(function (global, factory) {
  if (typeof define === "function" && define.amd) {
    define(["exports", "three"], factory);
  } else if (typeof exports !== "undefined") {
    factory(exports, require("three"));
  } else {
    var mod = {
      exports: {}
    };
    factory(mod.exports, global.three);
    global.CSMFrustum = mod.exports;
  }
})(typeof globalThis !== "undefined" ? globalThis : typeof self !== "undefined" ? self : this, function (_exports, _three) {
  "use strict";

  Object.defineProperty(_exports, "__esModule", {
    value: true
  });
  _exports.CSMFrustum = void 0;

  function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

  function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }

  function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); Object.defineProperty(Constructor, "prototype", { writable: false }); return Constructor; }

  var inverseProjectionMatrix = new _three.Matrix4();

  var CSMFrustum = /*#__PURE__*/function () {
    function CSMFrustum(data) {
      _classCallCheck(this, CSMFrustum);

      data = data || {};
      this.vertices = {
        near: [new _three.Vector3(), new _three.Vector3(), new _three.Vector3(), new _three.Vector3()],
        far: [new _three.Vector3(), new _three.Vector3(), new _three.Vector3(), new _three.Vector3()]
      };

      if (data.projectionMatrix !== undefined) {
        this.setFromProjectionMatrix(data.projectionMatrix, data.maxFar || 10000);
      }
    }

    _createClass(CSMFrustum, [{
      key: "setFromProjectionMatrix",
      value: function setFromProjectionMatrix(projectionMatrix, maxFar) {
        var isOrthographic = projectionMatrix.elements[2 * 4 + 3] === 0;
        inverseProjectionMatrix.copy(projectionMatrix).invert(); // 3 --- 0  vertices.near/far order
        // |     |
        // 2 --- 1
        // clip space spans from [-1, 1]

        this.vertices.near[0].set(1, 1, -1);
        this.vertices.near[1].set(1, -1, -1);
        this.vertices.near[2].set(-1, -1, -1);
        this.vertices.near[3].set(-1, 1, -1);
        this.vertices.near.forEach(function (v) {
          v.applyMatrix4(inverseProjectionMatrix);
        });
        this.vertices.far[0].set(1, 1, 1);
        this.vertices.far[1].set(1, -1, 1);
        this.vertices.far[2].set(-1, -1, 1);
        this.vertices.far[3].set(-1, 1, 1);
        this.vertices.far.forEach(function (v) {
          v.applyMatrix4(inverseProjectionMatrix);
          var absZ = Math.abs(v.z);

          if (isOrthographic) {
            v.z *= Math.min(maxFar / absZ, 1.0);
          } else {
            v.multiplyScalar(Math.min(maxFar / absZ, 1.0));
          }
        });
        return this.vertices;
      }
    }, {
      key: "split",
      value: function split(breaks, target) {
        while (breaks.length > target.length) {
          target.push(new CSMFrustum());
        }

        target.length = breaks.length;

        for (var i = 0; i < breaks.length; i++) {
          var cascade = target[i];

          if (i === 0) {
            for (var j = 0; j < 4; j++) {
              cascade.vertices.near[j].copy(this.vertices.near[j]);
            }
          } else {
            for (var _j = 0; _j < 4; _j++) {
              cascade.vertices.near[_j].lerpVectors(this.vertices.near[_j], this.vertices.far[_j], breaks[i - 1]);
            }
          }

          if (i === breaks.length - 1) {
            for (var _j2 = 0; _j2 < 4; _j2++) {
              cascade.vertices.far[_j2].copy(this.vertices.far[_j2]);
            }
          } else {
            for (var _j3 = 0; _j3 < 4; _j3++) {
              cascade.vertices.far[_j3].lerpVectors(this.vertices.near[_j3], this.vertices.far[_j3], breaks[i]);
            }
          }
        }
      }
    }, {
      key: "toSpace",
      value: function toSpace(cameraMatrix, target) {
        for (var i = 0; i < 4; i++) {
          target.vertices.near[i].copy(this.vertices.near[i]).applyMatrix4(cameraMatrix);
          target.vertices.far[i].copy(this.vertices.far[i]).applyMatrix4(cameraMatrix);
        }
      }
    }]);

    return CSMFrustum;
  }();

  _exports.CSMFrustum = CSMFrustum;
});