Add existing to tracked

node_modules/@cesium/engine/Source/Scene/BlendEquation.js

@@ -0,0 +1,58 @@
+// @ts-check
+
+import WebGLConstants from "../Core/WebGLConstants.js";
+
+/**
+ * Determines how two pixels' values are combined.
+ *
+ * @enum {number}
+ */
+const BlendEquation = {
+  /**
+   * Pixel values are added componentwise.  This is used in additive blending for translucency.
+   *
+   * @type {number}
+   * @constant
+   */
+  ADD: WebGLConstants.FUNC_ADD,
+
+  /**
+   * Pixel values are subtracted componentwise (source - destination).  This is used in alpha blending for translucency.
+   *
+   * @type {number}
+   * @constant
+   */
+  SUBTRACT: WebGLConstants.FUNC_SUBTRACT,
+
+  /**
+   * Pixel values are subtracted componentwise (destination - source).
+   *
+   * @type {number}
+   * @constant
+   */
+  REVERSE_SUBTRACT: WebGLConstants.FUNC_REVERSE_SUBTRACT,
+
+  /**
+   * Pixel values are given to the minimum function (min(source, destination)).
+   *
+   * This equation operates on each pixel color component.
+   *
+   * @type {number}
+   * @constant
+   */
+  MIN: WebGLConstants.MIN,
+
+  /**
+   * Pixel values are given to the maximum function (max(source, destination)).
+   *
+   * This equation operates on each pixel color component.
+   *
+   * @type {number}
+   * @constant
+   */
+  MAX: WebGLConstants.MAX,
+};
+
+Object.freeze(BlendEquation);
+
+export default BlendEquation;