Cache CroppedImageViews in ImagePreviewView for Improved Performance (#…

…237)
FluidGroup · Apr 11, 2024 · 4740ce4 · 4740ce4
1 parent 189f94e
commit 4740ce4
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Showing 2 changed files with 26 additions and 9 deletions.
diff --git a/Sources/BrightroomEngine/Core/EditingStack.swift b/Sources/BrightroomEngine/Core/EditingStack.swift
@@ -409,24 +409,23 @@ open class EditingStack: Hashable, StoreComponentType {
 
    For previewing image
    */
-  public func makeCroppedCIImage(loadedState: State.Loaded) -> CIImage {
+  public func makeCroppedCIImage(
+    sourceImage: CGImage,
+    crop: EditingCrop,
+    orientation: CGImagePropertyOrientation
+  ) -> CIImage {
 
     do {
-      let orientation = loadedState.metadata.orientation
-      let crop = loadedState.currentEdit.crop
-
-      // orientation is not respected
-      let image = loadedState.editingSourceCGImage
 
       // orientation-respected
-      let imageSize = image.size
+      let imageSize = sourceImage.size
         .applying(cgOrientation: orientation)
 
       let scaledCrop = crop.scaledWithPixelPerfect(
         maxPixelSize: max(imageSize.width, imageSize.height)
       )
 
-      return try image
+      return try sourceImage
       // TODO: better to combine these operations - oriented and cropping
         .oriented(orientation)
         .croppedWithColorspace(

diff --git a/Sources/BrightroomUI/Shared/Components/ImageViews/ImagePreviewView.swift b/Sources/BrightroomUI/Shared/Components/ImageViews/ImagePreviewView.swift
@@ -46,6 +46,7 @@ public final class ImagePreviewView: PixelEditorCodeBasedView {
   private weak var currentLoadingOverlay: UIView?
 
   private var isBinding = false
+  private var cachedCroppedImage: (state: EditingStack.State.Loaded, image: CIImage)? = nil
 
   // MARK: - Initializers
 
@@ -123,10 +124,27 @@ public final class ImagePreviewView: PixelEditorCodeBasedView {
   }
 
   private func requestPreviewImage(state: EditingStack.State.Loaded) {
-    let croppedImage = editingStack.makeCroppedCIImage(loadedState: state)
+
+    let croppedImage: CIImage
+    if
+      let cachedCroppedImage,
+      state.editingSourceCGImage == cachedCroppedImage.state.editingSourceCGImage,
+      state.metadata == cachedCroppedImage.state.metadata,
+      state.currentEdit.crop == cachedCroppedImage.state.currentEdit.crop
+    {
+      croppedImage = cachedCroppedImage.image
+    } else {
+      croppedImage = editingStack.makeCroppedCIImage(
+        sourceImage: state.editingSourceCGImage,
+        crop: state.currentEdit.crop,
+        orientation: state.metadata.orientation
+      )
+      cachedCroppedImage = (state, croppedImage)
+    }
     imageView.display(image: croppedImage)
     imageView.postProcessing = state.currentEdit.filters.apply
     originalImageView.display(image: croppedImage)
+
   }
 
   private func updateLoadingOverlay(displays: Bool) {