refactor(web): decouple FaceEditor from DOM element

Change-Id: I71f07ba8d0bc2d829c0b2af4da5ee5bc6a6a6964

web/src/lib/components/asset-viewer/AssetViewer.svelte

@@ -10,7 +10,6 @@
   import OnEvents from '$lib/components/OnEvents.svelte';
   import { AssetAction, ProjectionType } from '$lib/constants';
   import { activityManager } from '$lib/managers/activity-manager.svelte';
-  import { assetCacheManager } from '$lib/managers/AssetCacheManager.svelte';
   import { assetViewerManager } from '$lib/managers/asset-viewer-manager.svelte';
   import { authManager } from '$lib/managers/auth-manager.svelte';
   import { editManager, EditToolType } from '$lib/managers/edit/edit-manager.svelte';
@@ -103,10 +102,9 @@
   const stackSelectedThumbnailSize = 65;
 
   let previewStackedAsset: AssetResponseDto | undefined = $state();
-  let stack: StackResponseDto | undefined = $state();
-  let selectedStackAsset: AssetResponseDto | undefined = $state();
+  let stack: StackResponseDto | null = $state(null);
 
-  const asset = $derived(previewStackedAsset ?? selectedStackAsset ?? cursor.current);
+  const asset = $derived(previewStackedAsset ?? cursor.current);
   const nextAsset = $derived(cursor.nextAsset);
   const previousAsset = $derived(cursor.previousAsset);
   let sharedLink = getSharedLink();
@@ -119,29 +117,17 @@
     playOriginalVideo = value;
   };
 
-  const selectStackedAsset = async (id: string) => {
-    ocrManager.clear();
-    selectedStackAsset = await assetCacheManager.getAsset({ id });
-    if (!sharedLink) {
-      await ocrManager.getAssetOcr(id);
-    }
-  };
-
   const refreshStack = async () => {
     if (authManager.isSharedLink || !withStacked) {
       return;
     }
 
-    if (!cursor.current.stack) {
-      stack = undefined;
-      selectedStackAsset = undefined;
-      return;
+    if (asset.stack) {
+      stack = await getStack({ id: asset.stack.id });
     }
 
-    stack = await getStack({ id: cursor.current.stack.id });
-    const primaryAsset = stack?.assets.find(({ id }) => id === stack?.primaryAssetId);
-    if (primaryAsset) {
-      await selectStackedAsset(primaryAsset.id);
+    if (!stack?.assets.some(({ id }) => id === asset.id)) {
+      stack = null;
     }
   };
 
@@ -199,21 +185,11 @@
     onClose?.(asset.id);
   };
 
-  const refreshPreservingSelection = async () => {
-    const id = asset.id;
-    assetCacheManager.invalidateAsset(id);
-    if (selectedStackAsset) {
-      await selectStackedAsset(id);
-    } else {
-      const refreshedAsset = await assetCacheManager.getAsset({ id });
-      assetViewerManager.setAsset(refreshedAsset);
-    }
-    onAssetChange?.(asset);
-  };
-
   const closeEditor = async () => {
     if (editManager.hasAppliedEdits) {
-      await refreshPreservingSelection();
+      const refreshedAsset = await getAssetInfo({ id: asset.id });
+      onAssetChange?.(refreshedAsset);
+      assetViewerManager.setAsset(refreshedAsset);
     }
     assetViewerManager.closeEditor();
   };
@@ -328,6 +304,10 @@
     }
   };
 
+  const handleStackedAssetMouseEvent = (isMouseOver: boolean, stackedAsset: AssetResponseDto) => {
+    previewStackedAsset = isMouseOver ? stackedAsset : undefined;
+  };
+
   const handlePreAction = (action: Action) => {
     preAction?.(action);
   };
@@ -340,7 +320,7 @@
         break;
       }
       case AssetAction.REMOVE_ASSET_FROM_STACK: {
-        stack = action.stack ?? undefined;
+        stack = action.stack;
         if (stack) {
           cursor.current = stack.assets[0];
         }
@@ -348,7 +328,7 @@
       }
       case AssetAction.STACK:
       case AssetAction.SET_STACK_PRIMARY_ASSET: {
-        stack = action.stack ?? undefined;
+        stack = action.stack;
         break;
       }
       case AssetAction.SET_PERSON_FEATURED_PHOTO: {
@@ -411,7 +391,7 @@
 
   $effect(() => {
     // eslint-disable-next-line @typescript-eslint/no-unused-expressions
-    cursor.current;
+    asset;
     untrack(() => handlePromiseError(refresh()));
   });
 
@@ -580,12 +560,7 @@
     {:else if viewerKind === 'CropArea'}
       <CropArea {asset} />
     {:else if viewerKind === 'PhotoViewer'}
-      <PhotoViewer
-        cursor={{ ...cursor, current: asset }}
-        {sharedLink}
-        {onSwipe}
-        onTagFace={refreshPreservingSelection}
-      />
+      <PhotoViewer cursor={{ ...cursor, current: asset }} {sharedLink} {onSwipe} />
     {:else if viewerKind === 'VideoViewer'}
       <VideoViewer
         {asset}
@@ -642,7 +617,7 @@
       translate="yes"
     >
       {#if showDetailPanel}
-        <DetailPanel {asset} currentAlbum={album} onRefreshPeople={refreshPreservingSelection} />
+        <DetailPanel {asset} currentAlbum={album} />
       {:else if assetViewerManager.isShowEditor}
         <EditorPanel {asset} onClose={closeEditor} />
       {/if}
@@ -654,24 +629,27 @@
     <div id="stack-slideshow" class="pointer-events-none absolute bottom-0 col-span-4 col-start-1 w-full">
       <div class="no-wrap horizontal-scrollbar relative flex flex-row overflow-x-auto overflow-y-hidden">
         {#each stackedAssets as stackedAsset (stackedAsset.id)}
-          {@const isSelected = stackedAsset.id === (selectedStackAsset?.id ?? cursor.current.id)}
           <div
             class={['pointer-events-auto relative inline-block px-1 pb-2 transition-all']}
-            style:bottom={isSelected ? '0' : '-10px'}
+            style:bottom={stackedAsset.id === asset.id ? '0' : '-10px'}
           >
             <Thumbnail
-              imageClass={{ 'border-2 border-white': isSelected }}
+              imageClass={{ 'border-2 border-white': stackedAsset.id === asset.id }}
               brokenAssetClass="text-xs"
-              dimmed={!isSelected}
+              dimmed={stackedAsset.id !== asset.id}
               asset={toTimelineAsset(stackedAsset)}
-              onClick={() => selectStackedAsset(stackedAsset.id)}
+              onClick={() => {
+                cursor.current = stackedAsset;
+                previewStackedAsset = undefined;
+              }}
+              onMouseEvent={({ isMouseOver }) => handleStackedAssetMouseEvent(isMouseOver, stackedAsset)}
               readonly
-              thumbnailSize={isSelected ? stackSelectedThumbnailSize : stackThumbnailSize}
+              thumbnailSize={stackedAsset.id === asset.id ? stackSelectedThumbnailSize : stackThumbnailSize}
               showStackedIcon={false}
               disableLinkMouseOver
             />
 
-            {#if isSelected}
+            {#if stackedAsset.id === asset.id}
               <div class="flex w-full place-content-center place-items-center">
                 <div class="mt-0.5 flex size-2 rounded-full bg-white"></div>
               </div>

web/src/lib/components/asset-viewer/DetailPanel.svelte

@@ -16,7 +16,13 @@
   import { getByteUnitString } from '$lib/utils/byte-units';
   import { handleError } from '$lib/utils/handle-error';
   import { getParentPath } from '$lib/utils/tree-utils';
-  import { AssetMediaSize, getAllAlbums, type AlbumResponseDto, type AssetResponseDto } from '@immich/sdk';
+  import {
+    AssetMediaSize,
+    getAllAlbums,
+    getAssetInfo,
+    type AlbumResponseDto,
+    type AssetResponseDto,
+  } from '@immich/sdk';
   import { Icon, IconButton, LoadingSpinner, Text } from '@immich/ui';
   import { mdiCamera, mdiCameraIris, mdiClose, mdiImageOutline, mdiInformationOutline } from '@mdi/js';
   import { onDestroy } from 'svelte';
@@ -31,10 +37,9 @@
   interface Props {
     asset: AssetResponseDto;
     currentAlbum?: AlbumResponseDto | null;
-    onRefreshPeople?: () => Promise<void>;
   }
 
-  let { asset, currentAlbum = null, onRefreshPeople }: Props = $props();
+  let { asset, currentAlbum = null }: Props = $props();
 
   let isOwner = $derived(authManager.authenticated && authManager.user.id === asset.ownerId);
   let latlng = $derived(
@@ -89,6 +94,11 @@
     return undefined;
   };
 
+  const handleRefreshPeople = async () => {
+    asset = await getAssetInfo({ id: asset.id });
+    assetViewerManager.closeEditFacesPanel();
+  };
+
   const getAssetFolderHref = (asset: AssetResponseDto) => {
     // Remove the last part of the path to get the parent path
     return Route.folders({ path: getParentPath(asset.originalPath) });
@@ -375,6 +385,6 @@
     assetId={asset.id}
     assetType={asset.type}
     onClose={() => assetViewerManager.closeEditFacesPanel()}
-    onRefresh={() => void onRefreshPeople?.()}
+    onRefresh={handleRefreshPeople}
   />
 {/if}

web/src/lib/components/asset-viewer/PhotoViewer.svelte

@@ -31,10 +31,9 @@
     onReady?: () => void;
     onError?: () => void;
     onSwipe?: (event: SwipeCustomEvent) => void;
-    onTagFace?: () => Promise<void>;
   };
 
-  let { cursor, element = $bindable(), sharedLink, onReady, onError, onSwipe, onTagFace }: Props = $props();
+  let { cursor, element = $bindable(), sharedLink, onReady, onError, onSwipe }: Props = $props();
 
   const { slideshowState, slideshowLook } = slideshowStore;
   const asset = $derived(cursor.current);
@@ -287,13 +286,11 @@
     {/snippet}
   </AdaptiveImage>
 
-  {#if assetViewerManager.isFaceEditMode && assetViewerManager.imgRef}
+  {#if assetViewerManager.isFaceEditMode && assetViewerManager.imgRef && asset.width && asset.height}
     <FaceEditor
-      htmlElement={assetViewerManager.imgRef}
-      {containerWidth}
-      {containerHeight}
+      imageSize={{ width: asset.width, height: asset.height }}
+      containerSize={{ width: containerWidth, height: containerHeight }}
       assetId={asset.id}
-      {onTagFace}
     />
   {/if}
 </div>

web/src/lib/components/asset-viewer/VideoNativeViewer.svelte

@@ -308,9 +308,31 @@
   let containerHeight = $state(0);
 
   $effect(() => {
-    if (assetViewerManager.isFaceEditMode) {
-      videoPlayer?.pause();
+    if (!assetViewerManager.isFaceEditMode || !videoPlayer) {
+      return;
     }
+    videoPlayer.pause();
+
+    const { videoWidth, videoHeight } = videoPlayer;
+    if (videoWidth === 0 || videoHeight === 0) {
+      return;
+    }
+
+    const canvas = document.createElement('canvas');
+    canvas.width = videoWidth;
+    canvas.height = videoHeight;
+    canvas.getContext('2d')?.drawImage(videoPlayer, 0, 0);
+
+    const img = new Image();
+    const onImageLoad = () => (assetViewerManager.imgRef = img);
+    img.addEventListener('load', onImageLoad);
+    img.src = canvas.toDataURL('image/png');
+
+    return () => {
+      img.removeEventListener('load', onImageLoad);
+      img.src = '';
+      assetViewerManager.imgRef = undefined;
+    };
   });
 
   // The time is only refreshed on HLS fragment decode by default,
@@ -454,8 +476,12 @@
         </div>
       {/if}
 
-      {#if assetViewerManager.isFaceEditMode && videoPlayer}
-        <FaceEditor htmlElement={videoPlayer} {containerWidth} {containerHeight} {assetId} />
+      {#if assetViewerManager.isFaceEditMode}
+        <FaceEditor
+          imageSize={{ width: asset.width ?? 0, height: asset.height ?? 0 }}
+          containerSize={{ width: containerWidth, height: containerHeight }}
+          {assetId}
+        />
       {/if}
     {/if}
   </div>

web/src/lib/components/asset-viewer/face-editor/FaceEditor.svelte

@@ -4,7 +4,7 @@
   import { assetViewerManager } from '$lib/managers/asset-viewer-manager.svelte';
   import FaceCreateTagModal from '$lib/modals/CreateFaceModal.svelte';
   import { getPeopleThumbnailUrl } from '$lib/utils';
-  import { getNaturalSize, scaleToFit } from '$lib/utils/container-utils';
+  import { computeContentMetrics, mapContentRectToNatural, type Size } from '$lib/utils/container-utils';
   import { handleError } from '$lib/utils/handle-error';
   import { createFace, getAllPeople, type PersonResponseDto } from '@immich/sdk';
   import { Button, Input, modalManager, toastManager } from '@immich/ui';
@@ -14,14 +14,12 @@
   import { t } from 'svelte-i18n';
 
   type Props = {
-    htmlElement: HTMLImageElement | HTMLVideoElement;
-    containerWidth: number;
-    containerHeight: number;
+    imageSize: Size;
+    containerSize: Size;
     assetId: string;
-    onTagFace?: () => Promise<void>;
   };
 
-  let { htmlElement, containerWidth, containerHeight, assetId, onTagFace }: Props = $props();
+  let { imageSize, containerSize, assetId }: Props = $props();
 
   let canvasEl: HTMLCanvasElement | undefined = $state();
   let canvas: Canvas | undefined = $state();
@@ -55,7 +53,7 @@
   };
 
   const setupCanvas = () => {
-    if (!canvasEl || !htmlElement) {
+    if (!canvasEl) {
       return;
     }
 
@@ -87,17 +85,7 @@
     searchInputEl?.focus();
   });
 
-  const imageContentMetrics = $derived.by(() => {
-    const natural = getNaturalSize(htmlElement);
-    const container = { width: containerWidth, height: containerHeight };
-    const { width: contentWidth, height: contentHeight } = scaleToFit(natural, container);
-    return {
-      contentWidth,
-      contentHeight,
-      offsetX: (containerWidth - contentWidth) / 2,
-      offsetY: (containerHeight - contentHeight) / 2,
-    };
-  });
+  const imageContentMetrics = $derived(computeContentMetrics(imageSize, containerSize));
 
   const setDefaultFaceRectanglePosition = (faceRect: Rect) => {
     const { offsetX, offsetY } = imageContentMetrics;
@@ -117,8 +105,8 @@
     }
 
     canvas.setDimensions({
-      width: containerWidth,
-      height: containerHeight,
+      width: containerSize.width,
+      height: containerSize.height,
     });
 
     if (!faceRect) {
@@ -176,11 +164,11 @@
     };
     const selectorWidth = faceSelectorEl.offsetWidth;
     const chromeHeight = faceSelectorEl.offsetHeight - scrollableListEl.offsetHeight;
-    const listHeight = Math.min(MAX_LIST_HEIGHT, containerHeight - gap * 2 - chromeHeight);
+    const listHeight = Math.min(MAX_LIST_HEIGHT, containerSize.height - gap * 2 - chromeHeight);
     const selectorHeight = listHeight + chromeHeight;
 
-    const clampTop = (top: number) => clamp(top, gap, containerHeight - selectorHeight - gap);
-    const clampLeft = (left: number) => clamp(left, gap, containerWidth - selectorWidth - gap);
+    const clampTop = (top: number) => clamp(top, gap, containerSize.height - selectorHeight - gap);
+    const clampLeft = (left: number) => clamp(left, gap, containerSize.width - selectorWidth - gap);
 
     const overlapArea = (position: { top: number; left: number }) => {
       const selectorRight = position.left + selectorWidth;
@@ -239,61 +227,42 @@
   });
 
   const getFaceCroppedCoordinates = () => {
-    if (!faceRect || !htmlElement) {
+    if (!faceRect || imageContentMetrics.contentWidth === 0) {
       return;
     }
 
-    const { left, top, width, height } = faceRect.getBoundingRect();
-    const { offsetX, offsetY, contentWidth, contentHeight } = imageContentMetrics;
-    const natural = getNaturalSize(htmlElement);
-
-    const scaleX = natural.width / contentWidth;
-    const scaleY = natural.height / contentHeight;
-    const imageX = (left - offsetX) * scaleX;
-    const imageY = (top - offsetY) * scaleY;
+    const imageRect = mapContentRectToNatural(faceRect.getBoundingRect(), imageContentMetrics, imageSize);
 
     return {
-      imageWidth: natural.width,
-      imageHeight: natural.height,
-      x: Math.floor(imageX),
-      y: Math.floor(imageY),
-      width: Math.floor(width * scaleX),
-      height: Math.floor(height * scaleY),
+      imageWidth: imageSize.width,
+      imageHeight: imageSize.height,
+      x: Math.floor(imageRect.left),
+      y: Math.floor(imageRect.top),
+      width: Math.floor(imageRect.width),
+      height: Math.floor(imageRect.height),
     };
   };
 
   type FaceCoordinates = NonNullable<ReturnType<typeof getFaceCroppedCoordinates>>;
 
   const getFacePreviewUrl = (data: FaceCoordinates) => {
-    if (!htmlElement) {
+    const imgRef = assetViewerManager.imgRef;
+    if (!imgRef || imageContentMetrics.contentWidth === 0) {
       return;
     }
 
-    const natural = getNaturalSize(htmlElement);
-    if (natural.width <= 0 || natural.height <= 0) {
-      return;
-    }
-
-    const x = clamp(data.x, 0, natural.width - 1);
-    const y = clamp(data.y, 0, natural.height - 1);
-    const width = clamp(data.width, 1, natural.width - x);
-    const height = clamp(data.height, 1, natural.height - y);
-
-    if (width <= 0 || height <= 0) {
-      return;
-    }
+    const scaleX = imgRef.naturalWidth / imageSize.width;
+    const scaleY = imgRef.naturalHeight / imageSize.height;
+    const x = clamp(Math.floor(data.x * scaleX), 0, imgRef.naturalWidth - 1);
+    const y = clamp(Math.floor(data.y * scaleY), 0, imgRef.naturalHeight - 1);
+    const width = clamp(Math.floor(data.width * scaleX), 1, imgRef.naturalWidth - x);
+    const height = clamp(Math.floor(data.height * scaleY), 1, imgRef.naturalHeight - y);
 
     const canvas = document.createElement('canvas');
     canvas.width = width;
     canvas.height = height;
-
-    const context = canvas.getContext('2d');
-    if (!context) {
-      return;
-    }
-
     try {
-      context.drawImage(htmlElement, x, y, width, height, 0, 0, width, height);
+      canvas.getContext('2d')?.drawImage(imgRef, x, y, width, height, 0, 0, width, height);
       return canvas.toDataURL('image/png');
     } catch {
       return;
@@ -326,7 +295,7 @@
         },
       });
 
-      await onTagFace?.();
+      await assetViewerManager.setAssetId(assetId);
     } catch (error) {
       handleError(error, 'Error tagging face');
     } finally {

web/src/lib/components/faces-page/PersonSidePanel.svelte

@@ -178,10 +178,7 @@
 
       peopleWithFaces = peopleWithFaces.filter((f) => f.id !== face.id);
 
-      onRefresh();
-      if (peopleWithFaces.length === 0) {
-        onClose();
-      }
+      await assetViewerManager.setAssetId(assetId);
     } catch (error) {
       handleError(error, $t('error_delete_face'));
     }

web/src/lib/utils/container-utils.spec.ts

@@ -1,18 +1,15 @@
 import {
-  getContentMetrics,
+  computeContentMetrics,
   getNaturalSize,
+  mapContentRectToNatural,
   mapNormalizedRectToContent,
   mapNormalizedToContent,
   scaleToCover,
   scaleToFit,
 } from '$lib/utils/container-utils';
 
-const mockImage = (props: {
-  naturalWidth: number;
-  naturalHeight: number;
-  width: number;
-  height: number;
-}): HTMLImageElement => props as unknown as HTMLImageElement;
+const mockImage = (props: { naturalWidth: number; naturalHeight: number }): HTMLImageElement =>
+  props as unknown as HTMLImageElement;
 
 const mockVideo = (props: {
   videoWidth: number;
@@ -49,48 +46,85 @@ describe('scaleToFit', () => {
   });
 });
 
-describe('getContentMetrics', () => {
-  it('should compute zero offsets when aspect ratios match', () => {
-    const img = mockImage({ naturalWidth: 1600, naturalHeight: 900, width: 800, height: 450 });
-    expect(getContentMetrics(img)).toEqual({
+describe('computeContentMetrics', () => {
+  it('should return zero metrics for zero-width content', () => {
+    expect(computeContentMetrics({ width: 0, height: 1080 }, { width: 800, height: 600 })).toEqual({
+      contentWidth: 0,
+      contentHeight: 0,
+      offsetX: 0,
+      offsetY: 0,
+    });
+  });
+
+  it('should return zero metrics for zero-height content', () => {
+    expect(computeContentMetrics({ width: 1920, height: 0 }, { width: 800, height: 600 })).toEqual({
+      contentWidth: 0,
+      contentHeight: 0,
+      offsetX: 0,
+      offsetY: 0,
+    });
+  });
+
+  it('should center wide content vertically', () => {
+    expect(computeContentMetrics({ width: 2000, height: 1000 }, { width: 800, height: 600 })).toEqual({
+      contentWidth: 800,
+      contentHeight: 400,
+      offsetX: 0,
+      offsetY: 100,
+    });
+  });
+
+  it('should center tall content horizontally', () => {
+    expect(computeContentMetrics({ width: 1000, height: 2000 }, { width: 800, height: 600 })).toEqual({
+      contentWidth: 300,
+      contentHeight: 600,
+      offsetX: 250,
+      offsetY: 0,
+    });
+  });
+
+  it('should produce zero offsets when aspect ratios match', () => {
+    expect(computeContentMetrics({ width: 1600, height: 900 }, { width: 800, height: 450 })).toEqual({
       contentWidth: 800,
       contentHeight: 450,
       offsetX: 0,
       offsetY: 0,
     });
   });
+});
 
-  it('should compute horizontal letterbox offsets for tall image', () => {
-    const img = mockImage({ naturalWidth: 1000, naturalHeight: 2000, width: 800, height: 600 });
-    const metrics = getContentMetrics(img);
-    expect(metrics.contentWidth).toBe(300);
-    expect(metrics.contentHeight).toBe(600);
-    expect(metrics.offsetX).toBe(250);
-    expect(metrics.offsetY).toBe(0);
+describe('mapContentRectToNatural', () => {
+  it('should map a full-content rect back to natural size', () => {
+    const metrics = { contentWidth: 800, contentHeight: 400, offsetX: 0, offsetY: 100 };
+    const rect = mapContentRectToNatural({ left: 0, top: 100, width: 800, height: 400 }, metrics, {
+      width: 2000,
+      height: 1000,
+    });
+    expect(rect).toEqual({ left: 0, top: 0, width: 2000, height: 1000 });
   });
 
-  it('should compute vertical letterbox offsets for wide image', () => {
-    const img = mockImage({ naturalWidth: 2000, naturalHeight: 1000, width: 800, height: 600 });
-    const metrics = getContentMetrics(img);
-    expect(metrics.contentWidth).toBe(800);
-    expect(metrics.contentHeight).toBe(400);
-    expect(metrics.offsetX).toBe(0);
-    expect(metrics.offsetY).toBe(100);
+  it('should map a centered sub-rect to natural coordinates', () => {
+    const metrics = { contentWidth: 800, contentHeight: 400, offsetX: 0, offsetY: 100 };
+    const rect = mapContentRectToNatural({ left: 200, top: 200, width: 400, height: 200 }, metrics, {
+      width: 2000,
+      height: 1000,
+    });
+    expect(rect).toEqual({ left: 500, top: 250, width: 1000, height: 500 });
   });
 
-  it('should use clientWidth/clientHeight for video elements', () => {
-    const video = mockVideo({ videoWidth: 1920, videoHeight: 1080, clientWidth: 800, clientHeight: 600 });
-    const metrics = getContentMetrics(video);
-    expect(metrics.contentWidth).toBe(800);
-    expect(metrics.contentHeight).toBe(450);
-    expect(metrics.offsetX).toBe(0);
-    expect(metrics.offsetY).toBe(75);
+  it('should handle letterboxed content with horizontal offset', () => {
+    const metrics = { contentWidth: 300, contentHeight: 600, offsetX: 250, offsetY: 0 };
+    const rect = mapContentRectToNatural({ left: 250, top: 0, width: 300, height: 600 }, metrics, {
+      width: 1000,
+      height: 2000,
+    });
+    expect(rect).toEqual({ left: 0, top: 0, width: 1000, height: 2000 });
   });
 });
 
 describe('getNaturalSize', () => {
   it('should return naturalWidth/naturalHeight for images', () => {
-    const img = mockImage({ naturalWidth: 4000, naturalHeight: 3000, width: 800, height: 600 });
+    const img = mockImage({ naturalWidth: 4000, naturalHeight: 3000 });
     expect(getNaturalSize(img)).toEqual({ width: 4000, height: 3000 });
   });
 

web/src/lib/utils/container-utils.ts

@@ -49,13 +49,6 @@ export const scaleToFit = (dimensions: Size, container: Size): Size => {
   };
 };
 
-const getElementSize = (element: HTMLImageElement | HTMLVideoElement): Size => {
-  if (element instanceof HTMLVideoElement) {
-    return { width: element.clientWidth, height: element.clientHeight };
-  }
-  return { width: element.width, height: element.height };
-};
-
 export const getNaturalSize = (element: HTMLImageElement | HTMLVideoElement): Size => {
   if (element instanceof HTMLVideoElement) {
     return { width: element.videoWidth, height: element.videoHeight };
@@ -63,17 +56,18 @@ export const getNaturalSize = (element: HTMLImageElement | HTMLVideoElement): Si
   return { width: element.naturalWidth, height: element.naturalHeight };
 };
 
-export const getContentMetrics = (element: HTMLImageElement | HTMLVideoElement): ContentMetrics => {
-  const natural = getNaturalSize(element);
-  const client = getElementSize(element);
-  const { width: contentWidth, height: contentHeight } = scaleToFit(natural, client);
+export function computeContentMetrics(imageSize: Size, containerSize: Size): ContentMetrics {
+  if (imageSize.width === 0 || imageSize.height === 0) {
+    return { contentWidth: 0, contentHeight: 0, offsetX: 0, offsetY: 0 };
+  }
+  const { width: contentWidth, height: contentHeight } = scaleToFit(imageSize, containerSize);
   return {
     contentWidth,
     contentHeight,
-    offsetX: (client.width - contentWidth) / 2,
-    offsetY: (client.height - contentHeight) / 2,
+    offsetX: (containerSize.width - contentWidth) / 2,
+    offsetY: (containerSize.height - contentHeight) / 2,
   };
-};
+}
 
 export function mapNormalizedToContent(point: Point, sizeOrMetrics: Size | ContentMetrics): Point {
   if ('contentWidth' in sizeOrMetrics) {
@@ -109,3 +103,25 @@ export function mapNormalizedRectToContent(
     height: br.y - tl.y,
   };
 }
+
+export function mapContentToNatural(point: Point, metrics: ContentMetrics, naturalSize: Size): Point {
+  return {
+    x: ((point.x - metrics.offsetX) / metrics.contentWidth) * naturalSize.width,
+    y: ((point.y - metrics.offsetY) / metrics.contentHeight) * naturalSize.height,
+  };
+}
+
+export function mapContentRectToNatural(rect: Rect, metrics: ContentMetrics, naturalSize: Size): Rect {
+  const topLeft = mapContentToNatural({ x: rect.left, y: rect.top }, metrics, naturalSize);
+  const bottomRight = mapContentToNatural(
+    { x: rect.left + rect.width, y: rect.top + rect.height },
+    metrics,
+    naturalSize,
+  );
+  return {
+    top: topLeft.y,
+    left: topLeft.x,
+    width: bottomRight.x - topLeft.x,
+    height: bottomRight.y - topLeft.y,
+  };
+}