feat: implement inpainting functionality with mask handling

- Added `createMaskedPixelReplacementSource` function to handle pixel replacement using inpainting.
- Introduced `buildInpaintBundle` to prepare inpainting data including mask generation and validation.
- Created utility functions for mask operations such as `applyMaskedContentModeToRgba`, `expandRectWithinBounds`, and others for mask manipulation.
- Developed tests for inpainting preparation and mask raster utilities to ensure functionality and correctness.
- Implemented mask raster operations including inversion, feathering, blurring, and more.

renderer/layers.ts

@@ -1,7 +1,9 @@
+import type { Asset } from "@core/asset";
 import type { ImageDocument } from "@core/document";
+import type { Rect } from "@core/geometry";
 import type { Layer } from "@core/layer";
 import { createDocumentReadIndex, forEachLayerBackToFront, resolveIndexedLayerBounds, type DocumentReadIndex } from "@editor/document-indexes";
-import type { EditorState, MaskViewMode, ViewportState } from "@editor/state";
+import type { EditorState, GenerationCandidate, MaskViewMode, ViewportState } from "@editor/state";
 import { clearScreenRect } from "./clear-rect";
 import type { ImageTextureRenderer } from "./image-textures";
 import { documentRectToScreenRect } from "./screen-rect";
@@ -14,15 +16,21 @@ const maskRevealPreviewOpacity = 0.28;
 
 export function renderLayers(context: WebGlRendererContext, document: ImageDocument, editor: EditorState, imageTextureRenderer: ImageTextureRenderer) {
   const documentIndex = createDocumentReadIndex(document);
+  const generationCandidate = selectedGenerationCandidate(editor);
 
   for (const artboard of document.artboards) {
     if (!artboard.visible) continue;
     const clipRect = documentRectToScreenRect(context.canvas, artboard.bounds, editor.viewport);
     const maskLayerIds = documentIndex.maskLayerIdsByArtboardId.get(artboard.id) ?? emptyLayerIds;
     forEachLayerBackToFront(artboard.layers, (layer) => renderLayer(context, documentIndex, editor, layer, imageTextureRenderer, clipRect, maskLayerIds));
+    if (generationCandidate?.placement.artboardId === artboard.id) renderGenerationCandidatePreview(context, editor, generationCandidate, imageTextureRenderer, clipRect);
   }
 }
 
+export function generationCandidatePreviewAssets(editor: EditorState): Asset[] {
+  return editor.generation.candidates.map((candidate) => generationCandidateAsset(candidate));
+}
+
 function renderLayer(
   context: WebGlRendererContext,
   documentIndex: DocumentReadIndex,
@@ -102,6 +110,44 @@ function isIsolatedMaskView(mode: MaskViewMode) {
   return mode === "blackWhite" || mode === "alpha" || mode === "overlay";
 }
 
+function renderGenerationCandidatePreview(
+  context: WebGlRendererContext,
+  editor: EditorState,
+  candidate: GenerationCandidate,
+  imageTextureRenderer: ImageTextureRenderer,
+  clipRect: ScreenRect,
+) {
+  const rect = documentRectToScreenRect(context.canvas, generationCandidateBounds(candidate), editor.viewport);
+  imageTextureRenderer.render(generationCandidateAsset(candidate), rect, clipRect);
+}
+
+function selectedGenerationCandidate(editor: EditorState): GenerationCandidate | undefined {
+  return editor.generation.candidates.find((candidate) => candidate.id === editor.generation.selectedCandidateId) ?? editor.generation.candidates[0];
+}
+
+function generationCandidateAsset(candidate: GenerationCandidate): Asset {
+  return {
+    id: generationCandidateAssetId(candidate.id),
+    name: candidate.placement.layerName,
+    mimeType: candidate.mimeType,
+    source: candidate.source,
+    intrinsicSize: candidate.intrinsicSize,
+  };
+}
+
+function generationCandidateAssetId(candidateId: string) {
+  return `generation-candidate:${candidateId}`;
+}
+
+function generationCandidateBounds(candidate: GenerationCandidate): Rect {
+  return {
+    x: candidate.placement.transform.position.x,
+    y: candidate.placement.transform.position.y,
+    w: candidate.intrinsicSize.w * candidate.placement.transform.scale.x,
+    h: candidate.intrinsicSize.h * candidate.placement.transform.scale.y,
+  };
+}
+
 function assetWithBrushStrokePreview<TAsset extends ImageDocument["assets"][number] | undefined>(asset: TAsset, editor: EditorState): TAsset {
   if (!asset || editor.brushStrokePreview?.assetId !== asset.id) return asset;
   return { ...asset, source: editor.brushStrokePreview.source } as TAsset;