From d31c311fdaaa205acfbd66844a3c6ee194784921 Mon Sep 17 00:00:00 2001
From: Barret Rennie <barret@brennie.ca>
Date: Tue, 19 Feb 2019 14:54:12 +0000
Subject: [PATCH] Bug 1444449 - Implement
 CompositorD3D11::GetWindowRenderTarget API r=mstange,bas

Differential Revision: https://phabricator.services.mozilla.com/D18145

--HG--
extra : moz-landing-system : lando
---
 gfx/layers/d3d11/CompositorD3D11.cpp | 55 ++++++++++++++++++++++++++++
 gfx/layers/d3d11/CompositorD3D11.h   |  3 ++
 2 files changed, 58 insertions(+)

diff --git a/gfx/layers/d3d11/CompositorD3D11.cpp b/gfx/layers/d3d11/CompositorD3D11.cpp
index bd00ca1a7abe..f30e45b858f5 100644
--- a/gfx/layers/d3d11/CompositorD3D11.cpp
+++ b/gfx/layers/d3d11/CompositorD3D11.cpp
@@ -50,6 +50,7 @@ const FLOAT sBlendFactor[] = {0, 0, 0, 0};
 CompositorD3D11::CompositorD3D11(CompositorBridgeParent* aParent,
                                  widget::CompositorWidget* aWidget)
     : Compositor(aWidget, aParent),
+      mWindowRTCopy(nullptr),
       mAttachments(nullptr),
       mHwnd(nullptr),
       mDisableSequenceForNextFrame(false),
@@ -397,6 +398,55 @@ CompositorD3D11::CreateRenderTargetFromSource(
   return rt.forget();
 }
 
+already_AddRefed<CompositingRenderTarget>
+CompositorD3D11::GetWindowRenderTarget() const {
+#ifndef MOZ_GECKO_PROFILER
+  return nullptr;
+#else
+  if (!profiler_feature_active(ProfilerFeature::Screenshots)) {
+    return nullptr;
+  }
+
+  if (!mDefaultRT) {
+    return nullptr;
+  }
+
+  const IntSize size = mDefaultRT->GetSize();
+
+  RefPtr<ID3D11Texture2D> rtTexture;
+
+  if (!mWindowRTCopy || mWindowRTCopy->GetSize() != size) {
+    /*
+     * The compositor screenshots infrastructure is going to scale down the
+     * render target returned by this method. However, mDefaultRT does not
+     * contain a texture created wth the D3D11_BIND_SHADER_RESOURCE flag, so if
+     * we were to simply return mDefaultRT then scaling would fail.
+     */
+    CD3D11_TEXTURE2D_DESC desc(DXGI_FORMAT_B8G8R8A8_UNORM, size.width,
+                               size.height, 1, 1, D3D11_BIND_SHADER_RESOURCE);
+
+    HRESULT hr =
+        mDevice->CreateTexture2D(&desc, nullptr, getter_AddRefs(rtTexture));
+    if (FAILED(hr)) {
+      return nullptr;
+    }
+
+    mWindowRTCopy = MakeRefPtr<CompositingRenderTargetD3D11>(
+        rtTexture, IntPoint(0, 0), DXGI_FORMAT_B8G8R8A8_UNORM);
+    mWindowRTCopy->SetSize(size);
+  } else {
+    rtTexture = mWindowRTCopy->GetD3D11Texture();
+  }
+
+  const RefPtr<ID3D11Texture2D> sourceTexture = mDefaultRT->GetD3D11Texture();
+  mContext->CopyResource(rtTexture, sourceTexture);
+
+  return RefPtr<CompositingRenderTarget>(
+             static_cast<CompositingRenderTarget*>(mWindowRTCopy))
+      .forget();
+#endif
+}
+
 bool CompositorD3D11::CopyBackdrop(const gfx::IntRect& aRect,
                                    RefPtr<ID3D11Texture2D>* aOutTexture,
                                    RefPtr<ID3D11ShaderResourceView>* aOutView) {
@@ -1050,6 +1100,10 @@ void CompositorD3D11::BeginFrame(const nsIntRegion& aInvalidRegion,
 void CompositorD3D11::NormalDrawingDone() { mDiagnostics->End(); }
 
 void CompositorD3D11::EndFrame() {
+  if (!profiler_feature_active(ProfilerFeature::Screenshots) && mWindowRTCopy) {
+    mWindowRTCopy = nullptr;
+  }
+
   if (!mDefaultRT) {
     Compositor::EndFrame();
     return;
@@ -1281,6 +1335,7 @@ bool CompositorD3D11::VerifyBufferSize() {
     if (mCurrentRT == mDefaultRT) {
       mCurrentRT = nullptr;
     }
+
     MOZ_ASSERT(mDefaultRT->hasOneRef());
     mDefaultRT = nullptr;
 
diff --git a/gfx/layers/d3d11/CompositorD3D11.h b/gfx/layers/d3d11/CompositorD3D11.h
index 5e78c0158e2c..6ac4865561fe 100644
--- a/gfx/layers/d3d11/CompositorD3D11.h
+++ b/gfx/layers/d3d11/CompositorD3D11.h
@@ -58,6 +58,8 @@ class CompositorD3D11 : public Compositor {
       const override {
     return do_AddRef(mCurrentRT);
   }
+  virtual already_AddRefed<CompositingRenderTarget> GetWindowRenderTarget()
+      const override;
 
   virtual void SetDestinationSurfaceSize(const gfx::IntSize& aSize) override {}
 
@@ -206,6 +208,7 @@ class CompositorD3D11 : public Compositor {
   RefPtr<IDXGISwapChain> mSwapChain;
   RefPtr<CompositingRenderTargetD3D11> mDefaultRT;
   RefPtr<CompositingRenderTargetD3D11> mCurrentRT;
+  mutable RefPtr<CompositingRenderTargetD3D11> mWindowRTCopy;
 
   RefPtr<ID3D11Query> mQuery;