text: /**
   * @module ol/render/webgl/TextureReplay
   */
  import {getUid, inherits} from '../../index.js';
  import {intersects} from '../../extent.js';
  import {isEmpty} from '../../obj.js';
  import {fragment, vertex} from '../webgl/texturereplay/defaultshader.js';
  import Locations from '../webgl/texturereplay/defaultshader/Locations.js';
  import WebGLReplay from '../webgl/Replay.js';
  import {CLAMP_TO_EDGE, FLOAT, TEXTURE_2D} from '../../webgl.js';
  import {createTexture} from '../../webgl/Context.js';
  
  /**
   * @constructor
   * @abstract
   * @extends {ol.render.webgl.Replay}
   * @param {number} tolerance Tolerance.
   * @param {module:ol/extent~Extent} maxExtent Max extent.
   * @struct
   */
  const WebGLTextureReplay = function(tolerance, maxExtent) {
    WebGLReplay.call(this, tolerance, maxExtent);
  
    /**
     * @type {number|undefined}
     * @protected
     */
    this.anchorX = undefined;
  
    /**
     * @type {number|undefined}
     * @protected
     */
    this.anchorY = undefined;
  
    /**
     * @type {Array.<number>}
     * @protected
     */
    this.groupIndices = [];
  
    /**
     * @type {Array.<number>}
     * @protected
     */
    this.hitDetectionGroupIndices = [];
  
    /**
     * @type {number|undefined}
     * @protected
     */
    this.height = undefined;
  
    /**
     * @type {number|undefined}
     * @protected
     */
    this.imageHeight = undefined;
  
    /**
     * @type {number|undefined}
     * @protected
     */
    this.imageWidth = undefined;
  
    /**
     * @protected
     * @type {ol.render.webgl.texturereplay.defaultshader.Locations}
     */
    this.defaultLocations = null;
  
    /**
     * @protected
     * @type {number|undefined}
     */
    this.opacity = undefined;
  
    /**
     * @type {number|undefined}
     * @protected
     */
    this.originX = undefined;
  
    /**
     * @type {number|undefined}
     * @protected
     */
    this.originY = undefined;
  
    /**
     * @protected
     * @type {boolean|undefined}
     */
    this.rotateWithView = undefined;
  
    /**
     * @protected
     * @type {number|undefined}
     */
    this.rotation = undefined;
  
    /**
     * @protected
     * @type {number|undefined}
     */
    this.scale = undefined;
  
    /**
     * @type {number|undefined}
     * @protected
     */
    this.width = undefined;
  };
  
  inherits(WebGLTextureReplay, WebGLReplay);
  
  
  /**
   * @inheritDoc
   */
  WebGLTextureReplay.prototype.getDeleteResourcesFunction = function(context) {
    const verticesBuffer = this.verticesBuffer;
    const indicesBuffer = this.indicesBuffer;
    const textures = this.getTextures(true);
    const gl = context.getGL();
    return function() {
      if (!gl.isContextLost()) {
        let i, ii;
        for (i = 0, ii = textures.length; i < ii; ++i) {
          gl.deleteTexture(textures[i]);
        }
      }
      context.deleteBuffer(verticesBuffer);
      context.deleteBuffer(indicesBuffer);
    };
  };
  
  
  /**
   * @param {Array.<number>} flatCoordinates Flat coordinates.
   * @param {number} offset Offset.
   * @param {number} end End.
   * @param {number} stride Stride.
   * @return {number} My end.
   * @protected
   */
  WebGLTextureReplay.prototype.drawCoordinates = function(flatCoordinates, offset, end, stride) {
    const anchorX = /** @type {number} */ (this.anchorX);
    const anchorY = /** @type {number} */ (this.anchorY);
    const height = /** @type {number} */ (this.height);
    const imageHeight = /** @type {number} */ (this.imageHeight);
    const imageWidth = /** @type {number} */ (this.imageWidth);
    const opacity = /** @type {number} */ (this.opacity);
    const originX = /** @type {number} */ (this.originX);
    const originY = /** @type {number} */ (this.originY);
    const rotateWithView = this.rotateWithView ? 1.0 : 0.0;
    // this.rotation_ is anti-clockwise, but rotation is clockwise
    const rotation = /** @type {number} */ (-this.rotation);
    const scale = /** @type {number} */ (this.scale);
    const width = /** @type {number} */ (this.width);
    const cos = Math.cos(rotation);
    const sin = Math.sin(rotation);
    let numIndices = this.indices.length;
    let numVertices = this.vertices.length;
    let i, n, offsetX, offsetY, x, y;
    for (i = offset; i < end; i += stride) {
      x = flatCoordinates[i] - this.origin[0];
      y = flatCoordinates[i + 1] - this.origin[1];
  
      // There are 4 vertices per [x, y] point, one for each corner of the
      // rectangle we're going to draw. We'd use 1 vertex per [x, y] point if
      // WebGL supported Geometry Shaders (which can emit new vertices), but that
      // is not currently the case.
      //
      // And each vertex includes 8 values: the x and y coordinates, the x and
      // y offsets used to calculate the position of the corner, the u and
      // v texture coordinates for the corner, the opacity, and whether the
      // the image should be rotated with the view (rotateWithView).
  
      n = numVertices / 8;
  
      // bottom-left corner
      offsetX = -scale * anchorX;
      offsetY = -scale * (height - anchorY);
      this.vertices[numVertices++] = x;
      this.vertices[numVertices++] = y;
      this.vertices[numVertices++] = offsetX * cos - offsetY * sin;
      this.vertices[numVertices++] = offsetX * sin + offsetY * cos;
      this.vertices[numVertices++] = originX / imageWidth;
      this.vertices[numVertices++] = (originY + height) / imageHeight;
      this.vertices[numVertices++] = opacity;
      this.vertices[numVertices++] = rotateWithView;
  
      // bottom-right corner
      offsetX = scale * (width - anchorX);
      offsetY = -scale * (height - anchorY);
      this.vertices[numVertices++] = x;
      this.vertices[numVertices++] = y;
      this.vertices[numVertices++] = offsetX * cos - offsetY * sin;
      this.vertices[numVertices++] = offsetX * sin + offsetY * cos;
      this.vertices[numVertices++] = (originX + width) / imageWidth;
      this.vertices[numVertices++] = (originY + height) / imageHeight;
      this.vertices[numVertices++] = opacity;
      this.vertices[numVertices++] = rotateWithView;
  
      // top-right corner
      offsetX = scale * (width - anchorX);
      offsetY = scale * anchorY;
      this.vertices[numVertices++] = x;
      this.vertices[numVertices++] = y;
      this.vertices[numVertices++] = offsetX * cos - offsetY * sin;
      this.vertices[numVertices++] = offsetX * sin + offsetY * cos;
      this.vertices[numVertices++] = (originX + width) / imageWidth;
      this.vertices[numVertices++] = originY / imageHeight;
      this.vertices[numVertices++] = opacity;
      this.vertices[numVertices++] = rotateWithView;
  
      // top-left corner
      offsetX = -scale * anchorX;
      offsetY = scale * anchorY;
      this.vertices[numVertices++] = x;
      this.vertices[numVertices++] = y;
      this.vertices[numVertices++] = offsetX * cos - offsetY * sin;
      this.vertices[numVertices++] = offsetX * sin + offsetY * cos;
      this.vertices[numVertices++] = originX / imageWidth;
      this.vertices[numVertices++] = originY / imageHeight;
      this.vertices[numVertices++] = opacity;
      this.vertices[numVertices++] = rotateWithView;
  
      this.indices[numIndices++] = n;
      this.indices[numIndices++] = n + 1;
      this.indices[numIndices++] = n + 2;
      this.indices[numIndices++] = n;
      this.indices[numIndices++] = n + 2;
      this.indices[numIndices++] = n + 3;
    }
  
    return numVertices;
  };
  
  
  /**
   * @protected
   * @param {Array.<WebGLTexture>} textures Textures.
   * @param {Array.<HTMLCanvasElement|HTMLImageElement|HTMLVideoElement>} images Images.
   * @param {!Object.<string, WebGLTexture>} texturePerImage Texture cache.
   * @param {WebGLRenderingContext} gl Gl.
   */
  WebGLTextureReplay.prototype.createTextures = function(textures, images, texturePerImage, gl) {
    let texture, image, uid, i;
    const ii = images.length;
    for (i = 0; i < ii; ++i) {
      image = images[i];
  
      uid = getUid(image).toString();
      if (uid in texturePerImage) {
        texture = texturePerImage[uid];
      } else {
        texture = createTexture(
          gl, image, CLAMP_TO_EDGE, CLAMP_TO_EDGE);
        texturePerImage[uid] = texture;
      }
      textures[i] = texture;
    }
  };
  
  
  /**
   * @inheritDoc
   */
  WebGLTextureReplay.prototype.setUpProgram = function(gl, context, size, pixelRatio) {
    // get the program
    const program = context.getProgram(fragment, vertex);
  
    // get the locations
    let locations;
    if (!this.defaultLocations) {
      locations = new Locations(gl, program);
      this.defaultLocations = locations;
    } else {
      locations = this.defaultLocations;
    }
  
    // use the program (FIXME: use the return value)
    context.useProgram(program);
  
    // enable the vertex attrib arrays
    gl.enableVertexAttribArray(locations.a_position);
    gl.vertexAttribPointer(locations.a_position, 2, FLOAT,
      false, 32, 0);
  
    gl.enableVertexAttribArray(locations.a_offsets);
    gl.vertexAttribPointer(locations.a_offsets, 2, FLOAT,
      false, 32, 8);
  
    gl.enableVertexAttribArray(locations.a_texCoord);
    gl.vertexAttribPointer(locations.a_texCoord, 2, FLOAT,
      false, 32, 16);
  
    gl.enableVertexAttribArray(locations.a_opacity);
    gl.vertexAttribPointer(locations.a_opacity, 1, FLOAT,
      false, 32, 24);
  
    gl.enableVertexAttribArray(locations.a_rotateWithView);
    gl.vertexAttribPointer(locations.a_rotateWithView, 1, FLOAT,
      false, 32, 28);
  
    return locations;
  };
  
  
  /**
   * @inheritDoc
   */
  WebGLTextureReplay.prototype.shutDownProgram = function(gl, locations) {
    gl.disableVertexAttribArray(locations.a_position);
    gl.disableVertexAttribArray(locations.a_offsets);
    gl.disableVertexAttribArray(locations.a_texCoord);
    gl.disableVertexAttribArray(locations.a_opacity);
    gl.disableVertexAttribArray(locations.a_rotateWithView);
  };
  
  
  /**
   * @inheritDoc
   */
  WebGLTextureReplay.prototype.drawReplay = function(gl, context, skippedFeaturesHash, hitDetection) {
    const textures = hitDetection ? this.getHitDetectionTextures() : this.getTextures();
    const groupIndices = hitDetection ? this.hitDetectionGroupIndices : this.groupIndices;
  
    if (!isEmpty(skippedFeaturesHash)) {
      this.drawReplaySkipping(gl, context, skippedFeaturesHash, textures, groupIndices);
    } else {
      let i, ii, start;
      for (i = 0, ii = textures.length, start = 0; i < ii; ++i) {
        gl.bindTexture(TEXTURE_2D, textures[i]);
        const end = groupIndices[i];
        this.drawElements(gl, context, start, end);
        start = end;
      }
    }
  };
  
  
  /**
   * Draw the replay while paying attention to skipped features.
   *
   * This functions creates groups of features that can be drawn to together,
   * so that the number of `drawElements` calls is minimized.
   *
   * For example given the following texture groups:
   *
   *    Group 1: A B C
   *    Group 2: D [E] F G
   *
   * If feature E should be skipped, the following `drawElements` calls will be
   * made:
   *
   *    drawElements with feature A, B and C
   *    drawElements with feature D
   *    drawElements with feature F and G
   *
   * @protected
   * @param {WebGLRenderingContext} gl gl.
   * @param {module:ol/webgl/Context~WebGLContext} context Context.
   * @param {Object.<string, boolean>} skippedFeaturesHash Ids of features
   *  to skip.
   * @param {Array.<WebGLTexture>} textures Textures.
   * @param {Array.<number>} groupIndices Texture group indices.
   */
  WebGLTextureReplay.prototype.drawReplaySkipping = function(gl, context, skippedFeaturesHash, textures,
    groupIndices) {
    let featureIndex = 0;
  
    let i, ii;
    for (i = 0, ii = textures.length; i < ii; ++i) {
      gl.bindTexture(TEXTURE_2D, textures[i]);
      const groupStart = (i > 0) ? groupIndices[i - 1] : 0;
      const groupEnd = groupIndices[i];
  
      let start = groupStart;
      let end = groupStart;
      while (featureIndex < this.startIndices.length &&
          this.startIndices[featureIndex] <= groupEnd) {
        const feature = this.startIndicesFeature[featureIndex];
  
        const featureUid = getUid(feature).toString();
        if (skippedFeaturesHash[featureUid] !== undefined) {
          // feature should be skipped
          if (start !== end) {
            // draw the features so far
            this.drawElements(gl, context, start, end);
          }
          // continue with the next feature
          start = (featureIndex === this.startIndices.length - 1) ?
            groupEnd : this.startIndices[featureIndex + 1];
          end = start;
        } else {
          // the feature is not skipped, augment the end index
          end = (featureIndex === this.startIndices.length - 1) ?
            groupEnd : this.startIndices[featureIndex + 1];
        }
        featureIndex++;
      }
  
      if (start !== end) {
        // draw the remaining features (in case there was no skipped feature
        // in this texture group, all features of a group are drawn together)
        this.drawElements(gl, context, start, end);
      }
    }
  };
  
  
  /**
   * @inheritDoc
   */
  WebGLTextureReplay.prototype.drawHitDetectionReplayOneByOne = function(gl, context, skippedFeaturesHash,
    featureCallback, opt_hitExtent) {
    let i, groupStart, start, end, feature, featureUid;
    let featureIndex = this.startIndices.length - 1;
    const hitDetectionTextures = this.getHitDetectionTextures();
    for (i = hitDetectionTextures.length - 1; i >= 0; --i) {
      gl.bindTexture(TEXTURE_2D, hitDetectionTextures[i]);
      groupStart = (i > 0) ? this.hitDetectionGroupIndices[i - 1] : 0;
      end = this.hitDetectionGroupIndices[i];
  
      // draw all features for this texture group
      while (featureIndex >= 0 &&
          this.startIndices[featureIndex] >= groupStart) {
        start = this.startIndices[featureIndex];
        feature = this.startIndicesFeature[featureIndex];
        featureUid = getUid(feature).toString();
  
        if (skippedFeaturesHash[featureUid] === undefined &&
            feature.getGeometry() &&
            (opt_hitExtent === undefined || intersects(
              /** @type {Array<number>} */ (opt_hitExtent),
              feature.getGeometry().getExtent()))) {
          gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
          this.drawElements(gl, context, start, end);
  
          const result = featureCallback(feature);
          if (result) {
            return result;
          }
        }
  
        end = start;
        featureIndex--;
      }
    }
    return undefined;
  };
  
  
  /**
   * @inheritDoc
   */
  WebGLTextureReplay.prototype.finish = function(context) {
    this.anchorX = undefined;
    this.anchorY = undefined;
    this.height = undefined;
    this.imageHeight = undefined;
    this.imageWidth = undefined;
    this.indices = null;
    this.opacity = undefined;
    this.originX = undefined;
    this.originY = undefined;
    this.rotateWithView = undefined;
    this.rotation = undefined;
    this.scale = undefined;
    this.vertices = null;
    this.width = undefined;
  };
  
  
  /**
   * @abstract
   * @protected
   * @param {boolean=} opt_all Return hit detection textures with regular ones.
   * @returns {Array.<WebGLTexture>} Textures.
   */
  WebGLTextureReplay.prototype.getTextures = function(opt_all) {};
  
  
  /**
   * @abstract
   * @protected
   * @returns {Array.<WebGLTexture>} Textures.
   */
  WebGLTextureReplay.prototype.getHitDetectionTextures = function() {};
  export default WebGLTextureReplay;
  