Adopt BifurcatedGraphicsContext for backing store + display list Remo…

…teLayerBackingStore

https://bugs.webkit.org/show_bug.cgi?id=226425
<rdar://77929299>

Reviewed by Sam Weinig.

Instead of "display list backed RemoteLayerBackingStore" being its own
backing store type, we make "includes a display list" a separate bit.
This way, we can paint both a bitmap (IOSurface or CG bitmap, all
exactly as it normally is), and also carry a sidecar display list.

* Shared/RemoteLayerTree/RemoteLayerBackingStore.h:
* Shared/RemoteLayerTree/RemoteLayerBackingStore.mm:
(WebKit::RemoteLayerBackingStore::ensureBackingStore):
(WebKit::RemoteLayerBackingStore::encode const):
(WebKit::RemoteLayerBackingStore::decode):
(WebKit::RemoteLayerBackingStore::swapToValidFrontBuffer):
(WebKit::RemoteLayerBackingStore::supportsPartialRepaint):
We can't partially repaint the display list, and require its rendering
to match the painted backing store, so disable partial repaint entirely
if display lists are being used.

(WebKit::RemoteLayerBackingStore::display):
(WebKit::RemoteLayerBackingStore::drawInContext):
Adopt BifurcatedGraphicsContext in order to paint into the aforementioned
bitmap and display list simultaneously.
A future patch may abstract this into a new ImageBuffer type
instead of polluting RemoteLayerBackingStore with it.

Leave a temporary workaround for a CoreAnimation bug, which can be
disabled via `defaults write`, but is enabled by default.

(WebKit::layerContentsForBufferHandle):
(WebKit::RemoteLayerBackingStore::applyBackingStoreToLayer):
(WebKit::RemoteLayerBackingStore::Buffer::discard):
* UIProcess/RemoteLayerTree/cocoa/RemoteLayerTreeLayers.h:
* UIProcess/RemoteLayerTree/cocoa/RemoteLayerTreeLayers.mm:
(-[WKCompositingLayer _setWKContents:withDisplayList:]):
(-[WKCompositingLayer _setWKContentsDisplayList:]): Deleted.
(-[WKCompositingLayer _wkContentsDisplayList]): Deleted.
Pass the display list data to CoreAnimation alongside the bitmap.

* WebProcess/WebPage/RemoteLayerTree/PlatformCALayerRemote.cpp:
(WebKit::PlatformCALayerRemote::updateBackingStore):


Canonical link: https://commits.webkit.org/239735@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@279992 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebKit/ChangeLog

@@ -1,3 +1,50 @@
+2021-07-16  Tim Horton  <timothy_horton@apple.com>
+
+        Adopt BifurcatedGraphicsContext for backing store + display list RemoteLayerBackingStore
+        https://bugs.webkit.org/show_bug.cgi?id=226425
+        <rdar://77929299>
+
+        Reviewed by Sam Weinig.
+
+        Instead of "display list backed RemoteLayerBackingStore" being its own
+        backing store type, we make "includes a display list" a separate bit.
+        This way, we can paint both a bitmap (IOSurface or CG bitmap, all
+        exactly as it normally is), and also carry a sidecar display list.
+
+        * Shared/RemoteLayerTree/RemoteLayerBackingStore.h:
+        * Shared/RemoteLayerTree/RemoteLayerBackingStore.mm:
+        (WebKit::RemoteLayerBackingStore::ensureBackingStore):
+        (WebKit::RemoteLayerBackingStore::encode const):
+        (WebKit::RemoteLayerBackingStore::decode):
+        (WebKit::RemoteLayerBackingStore::swapToValidFrontBuffer):
+        (WebKit::RemoteLayerBackingStore::supportsPartialRepaint):
+        We can't partially repaint the display list, and require its rendering
+        to match the painted backing store, so disable partial repaint entirely
+        if display lists are being used.
+
+        (WebKit::RemoteLayerBackingStore::display):
+        (WebKit::RemoteLayerBackingStore::drawInContext):
+        Adopt BifurcatedGraphicsContext in order to paint into the aforementioned
+        bitmap and display list simultaneously.
+        A future patch may abstract this into a new ImageBuffer type
+        instead of polluting RemoteLayerBackingStore with it.
+
+        Leave a temporary workaround for a CoreAnimation bug, which can be
+        disabled via `defaults write`, but is enabled by default.
+
+        (WebKit::layerContentsForBufferHandle):
+        (WebKit::RemoteLayerBackingStore::applyBackingStoreToLayer):
+        (WebKit::RemoteLayerBackingStore::Buffer::discard):
+        * UIProcess/RemoteLayerTree/cocoa/RemoteLayerTreeLayers.h:
+        * UIProcess/RemoteLayerTree/cocoa/RemoteLayerTreeLayers.mm:
+        (-[WKCompositingLayer _setWKContents:withDisplayList:]):
+        (-[WKCompositingLayer _setWKContentsDisplayList:]): Deleted.
+        (-[WKCompositingLayer _wkContentsDisplayList]): Deleted.
+        Pass the display list data to CoreAnimation alongside the bitmap.
+
+        * WebProcess/WebPage/RemoteLayerTree/PlatformCALayerRemote.cpp:
+        (WebKit::PlatformCALayerRemote::updateBackingStore):
+
 2021-07-16  Megan Gardner  <megan_gardner@apple.com>
 
         Pipe App Highlight scrolling through UI Process in preparation for Note Overlay avoidance.

Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStore.h

@@ -54,13 +54,11 @@ class RemoteLayerBackingStore {
 
     enum class Type : uint8_t {
         IOSurface,
-        Bitmap,
-#if ENABLE(CG_DISPLAY_LIST_BACKED_IMAGE_BUFFER)
-        CGDisplayList,
-#endif
+        Bitmap
     };
 
-    void ensureBackingStore(Type, WebCore::FloatSize, float scale, bool deepColor, bool isOpaque);
+    enum class IncludeDisplayList : bool { No, Yes };
+    void ensureBackingStore(Type, WebCore::FloatSize, float scale, bool deepColor, bool isOpaque, IncludeDisplayList);
 
     void setNeedsDisplay(const WebCore::IntRect);
     void setNeedsDisplay();
@@ -88,7 +86,7 @@ class RemoteLayerBackingStore {
         return !!m_frontBuffer.imageBuffer;
     }
 
-    std::unique_ptr<WebCore::ThreadSafeImageBufferFlusher> takePendingFlusher();
+    Vector<std::unique_ptr<WebCore::ThreadSafeImageBufferFlusher>> takePendingFlushers();
 
     enum class BufferType {
         Front,
@@ -120,6 +118,9 @@ class RemoteLayerBackingStore {
 
     struct Buffer {
         RefPtr<WebCore::ImageBuffer> imageBuffer;
+#if ENABLE(CG_DISPLAY_LIST_BACKED_IMAGE_BUFFER)
+        RefPtr<WebCore::ImageBuffer> displayListImageBuffer;
+#endif
         bool isVolatile = false;
 
         explicit operator bool() const
@@ -134,10 +135,14 @@ class RemoteLayerBackingStore {
     Buffer m_backBuffer;
     Buffer m_secondaryBackBuffer;
     std::optional<ImageBufferBackendHandle> m_bufferHandle;
+#if ENABLE(CG_DISPLAY_LIST_BACKED_IMAGE_BUFFER)
+    std::optional<ImageBufferBackendHandle> m_displayListBufferHandle;
+#endif
 
-    std::unique_ptr<WebCore::ThreadSafeImageBufferFlusher> m_frontBufferFlusher;
+    Vector<std::unique_ptr<WebCore::ThreadSafeImageBufferFlusher>> m_frontBufferFlushers;
 
     Type m_type;
+    IncludeDisplayList m_includeDisplayList { IncludeDisplayList::No };
     bool m_deepColor { false };
 
     WebCore::RepaintRectList m_paintingRects;
@@ -151,12 +156,17 @@ namespace WTF {
 
 template<> struct EnumTraits<WebKit::RemoteLayerBackingStore::Type> {
     using values = EnumValues<
-        WebKit::RemoteLayerBackingStore::Type
-        , WebKit::RemoteLayerBackingStore::Type::IOSurface
-        , WebKit::RemoteLayerBackingStore::Type::Bitmap
-#if ENABLE(CG_DISPLAY_LIST_BACKED_IMAGE_BUFFER)
-        , WebKit::RemoteLayerBackingStore::Type::CGDisplayList
-#endif
+        WebKit::RemoteLayerBackingStore::Type,
+        WebKit::RemoteLayerBackingStore::Type::IOSurface,
+        WebKit::RemoteLayerBackingStore::Type::Bitmap
+    >;
+};
+
+template<> struct EnumTraits<WebKit::RemoteLayerBackingStore::IncludeDisplayList> {
+    using values = EnumValues<
+        WebKit::RemoteLayerBackingStore::IncludeDisplayList,
+        WebKit::RemoteLayerBackingStore::IncludeDisplayList::No,
+        WebKit::RemoteLayerBackingStore::IncludeDisplayList::Yes
     >;
 };