fix: holes in eraser tool

src/components/canvas/Canvas.tsx

@@ -189,6 +189,7 @@ function Canvas() {
 		updateCssCursor();
 
 		pencilTool.stop();
+		eraserTool.stop();
 
 		// History entries for pencil and eraser
 		if (tool === "pencil" || tool === "eraser") {
@@ -212,7 +213,7 @@ function Canvas() {
 				() => setSelectionCoords([...prevSelection])
 			);
 		}
-	}, [updateCssCursor, pencilTool, blocks, tool, addHistory, setBlocks, selectionCoords, setSelectionCoords]);
+	}, [updateCssCursor, pencilTool, eraserTool, blocks, tool, addHistory, setBlocks, selectionCoords, setSelectionCoords]);
 
 	const onWheel = useCallback(
 		(e: React.WheelEvent) => {

src/hooks/tools/eraser.ts

@@ -1,10 +1,11 @@
-import { useContext } from "react";
+import { useContext, useRef } from "react";
 
 import { CanvasContext } from "@/context/Canvas";
 import { SelectionContext } from "@/context/Selection";
 import { ToolContext } from "@/context/Tool";
 
 import { useRadiusPosition } from "../useRadiusPosition";
+import { interpolate } from "@/utils/interpolate";
 
 export function useEraserTool(mouseCoords: Position) {
 	const { blocks, setBlocks } = useContext(CanvasContext);
@@ -12,16 +13,41 @@ export function useEraserTool(mouseCoords: Position) {
 	const { radius } = useContext(ToolContext);
 
 	const radiusPosition = useRadiusPosition(mouseCoords);
+	const lastPosition = useRef<Position | null>(null);
 
-	const use = () => {
-		const updated = blocks.filter((block) => {
-			const withinRadius =
-				block.x >= radiusPosition.x && block.x < radiusPosition.x + radius && block.y >= radiusPosition.y && block.y < radiusPosition.y + radius;
-			return !withinRadius || !isInSelection(block.x, block.y);
-		});
-
-		setBlocks(updated);
+	const stop = () => {
+		lastPosition.current = null;
 	};
 
-	return { use };
+	const use = () => {
+		const positions: Position[] = [];
+
+		const eraseBlock = (x: number, y: number) => {
+			if (isInSelection(x, y)) {
+				positions.push({ x, y });
+			}
+		};
+
+		// Interpolate to ensure continuous erasing
+		if (lastPosition.current) {
+			const interpolatedPositions = interpolate(radius, lastPosition.current, radiusPosition);
+			if (!interpolatedPositions) return;
+
+			interpolatedPositions.forEach(({ x, y }) => eraseBlock(x, y));
+		} else {
+			for (let x = 0; x < radius; x++) {
+				for (let y = 0; y < radius; y++) {
+					eraseBlock(radiusPosition.x + x, radiusPosition.y + y);
+				}
+			}
+		}
+
+		// Filter out erased blocks
+		const updatedBlocks = blocks.filter((block) => !positions.some((b) => block.x === b.x && block.y === b.y));
+
+		setBlocks(updatedBlocks);
+		lastPosition.current = radiusPosition;
+	};
+
+	return { stop, use };
 }