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.

editor/initial-state.ts

@@ -12,6 +12,10 @@ export const initialEditorState: EditorState = {
     layerIds: [],
   },
   tools: initialToolState,
+  generation: {
+    candidates: [],
+    selectedCandidateId: undefined,
+  },
   transformSession: undefined,
   maskEdit: undefined,
   brushPreview: undefined,

editor/state.ts

@@ -1,7 +1,7 @@
 import type { ImageDocument } from "@core/document";
-import type { Angle, Size, Vec2D } from "@core/geometry";
+import type { Angle, Rect, Size, Transform, Vec2D } from "@core/geometry";
 import type { ArtboardId, AssetId, LayerId } from "@core/id";
-import type { ToolState } from "./tools";
+import type { GenerateSettings, ToolState } from "./tools";
 import type { TransformSession } from "./transform";
 
 export type ViewportState = {
@@ -34,10 +34,61 @@ export type BrushStrokePreviewState = {
   source: string;
 };
 
+export type GenerationCandidate = {
+  id: string;
+  source: string;
+  mimeType: string;
+  intrinsicSize: Size;
+  mode: GenerateSettings["mode"];
+  settings: GenerateSettings;
+  seed: number;
+  width: number;
+  height: number;
+  inputImage?: string;
+  maskImage?: string;
+  placement: {
+    artboardId: ArtboardId;
+    layerName: string;
+    transform: Transform;
+  };
+  inpaint?: {
+    targetLayerId: LayerId;
+    maskLayerId: LayerId;
+    sourceAssetId: AssetId;
+    maskAssetId: AssetId;
+    inputImage: string;
+    maskImage: string;
+    crop: {
+      assetBounds: Rect;
+      documentBounds: Rect;
+      padding: number;
+      maskedAreaOnly: boolean;
+    };
+    mask: {
+      polarity: GenerateSettings["inpaint"]["maskPolarity"];
+      activeBounds: Rect;
+    };
+    backend: {
+      growMaskBy: number;
+      maskedContent: GenerateSettings["inpaint"]["maskedContent"];
+      maskBlur: number;
+      maskFeather: number;
+      maskExpand: number;
+      cropPadding: number;
+    };
+  };
+};
+
+export type GenerationState = {
+  candidates: GenerationCandidate[];
+  selectedCandidateId?: string;
+};
+
 export type EditorState = {
   viewport: ViewportState;
   selection: SelectionState;
   tools: ToolState;
+  generation: GenerationState;
   transformSession?: TransformSession;
   maskEdit?: MaskEditState;
   brushPreview?: BrushPreviewState;

editor/tools.ts

@@ -27,6 +27,7 @@ export type MagicWandMode = "replace" | "add" | "subtract";
 export type GenerateMode = "text-to-image" | "image-to-image" | "inpaint" | "outpaint";
 
 export type GenerateModel = string;
+export type InpaintMaskedContent = "neutral" | "original" | "originalColor" | "edges";
 
 export type GenerateSettings = {
   mode: GenerateMode;
@@ -48,6 +49,17 @@ export type GenerateSettings = {
     bottom: number;
     feathering: number;
   };
+  inpaint: {
+    maskedAreaOnly: boolean;
+    cropPadding: number;
+    maskPolarity: "hidden" | "revealed";
+    maskedContent: InpaintMaskedContent;
+    growMaskBy: number;
+    maskExpand: number;
+    maskFeather: number;
+    maskBlur: number;
+    maskDespeckle: number;
+  };
 };
 
 export type MagicWandSettings = {
@@ -74,7 +86,22 @@ export const initialToolState: ToolState = {
   brush: { color: "#111827", size: 8, hardness: 100 },
   chromaKey: { color: "#00ff00", tolerance: 32, softness: 24, feather: 0, choke: 0, despeckle: 0, spill: 50 },
   magicWand: { tolerance: 32, feather: 0, choke: 0, despeckle: 0, contiguous: true, mode: "replace" },
-  generate: { mode: "text-to-image", model: "auto", prompt: "", negativePrompt: "", strength: 75, steps: 30, cfg: 7, seed: -1, sampler: "euler", scheduler: "normal", width: 1024, height: 1024, outpaint: { left: 128, top: 128, right: 128, bottom: 128, feathering: 32 } },
+  generate: {
+    mode: "text-to-image",
+    model: "auto",
+    prompt: "",
+    negativePrompt: "",
+    strength: 75,
+    steps: 30,
+    cfg: 7,
+    seed: -1,
+    sampler: "euler",
+    scheduler: "normal",
+    width: 1024,
+    height: 1024,
+    outpaint: { left: 128, top: 128, right: 128, bottom: 128, feathering: 32 },
+    inpaint: { maskedAreaOnly: true, cropPadding: 96, maskPolarity: "hidden", maskedContent: "neutral", growMaskBy: 6, maskExpand: 0, maskFeather: 0, maskBlur: 0, maskDespeckle: 0 },
+  },
 };
 
 export function isPanInteractionMode(interactionMode: InteractionMode): boolean {