Framebuffer.cpp

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Author : Geoff Lang
Date : 2018-05-01 16:48:21
Hash : bf7b95db
Message : Create a default framebuffer per surface/context pair on MakeCurrent. Sharing a gl::Framebuffer object between multiple contexts causes problems if contexts are not virtualized because the native framebuffer objects are not shared between these contexts. The FramebufferImpl created should be the glue that binds a specific context to a specific surface. Update the SurfaceImpl implementations to re-create the framebuffer object before passing it to FramebufferGL. No backing resources will be re-created. BUG=angleproject:2464 Change-Id: Id0b13a221c22b71517b25cb5b1ef2392ad2ecdd6 Reviewed-on: https://chromium-review.googlesource.com/1039985 Commit-Queue: Geoff Lang <geofflang@chromium.org> Reviewed-by: Frank Henigman <fjhenigman@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>
src/libANGLE/Framebuffer.cpp
//
// Copyright (c) 2002-2014 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.
//

// Framebuffer.cpp: Implements the gl::Framebuffer class. Implements GL framebuffer
// objects and related functionality. [OpenGL ES 2.0.24] section 4.4 page 105.

#include "libANGLE/Framebuffer.h"

#include "common/Optional.h"
#include "common/bitset_utils.h"
#include "common/utilities.h"
#include "libANGLE/Config.h"
#include "libANGLE/Context.h"
#include "libANGLE/Display.h"
#include "libANGLE/FramebufferAttachment.h"
#include "libANGLE/Renderbuffer.h"
#include "libANGLE/Surface.h"
#include "libANGLE/Texture.h"
#include "libANGLE/angletypes.h"
#include "libANGLE/formatutils.h"
#include "libANGLE/renderer/ContextImpl.h"
#include "libANGLE/renderer/FramebufferImpl.h"
#include "libANGLE/renderer/GLImplFactory.h"
#include "libANGLE/renderer/RenderbufferImpl.h"
#include "libANGLE/renderer/SurfaceImpl.h"

using namespace angle;

namespace gl
{

namespace
{

bool CheckMultiviewStateMatchesForCompleteness(const FramebufferAttachment *firstAttachment,
                                               const FramebufferAttachment *secondAttachment)
{
    ASSERT(firstAttachment && secondAttachment);
    ASSERT(firstAttachment->isAttached() && secondAttachment->isAttached());

    if (firstAttachment->getNumViews() != secondAttachment->getNumViews())
    {
        return false;
    }
    if (firstAttachment->getBaseViewIndex() != secondAttachment->getBaseViewIndex())
    {
        return false;
    }
    if (firstAttachment->getMultiviewLayout() != secondAttachment->getMultiviewLayout())
    {
        return false;
    }
    if (firstAttachment->getMultiviewViewportOffsets() !=
        secondAttachment->getMultiviewViewportOffsets())
    {
        return false;
    }
    return true;
}

bool CheckAttachmentCompleteness(const Context *context, const FramebufferAttachment &attachment)
{
    ASSERT(attachment.isAttached());

    const Extents &size = attachment.getSize();
    if (size.width == 0 || size.height == 0)
    {
        return false;
    }

    const InternalFormat &format = *attachment.getFormat().info;
    if (!format.renderSupport(context->getClientVersion(), context->getExtensions()))
    {
        return false;
    }

    if (attachment.type() == GL_TEXTURE)
    {
        if (attachment.layer() >= size.depth)
        {
            return false;
        }

        // ES3 specifies that cube map texture attachments must be cube complete.
        // This language is missing from the ES2 spec, but we enforce it here because some
        // desktop OpenGL drivers also enforce this validation.
        // TODO(jmadill): Check if OpenGL ES2 drivers enforce cube completeness.
        const Texture *texture = attachment.getTexture();
        ASSERT(texture);
        if (texture->getType() == TextureType::CubeMap &&
            !texture->getTextureState().isCubeComplete())
        {
            return false;
        }

        if (!texture->getImmutableFormat())
        {
            GLuint attachmentMipLevel = static_cast<GLuint>(attachment.mipLevel());

            // From the ES 3.0 spec, pg 213:
            // If the value of FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE is TEXTURE and the value of
            // FRAMEBUFFER_ATTACHMENT_OBJECT_NAME does not name an immutable-format texture,
            // then the value of FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL must be in the
            // range[levelbase, q], where levelbase is the value of TEXTURE_BASE_LEVEL and q is
            // the effective maximum texture level defined in the Mipmapping discussion of
            // section 3.8.10.4.
            if (attachmentMipLevel < texture->getBaseLevel() ||
                attachmentMipLevel > texture->getMipmapMaxLevel())
            {
                return false;
            }

            // Form the ES 3.0 spec, pg 213/214:
            // If the value of FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE is TEXTURE and the value of
            // FRAMEBUFFER_ATTACHMENT_OBJECT_NAME does not name an immutable-format texture and
            // the value of FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL is not levelbase, then the
            // texture must be mipmap complete, and if FRAMEBUFFER_ATTACHMENT_OBJECT_NAME names
            // a cubemap texture, the texture must also be cube complete.
            if (attachmentMipLevel != texture->getBaseLevel() && !texture->isMipmapComplete())
            {
                return false;
            }
        }
    }

    return true;
};

bool CheckAttachmentSampleCompleteness(const Context *context,
                                       const FramebufferAttachment &attachment,
                                       bool colorAttachment,
                                       Optional<int> *samples,
                                       Optional<bool> *fixedSampleLocations)
{
    ASSERT(attachment.isAttached());

    if (attachment.type() == GL_TEXTURE)
    {
        const Texture *texture = attachment.getTexture();
        ASSERT(texture);

        const ImageIndex &attachmentImageIndex = attachment.getTextureImageIndex();

        // ES3.1 (section 9.4) requires that the value of TEXTURE_FIXED_SAMPLE_LOCATIONS should be
        // the same for all attached textures.
        bool fixedSampleloc = texture->getFixedSampleLocations(
            attachmentImageIndex.getTarget(), attachmentImageIndex.getLevelIndex());
        if (fixedSampleLocations->valid() && fixedSampleloc != fixedSampleLocations->value())
        {
            return false;
        }
        else
        {
            *fixedSampleLocations = fixedSampleloc;
        }
    }

    if (samples->valid())
    {
        if (attachment.getSamples() != samples->value())
        {
            if (colorAttachment)
            {
                // APPLE_framebuffer_multisample, which EXT_draw_buffers refers to, requires that
                // all color attachments have the same number of samples for the FBO to be complete.
                return false;
            }
            else
            {
                // CHROMIUM_framebuffer_mixed_samples allows a framebuffer to be considered complete
                // when its depth or stencil samples are a multiple of the number of color samples.
                if (!context->getExtensions().framebufferMixedSamples)
                {
                    return false;
                }

                if ((attachment.getSamples() % std::max(samples->value(), 1)) != 0)
                {
                    return false;
                }
            }
        }
    }
    else
    {
        *samples = attachment.getSamples();
    }

    return true;
}

// Needed to index into the attachment arrays/bitsets.
static_assert(static_cast<size_t>(IMPLEMENTATION_MAX_FRAMEBUFFER_ATTACHMENTS) ==
                  Framebuffer::DIRTY_BIT_COLOR_ATTACHMENT_MAX,
              "Framebuffer Dirty bit mismatch");
static_assert(static_cast<size_t>(IMPLEMENTATION_MAX_FRAMEBUFFER_ATTACHMENTS) ==
                  Framebuffer::DIRTY_BIT_DEPTH_ATTACHMENT,
              "Framebuffer Dirty bit mismatch");
static_assert(static_cast<size_t>(IMPLEMENTATION_MAX_FRAMEBUFFER_ATTACHMENTS + 1) ==
                  Framebuffer::DIRTY_BIT_STENCIL_ATTACHMENT,
              "Framebuffer Dirty bit mismatch");

Error InitAttachment(const Context *context, FramebufferAttachment *attachment)
{
    ASSERT(attachment->isAttached());
    if (attachment->initState() == InitState::MayNeedInit)
    {
        ANGLE_TRY(attachment->initializeContents(context));
    }
    return NoError();
}

bool IsColorMaskedOut(const BlendState &blend)
{
    return (!blend.colorMaskRed && !blend.colorMaskGreen && !blend.colorMaskBlue &&
            !blend.colorMaskAlpha);
}

bool IsDepthMaskedOut(const DepthStencilState &depthStencil)
{
    return !depthStencil.depthMask;
}

bool IsStencilMaskedOut(const DepthStencilState &depthStencil)
{
    return ((depthStencil.stencilMask & depthStencil.stencilWritemask) == 0);
}

bool IsClearBufferMaskedOut(const Context *context, GLenum buffer)
{
    switch (buffer)
    {
        case GL_COLOR:
            return IsColorMaskedOut(context->getGLState().getBlendState());
        case GL_DEPTH:
            return IsDepthMaskedOut(context->getGLState().getDepthStencilState());
        case GL_STENCIL:
            return IsStencilMaskedOut(context->getGLState().getDepthStencilState());
        case GL_DEPTH_STENCIL:
            return IsDepthMaskedOut(context->getGLState().getDepthStencilState()) &&
                   IsStencilMaskedOut(context->getGLState().getDepthStencilState());
        default:
            UNREACHABLE();
            return true;
    }
}

}  // anonymous namespace

// This constructor is only used for default framebuffers.
FramebufferState::FramebufferState()
    : mId(0),
      mLabel(),
      mColorAttachments(1),
      mDrawBufferStates(1, GL_BACK),
      mReadBufferState(GL_BACK),
      mDrawBufferTypeMask(),
      mDefaultWidth(0),
      mDefaultHeight(0),
      mDefaultSamples(0),
      mDefaultFixedSampleLocations(GL_FALSE),
      mDefaultLayers(0),
      mWebGLDepthStencilConsistent(true)
{
    ASSERT(mDrawBufferStates.size() > 0);
    mEnabledDrawBuffers.set(0);
}

FramebufferState::FramebufferState(const Caps &caps, GLuint id)
    : mId(id),
      mLabel(),
      mColorAttachments(caps.maxColorAttachments),
      mDrawBufferStates(caps.maxDrawBuffers, GL_NONE),
      mReadBufferState(GL_COLOR_ATTACHMENT0_EXT),
      mDrawBufferTypeMask(),
      mDefaultWidth(0),
      mDefaultHeight(0),
      mDefaultSamples(0),
      mDefaultFixedSampleLocations(GL_FALSE),
      mDefaultLayers(0),
      mWebGLDepthStencilConsistent(true)
{
    ASSERT(mId != 0);
    ASSERT(mDrawBufferStates.size() > 0);
    mDrawBufferStates[0] = GL_COLOR_ATTACHMENT0_EXT;
}

FramebufferState::~FramebufferState()
{
}

const std::string &FramebufferState::getLabel()
{
    return mLabel;
}

const FramebufferAttachment *FramebufferState::getAttachment(const Context *context,
                                                             GLenum attachment) const
{
    if (attachment >= GL_COLOR_ATTACHMENT0 && attachment <= GL_COLOR_ATTACHMENT15)
    {
        return getColorAttachment(attachment - GL_COLOR_ATTACHMENT0);
    }

    // WebGL1 allows a developer to query for attachment parameters even when "inconsistant" (i.e.
    // multiple conflicting attachment points) and requires us to return the framebuffer attachment
    // associated with WebGL.
    switch (attachment)
    {
        case GL_COLOR:
        case GL_BACK:
            return getColorAttachment(0);
        case GL_DEPTH:
        case GL_DEPTH_ATTACHMENT:
            if (context->isWebGL1())
            {
                return getWebGLDepthAttachment();
            }
            else
            {
                return getDepthAttachment();
            }
        case GL_STENCIL:
        case GL_STENCIL_ATTACHMENT:
            if (context->isWebGL1())
            {
                return getWebGLStencilAttachment();
            }
            else
            {
                return getStencilAttachment();
            }
        case GL_DEPTH_STENCIL:
        case GL_DEPTH_STENCIL_ATTACHMENT:
            if (context->isWebGL1())
            {
                return getWebGLDepthStencilAttachment();
            }
            else
            {
                return getDepthStencilAttachment();
            }
        default:
            UNREACHABLE();
            return nullptr;
    }
}

size_t FramebufferState::getReadIndex() const
{
    ASSERT(mReadBufferState == GL_BACK ||
           (mReadBufferState >= GL_COLOR_ATTACHMENT0 && mReadBufferState <= GL_COLOR_ATTACHMENT15));
    size_t readIndex = (mReadBufferState == GL_BACK
                            ? 0
                            : static_cast<size_t>(mReadBufferState - GL_COLOR_ATTACHMENT0));
    ASSERT(readIndex < mColorAttachments.size());
    return readIndex;
}

const FramebufferAttachment *FramebufferState::getReadAttachment() const
{
    if (mReadBufferState == GL_NONE)
    {
        return nullptr;
    }
    size_t readIndex = getReadIndex();
    return mColorAttachments[readIndex].isAttached() ? &mColorAttachments[readIndex] : nullptr;
}

const FramebufferAttachment *FramebufferState::getFirstNonNullAttachment() const
{
    auto *colorAttachment = getFirstColorAttachment();
    if (colorAttachment)
    {
        return colorAttachment;
    }
    return getDepthOrStencilAttachment();
}

const FramebufferAttachment *FramebufferState::getFirstColorAttachment() const
{
    for (const FramebufferAttachment &colorAttachment : mColorAttachments)
    {
        if (colorAttachment.isAttached())
        {
            return &colorAttachment;
        }
    }

    return nullptr;
}

const FramebufferAttachment *FramebufferState::getDepthOrStencilAttachment() const
{
    if (mDepthAttachment.isAttached())
    {
        return &mDepthAttachment;
    }
    if (mStencilAttachment.isAttached())
    {
        return &mStencilAttachment;
    }
    return nullptr;
}

const FramebufferAttachment *FramebufferState::getStencilOrDepthStencilAttachment() const
{
    if (mStencilAttachment.isAttached())
    {
        return &mStencilAttachment;
    }
    return getDepthStencilAttachment();
}

const FramebufferAttachment *FramebufferState::getColorAttachment(size_t colorAttachment) const
{
    ASSERT(colorAttachment < mColorAttachments.size());
    return mColorAttachments[colorAttachment].isAttached() ? &mColorAttachments[colorAttachment]
                                                           : nullptr;
}

const FramebufferAttachment *FramebufferState::getDepthAttachment() const
{
    return mDepthAttachment.isAttached() ? &mDepthAttachment : nullptr;
}

const FramebufferAttachment *FramebufferState::getWebGLDepthAttachment() const
{
    return mWebGLDepthAttachment.isAttached() ? &mWebGLDepthAttachment : nullptr;
}

const FramebufferAttachment *FramebufferState::getWebGLDepthStencilAttachment() const
{
    return mWebGLDepthStencilAttachment.isAttached() ? &mWebGLDepthStencilAttachment : nullptr;
}

const FramebufferAttachment *FramebufferState::getStencilAttachment() const
{
    return mStencilAttachment.isAttached() ? &mStencilAttachment : nullptr;
}

const FramebufferAttachment *FramebufferState::getWebGLStencilAttachment() const
{
    return mWebGLStencilAttachment.isAttached() ? &mWebGLStencilAttachment : nullptr;
}

const FramebufferAttachment *FramebufferState::getDepthStencilAttachment() const
{
    // A valid depth-stencil attachment has the same resource bound to both the
    // depth and stencil attachment points.
    if (mDepthAttachment.isAttached() && mStencilAttachment.isAttached() &&
        mDepthAttachment == mStencilAttachment)
    {
        return &mDepthAttachment;
    }

    return nullptr;
}

bool FramebufferState::attachmentsHaveSameDimensions() const
{
    Optional<Extents> attachmentSize;

    auto hasMismatchedSize = [&attachmentSize](const FramebufferAttachment &attachment) {
        if (!attachment.isAttached())
        {
            return false;
        }

        if (!attachmentSize.valid())
        {
            attachmentSize = attachment.getSize();
            return false;
        }

        const auto &prevSize = attachmentSize.value();
        const auto &curSize  = attachment.getSize();
        return (curSize.width != prevSize.width || curSize.height != prevSize.height);
    };

    for (const auto &attachment : mColorAttachments)
    {
        if (hasMismatchedSize(attachment))
        {
            return false;
        }
    }

    if (hasMismatchedSize(mDepthAttachment))
    {
        return false;
    }

    return !hasMismatchedSize(mStencilAttachment);
}

const FramebufferAttachment *FramebufferState::getDrawBuffer(size_t drawBufferIdx) const
{
    ASSERT(drawBufferIdx < mDrawBufferStates.size());
    if (mDrawBufferStates[drawBufferIdx] != GL_NONE)
    {
        // ES3 spec: "If the GL is bound to a draw framebuffer object, the ith buffer listed in bufs
        // must be COLOR_ATTACHMENTi or NONE"
        ASSERT(mDrawBufferStates[drawBufferIdx] == GL_COLOR_ATTACHMENT0 + drawBufferIdx ||
               (drawBufferIdx == 0 && mDrawBufferStates[drawBufferIdx] == GL_BACK));

        if (mDrawBufferStates[drawBufferIdx] == GL_BACK)
        {
            return getColorAttachment(0);
        }
        else
        {
            return getColorAttachment(mDrawBufferStates[drawBufferIdx] - GL_COLOR_ATTACHMENT0);
        }
    }
    else
    {
        return nullptr;
    }
}

size_t FramebufferState::getDrawBufferCount() const
{
    return mDrawBufferStates.size();
}

bool FramebufferState::colorAttachmentsAreUniqueImages() const
{
    for (size_t firstAttachmentIdx = 0; firstAttachmentIdx < mColorAttachments.size();
         firstAttachmentIdx++)
    {
        const FramebufferAttachment &firstAttachment = mColorAttachments[firstAttachmentIdx];
        if (!firstAttachment.isAttached())
        {
            continue;
        }

        for (size_t secondAttachmentIdx = firstAttachmentIdx + 1;
             secondAttachmentIdx < mColorAttachments.size(); secondAttachmentIdx++)
        {
            const FramebufferAttachment &secondAttachment = mColorAttachments[secondAttachmentIdx];
            if (!secondAttachment.isAttached())
            {
                continue;
            }

            if (firstAttachment == secondAttachment)
            {
                return false;
            }
        }
    }

    return true;
}

bool FramebufferState::hasDepth() const
{
    return (mDepthAttachment.isAttached() && mDepthAttachment.getDepthSize() > 0);
}

bool FramebufferState::hasStencil() const
{
    return (mStencilAttachment.isAttached() && mStencilAttachment.getStencilSize() > 0);
}

GLsizei FramebufferState::getNumViews() const
{
    const FramebufferAttachment *attachment = getFirstNonNullAttachment();
    if (attachment == nullptr)
    {
        return FramebufferAttachment::kDefaultNumViews;
    }
    return attachment->getNumViews();
}

const std::vector<Offset> *FramebufferState::getViewportOffsets() const
{
    const FramebufferAttachment *attachment = getFirstNonNullAttachment();
    if (attachment == nullptr)
    {
        return nullptr;
    }
    return &attachment->getMultiviewViewportOffsets();
}

GLenum FramebufferState::getMultiviewLayout() const
{
    const FramebufferAttachment *attachment = getFirstNonNullAttachment();
    if (attachment == nullptr)
    {
        return GL_NONE;
    }
    return attachment->getMultiviewLayout();
}

int FramebufferState::getBaseViewIndex() const
{
    const FramebufferAttachment *attachment = getFirstNonNullAttachment();
    if (attachment == nullptr)
    {
        return GL_NONE;
    }
    return attachment->getBaseViewIndex();
}

Box FramebufferState::getDimensions() const
{
    ASSERT(attachmentsHaveSameDimensions());
    ASSERT(getFirstNonNullAttachment() != nullptr);
    Extents extents = getFirstNonNullAttachment()->getSize();
    return Box(0, 0, 0, extents.width, extents.height, extents.depth);
}

Framebuffer::Framebuffer(const Caps &caps, rx::GLImplFactory *factory, GLuint id)
    : mState(caps, id),
      mImpl(factory->createFramebuffer(mState)),
      mCachedStatus(),
      mDirtyDepthAttachmentBinding(this, DIRTY_BIT_DEPTH_ATTACHMENT),
      mDirtyStencilAttachmentBinding(this, DIRTY_BIT_STENCIL_ATTACHMENT)
{
    ASSERT(mImpl != nullptr);
    ASSERT(mState.mColorAttachments.size() == static_cast<size_t>(caps.maxColorAttachments));

    for (uint32_t colorIndex = 0;
         colorIndex < static_cast<uint32_t>(mState.mColorAttachments.size()); ++colorIndex)
    {
        mDirtyColorAttachmentBindings.emplace_back(this, DIRTY_BIT_COLOR_ATTACHMENT_0 + colorIndex);
    }
}

Framebuffer::Framebuffer(const Context *context, egl::Surface *surface)
    : mState(),
      mImpl(surface->getImplementation()->createDefaultFramebuffer(context, mState)),
      mCachedStatus(GL_FRAMEBUFFER_COMPLETE),
      mDirtyDepthAttachmentBinding(this, DIRTY_BIT_DEPTH_ATTACHMENT),
      mDirtyStencilAttachmentBinding(this, DIRTY_BIT_STENCIL_ATTACHMENT)
{
    ASSERT(mImpl != nullptr);
    mDirtyColorAttachmentBindings.emplace_back(this, DIRTY_BIT_COLOR_ATTACHMENT_0);

    setAttachmentImpl(context, GL_FRAMEBUFFER_DEFAULT, GL_BACK, ImageIndex(), surface,
                      FramebufferAttachment::kDefaultNumViews,
                      FramebufferAttachment::kDefaultBaseViewIndex,
                      FramebufferAttachment::kDefaultMultiviewLayout,
                      FramebufferAttachment::kDefaultViewportOffsets);

    if (surface->getConfig()->depthSize > 0)
    {
        setAttachmentImpl(context, GL_FRAMEBUFFER_DEFAULT, GL_DEPTH, ImageIndex(), surface,
                          FramebufferAttachment::kDefaultNumViews,
                          FramebufferAttachment::kDefaultBaseViewIndex,
                          FramebufferAttachment::kDefaultMultiviewLayout,
                          FramebufferAttachment::kDefaultViewportOffsets);
    }

    if (surface->getConfig()->stencilSize > 0)
    {
        setAttachmentImpl(context, GL_FRAMEBUFFER_DEFAULT, GL_STENCIL, ImageIndex(), surface,
                          FramebufferAttachment::kDefaultNumViews,
                          FramebufferAttachment::kDefaultBaseViewIndex,
                          FramebufferAttachment::kDefaultMultiviewLayout,
                          FramebufferAttachment::kDefaultViewportOffsets);
    }
    mState.mDrawBufferTypeMask.setIndex(getDrawbufferWriteType(0), 0);
}

Framebuffer::Framebuffer(rx::GLImplFactory *factory)
    : mState(),
      mImpl(factory->createFramebuffer(mState)),
      mCachedStatus(GL_FRAMEBUFFER_UNDEFINED_OES),
      mDirtyDepthAttachmentBinding(this, DIRTY_BIT_DEPTH_ATTACHMENT),
      mDirtyStencilAttachmentBinding(this, DIRTY_BIT_STENCIL_ATTACHMENT)
{
    mDirtyColorAttachmentBindings.emplace_back(this, DIRTY_BIT_COLOR_ATTACHMENT_0);
    mState.mDrawBufferTypeMask.setIndex(getDrawbufferWriteType(0), 0);
}

Framebuffer::~Framebuffer()
{
    SafeDelete(mImpl);
}

void Framebuffer::onDestroy(const Context *context)
{
    for (auto &attachment : mState.mColorAttachments)
    {
        attachment.detach(context);
    }
    mState.mDepthAttachment.detach(context);
    mState.mStencilAttachment.detach(context);
    mState.mWebGLDepthAttachment.detach(context);
    mState.mWebGLStencilAttachment.detach(context);
    mState.mWebGLDepthStencilAttachment.detach(context);

    mImpl->destroy(context);
}

void Framebuffer::setLabel(const std::string &label)
{
    mState.mLabel = label;
}

const std::string &Framebuffer::getLabel() const
{
    return mState.mLabel;
}

bool Framebuffer::detachTexture(const Context *context, GLuint textureId)
{
    return detachResourceById(context, GL_TEXTURE, textureId);
}

bool Framebuffer::detachRenderbuffer(const Context *context, GLuint renderbufferId)
{
    return detachResourceById(context, GL_RENDERBUFFER, renderbufferId);
}

bool Framebuffer::detachResourceById(const Context *context, GLenum resourceType, GLuint resourceId)
{
    bool found = false;

    for (size_t colorIndex = 0; colorIndex < mState.mColorAttachments.size(); ++colorIndex)
    {
        if (detachMatchingAttachment(context, &mState.mColorAttachments[colorIndex], resourceType,
                                     resourceId, DIRTY_BIT_COLOR_ATTACHMENT_0 + colorIndex))
        {
            found = true;
        }
    }

    if (context->isWebGL1())
    {
        const std::array<FramebufferAttachment *, 3> attachments = {
            {&mState.mWebGLDepthStencilAttachment, &mState.mWebGLDepthAttachment,
             &mState.mWebGLStencilAttachment}};
        for (FramebufferAttachment *attachment : attachments)
        {
            if (attachment->isAttached() && attachment->type() == resourceType &&
                attachment->id() == resourceId)
            {
                resetAttachment(context, attachment->getBinding());
                found = true;
            }
        }
    }
    else
    {
        if (detachMatchingAttachment(context, &mState.mDepthAttachment, resourceType, resourceId,
                                     DIRTY_BIT_DEPTH_ATTACHMENT))
        {
            found = true;
        }
        if (detachMatchingAttachment(context, &mState.mStencilAttachment, resourceType, resourceId,
                                     DIRTY_BIT_STENCIL_ATTACHMENT))
        {
            found = true;
        }
    }

    return found;
}

bool Framebuffer::detachMatchingAttachment(const Context *context,
                                           FramebufferAttachment *attachment,
                                           GLenum matchType,
                                           GLuint matchId,
                                           size_t dirtyBit)
{
    if (attachment->isAttached() && attachment->type() == matchType && attachment->id() == matchId)
    {
        attachment->detach(context);
        mDirtyBits.set(dirtyBit);
        mState.mResourceNeedsInit.set(dirtyBit, false);
        return true;
    }

    return false;
}

const FramebufferAttachment *Framebuffer::getColorbuffer(size_t colorAttachment) const
{
    return mState.getColorAttachment(colorAttachment);
}

const FramebufferAttachment *Framebuffer::getDepthbuffer() const
{
    return mState.getDepthAttachment();
}

const FramebufferAttachment *Framebuffer::getStencilbuffer() const
{
    return mState.getStencilAttachment();
}

const FramebufferAttachment *Framebuffer::getDepthStencilBuffer() const
{
    return mState.getDepthStencilAttachment();
}

const FramebufferAttachment *Framebuffer::getDepthOrStencilbuffer() const
{
    return mState.getDepthOrStencilAttachment();
}

const FramebufferAttachment *Framebuffer::getStencilOrDepthStencilAttachment() const
{
    return mState.getStencilOrDepthStencilAttachment();
}

const FramebufferAttachment *Framebuffer::getReadColorbuffer() const
{
    return mState.getReadAttachment();
}

GLenum Framebuffer::getReadColorbufferType() const
{
    const FramebufferAttachment *readAttachment = mState.getReadAttachment();
    return (readAttachment != nullptr ? readAttachment->type() : GL_NONE);
}

const FramebufferAttachment *Framebuffer::getFirstColorbuffer() const
{
    return mState.getFirstColorAttachment();
}

const FramebufferAttachment *Framebuffer::getFirstNonNullAttachment() const
{
    return mState.getFirstNonNullAttachment();
}

const FramebufferAttachment *Framebuffer::getAttachment(const Context *context,
                                                        GLenum attachment) const
{
    return mState.getAttachment(context, attachment);
}

size_t Framebuffer::getDrawbufferStateCount() const
{
    return mState.mDrawBufferStates.size();
}

GLenum Framebuffer::getDrawBufferState(size_t drawBuffer) const
{
    ASSERT(drawBuffer < mState.mDrawBufferStates.size());
    return mState.mDrawBufferStates[drawBuffer];
}

const std::vector<GLenum> &Framebuffer::getDrawBufferStates() const
{
    return mState.getDrawBufferStates();
}

void Framebuffer::setDrawBuffers(size_t count, const GLenum *buffers)
{
    auto &drawStates = mState.mDrawBufferStates;

    ASSERT(count <= drawStates.size());
    std::copy(buffers, buffers + count, drawStates.begin());
    std::fill(drawStates.begin() + count, drawStates.end(), GL_NONE);
    mDirtyBits.set(DIRTY_BIT_DRAW_BUFFERS);

    mState.mEnabledDrawBuffers.reset();
    mState.mDrawBufferTypeMask.reset();

    for (size_t index = 0; index < count; ++index)
    {
        mState.mDrawBufferTypeMask.setIndex(getDrawbufferWriteType(index), index);

        if (drawStates[index] != GL_NONE && mState.mColorAttachments[index].isAttached())
        {
            mState.mEnabledDrawBuffers.set(index);
        }
    }
}

const FramebufferAttachment *Framebuffer::getDrawBuffer(size_t drawBuffer) const
{
    return mState.getDrawBuffer(drawBuffer);
}

GLenum Framebuffer::getDrawbufferWriteType(size_t drawBuffer) const
{
    const FramebufferAttachment *attachment = mState.getDrawBuffer(drawBuffer);
    if (attachment == nullptr)
    {
        return GL_NONE;
    }

    GLenum componentType = attachment->getFormat().info->componentType;
    switch (componentType)
    {
        case GL_INT:
        case GL_UNSIGNED_INT:
            return componentType;

        default:
            return GL_FLOAT;
    }
}

ComponentTypeMask Framebuffer::getDrawBufferTypeMask() const
{
    return mState.mDrawBufferTypeMask;
}

DrawBufferMask Framebuffer::getDrawBufferMask() const
{
    return mState.mEnabledDrawBuffers;
}

bool Framebuffer::hasEnabledDrawBuffer() const
{
    for (size_t drawbufferIdx = 0; drawbufferIdx < mState.mDrawBufferStates.size(); ++drawbufferIdx)
    {
        if (getDrawBuffer(drawbufferIdx) != nullptr)
        {
            return true;
        }
    }

    return false;
}

GLenum Framebuffer::getReadBufferState() const
{
    return mState.mReadBufferState;
}

void Framebuffer::setReadBuffer(GLenum buffer)
{
    ASSERT(buffer == GL_BACK || buffer == GL_NONE ||
           (buffer >= GL_COLOR_ATTACHMENT0 &&
            (buffer - GL_COLOR_ATTACHMENT0) < mState.mColorAttachments.size()));
    mState.mReadBufferState = buffer;
    mDirtyBits.set(DIRTY_BIT_READ_BUFFER);
}

size_t Framebuffer::getNumColorBuffers() const
{
    return mState.mColorAttachments.size();
}

bool Framebuffer::hasDepth() const
{
    return mState.hasDepth();
}

bool Framebuffer::hasStencil() const
{
    return mState.hasStencil();
}

bool Framebuffer::usingExtendedDrawBuffers() const
{
    for (size_t drawbufferIdx = 1; drawbufferIdx < mState.mDrawBufferStates.size(); ++drawbufferIdx)
    {
        if (getDrawBuffer(drawbufferIdx) != nullptr)
        {
            return true;
        }
    }

    return false;
}

void Framebuffer::invalidateCompletenessCache()
{
    if (mState.mId != 0)
    {
        mCachedStatus.reset();
    }
}

GLenum Framebuffer::checkStatus(const Context *context)
{
    // The default framebuffer is always complete except when it is surfaceless in which
    // case it is always unsupported. We return early because the default framebuffer may
    // not be subject to the same rules as application FBOs. ie, it could have 0x0 size.
    if (mState.mId == 0)
    {
        ASSERT(mCachedStatus.valid());
        ASSERT(mCachedStatus.value() == GL_FRAMEBUFFER_COMPLETE ||
               mCachedStatus.value() == GL_FRAMEBUFFER_UNDEFINED_OES);
        return mCachedStatus.value();
    }

    if (hasAnyDirtyBit() || !mCachedStatus.valid())
    {
        mCachedStatus = checkStatusWithGLFrontEnd(context);

        if (mCachedStatus.value() == GL_FRAMEBUFFER_COMPLETE)
        {
            Error err = syncState(context);
            if (err.isError())
            {
                context->handleError(err);
                return GetDefaultReturnValue<EntryPoint::CheckFramebufferStatus, GLenum>();
            }
            if (!mImpl->checkStatus(context))
            {
                mCachedStatus = GL_FRAMEBUFFER_UNSUPPORTED;
            }
        }
    }

    return mCachedStatus.value();
}

GLenum Framebuffer::checkStatusWithGLFrontEnd(const Context *context)
{
    const ContextState &state = context->getContextState();

    ASSERT(mState.mId != 0);

    bool hasAttachments = false;
    Optional<unsigned int> colorbufferSize;
    Optional<int> samples;
    Optional<bool> fixedSampleLocations;
    bool hasRenderbuffer = false;

    const FramebufferAttachment *firstAttachment = getFirstNonNullAttachment();

    for (const FramebufferAttachment &colorAttachment : mState.mColorAttachments)
    {
        if (colorAttachment.isAttached())
        {
            if (!CheckAttachmentCompleteness(context, colorAttachment))
            {
                return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
            }

            const InternalFormat &format = *colorAttachment.getFormat().info;
            if (format.depthBits > 0 || format.stencilBits > 0)
            {
                return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
            }

            if (!CheckAttachmentSampleCompleteness(context, colorAttachment, true, &samples,
                                                   &fixedSampleLocations))
            {
                return GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE;
            }

            // in GLES 2.0, all color attachments attachments must have the same number of bitplanes
            // in GLES 3.0, there is no such restriction
            if (state.getClientMajorVersion() < 3)
            {
                if (colorbufferSize.valid())
                {
                    if (format.pixelBytes != colorbufferSize.value())
                    {
                        return GL_FRAMEBUFFER_UNSUPPORTED;
                    }
                }
                else
                {
                    colorbufferSize = format.pixelBytes;
                }
            }

            if (!CheckMultiviewStateMatchesForCompleteness(firstAttachment, &colorAttachment))
            {
                return GL_FRAMEBUFFER_INCOMPLETE_VIEW_TARGETS_ANGLE;
            }

            hasRenderbuffer = hasRenderbuffer || (colorAttachment.type() == GL_RENDERBUFFER);
            hasAttachments  = true;
        }
    }

    const FramebufferAttachment &depthAttachment = mState.mDepthAttachment;
    if (depthAttachment.isAttached())
    {
        if (!CheckAttachmentCompleteness(context, depthAttachment))
        {
            return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
        }

        const InternalFormat &format = *depthAttachment.getFormat().info;
        if (format.depthBits == 0)
        {
            return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
        }

        if (!CheckAttachmentSampleCompleteness(context, depthAttachment, false, &samples,
                                               &fixedSampleLocations))
        {
            return GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE;
        }

        if (!CheckMultiviewStateMatchesForCompleteness(firstAttachment, &depthAttachment))
        {
            return GL_FRAMEBUFFER_INCOMPLETE_VIEW_TARGETS_ANGLE;
        }

        hasRenderbuffer = hasRenderbuffer || (depthAttachment.type() == GL_RENDERBUFFER);
        hasAttachments  = true;
    }

    const FramebufferAttachment &stencilAttachment = mState.mStencilAttachment;
    if (stencilAttachment.isAttached())
    {
        if (!CheckAttachmentCompleteness(context, stencilAttachment))
        {
            return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
        }

        const InternalFormat &format = *stencilAttachment.getFormat().info;
        if (format.stencilBits == 0)
        {
            return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
        }

        if (!CheckAttachmentSampleCompleteness(context, stencilAttachment, false, &samples,
                                               &fixedSampleLocations))
        {
            return GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE;
        }

        if (!CheckMultiviewStateMatchesForCompleteness(firstAttachment, &stencilAttachment))
        {
            return GL_FRAMEBUFFER_INCOMPLETE_VIEW_TARGETS_ANGLE;
        }

        hasRenderbuffer = hasRenderbuffer || (stencilAttachment.type() == GL_RENDERBUFFER);
        hasAttachments  = true;
    }

    // Starting from ES 3.0 stencil and depth, if present, should be the same image
    if (state.getClientMajorVersion() >= 3 && depthAttachment.isAttached() &&
        stencilAttachment.isAttached() && stencilAttachment != depthAttachment)
    {
        return GL_FRAMEBUFFER_UNSUPPORTED;
    }

    // Special additional validation for WebGL 1 DEPTH/STENCIL/DEPTH_STENCIL.
    if (state.isWebGL1())
    {
        if (!mState.mWebGLDepthStencilConsistent)
        {
            return GL_FRAMEBUFFER_UNSUPPORTED;
        }

        if (mState.mWebGLDepthStencilAttachment.isAttached())
        {
            if (mState.mWebGLDepthStencilAttachment.getDepthSize() == 0 ||
                mState.mWebGLDepthStencilAttachment.getStencilSize() == 0)
            {
                return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
            }

            if (!CheckMultiviewStateMatchesForCompleteness(firstAttachment,
                                                           &mState.mWebGLDepthStencilAttachment))
            {
                return GL_FRAMEBUFFER_INCOMPLETE_VIEW_TARGETS_ANGLE;
            }
        }
        else if (mState.mStencilAttachment.isAttached() &&
                 mState.mStencilAttachment.getDepthSize() > 0)
        {
            return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
        }
        else if (mState.mDepthAttachment.isAttached() &&
                 mState.mDepthAttachment.getStencilSize() > 0)
        {
            return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
        }
    }

    // ES3.1(section 9.4) requires that if no image is attached to the framebuffer, and either the
    // value of the framebuffer's FRAMEBUFFER_DEFAULT_WIDTH or FRAMEBUFFER_DEFAULT_HEIGHT parameters
    // is zero, the framebuffer is considered incomplete.
    GLint defaultWidth  = mState.getDefaultWidth();
    GLint defaultHeight = mState.getDefaultHeight();
    if (!hasAttachments && (defaultWidth == 0 || defaultHeight == 0))
    {
        return GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT;
    }

    // In ES 2.0 and WebGL, all color attachments must have the same width and height.
    // In ES 3.0, there is no such restriction.
    if ((state.getClientMajorVersion() < 3 || state.getExtensions().webglCompatibility) &&
        !mState.attachmentsHaveSameDimensions())
    {
        return GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS;
    }

    // ES3.1(section 9.4) requires that if the attached images are a mix of renderbuffers and
    // textures, the value of TEXTURE_FIXED_SAMPLE_LOCATIONS must be TRUE for all attached textures.
    if (fixedSampleLocations.valid() && hasRenderbuffer && !fixedSampleLocations.value())
    {
        return GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE;
    }

    // The WebGL conformance tests implicitly define that all framebuffer
    // attachments must be unique. For example, the same level of a texture can
    // not be attached to two different color attachments.
    if (state.getExtensions().webglCompatibility)
    {
        if (!mState.colorAttachmentsAreUniqueImages())
        {
            return GL_FRAMEBUFFER_UNSUPPORTED;
        }
    }

    return GL_FRAMEBUFFER_COMPLETE;
}

Error Framebuffer::discard(const Context *context, size_t count, const GLenum *attachments)
{
    // Back-ends might make the contents of the FBO undefined. In WebGL 2.0, invalidate operations
    // can be no-ops, so we should probably do that to ensure consistency.
    // TODO(jmadill): WebGL behaviour, and robust resource init behaviour without WebGL.

    return mImpl->discard(context, count, attachments);
}

Error Framebuffer::invalidate(const Context *context, size_t count, const GLenum *attachments)
{
    // Back-ends might make the contents of the FBO undefined. In WebGL 2.0, invalidate operations
    // can be no-ops, so we should probably do that to ensure consistency.
    // TODO(jmadill): WebGL behaviour, and robust resource init behaviour without WebGL.

    return mImpl->invalidate(context, count, attachments);
}

bool Framebuffer::partialClearNeedsInit(const Context *context,
                                        bool color,
                                        bool depth,
                                        bool stencil)
{
    const auto &glState = context->getGLState();

    if (!glState.isRobustResourceInitEnabled())
    {
        return false;
    }

    // Scissors can affect clearing.
    // TODO(jmadill): Check for complete scissor overlap.
    if (glState.isScissorTestEnabled())
    {
        return true;
    }

    // If colors masked, we must clear before we clear. Do a simple check.
    // TODO(jmadill): Filter out unused color channels from the test.
    if (color)
    {
        const auto &blend = glState.getBlendState();
        if (!(blend.colorMaskRed && blend.colorMaskGreen && blend.colorMaskBlue &&
              blend.colorMaskAlpha))
        {
            return true;
        }
    }

    const auto &depthStencil = glState.getDepthStencilState();
    ASSERT(depthStencil.stencilBackMask == depthStencil.stencilMask);
    if (stencil && depthStencil.stencilMask != depthStencil.stencilWritemask)
    {
        return true;
    }

    return false;
}

Error Framebuffer::invalidateSub(const Context *context,
                                 size_t count,
                                 const GLenum *attachments,
                                 const Rectangle &area)
{
    // Back-ends might make the contents of the FBO undefined. In WebGL 2.0, invalidate operations
    // can be no-ops, so we should probably do that to ensure consistency.
    // TODO(jmadill): Make a invalidate no-op in WebGL 2.0.

    return mImpl->invalidateSub(context, count, attachments, area);
}

Error Framebuffer::clear(const Context *context, GLbitfield mask)
{
    const auto &glState = context->getGLState();
    if (glState.isRasterizerDiscardEnabled())
    {
        return NoError();
    }

    ANGLE_TRY(mImpl->clear(context, mask));

    return NoError();
}

Error Framebuffer::clearBufferfv(const Context *context,
                                 GLenum buffer,
                                 GLint drawbuffer,
                                 const GLfloat *values)
{
    if (context->getGLState().isRasterizerDiscardEnabled() ||
        IsClearBufferMaskedOut(context, buffer))
    {
        return NoError();
    }

    ANGLE_TRY(mImpl->clearBufferfv(context, buffer, drawbuffer, values));

    return NoError();
}

Error Framebuffer::clearBufferuiv(const Context *context,
                                  GLenum buffer,
                                  GLint drawbuffer,
                                  const GLuint *values)
{
    if (context->getGLState().isRasterizerDiscardEnabled() ||
        IsClearBufferMaskedOut(context, buffer))
    {
        return NoError();
    }

    ANGLE_TRY(mImpl->clearBufferuiv(context, buffer, drawbuffer, values));

    return NoError();
}

Error Framebuffer::clearBufferiv(const Context *context,
                                 GLenum buffer,
                                 GLint drawbuffer,
                                 const GLint *values)
{
    if (context->getGLState().isRasterizerDiscardEnabled() ||
        IsClearBufferMaskedOut(context, buffer))
    {
        return NoError();
    }

    ANGLE_TRY(mImpl->clearBufferiv(context, buffer, drawbuffer, values));

    return NoError();
}

Error Framebuffer::clearBufferfi(const Context *context,
                                 GLenum buffer,
                                 GLint drawbuffer,
                                 GLfloat depth,
                                 GLint stencil)
{
    if (context->getGLState().isRasterizerDiscardEnabled() ||
        IsClearBufferMaskedOut(context, buffer))
    {
        return NoError();
    }

    ANGLE_TRY(mImpl->clearBufferfi(context, buffer, drawbuffer, depth, stencil));

    return NoError();
}

Error Framebuffer::getImplementationColorReadFormat(const Context *context, GLenum *formatOut)
{
    ANGLE_TRY(syncState(context));
    *formatOut = mImpl->getImplementationColorReadFormat(context);
    return NoError();
}

Error Framebuffer::getImplementationColorReadType(const Context *context, GLenum *typeOut)
{
    ANGLE_TRY(syncState(context));
    *typeOut = mImpl->getImplementationColorReadType(context);
    return NoError();
}

Error Framebuffer::readPixels(const Context *context,
                              const Rectangle &area,
                              GLenum format,
                              GLenum type,
                              void *pixels)
{
    ANGLE_TRY(ensureReadAttachmentInitialized(context, GL_COLOR_BUFFER_BIT));
    ANGLE_TRY(mImpl->readPixels(context, area, format, type, pixels));

    Buffer *unpackBuffer = context->getGLState().getTargetBuffer(BufferBinding::PixelUnpack);
    if (unpackBuffer)
    {
        unpackBuffer->onPixelPack(context);
    }

    return NoError();
}

Error Framebuffer::blit(const Context *context,
                        const Rectangle &sourceArea,
                        const Rectangle &destArea,
                        GLbitfield mask,
                        GLenum filter)
{
    GLbitfield blitMask = mask;

    // Note that blitting is called against draw framebuffer.
    // See the code in gl::Context::blitFramebuffer.
    if ((mask & GL_COLOR_BUFFER_BIT) && !hasEnabledDrawBuffer())
    {
        blitMask &= ~GL_COLOR_BUFFER_BIT;
    }

    if ((mask & GL_STENCIL_BUFFER_BIT) && mState.getStencilAttachment() == nullptr)
    {
        blitMask &= ~GL_STENCIL_BUFFER_BIT;
    }

    if ((mask & GL_DEPTH_BUFFER_BIT) && mState.getDepthAttachment() == nullptr)
    {
        blitMask &= ~GL_DEPTH_BUFFER_BIT;
    }

    if (!blitMask)
    {
        return NoError();
    }

    auto *sourceFBO = context->getGLState().getReadFramebuffer();
    ANGLE_TRY(sourceFBO->ensureReadAttachmentInitialized(context, blitMask));

    // TODO(jmadill): Only clear if not the full FBO dimensions, and only specified bitmask.
    ANGLE_TRY(ensureDrawAttachmentsInitialized(context));

    return mImpl->blit(context, sourceArea, destArea, blitMask, filter);
}

int Framebuffer::getSamples(const Context *context)
{
    return (isComplete(context) ? getCachedSamples(context) : 0);
}

int Framebuffer::getCachedSamples(const Context *context)
{
    ASSERT(mCachedStatus.valid() && mCachedStatus.value() == GL_FRAMEBUFFER_COMPLETE);

    // For a complete framebuffer, all attachments must have the same sample count.
    // In this case return the first nonzero sample size.
    const auto *firstNonNullAttachment = mState.getFirstNonNullAttachment();
    if (firstNonNullAttachment)
    {
        ASSERT(firstNonNullAttachment->isAttached());
        return firstNonNullAttachment->getSamples();
    }

    // No attachments found.
    return 0;
}

Error Framebuffer::getSamplePosition(const Context *context, size_t index, GLfloat *xy) const
{
    ANGLE_TRY(mImpl->getSamplePosition(context, index, xy));
    return NoError();
}

bool Framebuffer::hasValidDepthStencil() const
{
    return mState.getDepthStencilAttachment() != nullptr;
}

void Framebuffer::setAttachment(const Context *context,
                                GLenum type,
                                GLenum binding,
                                const ImageIndex &textureIndex,
                                FramebufferAttachmentObject *resource)
{
    setAttachment(context, type, binding, textureIndex, resource,
                  FramebufferAttachment::kDefaultNumViews,
                  FramebufferAttachment::kDefaultBaseViewIndex,
                  FramebufferAttachment::kDefaultMultiviewLayout,
                  FramebufferAttachment::kDefaultViewportOffsets);
}

void Framebuffer::setAttachment(const Context *context,
                                GLenum type,
                                GLenum binding,
                                const ImageIndex &textureIndex,
                                FramebufferAttachmentObject *resource,
                                GLsizei numViews,
                                GLuint baseViewIndex,
                                GLenum multiviewLayout,
                                const GLint *viewportOffsets)
{
    // Context may be null in unit tests.
    if (!context || !context->isWebGL1())
    {
        setAttachmentImpl(context, type, binding, textureIndex, resource, numViews, baseViewIndex,
                          multiviewLayout, viewportOffsets);
        return;
    }

    switch (binding)
    {
        case GL_DEPTH_STENCIL:
        case GL_DEPTH_STENCIL_ATTACHMENT:
            mState.mWebGLDepthStencilAttachment.attach(context, type, binding, textureIndex,
                                                       resource, numViews, baseViewIndex,
                                                       multiviewLayout, viewportOffsets);
            break;
        case GL_DEPTH:
        case GL_DEPTH_ATTACHMENT:
            mState.mWebGLDepthAttachment.attach(context, type, binding, textureIndex, resource,
                                                numViews, baseViewIndex, multiviewLayout,
                                                viewportOffsets);
            break;
        case GL_STENCIL:
        case GL_STENCIL_ATTACHMENT:
            mState.mWebGLStencilAttachment.attach(context, type, binding, textureIndex, resource,
                                                  numViews, baseViewIndex, multiviewLayout,
                                                  viewportOffsets);
            break;
        default:
            setAttachmentImpl(context, type, binding, textureIndex, resource, numViews,
                              baseViewIndex, multiviewLayout, viewportOffsets);
            return;
    }

    commitWebGL1DepthStencilIfConsistent(context, numViews, baseViewIndex, multiviewLayout,
                                         viewportOffsets);
}

void Framebuffer::setAttachmentMultiviewLayered(const Context *context,
                                                GLenum type,
                                                GLenum binding,
                                                const ImageIndex &textureIndex,
                                                FramebufferAttachmentObject *resource,
                                                GLsizei numViews,
                                                GLint baseViewIndex)
{
    setAttachment(context, type, binding, textureIndex, resource, numViews, baseViewIndex,
                  GL_FRAMEBUFFER_MULTIVIEW_LAYERED_ANGLE,
                  FramebufferAttachment::kDefaultViewportOffsets);
}

void Framebuffer::setAttachmentMultiviewSideBySide(const Context *context,
                                                   GLenum type,
                                                   GLenum binding,
                                                   const ImageIndex &textureIndex,
                                                   FramebufferAttachmentObject *resource,
                                                   GLsizei numViews,
                                                   const GLint *viewportOffsets)
{
    setAttachment(context, type, binding, textureIndex, resource, numViews,
                  FramebufferAttachment::kDefaultBaseViewIndex,
                  GL_FRAMEBUFFER_MULTIVIEW_SIDE_BY_SIDE_ANGLE, viewportOffsets);
}

void Framebuffer::commitWebGL1DepthStencilIfConsistent(const Context *context,
                                                       GLsizei numViews,
                                                       GLuint baseViewIndex,
                                                       GLenum multiviewLayout,
                                                       const GLint *viewportOffsets)
{
    int count = 0;

    std::array<FramebufferAttachment *, 3> attachments = {{&mState.mWebGLDepthStencilAttachment,
                                                           &mState.mWebGLDepthAttachment,
                                                           &mState.mWebGLStencilAttachment}};
    for (FramebufferAttachment *attachment : attachments)
    {
        if (attachment->isAttached())
        {
            count++;
        }
    }

    mState.mWebGLDepthStencilConsistent = (count <= 1);
    if (!mState.mWebGLDepthStencilConsistent)
    {
        // Inconsistent.
        return;
    }

    auto getImageIndexIfTextureAttachment = [](const FramebufferAttachment &attachment) {
        if (attachment.type() == GL_TEXTURE)
        {
            return attachment.getTextureImageIndex();
        }
        else
        {
            return ImageIndex();
        }
    };

    if (mState.mWebGLDepthAttachment.isAttached())
    {
        const auto &depth = mState.mWebGLDepthAttachment;
        setAttachmentImpl(context, depth.type(), GL_DEPTH_ATTACHMENT,
                          getImageIndexIfTextureAttachment(depth), depth.getResource(), numViews,
                          baseViewIndex, multiviewLayout, viewportOffsets);
        setAttachmentImpl(context, GL_NONE, GL_STENCIL_ATTACHMENT, ImageIndex(), nullptr, numViews,
                          baseViewIndex, multiviewLayout, viewportOffsets);
    }
    else if (mState.mWebGLStencilAttachment.isAttached())
    {
        const auto &stencil = mState.mWebGLStencilAttachment;
        setAttachmentImpl(context, GL_NONE, GL_DEPTH_ATTACHMENT, ImageIndex(), nullptr, numViews,
                          baseViewIndex, multiviewLayout, viewportOffsets);
        setAttachmentImpl(context, stencil.type(), GL_STENCIL_ATTACHMENT,
                          getImageIndexIfTextureAttachment(stencil), stencil.getResource(),
                          numViews, baseViewIndex, multiviewLayout, viewportOffsets);
    }
    else if (mState.mWebGLDepthStencilAttachment.isAttached())
    {
        const auto &depthStencil = mState.mWebGLDepthStencilAttachment;
        setAttachmentImpl(context, depthStencil.type(), GL_DEPTH_ATTACHMENT,
                          getImageIndexIfTextureAttachment(depthStencil),
                          depthStencil.getResource(), numViews, baseViewIndex, multiviewLayout,
                          viewportOffsets);
        setAttachmentImpl(context, depthStencil.type(), GL_STENCIL_ATTACHMENT,
                          getImageIndexIfTextureAttachment(depthStencil),
                          depthStencil.getResource(), numViews, baseViewIndex, multiviewLayout,
                          viewportOffsets);
    }
    else
    {
        setAttachmentImpl(context, GL_NONE, GL_DEPTH_ATTACHMENT, ImageIndex(), nullptr, numViews,
                          baseViewIndex, multiviewLayout, viewportOffsets);
        setAttachmentImpl(context, GL_NONE, GL_STENCIL_ATTACHMENT, ImageIndex(), nullptr, numViews,
                          baseViewIndex, multiviewLayout, viewportOffsets);
    }
}

void Framebuffer::setAttachmentImpl(const Context *context,
                                    GLenum type,
                                    GLenum binding,
                                    const ImageIndex &textureIndex,
                                    FramebufferAttachmentObject *resource,
                                    GLsizei numViews,
                                    GLuint baseViewIndex,
                                    GLenum multiviewLayout,
                                    const GLint *viewportOffsets)
{
    switch (binding)
    {
        case GL_DEPTH_STENCIL:
        case GL_DEPTH_STENCIL_ATTACHMENT:
        {
            // ensure this is a legitimate depth+stencil format
            FramebufferAttachmentObject *attachmentObj = resource;
            if (resource)
            {
                const Format &format = resource->getAttachmentFormat(binding, textureIndex);
                if (format.info->depthBits == 0 || format.info->stencilBits == 0)
                {
                    // Attaching nullptr detaches the current attachment.
                    attachmentObj = nullptr;
                }
            }

            updateAttachment(context, &mState.mDepthAttachment, DIRTY_BIT_DEPTH_ATTACHMENT,
                             &mDirtyDepthAttachmentBinding, type, binding, textureIndex,
                             attachmentObj, numViews, baseViewIndex, multiviewLayout,
                             viewportOffsets);
            updateAttachment(context, &mState.mStencilAttachment, DIRTY_BIT_STENCIL_ATTACHMENT,
                             &mDirtyStencilAttachmentBinding, type, binding, textureIndex,
                             attachmentObj, numViews, baseViewIndex, multiviewLayout,
                             viewportOffsets);
            break;
        }

        case GL_DEPTH:
        case GL_DEPTH_ATTACHMENT:
            updateAttachment(context, &mState.mDepthAttachment, DIRTY_BIT_DEPTH_ATTACHMENT,
                             &mDirtyDepthAttachmentBinding, type, binding, textureIndex, resource,
                             numViews, baseViewIndex, multiviewLayout, viewportOffsets);
            break;

        case GL_STENCIL:
        case GL_STENCIL_ATTACHMENT:
            updateAttachment(context, &mState.mStencilAttachment, DIRTY_BIT_STENCIL_ATTACHMENT,
                             &mDirtyStencilAttachmentBinding, type, binding, textureIndex, resource,
                             numViews, baseViewIndex, multiviewLayout, viewportOffsets);
            break;

        case GL_BACK:
            updateAttachment(context, &mState.mColorAttachments[0], DIRTY_BIT_COLOR_ATTACHMENT_0,
                             &mDirtyColorAttachmentBindings[0], type, binding, textureIndex,
                             resource, numViews, baseViewIndex, multiviewLayout, viewportOffsets);
            break;

        default:
        {
            size_t colorIndex = binding - GL_COLOR_ATTACHMENT0;
            ASSERT(colorIndex < mState.mColorAttachments.size());
            size_t dirtyBit = DIRTY_BIT_COLOR_ATTACHMENT_0 + colorIndex;
            updateAttachment(context, &mState.mColorAttachments[colorIndex], dirtyBit,
                             &mDirtyColorAttachmentBindings[colorIndex], type, binding,
                             textureIndex, resource, numViews, baseViewIndex, multiviewLayout,
                             viewportOffsets);

            // TODO(jmadill): ASSERT instead of checking the attachment exists in
            // formsRenderingFeedbackLoopWith
            bool enabled = (type != GL_NONE && getDrawBufferState(colorIndex) != GL_NONE);
            mState.mEnabledDrawBuffers.set(colorIndex, enabled);
            mState.mDrawBufferTypeMask.setIndex(getDrawbufferWriteType(colorIndex), colorIndex);
        }
        break;
    }

    mAttachedTextures.reset();
}

void Framebuffer::updateAttachment(const Context *context,
                                   FramebufferAttachment *attachment,
                                   size_t dirtyBit,
                                   angle::ObserverBinding *onDirtyBinding,
                                   GLenum type,
                                   GLenum binding,
                                   const ImageIndex &textureIndex,
                                   FramebufferAttachmentObject *resource,
                                   GLsizei numViews,
                                   GLuint baseViewIndex,
                                   GLenum multiviewLayout,
                                   const GLint *viewportOffsets)
{
    attachment->attach(context, type, binding, textureIndex, resource, numViews, baseViewIndex,
                       multiviewLayout, viewportOffsets);
    mDirtyBits.set(dirtyBit);
    mState.mResourceNeedsInit.set(dirtyBit, attachment->initState() == InitState::MayNeedInit);
    onDirtyBinding->bind(resource ? resource->getSubject() : nullptr);

    invalidateCompletenessCache();
}

void Framebuffer::resetAttachment(const Context *context, GLenum binding)
{
    setAttachment(context, GL_NONE, binding, ImageIndex(), nullptr);
}

Error Framebuffer::syncState(const Context *context)
{
    if (mDirtyBits.any())
    {
        mDirtyBitsGuard = mDirtyBits;
        ANGLE_TRY(mImpl->syncState(context, mDirtyBits));
        mDirtyBits.reset();
        mDirtyBitsGuard.reset();
    }
    return NoError();
}

void Framebuffer::onSubjectStateChange(const Context *context,
                                       angle::SubjectIndex index,
                                       angle::SubjectMessage message)
{
    if (message == angle::SubjectMessage::DEPENDENT_DIRTY_BITS)
    {
        ASSERT(!mDirtyBitsGuard.valid() || mDirtyBitsGuard.value().test(index));
        mDirtyBits.set(index);
        context->getGLState().setFramebufferDirty(this);
        return;
    }

    // Only reset the cached status if this is not the default framebuffer.  The default framebuffer
    // will still use this channel to mark itself dirty.
    if (mState.mId != 0)
    {
        // TOOD(jmadill): Make this only update individual attachments to do less work.
        mCachedStatus.reset();
    }

    FramebufferAttachment *attachment = getAttachmentFromSubjectIndex(index);

    // Mark the appropriate init flag.
    mState.mResourceNeedsInit.set(index, attachment->initState() == InitState::MayNeedInit);
}

FramebufferAttachment *Framebuffer::getAttachmentFromSubjectIndex(angle::SubjectIndex index)
{
    switch (index)
    {
        case DIRTY_BIT_DEPTH_ATTACHMENT:
            return &mState.mDepthAttachment;
        case DIRTY_BIT_STENCIL_ATTACHMENT:
            return &mState.mStencilAttachment;
        default:
            size_t colorIndex = (index - DIRTY_BIT_COLOR_ATTACHMENT_0);
            ASSERT(colorIndex < mState.mColorAttachments.size());
            return &mState.mColorAttachments[colorIndex];
    }
}

bool Framebuffer::isComplete(const Context *context)
{
    return (checkStatus(context) == GL_FRAMEBUFFER_COMPLETE);
}

bool Framebuffer::formsRenderingFeedbackLoopWith(const State &state) const
{
    const Program *program = state.getProgram();

    // TODO(jmadill): Default framebuffer feedback loops.
    if (mState.mId == 0)
    {
        return false;
    }

    // The bitset will skip inactive draw buffers.
    for (size_t drawIndex : mState.mEnabledDrawBuffers)
    {
        const FramebufferAttachment &attachment = mState.mColorAttachments[drawIndex];
        ASSERT(attachment.isAttached());
        if (attachment.type() == GL_TEXTURE)
        {
            // Validate the feedback loop.
            if (program->samplesFromTexture(state, attachment.id()))
            {
                return true;
            }
        }
    }

    // Validate depth-stencil feedback loop.
    const auto &dsState = state.getDepthStencilState();

    // We can skip the feedback loop checks if depth/stencil is masked out or disabled.
    const FramebufferAttachment *depth = getDepthbuffer();
    if (depth && depth->type() == GL_TEXTURE && dsState.depthTest && dsState.depthMask)
    {
        if (program->samplesFromTexture(state, depth->id()))
        {
            return true;
        }
    }

    const FramebufferAttachment *stencil = getStencilbuffer();
    if (dsState.stencilTest && stencil)
    {
        GLuint stencilSize = stencil->getStencilSize();
        ASSERT(stencilSize <= 8);
        GLuint maxStencilValue = (1 << stencilSize) - 1;
        // We assume the front and back masks are the same for WebGL.
        ASSERT((dsState.stencilBackWritemask & maxStencilValue) ==
               (dsState.stencilWritemask & maxStencilValue));
        if (stencil->type() == GL_TEXTURE && dsState.stencilWritemask != 0)
        {
            // Skip the feedback loop check if depth/stencil point to the same resource.
            if (!depth || *stencil != *depth)
            {
                if (program->samplesFromTexture(state, stencil->id()))
                {
                    return true;
                }
            }
        }
    }

    return false;
}

bool Framebuffer::formsCopyingFeedbackLoopWith(GLuint copyTextureID,
                                               GLint copyTextureLevel,
                                               GLint copyTextureLayer) const
{
    if (mState.mId == 0)
    {
        // It seems impossible to form a texture copying feedback loop with the default FBO.
        return false;
    }

    const FramebufferAttachment *readAttachment = getReadColorbuffer();
    ASSERT(readAttachment);

    if (readAttachment->isTextureWithId(copyTextureID))
    {
        const auto &imageIndex = readAttachment->getTextureImageIndex();
        if (imageIndex.getLevelIndex() == copyTextureLevel)
        {
            // Check 3D/Array texture layers.
            return !imageIndex.hasLayer() || copyTextureLayer == ImageIndex::kEntireLevel ||
                   imageIndex.getLayerIndex() == copyTextureLayer;
        }
    }
    return false;
}

GLint Framebuffer::getDefaultWidth() const
{
    return mState.getDefaultWidth();
}

GLint Framebuffer::getDefaultHeight() const
{
    return mState.getDefaultHeight();
}

GLint Framebuffer::getDefaultSamples() const
{
    return mState.getDefaultSamples();
}

bool Framebuffer::getDefaultFixedSampleLocations() const
{
    return mState.getDefaultFixedSampleLocations();
}

GLint Framebuffer::getDefaultLayers() const
{
    return mState.getDefaultLayers();
}

void Framebuffer::setDefaultWidth(GLint defaultWidth)
{
    mState.mDefaultWidth = defaultWidth;
    mDirtyBits.set(DIRTY_BIT_DEFAULT_WIDTH);
    invalidateCompletenessCache();
}

void Framebuffer::setDefaultHeight(GLint defaultHeight)
{
    mState.mDefaultHeight = defaultHeight;
    mDirtyBits.set(DIRTY_BIT_DEFAULT_HEIGHT);
    invalidateCompletenessCache();
}

void Framebuffer::setDefaultSamples(GLint defaultSamples)
{
    mState.mDefaultSamples = defaultSamples;
    mDirtyBits.set(DIRTY_BIT_DEFAULT_SAMPLES);
    invalidateCompletenessCache();
}

void Framebuffer::setDefaultFixedSampleLocations(bool defaultFixedSampleLocations)
{
    mState.mDefaultFixedSampleLocations = defaultFixedSampleLocations;
    mDirtyBits.set(DIRTY_BIT_DEFAULT_FIXED_SAMPLE_LOCATIONS);
    invalidateCompletenessCache();
}

void Framebuffer::setDefaultLayers(GLint defaultLayers)
{
    mState.mDefaultLayers = defaultLayers;
    mDirtyBits.set(DIRTY_BIT_DEFAULT_LAYERS);
}

GLsizei Framebuffer::getNumViews() const
{
    return mState.getNumViews();
}

GLint Framebuffer::getBaseViewIndex() const
{
    return mState.getBaseViewIndex();
}

const std::vector<Offset> *Framebuffer::getViewportOffsets() const
{
    return mState.getViewportOffsets();
}

GLenum Framebuffer::getMultiviewLayout() const
{
    return mState.getMultiviewLayout();
}

Error Framebuffer::ensureClearAttachmentsInitialized(const Context *context, GLbitfield mask)
{
    const auto &glState = context->getGLState();
    if (!context->isRobustResourceInitEnabled() || glState.isRasterizerDiscardEnabled())
    {
        return NoError();
    }

    const BlendState &blend               = glState.getBlendState();
    const DepthStencilState &depthStencil = glState.getDepthStencilState();

    bool color   = (mask & GL_COLOR_BUFFER_BIT) != 0 && !IsColorMaskedOut(blend);
    bool depth   = (mask & GL_DEPTH_BUFFER_BIT) != 0 && !IsDepthMaskedOut(depthStencil);
    bool stencil = (mask & GL_STENCIL_BUFFER_BIT) != 0 && !IsStencilMaskedOut(depthStencil);

    if (!color && !depth && !stencil)
    {
        return NoError();
    }

    if (partialClearNeedsInit(context, color, depth, stencil))
    {
        ANGLE_TRY(ensureDrawAttachmentsInitialized(context));
    }

    // If the impl encounters an error during a a full (non-partial) clear, the attachments will
    // still be marked initialized. This simplifies design, allowing this method to be called before
    // the clear.
    markDrawAttachmentsInitialized(color, depth, stencil);

    return NoError();
}

Error Framebuffer::ensureClearBufferAttachmentsInitialized(const Context *context,
                                                           GLenum buffer,
                                                           GLint drawbuffer)
{
    if (!context->isRobustResourceInitEnabled() ||
        context->getGLState().isRasterizerDiscardEnabled() ||
        IsClearBufferMaskedOut(context, buffer))
    {
        return NoError();
    }

    if (partialBufferClearNeedsInit(context, buffer))
    {
        ANGLE_TRY(ensureBufferInitialized(context, buffer, drawbuffer));
    }

    // If the impl encounters an error during a a full (non-partial) clear, the attachments will
    // still be marked initialized. This simplifies design, allowing this method to be called before
    // the clear.
    markBufferInitialized(buffer, drawbuffer);

    return NoError();
}

Error Framebuffer::ensureDrawAttachmentsInitialized(const Context *context)
{
    if (!context->isRobustResourceInitEnabled())
    {
        return NoError();
    }

    // Note: we don't actually filter by the draw attachment enum. Just init everything.
    for (size_t bit : mState.mResourceNeedsInit)
    {
        switch (bit)
        {
            case DIRTY_BIT_DEPTH_ATTACHMENT:
                ANGLE_TRY(InitAttachment(context, &mState.mDepthAttachment));
                break;
            case DIRTY_BIT_STENCIL_ATTACHMENT:
                ANGLE_TRY(InitAttachment(context, &mState.mStencilAttachment));
                break;
            default:
                ANGLE_TRY(InitAttachment(context, &mState.mColorAttachments[bit]));
                break;
        }
    }

    mState.mResourceNeedsInit.reset();
    return NoError();
}

Error Framebuffer::ensureReadAttachmentInitialized(const Context *context, GLbitfield blitMask)
{
    if (!context->isRobustResourceInitEnabled() || mState.mResourceNeedsInit.none())
    {
        return NoError();
    }

    if ((blitMask & GL_COLOR_BUFFER_BIT) != 0 && mState.mReadBufferState != GL_NONE)
    {
        size_t readIndex = mState.getReadIndex();
        if (mState.mResourceNeedsInit[readIndex])
        {
            ANGLE_TRY(InitAttachment(context, &mState.mColorAttachments[readIndex]));
            mState.mResourceNeedsInit.reset(readIndex);
        }
    }

    if ((blitMask & GL_DEPTH_BUFFER_BIT) != 0 && hasDepth())
    {
        if (mState.mResourceNeedsInit[DIRTY_BIT_DEPTH_ATTACHMENT])
        {
            ANGLE_TRY(InitAttachment(context, &mState.mDepthAttachment));
            mState.mResourceNeedsInit.reset(DIRTY_BIT_DEPTH_ATTACHMENT);
        }
    }

    if ((blitMask & GL_STENCIL_BUFFER_BIT) != 0 && hasStencil())
    {
        if (mState.mResourceNeedsInit[DIRTY_BIT_STENCIL_ATTACHMENT])
        {
            ANGLE_TRY(InitAttachment(context, &mState.mStencilAttachment));
            mState.mResourceNeedsInit.reset(DIRTY_BIT_STENCIL_ATTACHMENT);
        }
    }

    return NoError();
}

void Framebuffer::markDrawAttachmentsInitialized(bool color, bool depth, bool stencil)
{
    // Mark attachments as initialized.
    if (color)
    {
        for (auto colorIndex : mState.mEnabledDrawBuffers)
        {
            auto &colorAttachment = mState.mColorAttachments[colorIndex];
            ASSERT(colorAttachment.isAttached());
            colorAttachment.setInitState(InitState::Initialized);
            mState.mResourceNeedsInit.reset(colorIndex);
        }
    }

    if (depth && mState.mDepthAttachment.isAttached())
    {
        mState.mDepthAttachment.setInitState(InitState::Initialized);
        mState.mResourceNeedsInit.reset(DIRTY_BIT_DEPTH_ATTACHMENT);
    }

    if (stencil && mState.mStencilAttachment.isAttached())
    {
        mState.mStencilAttachment.setInitState(InitState::Initialized);
        mState.mResourceNeedsInit.reset(DIRTY_BIT_STENCIL_ATTACHMENT);
    }
}

void Framebuffer::markBufferInitialized(GLenum bufferType, GLint bufferIndex)
{
    switch (bufferType)
    {
        case GL_COLOR:
        {
            ASSERT(bufferIndex < static_cast<GLint>(mState.mColorAttachments.size()));
            if (mState.mColorAttachments[bufferIndex].isAttached())
            {
                mState.mColorAttachments[bufferIndex].setInitState(InitState::Initialized);
                mState.mResourceNeedsInit.reset(bufferIndex);
            }
            break;
        }
        case GL_DEPTH:
        {
            if (mState.mDepthAttachment.isAttached())
            {
                mState.mDepthAttachment.setInitState(InitState::Initialized);
                mState.mResourceNeedsInit.reset(DIRTY_BIT_DEPTH_ATTACHMENT);
            }
            break;
        }
        case GL_STENCIL:
        {
            if (mState.mStencilAttachment.isAttached())
            {
                mState.mStencilAttachment.setInitState(InitState::Initialized);
                mState.mResourceNeedsInit.reset(DIRTY_BIT_STENCIL_ATTACHMENT);
            }
            break;
        }
        case GL_DEPTH_STENCIL:
        {
            if (mState.mDepthAttachment.isAttached())
            {
                mState.mDepthAttachment.setInitState(InitState::Initialized);
                mState.mResourceNeedsInit.reset(DIRTY_BIT_DEPTH_ATTACHMENT);
            }
            if (mState.mStencilAttachment.isAttached())
            {
                mState.mStencilAttachment.setInitState(InitState::Initialized);
                mState.mResourceNeedsInit.reset(DIRTY_BIT_STENCIL_ATTACHMENT);
            }
            break;
        }
        default:
            UNREACHABLE();
            break;
    }
}

Box Framebuffer::getDimensions() const
{
    return mState.getDimensions();
}

Error Framebuffer::ensureBufferInitialized(const Context *context,
                                           GLenum bufferType,
                                           GLint bufferIndex)
{
    ASSERT(context->isRobustResourceInitEnabled());

    if (mState.mResourceNeedsInit.none())
    {
        return NoError();
    }

    switch (bufferType)
    {
        case GL_COLOR:
        {
            ASSERT(bufferIndex < static_cast<GLint>(mState.mColorAttachments.size()));
            if (mState.mResourceNeedsInit[bufferIndex])
            {
                ANGLE_TRY(InitAttachment(context, &mState.mColorAttachments[bufferIndex]));
                mState.mResourceNeedsInit.reset(bufferIndex);
            }
            break;
        }
        case GL_DEPTH:
        {
            if (mState.mResourceNeedsInit[DIRTY_BIT_DEPTH_ATTACHMENT])
            {
                ANGLE_TRY(InitAttachment(context, &mState.mDepthAttachment));
                mState.mResourceNeedsInit.reset(DIRTY_BIT_DEPTH_ATTACHMENT);
            }
            break;
        }
        case GL_STENCIL:
        {
            if (mState.mResourceNeedsInit[DIRTY_BIT_STENCIL_ATTACHMENT])
            {
                ANGLE_TRY(InitAttachment(context, &mState.mStencilAttachment));
                mState.mResourceNeedsInit.reset(DIRTY_BIT_STENCIL_ATTACHMENT);
            }
            break;
        }
        case GL_DEPTH_STENCIL:
        {
            if (mState.mResourceNeedsInit[DIRTY_BIT_DEPTH_ATTACHMENT])
            {
                ANGLE_TRY(InitAttachment(context, &mState.mDepthAttachment));
                mState.mResourceNeedsInit.reset(DIRTY_BIT_DEPTH_ATTACHMENT);
            }
            if (mState.mResourceNeedsInit[DIRTY_BIT_STENCIL_ATTACHMENT])
            {
                ANGLE_TRY(InitAttachment(context, &mState.mStencilAttachment));
                mState.mResourceNeedsInit.reset(DIRTY_BIT_STENCIL_ATTACHMENT);
            }
            break;
        }
        default:
            UNREACHABLE();
            break;
    }

    return NoError();
}

bool Framebuffer::partialBufferClearNeedsInit(const Context *context, GLenum bufferType)
{
    if (!context->isRobustResourceInitEnabled() || mState.mResourceNeedsInit.none())
    {
        return false;
    }

    switch (bufferType)
    {
        case GL_COLOR:
            return partialClearNeedsInit(context, true, false, false);
        case GL_DEPTH:
            return partialClearNeedsInit(context, false, true, false);
        case GL_STENCIL:
            return partialClearNeedsInit(context, false, false, true);
        case GL_DEPTH_STENCIL:
            return partialClearNeedsInit(context, false, true, true);
        default:
            UNREACHABLE();
            return false;
    }
}

bool Framebuffer::hasTextureAttachment(const Texture *texture) const
{
    if (!mAttachedTextures.valid())
    {
        std::set<const FramebufferAttachmentObject *> attachedTextures;

        for (const auto &colorAttachment : mState.mColorAttachments)
        {
            if (colorAttachment.isAttached() && colorAttachment.type() == GL_TEXTURE)
            {
                attachedTextures.insert(colorAttachment.getResource());
            }
        }

        if (mState.mDepthAttachment.isAttached() && mState.mDepthAttachment.type() == GL_TEXTURE)
        {
            attachedTextures.insert(mState.mDepthAttachment.getResource());
        }

        if (mState.mStencilAttachment.isAttached() &&
            mState.mStencilAttachment.type() == GL_TEXTURE)
        {
            attachedTextures.insert(mState.mStencilAttachment.getResource());
        }

        mAttachedTextures = std::move(attachedTextures);
    }

    return (mAttachedTextures.value().count(texture) > 0);
}

}  // namespace gl
kc3-lang/angle/src/libANGLE/Framebuffer.cpp

Commit

kc3-lang/angle /src/libANGLE/Framebuffer.cpp
