openlayers/src/ol/renderer/Map.js

/**
 * @module ol/renderer/Map
 */
import {getUid, inherits} from '../index.js';
import Disposable from '../Disposable.js';
import {listen, unlistenByKey} from '../events.js';
import EventType from '../events/EventType.js';
import {getWidth} from '../extent.js';
import {TRUE, UNDEFINED} from '../functions.js';
import {visibleAtResolution} from '../layer/Layer.js';
import {iconImageCache} from '../style.js';
import {compose as composeTransform, invert as invertTransform, setFromArray as transformSetFromArray} from '../transform.js';

/**
 * @constructor
 * @abstract
 * @extends {module:ol/Disposable~Disposable}
 * @param {module:ol/PluggableMap~PluggableMap} map Map.
 * @struct
 */
const MapRenderer = function(map) {
  Disposable.call(this);

  /**
   * @private
   * @type {module:ol/PluggableMap~PluggableMap}
   */
  this.map_ = map;

  /**
   * @private
   * @type {!Object.<string, ol.renderer.Layer>}
   */
  this.layerRenderers_ = {};

  /**
   * @private
   * @type {Object.<string, module:ol/events~EventsKey>}
   */
  this.layerRendererListeners_ = {};

  /**
   * @private
   * @type {Array.<module:ol/renderer/Layer~LayerRenderer}
   */
  this.layerRendererConstructors_ = [];

};

inherits(MapRenderer, Disposable);


/**
 * Register layer renderer constructors.
 * @param {Array.<module:ol/renderer/Layer~LayerRenderer>} constructors Layer renderers.
 */
MapRenderer.prototype.registerLayerRenderers = function(constructors) {
  this.layerRendererConstructors_.push.apply(this.layerRendererConstructors_, constructors);
};


/**
 * Get the registered layer renderer constructors.
 * @return {Array.<module:ol/renderer/Layer~LayerRenderer>} Registered layer renderers.
 */
MapRenderer.prototype.getLayerRendererConstructors = function() {
  return this.layerRendererConstructors_;
};


/**
 * @param {module:ol/PluggableMap~FrameState} frameState FrameState.
 * @protected
 */
MapRenderer.prototype.calculateMatrices2D = function(frameState) {
  const viewState = frameState.viewState;
  const coordinateToPixelTransform = frameState.coordinateToPixelTransform;
  const pixelToCoordinateTransform = frameState.pixelToCoordinateTransform;

  composeTransform(coordinateToPixelTransform,
    frameState.size[0] / 2, frameState.size[1] / 2,
    1 / viewState.resolution, -1 / viewState.resolution,
    -viewState.rotation,
    -viewState.center[0], -viewState.center[1]);

  invertTransform(
    transformSetFromArray(pixelToCoordinateTransform, coordinateToPixelTransform));
};


/**
 * Removes all layer renderers.
 */
MapRenderer.prototype.removeLayerRenderers = function() {
  for (const key in this.layerRenderers_) {
    this.removeLayerRendererByKey_(key).dispose();
  }
};


/**
 * @param {module:ol/PluggableMap~PluggableMap} map Map.
 * @param {module:ol/PluggableMap~FrameState} frameState Frame state.
 */
function expireIconCache(map, frameState) {
  iconImageCache.expire();
}


/**
 * @param {module:ol/coordinate~Coordinate} coordinate Coordinate.
 * @param {module:ol/PluggableMap~FrameState} frameState FrameState.
 * @param {number} hitTolerance Hit tolerance in pixels.
 * @param {function(this: S, (module:ol/Feature~Feature|ol.render.Feature),
 *     module:ol/layer/Layer~Layer): T} callback Feature callback.
 * @param {S} thisArg Value to use as `this` when executing `callback`.
 * @param {function(this: U, module:ol/layer/Layer~Layer): boolean} layerFilter Layer filter
 *     function, only layers which are visible and for which this function
 *     returns `true` will be tested for features.  By default, all visible
 *     layers will be tested.
 * @param {U} thisArg2 Value to use as `this` when executing `layerFilter`.
 * @return {T|undefined} Callback result.
 * @template S,T,U
 */
MapRenderer.prototype.forEachFeatureAtCoordinate = function(coordinate, frameState, hitTolerance, callback, thisArg,
  layerFilter, thisArg2) {
  let result;
  const viewState = frameState.viewState;
  const viewResolution = viewState.resolution;

  /**
   * @param {module:ol/Feature~Feature|ol.render.Feature} feature Feature.
   * @param {module:ol/layer/Layer~Layer} layer Layer.
   * @return {?} Callback result.
   */
  function forEachFeatureAtCoordinate(feature, layer) {
    const key = getUid(feature).toString();
    const managed = frameState.layerStates[getUid(layer)].managed;
    if (!(key in frameState.skippedFeatureUids && !managed)) {
      return callback.call(thisArg, feature, managed ? layer : null);
    }
  }

  const projection = viewState.projection;

  let translatedCoordinate = coordinate;
  if (projection.canWrapX()) {
    const projectionExtent = projection.getExtent();
    const worldWidth = getWidth(projectionExtent);
    const x = coordinate[0];
    if (x < projectionExtent[0] || x > projectionExtent[2]) {
      const worldsAway = Math.ceil((projectionExtent[0] - x) / worldWidth);
      translatedCoordinate = [x + worldWidth * worldsAway, coordinate[1]];
    }
  }

  const layerStates = frameState.layerStatesArray;
  const numLayers = layerStates.length;
  let i;
  for (i = numLayers - 1; i >= 0; --i) {
    const layerState = layerStates[i];
    const layer = layerState.layer;
    if (visibleAtResolution(layerState, viewResolution) && layerFilter.call(thisArg2, layer)) {
      const layerRenderer = this.getLayerRenderer(layer);
      if (layer.getSource()) {
        result = layerRenderer.forEachFeatureAtCoordinate(
          layer.getSource().getWrapX() ? translatedCoordinate : coordinate,
          frameState, hitTolerance, forEachFeatureAtCoordinate, thisArg);
      }
      if (result) {
        return result;
      }
    }
  }
  return undefined;
};


/**
 * @abstract
 * @param {module:ol~Pixel} pixel Pixel.
 * @param {module:ol/PluggableMap~FrameState} frameState FrameState.
 * @param {function(this: S, module:ol/layer/Layer~Layer, (Uint8ClampedArray|Uint8Array)): T} callback Layer
 *     callback.
 * @param {S} thisArg Value to use as `this` when executing `callback`.
 * @param {function(this: U, module:ol/layer/Layer~Layer): boolean} layerFilter Layer filter
 *     function, only layers which are visible and for which this function
 *     returns `true` will be tested for features.  By default, all visible
 *     layers will be tested.
 * @param {U} thisArg2 Value to use as `this` when executing `layerFilter`.
 * @return {T|undefined} Callback result.
 * @template S,T,U
 */
MapRenderer.prototype.forEachLayerAtPixel = function(pixel, frameState, callback, thisArg,
  layerFilter, thisArg2) {};


/**
 * @param {module:ol/coordinate~Coordinate} coordinate Coordinate.
 * @param {module:ol/PluggableMap~FrameState} frameState FrameState.
 * @param {number} hitTolerance Hit tolerance in pixels.
 * @param {function(this: U, module:ol/layer/Layer~Layer): boolean} layerFilter Layer filter
 *     function, only layers which are visible and for which this function
 *     returns `true` will be tested for features.  By default, all visible
 *     layers will be tested.
 * @param {U} thisArg Value to use as `this` when executing `layerFilter`.
 * @return {boolean} Is there a feature at the given coordinate?
 * @template U
 */
MapRenderer.prototype.hasFeatureAtCoordinate = function(coordinate, frameState, hitTolerance, layerFilter, thisArg) {
  const hasFeature = this.forEachFeatureAtCoordinate(
    coordinate, frameState, hitTolerance, TRUE, this, layerFilter, thisArg);

  return hasFeature !== undefined;
};


/**
 * @param {module:ol/layer/Layer~Layer} layer Layer.
 * @protected
 * @return {ol.renderer.Layer} Layer renderer.
 */
MapRenderer.prototype.getLayerRenderer = function(layer) {
  const layerKey = getUid(layer).toString();
  if (layerKey in this.layerRenderers_) {
    return this.layerRenderers_[layerKey];
  } else {
    let renderer;
    for (let i = 0, ii = this.layerRendererConstructors_.length; i < ii; ++i) {
      const candidate = this.layerRendererConstructors_[i];
      if (candidate['handles'](layer)) {
        renderer = candidate['create'](this, layer);
        break;
      }
    }
    if (renderer) {
      this.layerRenderers_[layerKey] = renderer;
      this.layerRendererListeners_[layerKey] = listen(renderer,
        EventType.CHANGE, this.handleLayerRendererChange_, this);
    } else {
      throw new Error('Unable to create renderer for layer: ' + layer.getType());
    }
    return renderer;
  }
};


/**
 * @param {string} layerKey Layer key.
 * @protected
 * @return {ol.renderer.Layer} Layer renderer.
 */
MapRenderer.prototype.getLayerRendererByKey = function(layerKey) {
  return this.layerRenderers_[layerKey];
};


/**
 * @protected
 * @return {Object.<string, ol.renderer.Layer>} Layer renderers.
 */
MapRenderer.prototype.getLayerRenderers = function() {
  return this.layerRenderers_;
};


/**
 * @return {module:ol/PluggableMap~PluggableMap} Map.
 */
MapRenderer.prototype.getMap = function() {
  return this.map_;
};


/**
 * Handle changes in a layer renderer.
 * @private
 */
MapRenderer.prototype.handleLayerRendererChange_ = function() {
  this.map_.render();
};


/**
 * @param {string} layerKey Layer key.
 * @return {ol.renderer.Layer} Layer renderer.
 * @private
 */
MapRenderer.prototype.removeLayerRendererByKey_ = function(layerKey) {
  const layerRenderer = this.layerRenderers_[layerKey];
  delete this.layerRenderers_[layerKey];

  unlistenByKey(this.layerRendererListeners_[layerKey]);
  delete this.layerRendererListeners_[layerKey];

  return layerRenderer;
};


/**
 * Render.
 * @param {?module:ol/PluggableMap~FrameState} frameState Frame state.
 */
MapRenderer.prototype.renderFrame = UNDEFINED;


/**
 * @param {module:ol/PluggableMap~PluggableMap} map Map.
 * @param {module:ol/PluggableMap~FrameState} frameState Frame state.
 * @private
 */
MapRenderer.prototype.removeUnusedLayerRenderers_ = function(map, frameState) {
  for (const layerKey in this.layerRenderers_) {
    if (!frameState || !(layerKey in frameState.layerStates)) {
      this.removeLayerRendererByKey_(layerKey).dispose();
    }
  }
};


/**
 * @param {module:ol/PluggableMap~FrameState} frameState Frame state.
 * @protected
 */
MapRenderer.prototype.scheduleExpireIconCache = function(frameState) {
  frameState.postRenderFunctions.push(/** @type {module:ol/PluggableMap~PostRenderFunction} */ (expireIconCache));
};


/**
 * @param {!module:ol/PluggableMap~FrameState} frameState Frame state.
 * @protected
 */
MapRenderer.prototype.scheduleRemoveUnusedLayerRenderers = function(frameState) {
  for (const layerKey in this.layerRenderers_) {
    if (!(layerKey in frameState.layerStates)) {
      frameState.postRenderFunctions.push(
        /** @type {module:ol/PluggableMap~PostRenderFunction} */ (this.removeUnusedLayerRenderers_.bind(this))
      );
      return;
    }
  }
};


/**
 * @param {module:ol/layer/Layer~State} state1 First layer state.
 * @param {module:ol/layer/Layer~State} state2 Second layer state.
 * @return {number} The zIndex difference.
 */
export function sortByZIndex(state1, state2) {
  return state1.zIndex - state2.zIndex;
}
export default MapRenderer;