//
// 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.
//

// Display.cpp: Implements the egl::Display class, representing the abstract
// display on which graphics are drawn. Implements EGLDisplay.
// [EGL 1.4] section 2.1.2 page 3.

#include "libANGLE/Display.h"

#include <algorithm>
#include <iterator>
#include <map>
#include <sstream>
#include <vector>

#include <EGL/eglext.h>
#include <platform/Platform.h>

#include "anglebase/no_destructor.h"
#include "common/android_util.h"
#include "common/debug.h"
#include "common/mathutil.h"
#include "common/platform.h"
#include "common/string_utils.h"
#include "common/system_utils.h"
#include "common/utilities.h"
#include "libANGLE/Context.h"
#include "libANGLE/Device.h"
#include "libANGLE/EGLSync.h"
#include "libANGLE/Image.h"
#include "libANGLE/ResourceManager.h"
#include "libANGLE/Stream.h"
#include "libANGLE/Surface.h"
#include "libANGLE/Thread.h"
#include "libANGLE/histogram_macros.h"
#include "libANGLE/renderer/DeviceImpl.h"
#include "libANGLE/renderer/DisplayImpl.h"
#include "libANGLE/renderer/ImageImpl.h"
#include "libANGLE/trace.h"

#if defined(ANGLE_ENABLE_D3D9) || defined(ANGLE_ENABLE_D3D11)
#    include <versionhelpers.h>

#    include "libANGLE/renderer/d3d/DisplayD3D.h"
#endif

#if defined(ANGLE_ENABLE_OPENGL)
#    if defined(ANGLE_PLATFORM_WINDOWS)
#        include "libANGLE/renderer/gl/wgl/DisplayWGL.h"
#    elif defined(ANGLE_USE_X11)
#        include "libANGLE/renderer/gl/glx/DisplayGLX.h"
#    elif defined(ANGLE_PLATFORM_MACOS) || defined(ANGLE_PLATFORM_MACCATALYST)
#        include "libANGLE/renderer/gl/cgl/DisplayCGL.h"
#    elif defined(ANGLE_PLATFORM_IOS)
#        include "libANGLE/renderer/gl/eagl/DisplayEAGL.h"
#    elif defined(ANGLE_USE_OZONE)
#        include "libANGLE/renderer/gl/egl/ozone/DisplayOzone.h"
#    elif defined(ANGLE_PLATFORM_ANDROID)
#        include "libANGLE/renderer/gl/egl/android/DisplayAndroid.h"
#    else
#        error Unsupported OpenGL platform.
#    endif
#endif

#if defined(ANGLE_ENABLE_NULL)
#    include "libANGLE/renderer/null/DisplayNULL.h"
#endif  // defined(ANGLE_ENABLE_NULL)

#if defined(ANGLE_ENABLE_VULKAN)
#    if defined(ANGLE_PLATFORM_WINDOWS)
#        include "libANGLE/renderer/vulkan/win32/DisplayVkWin32.h"
#    elif defined(ANGLE_PLATFORM_LINUX)
#        include "libANGLE/renderer/vulkan/xcb/DisplayVkXcb.h"
#    elif defined(ANGLE_PLATFORM_ANDROID)
#        include "libANGLE/renderer/vulkan/android/DisplayVkAndroid.h"
#    elif defined(ANGLE_PLATFORM_FUCHSIA)
#        include "libANGLE/renderer/vulkan/fuchsia/DisplayVkFuchsia.h"
#    elif defined(ANGLE_PLATFORM_GGP)
#        include "libANGLE/renderer/vulkan/ggp/DisplayVkGGP.h"
#    else
#        error Unsupported Vulkan platform.
#    endif
#endif  // defined(ANGLE_ENABLE_VULKAN)

#if defined(ANGLE_ENABLE_METAL)
#    include "libANGLE/renderer/metal/DisplayMtl_api.h"
#endif  // defined(ANGLE_ENABLE_METAL)

namespace egl
{

namespace
{

typedef std::map<EGLNativeWindowType, Surface *> WindowSurfaceMap;
// Get a map of all EGL window surfaces to validate that no window has more than one EGL surface
// associated with it.
static WindowSurfaceMap *GetWindowSurfaces()
{
    static angle::base::NoDestructor<WindowSurfaceMap> windowSurfaces;
    return windowSurfaces.get();
}

typedef std::map<EGLNativeDisplayType, Display *> ANGLEPlatformDisplayMap;
static ANGLEPlatformDisplayMap *GetANGLEPlatformDisplayMap()
{
    static angle::base::NoDestructor<ANGLEPlatformDisplayMap> displays;
    return displays.get();
}

typedef std::map<Device *, Display *> DevicePlatformDisplayMap;
static DevicePlatformDisplayMap *GetDevicePlatformDisplayMap()
{
    static angle::base::NoDestructor<DevicePlatformDisplayMap> displays;
    return displays.get();
}

rx::DisplayImpl *CreateDisplayFromDevice(Device *eglDevice, const DisplayState &state)
{
    rx::DisplayImpl *impl = nullptr;

    switch (eglDevice->getType())
    {
#if defined(ANGLE_ENABLE_D3D11)
        case EGL_D3D11_DEVICE_ANGLE:
            impl = new rx::DisplayD3D(state);
            break;
#endif
#if defined(ANGLE_ENABLE_D3D9)
        case EGL_D3D9_DEVICE_ANGLE:
            // Currently the only way to get EGLDeviceEXT representing a D3D9 device
            // is to retrieve one from an already-existing EGLDisplay.
            // When eglGetPlatformDisplayEXT is called with a D3D9 EGLDeviceEXT,
            // the already-existing display should be returned.
            // Therefore this codepath to create a new display from the device
            // should never be hit.
            UNREACHABLE();
            break;
#endif
        default:
            UNREACHABLE();
            break;
    }

    ASSERT(impl != nullptr);
    return impl;
}

// On platforms with support for multiple back-ends, allow an environment variable to control
// the default.  This is useful to run angle with benchmarks without having to modify the
// benchmark source.  Possible values for this environment variable (ANGLE_DEFAULT_PLATFORM)
// are: vulkan, gl, d3d11, null.
EGLAttrib GetDisplayTypeFromEnvironment()
{
    std::string angleDefaultEnv = angle::GetEnvironmentVar("ANGLE_DEFAULT_PLATFORM");
    angle::ToLower(&angleDefaultEnv);

#if defined(ANGLE_ENABLE_VULKAN)
    if (angleDefaultEnv == "vulkan")
    {
        return EGL_PLATFORM_ANGLE_TYPE_VULKAN_ANGLE;
    }
#endif

#if defined(ANGLE_ENABLE_OPENGL)
    if (angleDefaultEnv == "gl")
    {
        return EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE;
    }
#endif

#if defined(ANGLE_ENABLE_D3D11)
    if (angleDefaultEnv == "d3d11")
    {
        return EGL_PLATFORM_ANGLE_TYPE_D3D11_ANGLE;
    }
#endif

#if defined(ANGLE_ENABLE_NULL)
    if (angleDefaultEnv == "null")
    {
        return EGL_PLATFORM_ANGLE_TYPE_NULL_ANGLE;
    }
#endif

#if defined(ANGLE_ENABLE_D3D11)
    return EGL_PLATFORM_ANGLE_TYPE_D3D11_ANGLE;
#elif defined(ANGLE_ENABLE_D3D9)
    return EGL_PLATFORM_ANGLE_TYPE_D3D9_ANGLE;
#elif defined(ANGLE_ENABLE_VULKAN) && defined(ANGLE_PLATFORM_ANDROID)
    return EGL_PLATFORM_ANGLE_TYPE_VULKAN_ANGLE;
#elif defined(ANGLE_ENABLE_OPENGL)
#    if defined(ANGLE_PLATFORM_ANDROID) || defined(ANGLE_USE_OZONE)
    return EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE;
#    else
    return EGL_PLATFORM_ANGLE_TYPE_OPENGL_ANGLE;
#    endif
#elif defined(ANGLE_ENABLE_METAL)
    return EGL_PLATFORM_ANGLE_TYPE_METAL_ANGLE;
#elif defined(ANGLE_ENABLE_VULKAN)
    return EGL_PLATFORM_ANGLE_TYPE_VULKAN_ANGLE;
#elif defined(ANGLE_ENABLE_NULL)
    return EGL_PLATFORM_ANGLE_TYPE_NULL_ANGLE;
#else
#    error No default ANGLE platform type
#endif
}

rx::DisplayImpl *CreateDisplayFromAttribs(const AttributeMap &attribMap, const DisplayState &state)
{
    rx::DisplayImpl *impl = nullptr;
    EGLAttrib displayType =
        attribMap.get(EGL_PLATFORM_ANGLE_TYPE_ANGLE, EGL_PLATFORM_ANGLE_TYPE_DEFAULT_ANGLE);

    if (displayType == EGL_PLATFORM_ANGLE_TYPE_DEFAULT_ANGLE)
    {
        displayType = GetDisplayTypeFromEnvironment();
    }

    switch (displayType)
    {
        case EGL_PLATFORM_ANGLE_TYPE_DEFAULT_ANGLE:
            UNREACHABLE();
            break;

        case EGL_PLATFORM_ANGLE_TYPE_D3D9_ANGLE:
        case EGL_PLATFORM_ANGLE_TYPE_D3D11_ANGLE:
#if defined(ANGLE_ENABLE_D3D9) || defined(ANGLE_ENABLE_D3D11)
            impl = new rx::DisplayD3D(state);
#else
            // A D3D display was requested on a platform that doesn't support it
            UNREACHABLE();
#endif
            break;

        case EGL_PLATFORM_ANGLE_TYPE_OPENGL_ANGLE:
#if defined(ANGLE_ENABLE_OPENGL)
#    if defined(ANGLE_PLATFORM_WINDOWS)
            impl = new rx::DisplayWGL(state);
#    elif defined(ANGLE_USE_X11)
            impl = new rx::DisplayGLX(state);
#    elif defined(ANGLE_PLATFORM_MACOS) || defined(ANGLE_PLATFORM_MACCATALYST)
            impl = new rx::DisplayCGL(state);
#    elif defined(ANGLE_PLATFORM_IOS)
            impl = new rx::DisplayEAGL(state);
#    elif defined(ANGLE_USE_OZONE)
            // This might work but has never been tried, so disallow for now.
            impl = nullptr;
#    elif defined(ANGLE_PLATFORM_ANDROID)
            // No GL support on this platform, fail display creation.
            impl = nullptr;
#    else
#        error Unsupported OpenGL platform.
#    endif
#else
            // No display available
            UNREACHABLE();
#endif  // defined(ANGLE_ENABLE_OPENGL)
            break;

        case EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE:
#if defined(ANGLE_ENABLE_OPENGL)
#    if defined(ANGLE_PLATFORM_WINDOWS)
            impl = new rx::DisplayWGL(state);
#    elif defined(ANGLE_USE_X11)
            impl = new rx::DisplayGLX(state);
#    elif defined(ANGLE_USE_OZONE)
            impl = new rx::DisplayOzone(state);
#    elif defined(ANGLE_PLATFORM_ANDROID)
            impl = new rx::DisplayAndroid(state);
#    else
            // No GLES support on this platform, fail display creation.
            impl = nullptr;
#    endif
#endif  // defined(ANGLE_ENABLE_OPENGL)
            break;

        case EGL_PLATFORM_ANGLE_TYPE_VULKAN_ANGLE:
#if defined(ANGLE_ENABLE_VULKAN)
#    if defined(ANGLE_PLATFORM_WINDOWS)
            impl = new rx::DisplayVkWin32(state);
#    elif defined(ANGLE_PLATFORM_LINUX)
            impl = new rx::DisplayVkXcb(state);
#    elif defined(ANGLE_PLATFORM_ANDROID)
            impl = new rx::DisplayVkAndroid(state);
#    elif defined(ANGLE_PLATFORM_FUCHSIA)
            impl = new rx::DisplayVkFuchsia(state);
#    elif defined(ANGLE_PLATFORM_GGP)
            impl = new rx::DisplayVkGGP(state);
#    else
#        error Unsupported Vulkan platform.
#    endif
#else
            // No display available
            UNREACHABLE();
#endif  // defined(ANGLE_ENABLE_VULKAN)
            break;
        case EGL_PLATFORM_ANGLE_TYPE_METAL_ANGLE:
#if defined(ANGLE_ENABLE_METAL)
            if (rx::IsMetalDisplayAvailable())
            {
                impl = rx::CreateMetalDisplay(state);
                break;
            }
#endif
            // No display available
            UNREACHABLE();
            break;
        case EGL_PLATFORM_ANGLE_TYPE_NULL_ANGLE:
#if defined(ANGLE_ENABLE_NULL)
            impl = new rx::DisplayNULL(state);
#else
            // No display available
            UNREACHABLE();
#endif  // defined(ANGLE_ENABLE_NULL)
            break;

        default:
            UNREACHABLE();
            break;
    }

    return impl;
}

void Display_logError(angle::PlatformMethods *platform, const char *errorMessage)
{
    gl::Trace(gl::LOG_ERR, errorMessage);
}

void Display_logWarning(angle::PlatformMethods *platform, const char *warningMessage)
{
    gl::Trace(gl::LOG_WARN, warningMessage);
}

void Display_logInfo(angle::PlatformMethods *platform, const char *infoMessage)
{
    // Uncomment to get info spam
#if defined(ANGLE_ENABLE_DEBUG_TRACE)
    gl::Trace(gl::LOG_INFO, infoMessage);
#endif
}

const std::vector<std::string> EGLStringArrayToStringVector(const char **ary)
{
    std::vector<std::string> vec;
    if (ary != nullptr)
    {
        for (; *ary != nullptr; ary++)
        {
            vec.push_back(std::string(*ary));
        }
    }
    return vec;
}

void ANGLESetDefaultDisplayPlatform(angle::EGLDisplayType display)
{
    angle::PlatformMethods *platformMethods = ANGLEPlatformCurrent();

    ANGLEResetDisplayPlatform(display);
    platformMethods->logError   = Display_logError;
    platformMethods->logWarning = Display_logWarning;
    platformMethods->logInfo    = Display_logInfo;
}

}  // anonymous namespace

DisplayState::DisplayState() : label(nullptr), featuresAllDisabled(false) {}

DisplayState::~DisplayState() {}

// static
Display *Display::GetDisplayFromNativeDisplay(EGLNativeDisplayType nativeDisplay,
                                              const AttributeMap &attribMap)
{
    Display *display = nullptr;

    ANGLEPlatformDisplayMap *displays = GetANGLEPlatformDisplayMap();
    const auto &iter                  = displays->find(nativeDisplay);
    if (iter != displays->end())
    {
        display = iter->second;
    }

    if (display == nullptr)
    {
        // Validate the native display
        if (!Display::isValidNativeDisplay(nativeDisplay))
        {
            return nullptr;
        }

        display = new Display(EGL_PLATFORM_ANGLE_ANGLE, nativeDisplay, nullptr);
        displays->insert(std::make_pair(nativeDisplay, display));
    }

    // Apply new attributes if the display is not initialized yet.
    if (!display->isInitialized())
    {
        rx::DisplayImpl *impl = CreateDisplayFromAttribs(attribMap, display->getState());
        if (impl == nullptr)
        {
            // No valid display implementation for these attributes
            return nullptr;
        }

        display->setAttributes(impl, attribMap);
    }

    return display;
}

// static
Display *Display::GetExistingDisplayFromNativeDisplay(EGLNativeDisplayType nativeDisplay)
{
    ANGLEPlatformDisplayMap *displays = GetANGLEPlatformDisplayMap();
    const auto &iter                  = displays->find(nativeDisplay);

    // Check that there is a matching display
    if (iter == displays->end())
    {
        return nullptr;
    }

    return iter->second;
}

// static
Display *Display::GetDisplayFromDevice(Device *device, const AttributeMap &attribMap)
{
    Display *display = nullptr;

    ASSERT(Device::IsValidDevice(device));

    ANGLEPlatformDisplayMap *anglePlatformDisplays   = GetANGLEPlatformDisplayMap();
    DevicePlatformDisplayMap *devicePlatformDisplays = GetDevicePlatformDisplayMap();

    // First see if this eglDevice is in use by a Display created using ANGLE platform
    for (auto &displayMapEntry : *anglePlatformDisplays)
    {
        egl::Display *iterDisplay = displayMapEntry.second;
        if (iterDisplay->getDevice() == device)
        {
            display = iterDisplay;
        }
    }

    if (display == nullptr)
    {
        // See if the eglDevice is in use by a Display created using the DEVICE platform
        const auto &iter = devicePlatformDisplays->find(device);
        if (iter != devicePlatformDisplays->end())
        {
            display = iter->second;
        }
    }

    if (display == nullptr)
    {
        // Otherwise create a new Display
        display = new Display(EGL_PLATFORM_DEVICE_EXT, 0, device);
        devicePlatformDisplays->insert(std::make_pair(device, display));
    }

    // Apply new attributes if the display is not initialized yet.
    if (!display->isInitialized())
    {
        rx::DisplayImpl *impl = CreateDisplayFromDevice(device, display->getState());
        display->setAttributes(impl, attribMap);
    }

    return display;
}

Display::Display(EGLenum platform, EGLNativeDisplayType displayId, Device *eglDevice)
    : mImplementation(nullptr),
      mDisplayId(displayId),
      mAttributeMap(),
      mConfigSet(),
      mContextSet(),
      mStreamSet(),
      mInitialized(false),
      mDeviceLost(false),
      mCaps(),
      mDisplayExtensions(),
      mDisplayExtensionString(),
      mVendorString(),
      mDevice(eglDevice),
      mSurface(nullptr),
      mPlatform(platform),
      mTextureManager(nullptr),
      mBlobCache(gl::kDefaultMaxProgramCacheMemoryBytes),
      mMemoryProgramCache(mBlobCache),
      mGlobalTextureShareGroupUsers(0)
{}

Display::~Display()
{
    // TODO(jmadill): When is this called?
    // terminate();

    if (mPlatform == EGL_PLATFORM_ANGLE_ANGLE)
    {
        ANGLEPlatformDisplayMap *displays      = GetANGLEPlatformDisplayMap();
        ANGLEPlatformDisplayMap::iterator iter = displays->find(mDisplayId);
        if (iter != displays->end())
        {
            displays->erase(iter);
        }
    }
    else if (mPlatform == EGL_PLATFORM_DEVICE_EXT)
    {
        DevicePlatformDisplayMap *displays      = GetDevicePlatformDisplayMap();
        DevicePlatformDisplayMap::iterator iter = displays->find(mDevice);
        if (iter != displays->end())
        {
            displays->erase(iter);
        }
    }
    else
    {
        UNREACHABLE();
    }

    SafeDelete(mDevice);
    SafeDelete(mImplementation);
}

void Display::setLabel(EGLLabelKHR label)
{
    mState.label = label;
}

EGLLabelKHR Display::getLabel() const
{
    return mState.label;
}

void Display::setAttributes(rx::DisplayImpl *impl, const AttributeMap &attribMap)
{
    ASSERT(!mInitialized);

    ASSERT(impl != nullptr);
    SafeDelete(mImplementation);
    mImplementation = impl;

    mAttributeMap = attribMap;

    // TODO(jmadill): Store Platform in Display and init here.
    const angle::PlatformMethods *platformMethods =
        reinterpret_cast<const angle::PlatformMethods *>(
            mAttributeMap.get(EGL_PLATFORM_ANGLE_PLATFORM_METHODS_ANGLEX, 0));
    if (platformMethods != nullptr)
    {
        *ANGLEPlatformCurrent() = *platformMethods;
    }
    else
    {
        ANGLESetDefaultDisplayPlatform(this);
    }

    const char **featuresForceEnabled =
        reinterpret_cast<const char **>(mAttributeMap.get(EGL_FEATURE_OVERRIDES_ENABLED_ANGLE, 0));
    const char **featuresForceDisabled =
        reinterpret_cast<const char **>(mAttributeMap.get(EGL_FEATURE_OVERRIDES_DISABLED_ANGLE, 0));
    mState.featureOverridesEnabled  = EGLStringArrayToStringVector(featuresForceEnabled);
    mState.featureOverridesDisabled = EGLStringArrayToStringVector(featuresForceDisabled);
    mState.featuresAllDisabled =
        static_cast<bool>(mAttributeMap.get(EGL_FEATURE_ALL_DISABLED_ANGLE, 0));
}

Error Display::initialize()
{
    ASSERT(mImplementation != nullptr);
    mImplementation->setBlobCache(&mBlobCache);

    gl::InitializeDebugAnnotations(&mAnnotator);

    gl::InitializeDebugMutexIfNeeded();

    SCOPED_ANGLE_HISTOGRAM_TIMER("GPU.ANGLE.DisplayInitializeMS");
    ANGLE_TRACE_EVENT0("gpu.angle", "egl::Display::initialize");

    if (isInitialized())
    {
        return NoError();
    }

    Error error = mImplementation->initialize(this);
    if (error.isError())
    {
        // Log extended error message here
        ERR() << "ANGLE Display::initialize error " << error.getID() << ": " << error.getMessage();
        return error;
    }

    mCaps = mImplementation->getCaps();

    mConfigSet = mImplementation->generateConfigs();
    if (mConfigSet.size() == 0)
    {
        mImplementation->terminate();
        return EglNotInitialized();
    }

    // OpenGL ES1 is implemented in the frontend, explicitly add ES1 support to all configs
    for (auto &config : mConfigSet)
    {
        // TODO(geofflang): Enable the conformant bit once we pass enough tests
        // config.second.conformant |= EGL_OPENGL_ES_BIT;

        config.second.renderableType |= EGL_OPENGL_ES_BIT;
    }

    if (!mState.featuresAllDisabled)
    {
        initializeFrontendFeatures();
    }

    mFeatures.clear();
    mFrontendFeatures.populateFeatureList(&mFeatures);
    mImplementation->populateFeatureList(&mFeatures);

    initDisplayExtensions();
    initVendorString();

    // Populate the Display's EGLDeviceEXT if the Display wasn't created using one
    if (mPlatform != EGL_PLATFORM_DEVICE_EXT)
    {
        if (mDisplayExtensions.deviceQuery)
        {
            std::unique_ptr<rx::DeviceImpl> impl(mImplementation->createDevice());
            ASSERT(impl != nullptr);
            error = impl->initialize();
            if (error.isError())
            {
                ERR() << "Failed to initialize display because device creation failed: "
                      << error.getMessage();
                mImplementation->terminate();
                return error;
            }
            mDevice = new Device(this, impl.release());
        }
        else
        {
            mDevice = nullptr;
        }
    }
    else
    {
        // For EGL_PLATFORM_DEVICE_EXT, mDevice should always be populated using
        // an external device
        ASSERT(mDevice != nullptr);
    }

    mInitialized = true;

    return NoError();
}

Error Display::terminate(const Thread *thread)
{
    if (!mInitialized)
    {
        return NoError();
    }

    mMemoryProgramCache.clear();
    mBlobCache.setBlobCacheFuncs(nullptr, nullptr);

    while (!mContextSet.empty())
    {
        ANGLE_TRY(destroyContext(thread, *mContextSet.begin()));
    }

    ANGLE_TRY(makeCurrent(thread, nullptr, nullptr, nullptr));

    // The global texture manager should be deleted with the last context that uses it.
    ASSERT(mGlobalTextureShareGroupUsers == 0 && mTextureManager == nullptr);

    while (!mImageSet.empty())
    {
        destroyImage(*mImageSet.begin());
    }

    while (!mStreamSet.empty())
    {
        destroyStream(*mStreamSet.begin());
    }

    while (!mSyncSet.empty())
    {
        destroySync(*mSyncSet.begin());
    }

    while (!mState.surfaceSet.empty())
    {
        ANGLE_TRY(destroySurface(*mState.surfaceSet.begin()));
    }

    mConfigSet.clear();

    if (mDevice != nullptr && mDevice->getOwningDisplay() != nullptr)
    {
        // Don't delete the device if it was created externally using eglCreateDeviceANGLE
        // We also shouldn't set it to null in case eglInitialize() is called again later
        SafeDelete(mDevice);
    }

    mImplementation->terminate();

    mDeviceLost = false;

    mInitialized = false;

    gl::UninitializeDebugAnnotations();

    // TODO(jmadill): Store Platform in Display and deinit here.
    ANGLEResetDisplayPlatform(this);

    return NoError();
}

std::vector<const Config *> Display::getConfigs(const egl::AttributeMap &attribs) const
{
    return mConfigSet.filter(attribs);
}

std::vector<const Config *> Display::chooseConfig(const egl::AttributeMap &attribs) const
{
    egl::AttributeMap attribsWithDefaults = AttributeMap();

    // Insert default values for attributes that have either an Exact or Mask selection criteria,
    // and a default value that matters (e.g. isn't EGL_DONT_CARE):
    attribsWithDefaults.insert(EGL_COLOR_BUFFER_TYPE, EGL_RGB_BUFFER);
    attribsWithDefaults.insert(EGL_LEVEL, 0);
    attribsWithDefaults.insert(EGL_RENDERABLE_TYPE, EGL_OPENGL_ES_BIT);
    attribsWithDefaults.insert(EGL_SURFACE_TYPE, EGL_WINDOW_BIT);
    attribsWithDefaults.insert(EGL_TRANSPARENT_TYPE, EGL_NONE);
    if (getExtensions().pixelFormatFloat)
    {
        attribsWithDefaults.insert(EGL_COLOR_COMPONENT_TYPE_EXT,
                                   EGL_COLOR_COMPONENT_TYPE_FIXED_EXT);
    }

    // Add the caller-specified values (Note: the poorly-named insert() method will replace any
    // of the default values from above):
    for (auto attribIter = attribs.begin(); attribIter != attribs.end(); attribIter++)
    {
        attribsWithDefaults.insert(attribIter->first, attribIter->second);
    }

    return mConfigSet.filter(attribsWithDefaults);
}

Error Display::createWindowSurface(const Config *configuration,
                                   EGLNativeWindowType window,
                                   const AttributeMap &attribs,
                                   Surface **outSurface)
{
    if (mImplementation->testDeviceLost())
    {
        ANGLE_TRY(restoreLostDevice());
    }

    SurfacePointer surface(new WindowSurface(mImplementation, configuration, window, attribs),
                           this);
    ANGLE_TRY(surface->initialize(this));

    ASSERT(outSurface != nullptr);
    *outSurface = surface.release();
    mState.surfaceSet.insert(*outSurface);

    WindowSurfaceMap *windowSurfaces = GetWindowSurfaces();
    ASSERT(windowSurfaces && windowSurfaces->find(window) == windowSurfaces->end());
    windowSurfaces->insert(std::make_pair(window, *outSurface));

    mSurface = *outSurface;

    return NoError();
}

Error Display::createPbufferSurface(const Config *configuration,
                                    const AttributeMap &attribs,
                                    Surface **outSurface)
{
    ASSERT(isInitialized());

    if (mImplementation->testDeviceLost())
    {
        ANGLE_TRY(restoreLostDevice());
    }

    SurfacePointer surface(new PbufferSurface(mImplementation, configuration, attribs), this);
    ANGLE_TRY(surface->initialize(this));

    ASSERT(outSurface != nullptr);
    *outSurface = surface.release();
    mState.surfaceSet.insert(*outSurface);

    return NoError();
}

Error Display::createPbufferFromClientBuffer(const Config *configuration,
                                             EGLenum buftype,
                                             EGLClientBuffer clientBuffer,
                                             const AttributeMap &attribs,
                                             Surface **outSurface)
{
    ASSERT(isInitialized());

    if (mImplementation->testDeviceLost())
    {
        ANGLE_TRY(restoreLostDevice());
    }

    SurfacePointer surface(
        new PbufferSurface(mImplementation, configuration, buftype, clientBuffer, attribs), this);
    ANGLE_TRY(surface->initialize(this));

    ASSERT(outSurface != nullptr);
    *outSurface = surface.release();
    mState.surfaceSet.insert(*outSurface);

    return NoError();
}

Error Display::createPixmapSurface(const Config *configuration,
                                   NativePixmapType nativePixmap,
                                   const AttributeMap &attribs,
                                   Surface **outSurface)
{
    ASSERT(isInitialized());

    if (mImplementation->testDeviceLost())
    {
        ANGLE_TRY(restoreLostDevice());
    }

    SurfacePointer surface(new PixmapSurface(mImplementation, configuration, nativePixmap, attribs),
                           this);
    ANGLE_TRY(surface->initialize(this));

    ASSERT(outSurface != nullptr);
    *outSurface = surface.release();
    mState.surfaceSet.insert(*outSurface);

    return NoError();
}

Error Display::createImage(const gl::Context *context,
                           EGLenum target,
                           EGLClientBuffer buffer,
                           const AttributeMap &attribs,
                           Image **outImage)
{
    ASSERT(isInitialized());

    if (mImplementation->testDeviceLost())
    {
        ANGLE_TRY(restoreLostDevice());
    }

    egl::ImageSibling *sibling = nullptr;
    if (IsTextureTarget(target))
    {
        sibling = context->getTexture({egl_gl::EGLClientBufferToGLObjectHandle(buffer)});
    }
    else if (IsRenderbufferTarget(target))
    {
        sibling = context->getRenderbuffer({egl_gl::EGLClientBufferToGLObjectHandle(buffer)});
    }
    else if (IsExternalImageTarget(target))
    {
        sibling = new ExternalImageSibling(mImplementation, context, target, buffer, attribs);
    }
    else
    {
        UNREACHABLE();
    }
    ASSERT(sibling != nullptr);

    angle::UniqueObjectPointer<Image, Display> imagePtr(
        new Image(mImplementation, context, target, sibling, attribs), this);
    ANGLE_TRY(imagePtr->initialize(this));

    Image *image = imagePtr.release();

    ASSERT(outImage != nullptr);
    *outImage = image;

    // Add this image to the list of all images and hold a ref to it.
    image->addRef();
    mImageSet.insert(image);

    return NoError();
}

Error Display::createStream(const AttributeMap &attribs, Stream **outStream)
{
    ASSERT(isInitialized());

    Stream *stream = new Stream(this, attribs);

    ASSERT(stream != nullptr);
    mStreamSet.insert(stream);

    ASSERT(outStream != nullptr);
    *outStream = stream;

    return NoError();
}

Error Display::createContext(const Config *configuration,
                             gl::Context *shareContext,
                             EGLenum clientType,
                             const AttributeMap &attribs,
                             gl::Context **outContext)
{
    ASSERT(isInitialized());

    if (mImplementation->testDeviceLost())
    {
        ANGLE_TRY(restoreLostDevice());
    }

    // This display texture sharing will allow the first context to create the texture share group.
    bool usingDisplayTextureShareGroup =
        attribs.get(EGL_DISPLAY_TEXTURE_SHARE_GROUP_ANGLE, EGL_FALSE) == EGL_TRUE;
    gl::TextureManager *shareTextures = nullptr;

    if (usingDisplayTextureShareGroup)
    {
        ASSERT((mTextureManager == nullptr) == (mGlobalTextureShareGroupUsers == 0));
        if (mTextureManager == nullptr)
        {
            mTextureManager = new gl::TextureManager();
        }

        mGlobalTextureShareGroupUsers++;
        shareTextures = mTextureManager;
    }

    gl::MemoryProgramCache *cachePointer = &mMemoryProgramCache;

    // Check context creation attributes to see if we are using EGL_ANGLE_program_cache_control.
    // If not, keep caching enabled for EGL_ANDROID_blob_cache, which can have its callbacks set
    // at any time.
    bool usesProgramCacheControl =
        mAttributeMap.contains(EGL_CONTEXT_PROGRAM_BINARY_CACHE_ENABLED_ANGLE);
    if (usesProgramCacheControl)
    {
        bool programCacheControlEnabled =
            (mAttributeMap.get(EGL_CONTEXT_PROGRAM_BINARY_CACHE_ENABLED_ANGLE, GL_FALSE) ==
             GL_TRUE);
        // A program cache size of zero indicates it should be disabled.
        if (!programCacheControlEnabled || mMemoryProgramCache.maxSize() == 0)
        {
            cachePointer = nullptr;
        }
    }

    gl::Context *context =
        new gl::Context(this, configuration, shareContext, shareTextures, cachePointer, clientType,
                        attribs, mDisplayExtensions, GetClientExtensions());
    if (shareContext != nullptr)
    {
        shareContext->setShared();
    }

    ASSERT(context != nullptr);
    mContextSet.insert(context);

    ASSERT(outContext != nullptr);
    *outContext = context;
    return NoError();
}

Error Display::createSync(const gl::Context *currentContext,
                          EGLenum type,
                          const AttributeMap &attribs,
                          Sync **outSync)
{
    ASSERT(isInitialized());

    if (mImplementation->testDeviceLost())
    {
        ANGLE_TRY(restoreLostDevice());
    }

    angle::UniqueObjectPointer<egl::Sync, Display> syncPtr(new Sync(mImplementation, type, attribs),
                                                           this);

    ANGLE_TRY(syncPtr->initialize(this, currentContext));

    Sync *sync = syncPtr.release();

    sync->addRef();
    mSyncSet.insert(sync);

    *outSync = sync;
    return NoError();
}

Error Display::makeCurrent(const Thread *thread,
                           egl::Surface *drawSurface,
                           egl::Surface *readSurface,
                           gl::Context *context)
{
    if (!mInitialized)
    {
        return NoError();
    }

    gl::Context *previousContext = thread->getContext();
    if (previousContext)
    {
        ANGLE_TRY(previousContext->unMakeCurrent(this));
    }

    ANGLE_TRY(mImplementation->makeCurrent(drawSurface, readSurface, context));

    if (context != nullptr)
    {
        ANGLE_TRY(context->makeCurrent(this, drawSurface, readSurface));
    }

    return NoError();
}

Error Display::restoreLostDevice()
{
    for (ContextSet::iterator ctx = mContextSet.begin(); ctx != mContextSet.end(); ctx++)
    {
        if ((*ctx)->isResetNotificationEnabled())
        {
            // If reset notifications have been requested, application must delete all contexts
            // first
            return EglContextLost();
        }
    }

    return mImplementation->restoreLostDevice(this);
}

Error Display::destroySurface(Surface *surface)
{
    if (surface->getType() == EGL_WINDOW_BIT)
    {
        WindowSurfaceMap *windowSurfaces = GetWindowSurfaces();
        ASSERT(windowSurfaces);

        bool surfaceRemoved = false;
        for (WindowSurfaceMap::iterator iter = windowSurfaces->begin();
             iter != windowSurfaces->end(); iter++)
        {
            if (iter->second == surface)
            {
                windowSurfaces->erase(iter);
                surfaceRemoved = true;
                break;
            }
        }

        ASSERT(surfaceRemoved);
    }

    mState.surfaceSet.erase(surface);
    ANGLE_TRY(surface->onDestroy(this));
    return NoError();
}

void Display::destroyImage(egl::Image *image)
{
    auto iter = mImageSet.find(image);
    ASSERT(iter != mImageSet.end());
    (*iter)->release(this);
    mImageSet.erase(iter);
}

void Display::destroyStream(egl::Stream *stream)
{
    mStreamSet.erase(stream);
    SafeDelete(stream);
}

Error Display::destroyContext(const Thread *thread, gl::Context *context)
{
    gl::Context *currentContext   = thread->getContext();
    Surface *currentDrawSurface   = thread->getCurrentDrawSurface();
    Surface *currentReadSurface   = thread->getCurrentReadSurface();
    bool changeContextForDeletion = context != currentContext;

    // Make the context being deleted current during it's deletion.  This allows it to delete
    // any resources it's holding.
    if (changeContextForDeletion)
    {
        ANGLE_TRY(makeCurrent(thread, nullptr, nullptr, context));
    }

    if (context->usingDisplayTextureShareGroup())
    {
        ASSERT(mGlobalTextureShareGroupUsers >= 1 && mTextureManager != nullptr);
        if (mGlobalTextureShareGroupUsers == 1)
        {
            // If this is the last context using the global share group, destroy the global
            // texture manager so that the textures can be destroyed while a context still
            // exists
            mTextureManager->release(context);
            mTextureManager = nullptr;
        }
        mGlobalTextureShareGroupUsers--;
    }

    ANGLE_TRY(context->onDestroy(this));
    mContextSet.erase(context);
    SafeDelete(context);

    // Set the previous context back to current
    if (changeContextForDeletion)
    {
        ANGLE_TRY(makeCurrent(thread, currentDrawSurface, currentReadSurface, currentContext));
    }

    return NoError();
}

void Display::destroySync(egl::Sync *sync)
{
    auto iter = mSyncSet.find(sync);
    ASSERT(iter != mSyncSet.end());
    (*iter)->release(this);
    mSyncSet.erase(iter);
}

bool Display::isDeviceLost() const
{
    ASSERT(isInitialized());
    return mDeviceLost;
}

bool Display::testDeviceLost()
{
    ASSERT(isInitialized());

    if (!mDeviceLost && mImplementation->testDeviceLost())
    {
        notifyDeviceLost();
    }

    return mDeviceLost;
}

void Display::notifyDeviceLost()
{
    if (mDeviceLost)
    {
        return;
    }

    for (ContextSet::iterator context = mContextSet.begin(); context != mContextSet.end();
         context++)
    {
        (*context)->markContextLost(gl::GraphicsResetStatus::UnknownContextReset);
    }

    mDeviceLost = true;
}

void Display::setBlobCacheFuncs(EGLSetBlobFuncANDROID set, EGLGetBlobFuncANDROID get)
{
    mBlobCache.setBlobCacheFuncs(set, get);
    mImplementation->setBlobCacheFuncs(set, get);
}

// static
EGLClientBuffer Display::GetNativeClientBuffer(const AHardwareBuffer *buffer)
{
    return angle::android::AHardwareBufferToClientBuffer(buffer);
}

Error Display::waitClient(const gl::Context *context)
{
    return mImplementation->waitClient(context);
}

Error Display::waitNative(const gl::Context *context, EGLint engine)
{
    return mImplementation->waitNative(context, engine);
}

const Caps &Display::getCaps() const
{
    return mCaps;
}

bool Display::isInitialized() const
{
    return mInitialized;
}

bool Display::isValidConfig(const Config *config) const
{
    return mConfigSet.contains(config);
}

bool Display::isValidContext(const gl::Context *context) const
{
    return mContextSet.find(const_cast<gl::Context *>(context)) != mContextSet.end();
}

bool Display::isValidSurface(const Surface *surface) const
{
    return mState.surfaceSet.find(const_cast<Surface *>(surface)) != mState.surfaceSet.end();
}

bool Display::isValidImage(const Image *image) const
{
    return mImageSet.find(const_cast<Image *>(image)) != mImageSet.end();
}

bool Display::isValidStream(const Stream *stream) const
{
    return mStreamSet.find(const_cast<Stream *>(stream)) != mStreamSet.end();
}

bool Display::isValidSync(const Sync *sync) const
{
    return mSyncSet.find(const_cast<Sync *>(sync)) != mSyncSet.end();
}

bool Display::hasExistingWindowSurface(EGLNativeWindowType window)
{
    WindowSurfaceMap *windowSurfaces = GetWindowSurfaces();
    ASSERT(windowSurfaces);

    return windowSurfaces->find(window) != windowSurfaces->end();
}

static ClientExtensions GenerateClientExtensions()
{
    ClientExtensions extensions;

    extensions.clientExtensions = true;
    extensions.platformBase     = true;
    extensions.platformANGLE    = true;

#if defined(ANGLE_ENABLE_D3D9) || defined(ANGLE_ENABLE_D3D11)
    extensions.platformANGLED3D = true;
    extensions.platformDevice   = true;
#endif

#if defined(ANGLE_ENABLE_D3D11)
#    if defined(ANGLE_ENABLE_WINDOWS_UWP)
    extensions.platformANGLED3D11ON12 = true;
#    else
    extensions.platformANGLED3D11ON12 = IsWindows10OrGreater();
#    endif
#endif

#if defined(ANGLE_ENABLE_OPENGL)
    extensions.platformANGLEOpenGL = true;

    // Selecting context virtualization is currently only supported in the OpenGL backend.
    extensions.platformANGLEContextVirtualization = true;
#endif

#if defined(ANGLE_ENABLE_NULL)
    extensions.platformANGLENULL = true;
#endif

#if defined(ANGLE_ENABLE_D3D11)
    extensions.deviceCreation          = true;
    extensions.deviceCreationD3D11     = true;
    extensions.experimentalPresentPath = true;
#endif

#if defined(ANGLE_ENABLE_VULKAN)
    extensions.platformANGLEVulkan                = true;
    extensions.platformANGLEDeviceTypeSwiftShader = true;
#endif

#if defined(ANGLE_ENABLE_METAL)
    extensions.platformANGLEMetal = true;
#endif

#if defined(ANGLE_USE_X11)
    extensions.x11Visual = true;
#endif

    extensions.clientGetAllProcAddresses = true;
    extensions.debug                     = true;
    extensions.explicitContext           = true;
    extensions.featureControlANGLE       = true;

    return extensions;
}

template <typename T>
static std::string GenerateExtensionsString(const T &extensions)
{
    std::vector<std::string> extensionsVector = extensions.getStrings();

    std::ostringstream stream;
    std::copy(extensionsVector.begin(), extensionsVector.end(),
              std::ostream_iterator<std::string>(stream, " "));
    return stream.str();
}

// static
const ClientExtensions &Display::GetClientExtensions()
{
    static const ClientExtensions clientExtensions = GenerateClientExtensions();
    return clientExtensions;
}

// static
const std::string &Display::GetClientExtensionString()
{
    static const angle::base::NoDestructor<std::string> clientExtensionsString(
        GenerateExtensionsString(GetClientExtensions()));
    return *clientExtensionsString;
}

void Display::initDisplayExtensions()
{
    mDisplayExtensions = mImplementation->getExtensions();

    // Some extensions are always available because they are implemented in the EGL layer.
    mDisplayExtensions.createContext                      = true;
    mDisplayExtensions.createContextNoError               = true;
    mDisplayExtensions.createContextWebGLCompatibility    = true;
    mDisplayExtensions.createContextBindGeneratesResource = true;
    mDisplayExtensions.createContextClientArrays          = true;
    mDisplayExtensions.pixelFormatFloat                   = true;

    // Force EGL_KHR_get_all_proc_addresses on.
    mDisplayExtensions.getAllProcAddresses = true;

    // Enable program cache control since it is not back-end dependent.
    mDisplayExtensions.programCacheControl = true;

    // Request extension is implemented in the ANGLE frontend
    mDisplayExtensions.createContextExtensionsEnabled = true;

    // Blob cache extension is provided by the ANGLE frontend
    mDisplayExtensions.blobCache = true;

    // The EGL_ANDROID_recordable extension is provided by the ANGLE frontend, and will always
    // say that ANativeWindow is not recordable.
    mDisplayExtensions.recordable = true;

    // All backends support specific context versions
    mDisplayExtensions.createContextBackwardsCompatible = true;

    mDisplayExtensionString = GenerateExtensionsString(mDisplayExtensions);
}

bool Display::isValidNativeWindow(EGLNativeWindowType window) const
{
    return mImplementation->isValidNativeWindow(window);
}

Error Display::validateClientBuffer(const Config *configuration,
                                    EGLenum buftype,
                                    EGLClientBuffer clientBuffer,
                                    const AttributeMap &attribs) const
{
    return mImplementation->validateClientBuffer(configuration, buftype, clientBuffer, attribs);
}

Error Display::validateImageClientBuffer(const gl::Context *context,
                                         EGLenum target,
                                         EGLClientBuffer clientBuffer,
                                         const egl::AttributeMap &attribs) const
{
    return mImplementation->validateImageClientBuffer(context, target, clientBuffer, attribs);
}

bool Display::isValidDisplay(const egl::Display *display)
{
    const ANGLEPlatformDisplayMap *anglePlatformDisplayMap = GetANGLEPlatformDisplayMap();
    for (const auto &displayPair : *anglePlatformDisplayMap)
    {
        if (displayPair.second == display)
        {
            return true;
        }
    }

    const DevicePlatformDisplayMap *devicePlatformDisplayMap = GetDevicePlatformDisplayMap();
    for (const auto &displayPair : *devicePlatformDisplayMap)
    {
        if (displayPair.second == display)
        {
            return true;
        }
    }

    return false;
}

bool Display::isValidNativeDisplay(EGLNativeDisplayType display)
{
    // TODO(jmadill): handle this properly
    if (display == EGL_DEFAULT_DISPLAY)
    {
        return true;
    }

#if defined(ANGLE_PLATFORM_WINDOWS) && !defined(ANGLE_ENABLE_WINDOWS_UWP)
    if (display == EGL_SOFTWARE_DISPLAY_ANGLE || display == EGL_D3D11_ELSE_D3D9_DISPLAY_ANGLE ||
        display == EGL_D3D11_ONLY_DISPLAY_ANGLE)
    {
        return true;
    }
    return (WindowFromDC(display) != nullptr);
#else
    return true;
#endif
}

void Display::initVendorString()
{
    mVendorString = mImplementation->getVendorString();
}

void Display::initializeFrontendFeatures()
{
    // Enable on all Impls
    ANGLE_FEATURE_CONDITION((&mFrontendFeatures), loseContextOnOutOfMemory, true);
    ANGLE_FEATURE_CONDITION((&mFrontendFeatures), scalarizeVecAndMatConstructorArgs, true);

    mImplementation->initializeFrontendFeatures(&mFrontendFeatures);

    rx::OverrideFeaturesWithDisplayState(&mFrontendFeatures, mState);
}

const DisplayExtensions &Display::getExtensions() const
{
    return mDisplayExtensions;
}

const std::string &Display::getExtensionString() const
{
    return mDisplayExtensionString;
}

const std::string &Display::getVendorString() const
{
    return mVendorString;
}

Device *Display::getDevice() const
{
    return mDevice;
}

Surface *Display::getWGLSurface() const
{
    return mSurface;
}

gl::Version Display::getMaxSupportedESVersion() const
{
    return mImplementation->getMaxSupportedESVersion();
}

EGLint Display::programCacheGetAttrib(EGLenum attrib) const
{
    switch (attrib)
    {
        case EGL_PROGRAM_CACHE_KEY_LENGTH_ANGLE:
            return static_cast<EGLint>(BlobCache::kKeyLength);

        case EGL_PROGRAM_CACHE_SIZE_ANGLE:
            return static_cast<EGLint>(mMemoryProgramCache.entryCount());

        default:
            UNREACHABLE();
            return 0;
    }
}

Error Display::programCacheQuery(EGLint index,
                                 void *key,
                                 EGLint *keysize,
                                 void *binary,
                                 EGLint *binarysize)
{
    ASSERT(index >= 0 && index < static_cast<EGLint>(mMemoryProgramCache.entryCount()));

    const BlobCache::Key *programHash = nullptr;
    BlobCache::Value programBinary;
    // TODO(jmadill): Make this thread-safe.
    bool result =
        mMemoryProgramCache.getAt(static_cast<size_t>(index), &programHash, &programBinary);
    if (!result)
    {
        return EglBadAccess() << "Program binary not accessible.";
    }

    ASSERT(keysize && binarysize);

    if (key)
    {
        ASSERT(*keysize == static_cast<EGLint>(BlobCache::kKeyLength));
        memcpy(key, programHash->data(), BlobCache::kKeyLength);
    }

    if (binary)
    {
        // Note: we check the size here instead of in the validation code, since we need to
        // access the cache as atomically as possible. It's possible that the cache contents
        // could change between the validation size check and the retrieval.
        if (programBinary.size() > static_cast<size_t>(*binarysize))
        {
            return EglBadAccess() << "Program binary too large or changed during access.";
        }

        memcpy(binary, programBinary.data(), programBinary.size());
    }

    *binarysize = static_cast<EGLint>(programBinary.size());
    *keysize    = static_cast<EGLint>(BlobCache::kKeyLength);

    return NoError();
}

Error Display::programCachePopulate(const void *key,
                                    EGLint keysize,
                                    const void *binary,
                                    EGLint binarysize)
{
    ASSERT(keysize == static_cast<EGLint>(BlobCache::kKeyLength));

    BlobCache::Key programHash;
    memcpy(programHash.data(), key, BlobCache::kKeyLength);

    mMemoryProgramCache.putBinary(programHash, reinterpret_cast<const uint8_t *>(binary),
                                  static_cast<size_t>(binarysize));
    return NoError();
}

EGLint Display::programCacheResize(EGLint limit, EGLenum mode)
{
    switch (mode)
    {
        case EGL_PROGRAM_CACHE_RESIZE_ANGLE:
        {
            size_t initialSize = mMemoryProgramCache.size();
            mMemoryProgramCache.resize(static_cast<size_t>(limit));
            return static_cast<EGLint>(initialSize);
        }

        case EGL_PROGRAM_CACHE_TRIM_ANGLE:
            return static_cast<EGLint>(mMemoryProgramCache.trim(static_cast<size_t>(limit)));

        default:
            UNREACHABLE();
            return 0;
    }
}

const char *Display::queryStringi(const EGLint name, const EGLint index)
{
    const char *result = nullptr;
    switch (name)
    {
        case EGL_FEATURE_NAME_ANGLE:
            result = mFeatures[index]->name;
            break;
        case EGL_FEATURE_CATEGORY_ANGLE:
            result = angle::FeatureCategoryToString(mFeatures[index]->category);
            break;
        case EGL_FEATURE_DESCRIPTION_ANGLE:
            result = mFeatures[index]->description;
            break;
        case EGL_FEATURE_BUG_ANGLE:
            result = mFeatures[index]->bug;
            break;
        case EGL_FEATURE_STATUS_ANGLE:
            result = angle::FeatureStatusToString(mFeatures[index]->enabled);
            break;
        case EGL_FEATURE_CONDITION_ANGLE:
            result = mFeatures[index]->condition;
            break;
        default:
            UNREACHABLE();
            return nullptr;
    }
    return result;
}

EGLAttrib Display::queryAttrib(const EGLint attribute)
{
    EGLAttrib value = 0;
    switch (attribute)
    {
        case EGL_DEVICE_EXT:
            value = reinterpret_cast<EGLAttrib>(mDevice);
            break;

        case EGL_FEATURE_COUNT_ANGLE:
            value = mFeatures.size();
            break;

        default:
            UNREACHABLE();
    }
    return value;
}
}  // namespace egl