feat: Add rounded corners shape

src/shapes/index.ts

@@ -10,3 +10,4 @@ export * from './trim-shape';
 export * from './gradient-stroke-shape';
 export * from './repeater-shape';
 export * from './star-shape';
+export * from './rounded-corners-shape';

src/shapes/rounded-corners-shape.ts

@@ -0,0 +1,59 @@
+import { PropertyType, ShapeType } from '../constants';
+import { Property } from '../properties';
+import { Shape } from './shape';
+
+/**
+ * Rounded Corners shape type.
+ */
+export class RoundedCornersShape extends Shape {
+  /**
+   * RoundedCorners shape type: rp
+   */
+  public readonly type = ShapeType.ROUNDED_CORNERS;
+
+  public roundness: Property = new Property(this, PropertyType.NUMBER);
+
+  /**
+   * Convert the Lottie JSON object to class instance.
+   *
+   * @param json    JSON object
+   * @returns       GroupShape instance
+   */
+  public fromJSON(json: Record<string, any>): RoundedCornersShape {
+    // Base shape
+    this.classNames = json.cl;
+    this.id = json.ln;
+    this.isHidden = json.hd;
+    this.matchName = json.mn;
+    this.name = json.nm;
+
+    // This shape
+    this.roundness.fromJSON(json.r);
+
+    return this;
+  }
+
+  /**
+   * Convert the class instance to Lottie JSON object.
+   *
+   * Called by Javascript when serializing object with JSON.stringify()
+   *
+   * @returns       JSON object
+   */
+  public toJSON(): Record<string, any> {
+
+    return {
+      ty: this.type,
+
+      // Base shape
+      cl: this.classNames,
+      hd: this.isHidden,
+      ln: this.id,
+      mn: this.matchName,
+      nm: this.name,
+
+      // This shape
+      r: this.roundness,
+    };
+  }
+}