1 files changed, 75 insertions, 0 deletions
diff --git a/apps/web/src/masks/definitions/ellipse.ts b/apps/web/src/masks/definitions/ellipse.ts
new file mode 100644
index 00000000..d0567817
--- /dev/null
+++ b/apps/web/src/masks/definitions/ellipse.ts
@@ -0,0 +1,75 @@
+import type { MaskDefinition, RectangleMaskParams } from "@/masks/types";
+import {
+	BOX_LIKE_MASK_PARAMS,
+	buildBoxMaskInteraction,
+	computeBoxMaskParamUpdate,
+	getBoxLikeGeometry,
+	getDefaultSquareMaskParams,
+	getStrokeOffset,
+} from "./box-like";
+
+export const ellipseMaskDefinition: MaskDefinition<RectangleMaskParams> = {
+	type: "ellipse",
+	name: "Ellipse",
+	features: {
+		hasPosition: true,
+		hasRotation: true,
+		sizeMode: "width-height",
+	},
+	params: BOX_LIKE_MASK_PARAMS,
+	interaction: buildBoxMaskInteraction({
+		sizeMode: "width-height",
+		buildOverlayPath({ width, height }) {
+			const rx = Math.max((width - 1) / 2, 0);
+			const ry = Math.max((height - 1) / 2, 0);
+			const cx = width / 2;
+			const cy = height / 2;
+			return `M ${cx},${cy - ry} A ${rx},${ry} 0 1,1 ${cx},${cy + ry} A ${rx},${ry} 0 1,1 ${cx},${cy - ry} Z`;
+		},
+	}),
+	buildDefault(context) {
+		return {
+			type: "ellipse",
+			params: getDefaultSquareMaskParams(context),
+		};
+	},
+	computeParamUpdate: computeBoxMaskParamUpdate,
+	renderer: {
+		buildPath({ resolvedParams, width, height }) {
+			const params = resolvedParams as RectangleMaskParams;
+			const { centerX, centerY, maskWidth, maskHeight, rotationRad } =
+				getBoxLikeGeometry({ params, width, height });
+			const path = new Path2D();
+			path.ellipse(
+				centerX,
+				centerY,
+				maskWidth / 2,
+				maskHeight / 2,
+				rotationRad,
+				0,
+				Math.PI * 2,
+			);
+			return path;
+		},
+		buildStrokePath({ resolvedParams, width, height }) {
+			const params = resolvedParams as RectangleMaskParams;
+			const { centerX, centerY, maskWidth, maskHeight, rotationRad } =
+				getBoxLikeGeometry({ params, width, height });
+			const offset = getStrokeOffset({
+				strokeAlign: params.strokeAlign,
+				strokeWidth: params.strokeWidth,
+			});
+			const path = new Path2D();
+			path.ellipse(
+				centerX,
+				centerY,
+				Math.max(1, maskWidth / 2 + offset),
+				Math.max(1, maskHeight / 2 + offset),
+				rotationRad,
+				0,
+				Math.PI * 2,
+			);
+			return path;
+		},
+	},
+};