"use strict";
Object.defineProperty(exports, Symbol.toStringTag, { value: "Module" });
const THREE = require("three");
const CSMFrustum = require("./CSMFrustum.cjs");
const CSMShader = require("./CSMShader.cjs");
const _cameraToLightMatrix = /* @__PURE__ */ new THREE.Matrix4();
const _lightSpaceFrustum = /* @__PURE__ */ new CSMFrustum.CSMFrustum();
const _center = /* @__PURE__ */ new THREE.Vector3();
const _bbox = /* @__PURE__ */ new THREE.Box3();
const _uniformArray = [];
const _logArray = [];
class CSM {
  constructor(data) {
    data = data || {};
    this.camera = data.camera;
    this.parent = data.parent;
    this.cascades = data.cascades || 3;
    this.maxFar = data.maxFar || 1e5;
    this.mode = data.mode || "practical";
    this.shadowMapSize = data.shadowMapSize || 2048;
    this.shadowBias = data.shadowBias || 1e-6;
    this.lightDirection = data.lightDirection || new THREE.Vector3(1, -1, 1).normalize();
    this.lightIntensity = data.lightIntensity || 1;
    this.lightNear = data.lightNear || 1;
    this.lightFar = data.lightFar || 2e3;
    this.lightMargin = data.lightMargin || 200;
    this.customSplitsCallback = data.customSplitsCallback;
    this.fade = false;
    this.mainFrustum = new CSMFrustum.CSMFrustum();
    this.frustums = [];
    this.breaks = [];
    this.lights = [];
    this.shaders = /* @__PURE__ */ new Map();
    this.createLights();
    this.updateFrustums();
    this.injectInclude();
  }
  createLights() {
    for (let i = 0; i < this.cascades; i++) {
      const light = new THREE.DirectionalLight(16777215, this.lightIntensity);
      light.castShadow = true;
      light.shadow.mapSize.width = this.shadowMapSize;
      light.shadow.mapSize.height = this.shadowMapSize;
      light.shadow.camera.near = this.lightNear;
      light.shadow.camera.far = this.lightFar;
      light.shadow.bias = this.shadowBias;
      this.parent.add(light);
      this.parent.add(light.target);
      this.lights.push(light);
    }
  }
  initCascades() {
    const camera = this.camera;
    camera.updateProjectionMatrix();
    this.mainFrustum.setFromProjectionMatrix(camera.projectionMatrix, this.maxFar);
    this.mainFrustum.split(this.breaks, this.frustums);
  }
  updateShadowBounds() {
    const frustums = this.frustums;
    for (let i = 0; i < frustums.length; i++) {
      const light = this.lights[i];
      const shadowCam = light.shadow.camera;
      const frustum = this.frustums[i];
      const nearVerts = frustum.vertices.near;
      const farVerts = frustum.vertices.far;
      const point1 = farVerts[0];
      let point2;
      if (point1.distanceTo(farVerts[2]) > point1.distanceTo(nearVerts[2])) {
        point2 = farVerts[2];
      } else {
        point2 = nearVerts[2];
      }
      let squaredBBWidth = point1.distanceTo(point2);
      if (this.fade) {
        const camera = this.camera;
        const far = Math.max(camera.far, this.maxFar);
        const linearDepth = frustum.vertices.far[0].z / (far - camera.near);
        const margin = 0.25 * Math.pow(linearDepth, 2) * (far - camera.near);
        squaredBBWidth += margin;
      }
      shadowCam.left = -squaredBBWidth / 2;
      shadowCam.right = squaredBBWidth / 2;
      shadowCam.top = squaredBBWidth / 2;
      shadowCam.bottom = -squaredBBWidth / 2;
      shadowCam.updateProjectionMatrix();
    }
  }
  getBreaks() {
    const camera = this.camera;
    const far = Math.min(camera.far, this.maxFar);
    this.breaks.length = 0;
    switch (this.mode) {
      case "uniform":
        uniformSplit(this.cascades, camera.near, far, this.breaks);
        break;
      case "logarithmic":
        logarithmicSplit(this.cascades, camera.near, far, this.breaks);
        break;
      case "practical":
        practicalSplit(this.cascades, camera.near, far, 0.5, this.breaks);
        break;
      case "custom":
        if (this.customSplitsCallback === void 0)
          console.error("CSM: Custom split scheme callback not defined.");
        this.customSplitsCallback(this.cascades, camera.near, far, this.breaks);
        break;
    }
    function uniformSplit(amount, near, far2, target) {
      for (let i = 1; i < amount; i++) {
        target.push((near + (far2 - near) * i / amount) / far2);
      }
      target.push(1);
    }
    function logarithmicSplit(amount, near, far2, target) {
      for (let i = 1; i < amount; i++) {
        target.push(near * (far2 / near) ** (i / amount) / far2);
      }
      target.push(1);
    }
    function practicalSplit(amount, near, far2, lambda, target) {
      _uniformArray.length = 0;
      _logArray.length = 0;
      logarithmicSplit(amount, near, far2, _logArray);
      uniformSplit(amount, near, far2, _uniformArray);
      for (let i = 1; i < amount; i++) {
        target.push(THREE.MathUtils.lerp(_uniformArray[i - 1], _logArray[i - 1], lambda));
      }
      target.push(1);
    }
  }
  update() {
    const camera = this.camera;
    const frustums = this.frustums;
    for (let i = 0; i < frustums.length; i++) {
      const light = this.lights[i];
      const shadowCam = light.shadow.camera;
      const texelWidth = (shadowCam.right - shadowCam.left) / this.shadowMapSize;
      const texelHeight = (shadowCam.top - shadowCam.bottom) / this.shadowMapSize;
      light.shadow.camera.updateMatrixWorld(true);
      _cameraToLightMatrix.multiplyMatrices(light.shadow.camera.matrixWorldInverse, camera.matrixWorld);
      frustums[i].toSpace(_cameraToLightMatrix, _lightSpaceFrustum);
      const nearVerts = _lightSpaceFrustum.vertices.near;
      const farVerts = _lightSpaceFrustum.vertices.far;
      _bbox.makeEmpty();
      for (let j = 0; j < 4; j++) {
        _bbox.expandByPoint(nearVerts[j]);
        _bbox.expandByPoint(farVerts[j]);
      }
      _bbox.getCenter(_center);
      _center.z = _bbox.max.z + this.lightMargin;
      _center.x = Math.floor(_center.x / texelWidth) * texelWidth;
      _center.y = Math.floor(_center.y / texelHeight) * texelHeight;
      _center.applyMatrix4(light.shadow.camera.matrixWorld);
      light.position.copy(_center);
      light.target.position.copy(_center);
      light.target.position.x += this.lightDirection.x;
      light.target.position.y += this.lightDirection.y;
      light.target.position.z += this.lightDirection.z;
    }
  }
  injectInclude() {
    THREE.ShaderChunk.lights_fragment_begin = CSMShader.CSMShader.lights_fragment_begin;
    THREE.ShaderChunk.lights_pars_begin = CSMShader.CSMShader.lights_pars_begin;
  }
  setupMaterial(material) {
    material.defines = material.defines || {};
    material.defines.USE_CSM = 1;
    material.defines.CSM_CASCADES = this.cascades;
    if (this.fade) {
      material.defines.CSM_FADE = "";
    }
    const breaksVec2 = [];
    const scope = this;
    const shaders = this.shaders;
    material.onBeforeCompile = function(shader) {
      const far = Math.min(scope.camera.far, scope.maxFar);
      scope.getExtendedBreaks(breaksVec2);
      shader.uniforms.CSM_cascades = { value: breaksVec2 };
      shader.uniforms.cameraNear = { value: scope.camera.near };
      shader.uniforms.shadowFar = { value: far };
      shaders.set(material, shader);
    };
    shaders.set(material, null);
  }
  updateUniforms() {
    const far = Math.min(this.camera.far, this.maxFar);
    const shaders = this.shaders;
    shaders.forEach(function(shader, material) {
      if (shader !== null) {
        const uniforms = shader.uniforms;
        this.getExtendedBreaks(uniforms.CSM_cascades.value);
        uniforms.cameraNear.value = this.camera.near;
        uniforms.shadowFar.value = far;
      }
      if (!this.fade && "CSM_FADE" in material.defines) {
        delete material.defines.CSM_FADE;
        material.needsUpdate = true;
      } else if (this.fade && !("CSM_FADE" in material.defines)) {
        material.defines.CSM_FADE = "";
        material.needsUpdate = true;
      }
    }, this);
  }
  getExtendedBreaks(target) {
    while (target.length < this.breaks.length) {
      target.push(new THREE.Vector2());
    }
    target.length = this.breaks.length;
    for (let i = 0; i < this.cascades; i++) {
      const amount = this.breaks[i];
      const prev = this.breaks[i - 1] || 0;
      target[i].x = prev;
      target[i].y = amount;
    }
  }
  updateFrustums() {
    this.getBreaks();
    this.initCascades();
    this.updateShadowBounds();
    this.updateUniforms();
  }
  remove() {
    for (let i = 0; i < this.lights.length; i++) {
      this.parent.remove(this.lights[i]);
    }
  }
  dispose() {
    const shaders = this.shaders;
    shaders.forEach(function(shader, material) {
      delete material.onBeforeCompile;
      delete material.defines.USE_CSM;
      delete material.defines.CSM_CASCADES;
      delete material.defines.CSM_FADE;
      if (shader !== null) {
        delete shader.uniforms.CSM_cascades;
        delete shader.uniforms.cameraNear;
        delete shader.uniforms.shadowFar;
      }
      material.needsUpdate = true;
    });
    shaders.clear();
  }
}
exports.CSM = CSM;
//# sourceMappingURL=CSM.cjs.map