feat(masks): add mask editing mode

commands/tool.ts

@@ -1,3 +1,4 @@
+import type { LayerId } from "@core/id";
 import type { BrushSettings, ToolId } from "@editor/tools";
 import type { Command } from "./command";
 import { commandIds } from "./ids";
@@ -8,6 +9,10 @@ export type ToolSetActivePayload = {
 
 export type ToolSetBrushSettingsPayload = Partial<BrushSettings>;
 
+export type ToolSetMaskEditLayerPayload = {
+  layerId?: LayerId;
+};
+
 export const toolSetActiveCommand: Command<ToolSetActivePayload> = {
   id: commandIds.toolSetActive,
   name: "Set active tool",
@@ -47,6 +52,20 @@ export const toolSetBrushSettingsCommand: Command<ToolSetBrushSettingsPayload> =
   },
 };
 
+export const toolSetMaskEditLayerCommand: Command<ToolSetMaskEditLayerPayload> = {
+  id: commandIds.toolSetMaskEditLayer,
+  name: "Set mask edit layer",
+  execute({ state }, payload) {
+    return {
+      ...state,
+      editor: {
+        ...state.editor,
+        maskEditLayerId: payload.layerId,
+      },
+    };
+  },
+};
+
 export const toolEnterTemporaryPanCommand: Command = {
   id: commandIds.toolEnterTemporaryPan,
   name: "Enter temporary pan",
@@ -87,7 +106,7 @@ export const toolExitTemporaryPanCommand: Command = {
   },
 };
 
-export const toolCommands = [toolSetActiveCommand, toolSetBrushSettingsCommand, toolEnterTemporaryPanCommand, toolExitTemporaryPanCommand] satisfies Command<unknown>[];
+export const toolCommands = [toolSetActiveCommand, toolSetBrushSettingsCommand, toolSetMaskEditLayerCommand, toolEnterTemporaryPanCommand, toolExitTemporaryPanCommand] satisfies Command<unknown>[];
 
 function clampNumber(value: number, min: number, max: number) {
   if (!Number.isFinite(value)) return min;