/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* 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 "LayerManagerMLGPU.h"
#include "LayerTreeInvalidation.h"
#include "PaintedLayerMLGPU.h"
#include "ImageLayerMLGPU.h"
#include "CanvasLayerMLGPU.h"
#include "GeckoProfiler.h"              // for profiler_*
#include "MLGDevice.h"
#include "RenderPassMLGPU.h"
#include "RenderViewMLGPU.h"
#include "ShaderDefinitionsMLGPU.h"
#include "SharedBufferMLGPU.h"
#include "UnitTransforms.h"
#include "TextureSourceProviderMLGPU.h"
#include "TreeTraversal.h"
#include "FrameBuilder.h"
#include "LayersLogging.h"
#include "UtilityMLGPU.h"
#include "mozilla/layers/Diagnostics.h"
#include "mozilla/layers/TextRenderer.h"

#ifdef XP_WIN
#include "mozilla/widget/WinCompositorWidget.h"
#include "mozilla/gfx/DeviceManagerDx.h"
#endif

using namespace std;

namespace mozilla {
namespace layers {

using namespace gfx;

static const int kDebugOverlayX = 2;
static const int kDebugOverlayY = 5;
static const int kDebugOverlayMaxWidth = 600;
static const int kDebugOverlayMaxHeight = 96;

LayerManagerMLGPU::LayerManagerMLGPU(widget::CompositorWidget* aWidget)
 : mWidget(aWidget),
   mDrawDiagnostics(false),
   mUsingInvalidation(false),
   mCurrentFrame(nullptr)
{
  if (!aWidget) {
    return;
  }

#ifdef WIN32
  mDevice = DeviceManagerDx::Get()->GetMLGDevice();
#endif
  if (!mDevice || !mDevice->IsValid()) {
    gfxWarning() << "Could not acquire an MLGDevice!";
    return;
  }

  mSwapChain = mDevice->CreateSwapChainForWidget(aWidget);
  if (!mSwapChain) {
    gfxWarning() << "Could not acquire an MLGSwapChain!";
    return;
  }

  mDiagnostics = MakeUnique<Diagnostics>();
  mTextRenderer = new TextRenderer();
}

LayerManagerMLGPU::~LayerManagerMLGPU()
{
  if (mTextureSourceProvider) {
    mTextureSourceProvider->Destroy();
  }
}

bool
LayerManagerMLGPU::Initialize()
{
  if (!mDevice || !mSwapChain) {
    return false;
  }

  mTextureSourceProvider = new TextureSourceProviderMLGPU(this, mDevice);
  return true;
}

void
LayerManagerMLGPU::Destroy()
{
  if (IsDestroyed()) {
    return;
  }

  LayerManager::Destroy();

  if (mDevice && mDevice->IsValid()) {
    mDevice->Flush();
  }
  if (mSwapChain) {
    mSwapChain->Destroy();
    mSwapChain = nullptr;
  }
  if (mTextureSourceProvider) {
    mTextureSourceProvider->Destroy();
    mTextureSourceProvider = nullptr;
  }
  mWidget = nullptr;
  mDevice = nullptr;
}

void
LayerManagerMLGPU::ForcePresent()
{
  if (!mDevice->IsValid()) {
    return;
  }

  IntSize windowSize = mWidget->GetClientSize().ToUnknownSize();
  if (mSwapChain->GetSize() != windowSize) {
    return;
  }

  mSwapChain->ForcePresent();
}

already_AddRefed<ContainerLayer>
LayerManagerMLGPU::CreateContainerLayer()
{
  return MakeAndAddRef<ContainerLayerMLGPU>(this);
}

already_AddRefed<ColorLayer>
LayerManagerMLGPU::CreateColorLayer()
{
  return MakeAndAddRef<ColorLayerMLGPU>(this);
}

already_AddRefed<RefLayer>
LayerManagerMLGPU::CreateRefLayer()
{
  return MakeAndAddRef<RefLayerMLGPU>(this);
}

already_AddRefed<PaintedLayer>
LayerManagerMLGPU::CreatePaintedLayer()
{
  return MakeAndAddRef<PaintedLayerMLGPU>(this);
}

already_AddRefed<ImageLayer>
LayerManagerMLGPU::CreateImageLayer()
{
  return MakeAndAddRef<ImageLayerMLGPU>(this);
}

already_AddRefed<BorderLayer>
LayerManagerMLGPU::CreateBorderLayer()
{
  MOZ_ASSERT_UNREACHABLE("Not yet implemented");
  return nullptr;
}

already_AddRefed<TextLayer>
LayerManagerMLGPU::CreateTextLayer()
{
  MOZ_ASSERT_UNREACHABLE("Not yet implemented");
  return nullptr;
}

already_AddRefed<CanvasLayer>
LayerManagerMLGPU::CreateCanvasLayer()
{
  return MakeAndAddRef<CanvasLayerMLGPU>(this);
}

TextureFactoryIdentifier
LayerManagerMLGPU::GetTextureFactoryIdentifier()
{
  TextureFactoryIdentifier ident;
  if (mDevice) {
    ident = mDevice->GetTextureFactoryIdentifier();
  }
  ident.mSupportsBackdropCopyForComponentAlpha = SupportsBackdropCopyForComponentAlpha();
  return ident;
}

LayersBackend
LayerManagerMLGPU::GetBackendType()
{
  return mDevice ? mDevice->GetLayersBackend() : LayersBackend::LAYERS_NONE;
}

bool
LayerManagerMLGPU::BeginTransaction()
{
  MOZ_ASSERT(!mTarget);
  return true;
}

void
LayerManagerMLGPU::BeginTransactionWithDrawTarget(gfx::DrawTarget* aTarget,
                                                  const gfx::IntRect& aRect)
{
  MOZ_ASSERT(!mTarget);

  mTarget = aTarget;
  mTargetRect = aRect;
  return;
}

// Helper class for making sure textures are unlocked.
class MOZ_STACK_CLASS AutoUnlockAllTextures
{
public:
  explicit AutoUnlockAllTextures(MLGDevice* aDevice)
   : mDevice(aDevice)
  {}
  ~AutoUnlockAllTextures() {
    mDevice->UnlockAllTextures();
  }

private:
  RefPtr<MLGDevice> mDevice;
};

void
LayerManagerMLGPU::EndTransaction(const TimeStamp& aTimeStamp, EndTransactionFlags aFlags)
{
  PROFILER_LABEL("LayerManager", "EndTransaction",
    js::ProfileEntry::Category::GRAPHICS);

  SetCompositionTime(aTimeStamp);

  TextureSourceProvider::AutoReadUnlockTextures unlock(mTextureSourceProvider);

  if (!mRoot || (aFlags & END_NO_IMMEDIATE_REDRAW) || !mWidget) {
    return;
  }

  mCompositionStartTime = TimeStamp::Now();

  IntSize windowSize = mWidget->GetClientSize().ToUnknownSize();
  if (windowSize.IsEmpty()) {
    return;
  }

  // Resize the window if needed.
  if (mSwapChain->GetSize() != windowSize) {
    // Note: all references to the backbuffer must be cleared.
    mDevice->SetRenderTarget(nullptr);
    if (!mSwapChain->ResizeBuffers(windowSize)) {
      gfxCriticalNote << "Could not resize the swapchain (" <<
        hexa(windowSize.width) << "," << hexa(windowSize.height) << ")";
      return;
    }
  }

  mDrawDiagnostics = gfxPrefs::LayersDrawFPS();
  mUsingInvalidation = gfxPrefs::AdvancedLayersUseInvalidation();

  // Compute transforms - and the changed area, if enabled.
  mRoot->ComputeEffectiveTransforms(Matrix4x4());
  ComputeInvalidRegion();

  // Build and execute draw commands, and present.
  if (PreRender()) {
    Composite();
    PostRender();
  }

  // Finish composition.
  mLastCompositionEndTime = TimeStamp::Now();
}

void
LayerManagerMLGPU::Composite()
{
  PROFILER_LABEL("LayerManagerMLGPU", "Composite",
    js::ProfileEntry::Category::GRAPHICS);

  // Don't composite if we're minimized/hidden, or if there is nothing to draw.
  if (mWidget->IsHidden()) {
    return;
  }

  // Make sure the diagnostic area gets invalidated. We do this now, rather than
  // earlier, so we don't accidentally cause extra composites.
  Maybe<IntRect> diagnosticRect;
  if (mDrawDiagnostics) {
    diagnosticRect = Some(IntRect(
      kDebugOverlayX, kDebugOverlayY,
      kDebugOverlayMaxWidth, kDebugOverlayMaxHeight));
  }

  AL_LOG("Computed invalid region: %s\n", Stringify(mInvalidRegion).c_str());

  // Now that we have the final invalid region, give it to the swap chain which
  // will tell us if we still need to render.
  if (!mSwapChain->ApplyNewInvalidRegion(Move(mInvalidRegion), diagnosticRect)) {
    return;
  }

  AutoUnlockAllTextures autoUnlock(mDevice);

  mDevice->BeginFrame();

  RenderLayers();

  if (mDrawDiagnostics) {
    DrawDebugOverlay();
  }

  if (mTarget) {
    mSwapChain->CopyBackbuffer(mTarget, mTargetRect);
    mTarget = nullptr;
    mTargetRect = IntRect();
  }
  mSwapChain->Present();

  // We call this here to mimic the behavior in LayerManagerComposite, as to
  // not change what Talos measures. That is, we do not record an empty frame
  // as a frame, since we short-circuit at the top of this function.
  RecordFrame();

  mDevice->EndFrame();
}

void
LayerManagerMLGPU::RenderLayers()
{
  PROFILER_LABEL("LayerManagerMLGPU", "RenderLayers",
    js::ProfileEntry::Category::GRAPHICS);

  // Traverse the layer tree and assign each layer to a render target.
  FrameBuilder builder(this, mSwapChain);
  mCurrentFrame = &builder;

  if (!builder.Build()) {
    return;
  }

  if (mDrawDiagnostics) {
    mDiagnostics->RecordPrepareTime((TimeStamp::Now() - mCompositionStartTime).ToMilliseconds());
  }

  // Make sure we acquire/release the sync object.
  if (!mDevice->Synchronize()) {
    // Catastrophic failure - probably a device reset.
    return;
  }

  TimeStamp start = TimeStamp::Now();

  // Upload shared buffers.
  mDevice->FinishSharedBufferUse();

  // Prepare the pipeline.
  if (mDrawDiagnostics) {
    IntSize size = mSwapChain->GetBackBufferInvalidRegion().GetBounds().Size();
    uint32_t numPixels = size.width * size.height;
    mDevice->StartDiagnostics(numPixels);
  }

  // Execute all render passes.
  builder.Render();
  mCurrentFrame = nullptr;

  if (mDrawDiagnostics) {
    mDiagnostics->RecordCompositeTime((TimeStamp::Now() - start).ToMilliseconds());
    mDevice->EndDiagnostics();
  }
}

void
LayerManagerMLGPU::DrawDebugOverlay()
{
  IntSize windowSize = mSwapChain->GetSize();

  GPUStats stats;
  mDevice->GetDiagnostics(&stats);
  stats.mScreenPixels = windowSize.width * windowSize.height;

  std::string text = mDiagnostics->GetFrameOverlayString(stats);
  RefPtr<TextureSource> texture = mTextRenderer->RenderText(
    mTextureSourceProvider,
    text,
    30,
    600,
    TextRenderer::FontType::FixedWidth);
  if (!texture) {
    return;
  }

  if (mUsingInvalidation &&
      (texture->GetSize().width > kDebugOverlayMaxWidth ||
       texture->GetSize().height > kDebugOverlayMaxHeight))
  {
    gfxCriticalNote << "Diagnostic overlay exceeds invalidation area: %s" << Stringify(texture->GetSize()).c_str();
  }

  struct DebugRect {
    Rect bounds;
    Rect texCoords;
  };

  if (!mDiagnosticVertices) {
    DebugRect rect;
    rect.bounds = Rect(Point(kDebugOverlayX, kDebugOverlayY), Size(texture->GetSize()));
    rect.texCoords = Rect(0.0, 0.0, 1.0, 1.0);

    VertexStagingBuffer instances;
    if (!instances.AppendItem(rect)) {
      return;
    }

    mDiagnosticVertices = mDevice->CreateBuffer(
      MLGBufferType::Vertex,
      instances.NumItems() * instances.SizeOfItem(),
      MLGUsage::Immutable,
      instances.GetBufferStart());
    if (!mDiagnosticVertices) {
      return;
    }
  }

  // Note: we rely on the world transform being correctly left bound by the
  // outermost render view.
  mDevice->SetScissorRect(Nothing());
  mDevice->SetDepthTestMode(MLGDepthTestMode::Disabled);
  mDevice->SetTopology(MLGPrimitiveTopology::UnitQuad);
  mDevice->SetVertexShader(VertexShaderID::DiagnosticText);
  mDevice->SetVertexBuffer(1, mDiagnosticVertices, sizeof(DebugRect));
  mDevice->SetPixelShader(PixelShaderID::DiagnosticText);
  mDevice->SetBlendState(MLGBlendState::Over);
  mDevice->SetPSTexture(0, texture);
  mDevice->SetSamplerMode(0, SamplerMode::Point);
  mDevice->DrawInstanced(4, 1, 0, 0);
}

void
LayerManagerMLGPU::ComputeInvalidRegion()
{
  // If invalidation is disabled, throw away cloned properties and redraw the
  // whole target area.
  if (!mUsingInvalidation) {
    mInvalidRegion = mTarget ? mTargetRect : mRenderBounds;
    mNextFrameInvalidRegion.SetEmpty();
    return;
  }

  nsIntRegion changed;
  if (mClonedLayerTreeProperties) {
    changed = mClonedLayerTreeProperties->ComputeDifferences(mRoot, nullptr);
  } else {
    changed = mRenderBounds;
  }

  // We compute the change region, but if we're painting to a target, we save
  // it for the next frame instead.
  if (mTarget) {
    mInvalidRegion = mTargetRect;
    mNextFrameInvalidRegion.OrWith(changed);
  } else {
    mInvalidRegion = Move(mNextFrameInvalidRegion);
    mInvalidRegion.OrWith(changed);
  }

  // Free the old cloned property tree, then clone a new one. Note that we do
  // this before compositing since our CPU-based occlusion culling will update
  // the visible region to contain non-occluded draw rects. If a layer will not
  // be drawn, it will have no visible region. LTI might save this, and if the
  // layer is removed next frame, LTI will invalidate the wrong area.
  //
  // Instead, we always invalidate based on the full shadow tree.
  //
  // Note that the old compositor performs CPU-based occlusion culling *before*
  // invalidation. This maintains consistency, but we have more accurate draw
  // regions.
  mClonedLayerTreeProperties = nullptr;
  mClonedLayerTreeProperties = LayerProperties::CloneFrom(mRoot);
}

void
LayerManagerMLGPU::AddInvalidRegion(const nsIntRegion& aRegion)
{
  mNextFrameInvalidRegion.OrWith(aRegion);
}

TextureSourceProvider*
LayerManagerMLGPU::GetTextureSourceProvider() const
{
  return mTextureSourceProvider;
}

bool
LayerManagerMLGPU::IsCompositingToScreen() const
{
  return !mTarget;
}

bool
LayerManagerMLGPU::AreComponentAlphaLayersEnabled()
{
  return LayerManager::AreComponentAlphaLayersEnabled();
}

bool
LayerManagerMLGPU::BlendingRequiresIntermediateSurface()
{
  return true;
}

bool
LayerManagerMLGPU::SupportsBackdropCopyForComponentAlpha()
{
  return false;
}

void
LayerManagerMLGPU::EndTransaction(DrawPaintedLayerCallback aCallback,
                                  void* aCallbackData,
                                  EndTransactionFlags aFlags)
{
  MOZ_CRASH("GFX: Use EndTransaction(aTimeStamp)");
}

void
LayerManagerMLGPU::ClearCachedResources(Layer* aSubtree)
{
  Layer* root = aSubtree ? aSubtree : mRoot.get();
  if (!root) {
    return;
  }

  ForEachNode<ForwardIterator>(root, [](Layer* aLayer) {
    LayerMLGPU* layer = aLayer->AsHostLayer()->AsLayerMLGPU();
    if (!layer) {
      return;
    }
    layer->ClearCachedResources();
  });
}

void
LayerManagerMLGPU::NotifyShadowTreeTransaction()
{
  if (gfxPrefs::LayersDrawFPS()) {
    mDiagnostics->AddTxnFrame();
  }
}

void
LayerManagerMLGPU::UpdateRenderBounds(const gfx::IntRect& aRect)
{
  mRenderBounds = aRect;
}

bool
LayerManagerMLGPU::PreRender()
{
  PROFILER_LABEL("LayerManagerMLGPU", "PreRender",
    js::ProfileEntry::Category::GRAPHICS);

  widget::WidgetRenderingContext context;
  if (!mWidget->PreRender(&context)) {
    return false;
  }
  mWidgetContext = Some(context);
  return true;
}

void
LayerManagerMLGPU::PostRender()
{
  mWidget->PostRender(mWidgetContext.ptr());
  mWidgetContext = Nothing();
}

} // namespace layers
} // namespace mozilla