ol
Version:
OpenLayers mapping library
151 lines • 6.75 kB
JavaScript
/**
* @module ol/render/canvas/hitdetet
*/
import CanvasImmediateRenderer from './Immediate.js';
import { createCanvasContext2D } from '../../dom.js';
import { Icon } from '../../style.js';
import IconAnchorUnits from '../../style/IconAnchorUnits.js';
import GeometryType from '../../geom/GeometryType.js';
import { intersects } from '../../extent.js';
import { numberSafeCompareFunction } from '../../array.js';
/**
* @param {import("../../size.js").Size} size Canvas size in css pixels.
* @param {Array<import("../../transform.js").Transform>} transforms Transforms
* for rendering features to all worlds of the viewport, from coordinates to css
* pixels.
* @param {Array<import("../../Feature.js").FeatureLike>} features
* Features to consider for hit detection.
* @param {import("../../style/Style.js").StyleFunction|undefined} styleFunction
* Layer style function.
* @param {import("../../extent.js").Extent} extent Extent.
* @param {number} resolution Resolution.
* @param {number} rotation Rotation.
* @return {ImageData} Hit detection image data.
*/
export function createHitDetectionImageData(size, transforms, features, styleFunction, extent, resolution, rotation) {
var width = size[0] / 2;
var height = size[1] / 2;
var context = createCanvasContext2D(width, height);
context.imageSmoothingEnabled = false;
var canvas = context.canvas;
var renderer = new CanvasImmediateRenderer(context, 0.5, extent, null, rotation);
var featureCount = features.length;
// Stretch hit detection index to use the whole available color range
var indexFactor = Math.floor((256 * 256 * 256 - 1) / featureCount);
var featuresByZIndex = {};
for (var i = 1; i <= featureCount; ++i) {
var feature = features[i - 1];
var featureStyleFunction = feature.getStyleFunction() || styleFunction;
if (!styleFunction) {
continue;
}
var styles = featureStyleFunction(feature, resolution);
if (!styles) {
continue;
}
if (!Array.isArray(styles)) {
styles = [styles];
}
var index = i * indexFactor;
var color = '#' + ('000000' + index.toString(16)).slice(-6);
for (var j = 0, jj = styles.length; j < jj; ++j) {
var originalStyle = styles[j];
var style = originalStyle.clone();
var fill = style.getFill();
if (fill) {
fill.setColor(color);
}
var stroke = style.getStroke();
if (stroke) {
stroke.setColor(color);
}
style.setText(undefined);
var image = originalStyle.getImage();
if (image) {
var imgSize = image.getImageSize();
if (!imgSize) {
continue;
}
var canvas_1 = document.createElement('canvas');
canvas_1.width = imgSize[0];
canvas_1.height = imgSize[1];
var imgContext = canvas_1.getContext('2d', { alpha: false });
imgContext.fillStyle = color;
var img = imgContext.canvas;
imgContext.fillRect(0, 0, img.width, img.height);
var width_1 = imgSize ? imgSize[0] : img.width;
var height_1 = imgSize ? imgSize[1] : img.height;
var iconContext = createCanvasContext2D(width_1, height_1);
iconContext.drawImage(img, 0, 0);
style.setImage(new Icon({
img: img,
imgSize: imgSize,
anchor: image.getAnchor(),
anchorXUnits: IconAnchorUnits.PIXELS,
anchorYUnits: IconAnchorUnits.PIXELS,
offset: image.getOrigin(),
size: image.getSize(),
opacity: image.getOpacity(),
scale: image.getScale(),
rotation: image.getRotation(),
rotateWithView: image.getRotateWithView()
}));
}
var zIndex = Number(style.getZIndex());
var byGeometryType = featuresByZIndex[zIndex];
if (!byGeometryType) {
byGeometryType = {};
featuresByZIndex[zIndex] = byGeometryType;
byGeometryType[GeometryType.POLYGON] = [];
byGeometryType[GeometryType.CIRCLE] = [];
byGeometryType[GeometryType.LINE_STRING] = [];
byGeometryType[GeometryType.POINT] = [];
}
var geometry = style.getGeometryFunction()(feature);
if (geometry && intersects(extent, geometry.getExtent())) {
byGeometryType[geometry.getType().replace('Multi', '')].push(geometry, style);
}
}
}
var zIndexKeys = Object.keys(featuresByZIndex).map(Number).sort(numberSafeCompareFunction);
for (var i = 0, ii = zIndexKeys.length; i < ii; ++i) {
var byGeometryType = featuresByZIndex[zIndexKeys[i]];
for (var type in byGeometryType) {
var geomAndStyle = byGeometryType[type];
for (var j = 0, jj = geomAndStyle.length; j < jj; j += 2) {
renderer.setStyle(geomAndStyle[j + 1]);
for (var k = 0, kk = transforms.length; k < kk; ++k) {
renderer.setTransform(transforms[k]);
renderer.drawGeometry(geomAndStyle[j]);
}
}
}
}
document.body.appendChild(context.canvas);
return context.getImageData(0, 0, canvas.width, canvas.height);
}
/**
* @param {import("../../pixel").Pixel} pixel Pixel coordinate on the hit
* detection canvas in css pixels.
* @param {Array<import("../../Feature").FeatureLike>} features Features. Has to
* match the `features` array that was passed to `createHitDetectionImageData()`.
* @param {ImageData} imageData Hit detection image data generated by
* `createHitDetectionImageData()`.
* @return {Array<import("../../Feature").FeatureLike>} features Features.
*/
export function hitDetect(pixel, features, imageData) {
var resultFeatures = [];
if (imageData) {
var index = (Math.round(pixel[0] / 2) + Math.round(pixel[1] / 2) * imageData.width) * 4;
var r = imageData.data[index];
var g = imageData.data[index + 1];
var b = imageData.data[index + 2];
var i = b + (256 * (g + (256 * r)));
var indexFactor = Math.floor((256 * 256 * 256 - 1) / features.length);
if (i && i % indexFactor === 0) {
resultFeatures.push(features[i / indexFactor - 1]);
}
}
return resultFeatures;
}
//# sourceMappingURL=hitdetect.js.map