/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "ShareableCanvasRenderer.h"

#include "GLContext.h"                  // for GLContext

#include "GLScreenBuffer.h"             // for GLScreenBuffer

#include "SharedSurfaceGL.h"            // for SurfaceFactory_GLTexture, etc

#include "gfxUtils.h"

#include "mozilla/gfx/2D.h"

#include "mozilla/layers/AsyncCanvasRenderer.h"

#include "mozilla/layers/TextureClientSharedSurface.h"

#include "mozilla/layers/CompositableForwarder.h"

using namespace mozilla::gfx;

namespace mozilla {

namespace layers {

ShareableCanvasRenderer::ShareableCanvasRenderer()

  : mCanvasClient(nullptr)

  , mFactory(nullptr)

  , mFlags(TextureFlags::NO_FLAGS)

{

  MOZ_COUNT_CTOR(ShareableCanvasRenderer);

}

ShareableCanvasRenderer::~ShareableCanvasRenderer()

{

  MOZ_COUNT_DTOR(ShareableCanvasRenderer);

  Destroy();

}

void

ShareableCanvasRenderer::Initialize(const CanvasInitializeData& aData)

{

  CopyableCanvasRenderer::Initialize(aData);

  mCanvasClient = nullptr;

  if (!mGLContext)

    return;

  gl::GLScreenBuffer* screen = mGLContext->Screen();

  gl::SurfaceCaps caps;

  if (mGLFrontbuffer) {

    // The screen caps are irrelevant if we're using a separate frontbuffer.

    caps = mGLFrontbuffer->mHasAlpha ? gl::SurfaceCaps::ForRGBA()

                                     : gl::SurfaceCaps::ForRGB();

  } else {

    MOZ_ASSERT(screen);

    caps = screen->mCaps;

  }

  auto forwarder = GetForwarder();

  mFlags = TextureFlags::ORIGIN_BOTTOM_LEFT;

  if (!aData.mIsGLAlphaPremult) {

    mFlags |= TextureFlags::NON_PREMULTIPLIED;

  }

  UniquePtr<gl::SurfaceFactory> factory =

    gl::GLScreenBuffer::CreateFactory(mGLContext, caps, forwarder, mFlags);

  if (mGLFrontbuffer) {

    // We're using a source other than the one in the default screen.

    // (SkiaGL)

    mFactory = std::move(factory);

    if (!mFactory) {

      // Absolutely must have a factory here, so create a basic one

      mFactory = MakeUnique<gl::SurfaceFactory_Basic>(mGLContext, caps, mFlags);

    }

  } else {

    if (factory)

      screen->Morph(std::move(factory));

  }

}

void

ShareableCanvasRenderer::ClearCachedResources()

{

  CopyableCanvasRenderer::ClearCachedResources();

  if (mCanvasClient) {

    mCanvasClient->Clear();

  }

}

void

ShareableCanvasRenderer::Destroy()

{

  CopyableCanvasRenderer::Destroy();

  if (mCanvasClient) {

    mCanvasClient->OnDetach();

    mCanvasClient = nullptr;

  }

}

bool

ShareableCanvasRenderer::UpdateTarget(DrawTarget* aDestTarget)

{

  MOZ_ASSERT(aDestTarget);

  if (!aDestTarget) {

    return false;

  }

  RefPtr<SourceSurface> surface;

  if (!mGLContext) {

    AutoReturnSnapshot autoReturn;

    if (mAsyncRenderer) {

      surface = mAsyncRenderer->GetSurface();

    } else if (mBufferProvider) {

      surface = mBufferProvider->BorrowSnapshot();

      autoReturn.mSnapshot = &surface;

      autoReturn.mBufferProvider = mBufferProvider;

    }

    MOZ_ASSERT(surface);

    if (!surface) {

      return false;

    }

    aDestTarget->CopySurface(surface,

                             IntRect(0, 0, mSize.width, mSize.height),

                             IntPoint(0, 0));

    return true;

  }

  gl::SharedSurface* frontbuffer = nullptr;

  if (mGLFrontbuffer) {

    frontbuffer = mGLFrontbuffer.get();

  } else {

    gl::GLScreenBuffer* screen = mGLContext->Screen();

    const auto& front = screen->Front();

    if (front) {

      frontbuffer = front->Surf();

    }

  }

  if (!frontbuffer) {

    NS_WARNING("Null frame received.");

    return false;

  }

  IntSize readSize(frontbuffer->mSize);

  SurfaceFormat format =

    mOpaque ? SurfaceFormat::B8G8R8X8 : SurfaceFormat::B8G8R8A8;

  bool needsPremult = frontbuffer->mHasAlpha && !mIsAlphaPremultiplied;

  // Try to read back directly into aDestTarget's output buffer

  uint8_t* destData;

  IntSize destSize;

  int32_t destStride;

  SurfaceFormat destFormat;

  if (aDestTarget->LockBits(&destData, &destSize, &destStride, &destFormat)) {

    if (destSize == readSize && destFormat == format) {

      RefPtr<DataSourceSurface> data =

        Factory::CreateWrappingDataSourceSurface(destData, destStride, destSize, destFormat);

      if (!mGLContext->Readback(frontbuffer, data)) {

        aDestTarget->ReleaseBits(destData);

        return false;

      }

      if (needsPremult) {

        gfxUtils::PremultiplyDataSurface(data, data);

      }

      aDestTarget->ReleaseBits(destData);

      return true;

    }

    aDestTarget->ReleaseBits(destData);

  }

  RefPtr<DataSourceSurface> resultSurf = GetTempSurface(readSize, format);

  // There will already be a warning from inside of GetTempSurface, but

  // it doesn't hurt to complain:

  if (NS_WARN_IF(!resultSurf)) {

    return false;

  }

  // Readback handles Flush/MarkDirty.

  if (!mGLContext->Readback(frontbuffer, resultSurf)) {

    return false;

  }

  if (needsPremult) {

    gfxUtils::PremultiplyDataSurface(resultSurf, resultSurf);

  }

  aDestTarget->CopySurface(resultSurf,

                           IntRect(0, 0, readSize.width, readSize.height),

                           IntPoint(0, 0));

  return true;

}

CanvasClient::CanvasClientType

ShareableCanvasRenderer::GetCanvasClientType()

{

  if (mAsyncRenderer) {

    return CanvasClient::CanvasClientAsync;

  }

  if (mGLContext) {

    return CanvasClient::CanvasClientTypeShSurf;

  }

  return CanvasClient::CanvasClientSurface;

}

void

ShareableCanvasRenderer::UpdateCompositableClient()

{

  if (!CreateCompositable()) {

    return;

  }

  if (mCanvasClient && mAsyncRenderer) {

    mCanvasClient->UpdateAsync(mAsyncRenderer);

  }

  if (!IsDirty()) {

    return;

  }

  ResetDirty();

  FirePreTransactionCallback();

  if (mBufferProvider && mBufferProvider->GetTextureClient()) {

    if (!mBufferProvider->SetKnowsCompositor(GetForwarder())) {

      gfxCriticalNote << "BufferProvider::SetForwarder failed";

      return;

    }

    mCanvasClient->UpdateFromTexture(mBufferProvider->GetTextureClient());

  } else {

    mCanvasClient->Update(gfx::IntSize(mSize.width, mSize.height), this);

  }

  FireDidTransactionCallback();

  mCanvasClient->Updated();

}

} // namespace layers

} // namespace mozilla