent(this)));

    ANGLE_TRY(unsetDefaultFramebuffer());

    // Return the scratch buffers to the display so they can be shared with other contexts while
    // this one is not current.
    if (mScratchBuffer.valid())
    {
        mDisplay->returnScratchBuffer(mScratchBuffer.release());
    }
    if (mZeroFilledBuffer.valid())
    {
        mDisplay->returnZeroFilledBuffer(mZeroFilledBuffer.release());
    }

    return egl::NoError();
}

BufferID Context::createBuffer()
{
    return mState.mBufferManager->createBuffer();
}

GLuint Context::createProgram()
{
    return mState.mShaderProgramManager->createProgram(mImplementation.get()).value;
}

GLuint Context::createShader(ShaderType type)
{
    return mState.mShaderProgramManager
        ->createShader(mImplementation.get(), mState.mLimitations, type)
        .value;
}

TextureID Context::createTexture()
{
    return mState.mTextureManager->createTexture();
}

RenderbufferID Context::createRenderbuffer()
{
    return mState.mRenderbufferManager->createRenderbuffer();
}

// Returns an unused framebuffer name
FramebufferID Context::createFramebuffer()
{
    return mState.mFramebufferManager->createFramebuffer();
}

void Context::genFencesNV(GLsizei n, FenceNVID *fences)
{
    for (int i = 0; i < n; i++)
    {
        GLuint handle = mFenceNVHandleAllocator.allocate();
        mFenceNVMap.assign({handle}, new FenceNV(mImplementation.get()));
        fences[i] = {handle};
    }
}

ProgramPipelineID Context::createProgramPipeline()
{
    return mState.mProgramPipelineManager->createProgramPipeline();
}

GLuint Context::createShaderProgramv(ShaderType type, GLsizei count, const GLchar *const *strings)
{
    const ShaderProgramID shaderID = PackParam<ShaderProgramID>(createShader(type));
    if (shaderID.value)
    {
        Shader *shaderObject = getShader(shaderID);
        ASSERT(shaderObject);
        shaderObject->setSource(count, strings, nullptr);
        shaderObject->compile(this);
        const ShaderProgramID programID = PackParam<ShaderProgramID>(createProgram());
        if (programID.value)
        {
            gl::Program *programObject = getProgramNoResolveLink(programID);
            ASSERT(programObject);

            if (shaderObject->isCompiled(this))
            {
                // As per Khronos issue 2261:
                // https://gitlab.khronos.org/Tracker/vk-gl-cts/issues/2261
                // We must wait to mark the program separable until it's successfully compiled.
                programObject->setSeparable(true);

                programObject->attachShader(shaderObject);

                if (programObject->link(this) != angle::Result::Continue)
                {
                    deleteShader(shaderID);
                    deleteProgram(programID);
                    return 0u;
                }
                if (onProgramLink(programObject) != angle::Result::Continue)
                {
                    deleteShader(shaderID);
                    deleteProgram(programID);
                    return 0u;
                }

                programObject->detachShader(this, shaderObject);
            }

            InfoLog &programInfoLog = programObject->getExecutable().getInfoLog();
            programInfoLog << shaderObject->getInfoLogString();
        }

        deleteShader(shaderID);

        return programID.value;
    }

    return 0u;
}

MemoryObjectID Context::createMemoryObject()
{
    return mState.mMemoryObjectManager->createMemoryObject(mImplementation.get());
}

SemaphoreID Context::createSemaphore()
{
    return mState.mSemaphoreManager->createSemaphore(mImplementation.get());
}

void Context::deleteBuffer(BufferID bufferName)
{
    Buffer *buffer = mState.mBufferManager->getBuffer(bufferName);
    if (buffer)
    {
        detachBuffer(buffer);
    }

    mState.mBufferManager->deleteObject(this, bufferName);
}

void Context::deleteShader(ShaderProgramID shader)
{
    mState.mShaderProgramManager->deleteShader(this, shader);
}

void Context::deleteProgram(ShaderProgramID program)
{
    mState.mShaderProgramManager->deleteProgram(this, program);
}

void Context::deleteTexture(TextureID texture)
{
    if (mState.mTextureManager->getTexture(texture))
    {
        detachTexture(texture);
    }

    mState.mTextureManager->deleteObject(this, texture);
}

void Context::deleteRenderbuffer(RenderbufferID renderbuffer)
{
    if (mState.mRenderbufferManager->getRenderbuffer(renderbuffer))
    {
        detachRenderbuffer(renderbuffer);
    }

    mState.mRenderbufferManager->deleteObject(this, renderbuffer);
}

void Context::deleteSync(GLsync sync)
{
    // The spec specifies the underlying Fence object is not deleted until all current
    // wait commands finish. However, since the name becomes invalid, we cannot query the fence,
    // and since our API is currently designed for being called from a single thread, we can delete
    // the fence immediately.
    mState.mSyncManager->deleteObject(this, static_cast<GLuint>(reinterpret_cast<uintptr_t>(sync)));
}

void Context::deleteProgramPipeline(ProgramPipelineID pipelineID)
{
    ProgramPipeline *pipeline = mState.mProgramPipelineManager->getProgramPipeline(pipelineID);
    if (pipeline)
    {
        detachProgramPipeline(pipelineID);
    }

    mState.mProgramPipelineManager->deleteObject(this, pipelineID);
}

void Context::deleteMemoryObject(MemoryObjectID memoryObject)
{
    mState.mMemoryObjectManager->deleteMemoryObject(this, memoryObject);
}

void Context::deleteSemaphore(SemaphoreID semaphore)
{
    mState.mSemaphoreManager->deleteSemaphore(this, semaphore);
}

// GL_CHROMIUM_lose_context
void Context::loseContext(GraphicsResetStatus current, GraphicsResetStatus other)
{
    // TODO(geofflang): mark the rest of the share group lost. Requires access to the entire share
    // group from a context. http://anglebug.com/3379
    markContextLost(current);
}

void Context::deleteFramebuffer(FramebufferID framebufferID)
{
    // We are responsible for deleting the GL objects from the Framebuffer's pixel local storage.
    std::unique_ptr<PixelLocalStorage> plsToDelete;

    Framebuffer *framebuffer = mState.mFramebufferManager->getFramebuffer(framebufferID);
    if (framebuffer)
    {
        plsToDelete = framebuffer->detachPixelLocalStorage();
        detachFramebuffer(framebufferID);
    }

    mState.mFramebufferManager->deleteObject(this, framebufferID);

    // Delete the pixel local storage GL objects after the framebuffer, in order to avoid any
    // potential trickyness with orphaning.
    if (plsToDelete)
    {
        plsToDelete->deleteContextObjects(this);
    }
}

void Context::deleteFencesNV(GLsizei n, const FenceNVID *fences)
{
    for (int i = 0; i < n; i++)
    {
        FenceNVID fence = fences[i];

        FenceNV *fenceObject = nullptr;
        if (mFenceNVMap.erase(fence, &fenceObject))
        {
            mFenceNVHandleAllocator.release(fence.value);
            if (fenceObject)
            {
                fenceObject->onDestroy(this);
            }
            delete fenceObject;
        }
    }
}

Buffer *Context::getBuffer(BufferID handle) const
{
    return mState.mBufferManager->getBuffer(handle);
}

Renderbuffer *Context::getRenderbuffer(RenderbufferID handle) const
{
    return mState.mRenderbufferManager->getRenderbuffer(handle);
}

EGLenum Context::getContextPriority() const
{
    return egl::ToEGLenum(mImplementation->getContextPriority());
}

Sync *Context::getSync(GLsync handle) const
{
    return mState.mSyncManager->getSync(static_cast<GLuint>(reinterpret_cast<uintptr_t>(handle)));
}

VertexArray *Context::getVertexArray(VertexArrayID handle) const
{
    return mVertexArrayMap.query(handle);
}

Sampler *Context::getSampler(SamplerID handle) const
{
    return mState.mSamplerManager->getSampler(handle);
}

TransformFeedback *Context::getTransformFeedback(TransformFeedbackID handle) const
{
    return mTransformFeedbackMap.query(handle);
}

ProgramPipeline *Context::getProgramPipeline(ProgramPipelineID handle) const
{
    return mState.mProgramPipelineManager->getProgramPipeline(handle);
}

gl::LabeledObject *Context::getLabeledObject(GLenum identifier, GLuint name) const
{
    switch (identifier)
    {
        case GL_BUFFER:
        case GL_BUFFER_OBJECT_EXT:
            return getBuffer({name});
        case GL_SHADER:
        case GL_SHADER_OBJECT_EXT:
            return getShader({name});
        case GL_PROGRAM:
        case GL_PROGRAM_OBJECT_EXT:
            return getProgramNoResolveLink({name});
        case GL_VERTEX_ARRAY:
        case GL_VERTEX_ARRAY_OBJECT_EXT:
            return getVertexArray({name});
        case GL_QUERY:
        case GL_QUERY_OBJECT_EXT:
            return getQuery({name});
        case GL_TRANSFORM_FEEDBACK:
            return getTransformFeedback({name});
        case GL_SAMPLER:
            return getSampler({name});
        case GL_TEXTURE:
            return getTexture({name});
        case GL_RENDERBUFFER:
            return getRenderbuffer({name});
        case GL_FRAMEBUFFER:
            return getFramebuffer({name});
        case GL_PROGRAM_PIPELINE:
        case GL_PROGRAM_PIPELINE_OBJECT_EXT:
            return getProgramPipeline({name});
        default:
            UNREACHABLE();
            return nullptr;
    }
}

gl::LabeledObject *Context::getLabeledObjectFromPtr(const void *ptr) const
{
    return getSync(reinterpret_cast<GLsync>(const_cast<void *>(ptr)));
}

void Context::objectLabel(GLenum identifier, GLuint name, GLsizei length, const GLchar *label)
{
    gl::LabeledObject *object = getLabeledObject(identifier, name);
    ASSERT(object != nullptr);

    std::string labelName = GetObjectLabelFromPointer(length, label);
    ANGLE_CONTEXT_TRY(object->setLabel(this, labelName));

    // TODO(jmadill): Determine if the object is dirty based on 'name'. Conservatively assume the
    // specified object is active until we do this.
    mState.setObjectDirty(identifier);
}

void Context::labelObject(GLenum type, GLuint object, GLsizei length, const GLchar *label)
{
    gl::LabeledObject *obj = getLabeledObject(type, object);
    ASSERT(obj != nullptr);

    std::string labelName = "";
    if (label != nullptr)
    {
        size_t labelLength = length == 0 ? strlen(label) : length;
        labelName          = std::string(label, labelLength);
    }
    ANGLE_CONTEXT_TRY(obj->setLabel(this, labelName));
    mState.setObjectDirty(type);
}

void Context::objectPtrLabel(const void *ptr, GLsizei length, const GLchar *label)
{
    gl::LabeledObject *object = getLabeledObjectFromPtr(ptr);
    ASSERT(object != nullptr);

    std::string labelName = GetObjectLabelFromPointer(length, label);
    ANGLE_CONTEXT_TRY(object->setLabel(this, labelName));
}

void Context::getObjectLabel(GLenum identifier,
                             GLuint name,
                             GLsizei bufSize,
                             GLsizei *length,
                             GLchar *label)
{
    gl::LabeledObject *object = getLabeledObject(identifier, name);
    ASSERT(object != nullptr);

    const std::string &objectLabel = object->getLabel();
    GetObjectLabelBase(objectLabel, bufSize, length, label);
}

void Context::getObjectPtrLabel(const void *ptr, GLsizei bufSize, GLsizei *length, GLchar *label)
{
    gl::LabeledObject *object = getLabeledObjectFromPtr(ptr);
    ASSERT(object != nullptr);

    const std::string &objectLabel = object->getLabel();
    GetObjectLabelBase(objectLabel, bufSize, length, label);
}

GLboolean Context::isSampler(SamplerID samplerName) const
{
    return mState.mSamplerManager->isSampler(samplerName);
}

void Context::bindTexture(TextureType target, TextureID handle)
{
    // Some apps enable KHR_create_context_no_error but pass in an invalid texture type.
    // Workaround this by silently returning in such situations.
    if (target == TextureType::InvalidEnum)
    {
        return;
    }

    Texture *texture = nullptr;
    if (handle.value == 0)
    {
        texture = mZeroTextures[target].get();
    }
    else
    {
        texture =
            mState.mTextureManager->checkTextureAllocation(mImplementation.get(), handle, target);
    }

    ASSERT(texture);
    // Early return if rebinding the same texture
    if (texture == mState.getTargetTexture(target))
    {
        return;
    }

    mState.setSamplerTexture(this, target, texture);
    mStateCache.onActiveTextureChange(this);
}

void Context::bindReadFramebuffer(FramebufferID framebufferHandle)
{
    Framebuffer *framebuffer = mState.mFramebufferManager->checkFramebufferAllocation(
        mImplementation.get(), this, framebufferHandle);
    mState.setReadFramebufferBinding(framebuffer);
    mReadFramebufferObserverBinding.bind(framebuffer);
}

void Context::bindDrawFramebuffer(FramebufferID framebufferHandle)
{
    Framebuffer *framebuffer = mState.mFramebufferManager->checkFramebufferAllocation(
        mImplementation.get(), this, framebufferHandle);
    mState.setDrawFramebufferBinding(framebuffer);
    mDrawFramebufferObserverBinding.bind(framebuffer);
    mStateCache.onDrawFramebufferChange(this);
}

void Context::bindVertexArray(VertexArrayID vertexArrayHandle)
{
    VertexArray *vertexArray = checkVertexArrayAllocation(vertexArrayHandle);
    mState.setVertexArrayBinding(this, vertexArray);
    mVertexArrayObserverBinding.bind(vertexArray);
    mStateCache.onVertexArrayBindingChange(this);
}

void Context::bindVertexBuffer(GLuint bindingIndex,
                               BufferID bufferHandle,
                               GLintptr offset,
                               GLsizei stride)
{
    Buffer *buffer =
        mState.mBufferManager->checkBufferAllocation(mImplementation.get(), bufferHandle);
    mState.bindVertexBuffer(this, bindingIndex, buffer, offset, stride);
    mStateCache.onVertexArrayStateChange(this);
}

void Context::bindSampler(GLuint textureUnit, SamplerID samplerHandle)
{
    ASSERT(textureUnit < static_cast<GLuint>(mState.mCaps.maxCombinedTextureImageUnits));
    Sampler *sampler =
        mState.mSamplerManager->checkSamplerAllocation(mImplementation.get(), samplerHandle);

    // Early return if rebinding the same sampler
    if (sampler == mState.getSampler(textureUnit))
    {
        return;
    }

    mState.setSamplerBinding(this, textureUnit, sampler);
    mSamplerObserverBindings[textureUnit].bind(sampler);
    mStateCache.onActiveTextureChange(this);
}

void Context::bindImageTexture(GLuint unit,
                               TextureID texture,
                               GLint level,
                               GLboolean layered,
                               GLint layer,
                               GLenum access,
                               GLenum format)
{
    Texture *tex = mState.mTextureManager->getTexture(texture);
    mState.setImageUnit(this, unit, tex, level, layered, layer, access, format);
    mImageObserverBindings[unit].bind(tex);
}

void Context::useProgram(ShaderProgramID program)
{
    ANGLE_CONTEXT_TRY(mState.setProgram(this, getProgramResolveLink(program)));
    mStateCache.onProgramExecutableChange(this);
}

void Context::useProgramStages(ProgramPipelineID pipeline,
                               GLbitfield stages,
                               ShaderProgramID program)
{
    Program *shaderProgram = getProgramNoResolveLink(program);
    ProgramPipeline *programPipeline =
        mState.mProgramPipelineManager->checkProgramPipelineAllocation(mImplementation.get(),
                                                                       pipeline);

    ASSERT(programPipeline);
    ANGLE_CONTEXT_TRY(programPipeline->useProgramStages(this, stages, shaderProgram));
}

void Context::bindTransformFeedback(GLenum target, TransformFeedbackID transformFeedbackHandle)
{
    ASSERT(target == GL_TRANSFORM_FEEDBACK);
    TransformFeedback *transformFeedback =
        checkTransformFeedbackAllocation(transformFeedbackHandle);
    mState.setTransformFeedbackBinding(this, transformFeedback);
    mStateCache.onActiveTransformFeedbackChange(this);
}

void Context::bindProgramPipeline(ProgramPipelineID pipelineHandle)
{
    ProgramPipeline *pipeline = mState.mProgramPipelineManager->checkProgramPipelineAllocation(
        mImplementation.get(), pipelineHandle);
    ANGLE_CONTEXT_TRY(mState.setProgramPipelineBinding(this, pipeline));
    mStateCache.onProgramExecutableChange(this);
    mProgramPipelineObserverBinding.bind(pipeline);
}

void Context::beginQuery(QueryType target, QueryID query)
{
    Query *queryObject = getOrCreateQuery(query, target);
    ASSERT(queryObject);

    // begin query
    ANGLE_CONTEXT_TRY(queryObject->begin(this));

    // set query as active for specified target only if begin succeeded
    mState.setActiveQuery(this, target, queryObject);
    mStateCache.onQueryChange(this);
}

void Context::endQuery(QueryType target)
{
    Query *queryObject = mState.getActiveQuery(target);
    ASSERT(queryObject);

    // Intentionally don't call try here. We don't want an early return.
    (void)(queryObject->end(this));

    // Always unbind the query, even if there was an error. This may delete the query object.
    mState.setActiveQuery(this, target, nullptr);
    mStateCache.onQueryChange(this);
}

void Context::queryCounter(QueryID id, QueryType target)
{
    ASSERT(target == QueryType::Timestamp);

    Query *queryObject = getOrCreateQuery(id, target);
    ASSERT(queryObject);

    ANGLE_CONTEXT_TRY(queryObject->queryCounter(this));
}

void Context::getQueryiv(QueryType target, GLenum pname, GLint *params)
{
    switch (pname)
    {
        case GL_CURRENT_QUERY_EXT:
            params[0] = mState.getActiveQueryId(target).value;
            break;
        case GL_QUERY_COUNTER_BITS_EXT:
            switch (target)
            {
                case QueryType::TimeElapsed:
                    params[0] = getCaps().queryCounterBitsTimeElapsed;
                    break;
                case QueryType::Timestamp:
                    params[0] = getCaps().queryCounterBitsTimestamp;
                    break;
                default:
                    UNREACHABLE();
                    params[0] = 0;
                    break;
            }
            break;
        default:
            UNREACHABLE();
            return;
    }
}

void Context::getQueryivRobust(QueryType target,
                               GLenum pname,
                               GLsizei bufSize,
                               GLsizei *length,
                               GLint *params)
{
    getQueryiv(target, pname, params);
}

void Context::getUnsignedBytev(GLenum pname, GLubyte *data)
{
    UNIMPLEMENTED();
}

void Context::getUnsignedBytei_v(GLenum target, GLuint index, GLubyte *data)
{
    UNIMPLEMENTED();
}

void Context::getQueryObjectiv(QueryID id, GLenum pname, GLint *params)
{
    ANGLE_CONTEXT_TRY(GetQueryObjectParameter(this, getQuery(id), pname, params));
}

void Context::getQueryObjectivRobust(QueryID id,
                                     GLenum pname,
                                     GLsizei bufSize,
                                     GLsizei *length,
                                     GLint *params)
{
    getQueryObjectiv(id, pname, params);
}

void Context::getQueryObjectuiv(QueryID id, GLenum pname, GLuint *params)
{
    ANGLE_CONTEXT_TRY(GetQueryObjectParameter(this, getQuery(id), pname, params));
}

void Context::getQueryObjectuivRobust(QueryID id,
                                      GLenum pname,
                                      GLsizei bufSize,
                                      GLsizei *length,
                                      GLuint *params)
{
    getQueryObjectuiv(id, pname, params);
}

void Context::getQueryObjecti64v(QueryID id, GLenum pname, GLint64 *params)
{
    ANGLE_CONTEXT_TRY(GetQueryObjectParameter(this, getQuery(id), pname, params));
}

void Context::getQueryObjecti64vRobust(QueryID id,
                                       GLenum pname,
                                       GLsizei bufSize,
                                       GLsizei *length,
                                       GLint64 *params)
{
    getQueryObjecti64v(id, pname, params);
}

void Context::getQueryObjectui64v(QueryID id, GLenum pname, GLuint64 *params)
{
    ANGLE_CONTEXT_TRY(GetQueryObjectParameter(this, getQuery(id), pname, params));
}

void Context::getQueryObjectui64vRobust(QueryID id,
                                        GLenum pname,
                                        GLsizei bufSize,
                                        GLsizei *length,
                                        GLuint64 *params)
{
    getQueryObjectui64v(id, pname, params);
}

Framebuffer *Context::getFramebuffer(FramebufferID handle) const
{
    return mState.mFramebufferManager->getFramebuffer(handle);
}

FenceNV *Context::getFenceNV(FenceNVID handle) const
{
    return mFenceNVMap.query(handle);
}

Query *Context::getOrCreateQuery(QueryID handle, QueryType type)
{
    if (!mQueryMap.contains(handle))
    {
        return nullptr;
    }

    Query *query = mQueryMap.query(handle);
    if (!query)
    {
        ASSERT(type != QueryType::InvalidEnum);
        query = new Query(mImplementation.get(), type, handle);
        query->addRef();
        mQueryMap.assign(handle, query);
    }
    return query;
}

Query *Context::getQuery(QueryID handle) const
{
    return mQueryMap.query(handle);
}

Texture *Context::getTextureByType(TextureType type) const
{
    ASSERT(ValidTextureTarget(this, type) || ValidTextureExternalTarget(this, type));
    return mState.getTargetTexture(type);
}

Texture *Context::getTextureByTarget(TextureTarget target) const
{
    return getTextureByType(TextureTargetToType(target));
}

Texture *Context::getSamplerTexture(unsigned int sampler, TextureType type) const
{
    return mState.getSamplerTexture(sampler, type);
}

Compiler *Context::getCompiler() const
{
    if (mCompiler.get() == nullptr)
    {
        mCompiler.set(this, new Compiler(mImplementation.get(), mState, mDisplay));
    }
    return mCompiler.get();
}

void Context::getBooleanvImpl(GLenum pname, GLboolean *params) const
{
    switch (pname)
    {
        case GL_SHADER_COMPILER:
            *params = GL_TRUE;
            break;
        case GL_CONTEXT_ROBUST_ACCESS_EXT:
            *params = ConvertToGLBoolean(mState.hasRobustAccess());
            break;

        default:
            mState.getBooleanv(pname, params);
            break;
    }
}

void Context::getFloatvImpl(GLenum pname, GLfloat *params) const
{
    // Queries about context capabilities and maximums are answered by Context.
    // Queries about current GL state values are answered by State.
    switch (pname)
    {
        case GL_ALIASED_LINE_WIDTH_RANGE:
            params[0] = mState.mCaps.minAliasedLineWidth;
            params[1] = mState.mCaps.maxAliasedLineWidth;
            break;
        case GL_ALIASED_POINT_SIZE_RANGE:
            params[0] = mState.mCaps.minAliasedPointSize;
            params[1] = mState.mCaps.maxAliasedPointSize;
            break;
        case GL_SMOOTH_POINT_SIZE_RANGE:
            params[0] = mState.mCaps.minSmoothPointSize;
            params[1] = mState.mCaps.maxSmoothPointSize;
            break;
        case GL_SMOOTH_LINE_WIDTH_RANGE:
            params[0] = mState.mCaps.minSmoothLineWidth;
            params[1] = mState.mCaps.maxSmoothLineWidth;
            break;
        case GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT:
            ASSERT(mState.mExtensions.textureFilterAnisotropicEXT);
            *params = mState.mCaps.maxTextureAnisotropy;
            break;
        case GL_MAX_TEXTURE_LOD_BIAS:
            *params = mState.mCaps.maxLODBias;
            break;
        case GL_MIN_FRAGMENT_INTERPOLATION_OFFSET:
            *params = mState.mCaps.minInterpolationOffset;
            break;
        case GL_MAX_FRAGMENT_INTERPOLATION_OFFSET:
            *params = mState.mCaps.maxInterpolationOffset;
            break;
        case GL_PRIMITIVE_BOUNDING_BOX:
            params[0] = mState.mBoundingBoxMinX;
            params[1] = mState.mBoundingBoxMinY;
            params[2] = mState.mBoundingBoxMinZ;
            params[3] = mState.mBoundingBoxMinW;
            params[4] = mState.mBoundingBoxMaxX;
            params[5] = mState.mBoundingBoxMaxY;
            params[6] = mState.mBoundingBoxMaxZ;
            params[7] = mState.mBoundingBoxMaxW;
            break;
        default:
            mState.getFloatv(pname, params);
            break;
    }
}

void Context::getIntegervImpl(GLenum pname, GLint *params) const
{
    // Queries about context capabilities and maximums are answered by Context.
    // Queries about current GL state values are answered by State.

    switch (pname)
    {
        case GL_MAX_VERTEX_ATTRIBS:
            *params = mState.mCaps.maxVertexAttributes;
            break;
        case GL_MAX_VERTEX_UNIFORM_VECTORS:
            *params = mState.mCaps.maxVertexUniformVectors;
            break;
        case GL_MAX_VERTEX_UNIFORM_COMPONENTS:
            *params = mState.mCaps.maxShaderUniformComponents[ShaderType::Vertex];
            break;
        case GL_MAX_VARYING_VECTORS:
            *params = mState.mCaps.maxVaryingVectors;
            break;
        case GL_MAX_VARYING_COMPONENTS:
            *params = mState.mCaps.maxVaryingVectors * 4;
            break;
        case GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS:
            *params = mState.mCaps.maxCombinedTextureImageUnits;
            break;
        case GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS:
            *params = mState.mCaps.maxShaderTextureImageUnits[ShaderType::Vertex];
            break;
        case GL_MAX_TEXTURE_IMAGE_UNITS:
            *params = mState.mCaps.maxShaderTextureImageUnits[ShaderType::Fragment];
            break;
        case GL_MAX_FRAGMENT_UNIFORM_VECTORS:
            *params = mState.mCaps.maxFragmentUniformVectors;
            break;
        case GL_MAX_FRAGMENT_UNIFORM_COMPONENTS:
            *params = mState.mCaps.maxShaderUniformComponents[ShaderType::Fragment];
            break;
        case GL_MAX_RENDERBUFFER_SIZE:
            *params = mState.mCaps.maxRenderbufferSize;
            break;
        case GL_MAX_COLOR_ATTACHMENTS_EXT:
            *params = mState.mCaps.maxColorAttachments;
            break;
        case GL_MAX_DRAW_BUFFERS_EXT:
            *params = mState.mCaps.maxDrawBuffers;
            break;
        case GL_SUBPIXEL_BITS:
            *params = mState.mCaps.subPixelBits;
            break;
        case GL_MAX_TEXTURE_SIZE:
            *params = mState.mCaps.max2DTextureSize;
            break;
        case GL_MAX_RECTANGLE_TEXTURE_SIZE_ANGLE:
            *params = mState.mCaps.maxRectangleTextureSize;
            break;
        case GL_MAX_CUBE_MAP_TEXTURE_SIZE:
            *params = mState.mCaps.maxCubeMapTextureSize;
            break;
        case GL_MAX_3D_TEXTURE_SIZE:
            *params = mState.mCaps.max3DTextureSize;
            break;
        case GL_MAX_ARRAY_TEXTURE_LAYERS:
            *params = mState.mCaps.maxArrayTextureLayers;
            break;
        case GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT:
            *params = mState.mCaps.uniformBufferOffsetAlignment;
            break;
        case GL_MAX_UNIFORM_BUFFER_BINDINGS:
            *params = mState.mCaps.maxUniformBufferBindings;
            break;
        case GL_MAX_VERTEX_UNIFORM_BLOCKS:
            *params = mState.mCaps.maxShaderUniformBlocks[ShaderType::Vertex];
            break;
        case GL_MAX_FRAGMENT_UNIFORM_BLOCKS:
            *params = mState.mCaps.maxShaderUniformBlocks[ShaderType::Fragment];
            break;
        case GL_MAX_COMBINED_UNIFORM_BLOCKS:
            *params = mState.mCaps.maxCombinedUniformBlocks;
            break;
        case GL_MAX_VERTEX_OUTPUT_COMPONENTS:
            *params = mState.mCaps.maxVertexOutputComponents;
            break;
        case GL_MAX_FRAGMENT_INPUT_COMPONENTS:
            *params = mState.mCaps.maxFragmentInputComponents;
            break;
        case GL_MIN_PROGRAM_TEXEL_OFFSET:
            *params = mState.mCaps.minProgramTexelOffset;
            break;
        case GL_MAX_PROGRAM_TEXEL_OFFSET:
            *params = mState.mCaps.maxProgramTexelOffset;
            break;
        case GL_MAJOR_VERSION:
            *params = getClientVersion().major;
            break;
        case GL_MINOR_VERSION:
            *params = getClientVersion().minor;
            break;
        case GL_MAX_ELEMENTS_INDICES:
            *params = mState.mCaps.maxElementsIndices;
            break;
        case GL_MAX_ELEMENTS_VERTICES:
            *params = mState.mCaps.maxElementsVertices;
            break;
        case GL_MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS:
            *params = mState.mCaps.maxTransformFeedbackInterleavedComponents;
            break;
        case GL_MAX_TRANSFORM_FEEDBACK_SEPARATE_ATTRIBS:
            *params = mState.mCaps.maxTransformFeedbackSeparateAttributes;
            break;
        case GL_MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS:
            *params = mState.mCaps.maxTransformFeedbackSeparateComponents;
            break;
        case GL_NUM_COMPRESSED_TEXTURE_FORMATS:
            *params = static_cast<GLint>(mState.mCaps.compressedTextureFormats.size());
            break;
        case GL_MAX_SAMPLES_ANGLE:
            *params = mState.mCaps.maxSamples;
            break;
        case GL_MAX_VIEWPORT_DIMS:
        {
            params[0] = mState.mCaps.maxViewportWidth;
            params[1] = mState.mCaps.maxViewportHeight;
        }
        break;
        case GL_COMPRESSED_TEXTURE_FORMATS:
            std::copy(mState.mCaps.compressedTextureFormats.begin(),
                      mState.mCaps.compressedTextureFormats.end(), params);
            break;
        case GL_RESET_NOTIFICATION_STRATEGY_EXT:
            *params = mResetStrategy;
            break;
        case GL_NUM_SHADER_BINARY_FORMATS:
            *params = static_cast<GLint>(mState.mCaps.shaderBinaryFormats.size());
            break;
        case GL_SHADER_BINARY_FORMATS:
            std::copy(mState.mCaps.shaderBinaryFormats.begin(),
                      mState.mCaps.shaderBinaryFormats.end(), params);
            break;
        case GL_NUM_PROGRAM_BINARY_FORMATS:
            *params = static_cast<GLint>(mState.mCaps.programBinaryFormats.size());
            break;
        case GL_PROGRAM_BINARY_FORMATS:
            std::copy(mState.mCaps.programBinaryFormats.begin(),
                      mState.mCaps.programBinaryFormats.end(), params);
            break;
        case GL_NUM_EXTENSIONS:
            *params = static_cast<GLint>(mExtensionStrings.size());
            break;

        // Desktop client flags
        case GL_CONTEXT_FLAGS:
        {
            GLint contextFlags = 0;
            if (mState.hasProtectedContent())
            {
                contextFlags |= GL_CONTEXT_FLAG_PROTECTED_CONTENT_BIT_EXT;
            }

            if (mState.isDebugContext())
            {
                contextFlags |= GL_CONTEXT_FLAG_DEBUG_BIT_KHR;
            }

            if (mState.hasRobustAccess())
            {
                contextFlags |= GL_CONTEXT_FLAG_ROBUST_ACCESS_BIT;
            }
            *params = contextFlags;
        }
        break;
        case GL_CONTEXT_PROFILE_MASK:
            ASSERT(getClientType() == EGL_OPENGL_API);
            *params = mState.getProfileMask();
            break;

        // GL_ANGLE_request_extension
        case GL_NUM_REQUESTABLE_EXTENSIONS_ANGLE:
            *params = static_cast<GLint>(mRequestableExtensionStrings.size());
            break;

        // GL_KHR_debug
        case GL_MAX_DEBUG_MESSAGE_LENGTH:
            *params = mState.mCaps.maxDebugMessageLength;
            break;
        case GL_MAX_DEBUG_LOGGED_MESSAGES:
            *params = mState.mCaps.maxDebugLoggedMessages;
            break;
        case GL_MAX_DEBUG_GROUP_STACK_DEPTH:
            *params = mState.mCaps.maxDebugGroupStackDepth;
            break;
        case GL_MAX_LABEL_LENGTH:
            *params = mState.mCaps.maxLabelLength;
            break;

        // GL_OVR_multiview2
        case GL_MAX_VIEWS_OVR:
--> --------------------

--> maximum size reached

--> --------------------