AtlasEngine: Improve scroll and swap chain invalidation (#15425)

`_p.MarkAllAsDirty()` sets `_p.scrollOffset` to 0, so we need to use
that instead of `_api.scrollOffset` when getting the offset.
Additionally, the previous code failed to release the swap chain
when recreating the backend, which is technically not correct.
I'm not sure to what issues this might have led, as it didn't had any
negative effects on my PC, but it's definitely not according to spec.

## Validation Steps Performed
Difficult to test but it seems alright.

(cherry picked from commit a19d30a)
Service-Card-Id: 89315195
Service-Version: 1.18

src/renderer/atlas/AtlasEngine.cpp

@@ -134,12 +134,12 @@ try
     //   the contents of the entire swap chain is redundant, but more importantly because the scroll rect
     //   is the subset of the contents that are being scrolled into. If you scroll the entire viewport
     //   then the scroll rect is empty, which Present1() will loudly complain about.
-    if (_api.invalidatedRows == range<u16>{ 0, _p.s->cellCount.y })
+    if (_p.invalidatedRows == range<u16>{ 0, _p.s->cellCount.y })
     {
         _p.MarkAllAsDirty();
     }
 
-    if (const auto offset = _api.scrollOffset)
+    if (const auto offset = _p.scrollOffset)
     {
         if (offset < 0)
         {
@@ -212,17 +212,17 @@ try
     // * Get the old dirty rect and mark that region as needing invalidation during the upcoming Present1(),
     //   because it'll now be replaced with something else (for instance nothing/whitespace).
     // * Clear() them to prepare them for the new incoming content from the TextBuffer.
-    if (_api.invalidatedRows.non_empty())
+    if (_p.invalidatedRows.non_empty())
     {
         const til::CoordType targetSizeX = _p.s->targetSize.x;
         const til::CoordType targetSizeY = _p.s->targetSize.y;
 
         _p.dirtyRectInPx.left = 0;
-        _p.dirtyRectInPx.top = std::min(_p.dirtyRectInPx.top, _api.invalidatedRows.start * _p.s->font->cellSize.y);
+        _p.dirtyRectInPx.top = std::min(_p.dirtyRectInPx.top, _p.invalidatedRows.start * _p.s->font->cellSize.y);
         _p.dirtyRectInPx.right = targetSizeX;
-        _p.dirtyRectInPx.bottom = std::max(_p.dirtyRectInPx.bottom, _api.invalidatedRows.end * _p.s->font->cellSize.y);
+        _p.dirtyRectInPx.bottom = std::max(_p.dirtyRectInPx.bottom, _p.invalidatedRows.end * _p.s->font->cellSize.y);
 
-        for (auto y = _api.invalidatedRows.start; y < _api.invalidatedRows.end; ++y)
+        for (auto y = _p.invalidatedRows.start; y < _p.invalidatedRows.end; ++y)
         {
             const auto r = _p.rows[y];
             const auto clampedTop = clamp(r->dirtyTop, 0, targetSizeY);

src/renderer/atlas/AtlasEngine.h

@@ -99,6 +99,7 @@ namespace Microsoft::Console::Render::Atlas
         ATLAS_ATTR_COLD void _recreateBackend();
         ATLAS_ATTR_COLD void _handleSwapChainUpdate();
         void _createSwapChain();
+        void _destroySwapChain();
         void _resizeBuffers();
         void _updateMatrixTransform();
         void _waitUntilCanRender() noexcept;

src/renderer/atlas/AtlasEngine.r.cpp

@@ -162,6 +162,10 @@ void AtlasEngine::_recreateAdapter()
 
 void AtlasEngine::_recreateBackend()
 {
+    // D3D11 defers the destruction of objects and only one swap chain can be associated with a
+    // HWND, IWindow, or composition surface at a time. --> Destroy it while we still have the old device.
+    _destroySwapChain();
+
     auto d2dMode = ATLAS_DEBUG_FORCE_D2D_MODE;
     auto deviceFlags =
         D3D11_CREATE_DEVICE_SINGLETHREADED
@@ -260,7 +264,6 @@ void AtlasEngine::_recreateBackend()
         d2dMode |= !options.ComputeShaders_Plus_RawAndStructuredBuffers_Via_Shader_4_x;
     }
 
-    _p.swapChain = {};
     _p.device = std::move(device);
     _p.deviceContext = std::move(deviceContext);
 
@@ -285,18 +288,10 @@ void AtlasEngine::_handleSwapChainUpdate()
 {
     if (_p.swapChain.targetGeneration != _p.s->target.generation())
     {
-        if (_p.swapChain.swapChain)
-        {
-            _b->ReleaseResources();
-            _p.deviceContext->ClearState();
-            _p.deviceContext->Flush();
-        }
         _createSwapChain();
     }
     else if (_p.swapChain.targetSize != _p.s->targetSize)
     {
-        _b->ReleaseResources();
-        _p.deviceContext->ClearState();
         _resizeBuffers();
     }
 
@@ -312,8 +307,7 @@ static constexpr DXGI_SWAP_CHAIN_FLAG swapChainFlags = ATLAS_DEBUG_DISABLE_FRAME
 
 void AtlasEngine::_createSwapChain()
 {
-    _p.swapChain.swapChain.reset();
-    _p.swapChain.frameLatencyWaitableObject.reset();
+    _destroySwapChain();
 
     DXGI_SWAP_CHAIN_DESC1 desc{
         .Width = _p.s->targetSize.x,
@@ -340,6 +334,7 @@ void AtlasEngine::_createSwapChain()
     };
 
     wil::com_ptr<IDXGISwapChain1> swapChain1;
+    wil::unique_handle handle;
 
     if (_p.s->target->hwnd)
     {
@@ -354,14 +349,14 @@ void AtlasEngine::_createSwapChain()
 
         // As per: https://docs.microsoft.com/en-us/windows/win32/api/dcomp/nf-dcomp-dcompositioncreatesurfacehandle
         static constexpr DWORD COMPOSITIONSURFACE_ALL_ACCESS = 0x0003L;
-        THROW_IF_FAILED(DCompositionCreateSurfaceHandle(COMPOSITIONSURFACE_ALL_ACCESS, nullptr, _p.swapChain.handle.addressof()));
-        THROW_IF_FAILED(_p.dxgi.factory.query<IDXGIFactoryMedia>()->CreateSwapChainForCompositionSurfaceHandle(_p.device.get(), _p.swapChain.handle.get(), &desc, nullptr, swapChain1.addressof()));
+        THROW_IF_FAILED(DCompositionCreateSurfaceHandle(COMPOSITIONSURFACE_ALL_ACCESS, nullptr, handle.addressof()));
+        THROW_IF_FAILED(_p.dxgi.factory.query<IDXGIFactoryMedia>()->CreateSwapChainForCompositionSurfaceHandle(_p.device.get(), handle.get(), &desc, nullptr, swapChain1.addressof()));
     }
 
     _p.swapChain.swapChain = swapChain1.query<IDXGISwapChain2>();
+    _p.swapChain.handle = std::move(handle);
     _p.swapChain.frameLatencyWaitableObject.reset(_p.swapChain.swapChain->GetFrameLatencyWaitableObject());
     _p.swapChain.targetGeneration = _p.s->target.generation();
-    _p.swapChain.fontGeneration = {};
     _p.swapChain.targetSize = _p.s->targetSize;
     _p.swapChain.waitForPresentation = true;
 
@@ -377,8 +372,30 @@ void AtlasEngine::_createSwapChain()
     }
 }
 
+void AtlasEngine::_destroySwapChain()
+{
+    if (_p.swapChain.swapChain)
+    {
+        // D3D11 defers the destruction of objects and only one swap chain can be associated with a
+        // HWND, IWindow, or composition surface at a time. --> Force the destruction of all objects.
+        _p.swapChain = {};
+        if (_b)
+        {
+            _b->ReleaseResources();
+        }
+        if (_p.deviceContext)
+        {
+            _p.deviceContext->ClearState();
+            _p.deviceContext->Flush();
+        }
+    }
+}
+
 void AtlasEngine::_resizeBuffers()
 {
+    _b->ReleaseResources();
+    _p.deviceContext->ClearState();
+
     THROW_IF_FAILED(_p.swapChain.swapChain->ResizeBuffers(0, _p.s->targetSize.x, _p.s->targetSize.y, DXGI_FORMAT_UNKNOWN, swapChainFlags));
     _p.swapChain.targetSize = _p.s->targetSize;
 }