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Merge pull request #11995 from MoonE/vectorlayer-hitdetect-rounding

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Fix hitdetect inaccuracy for VectorLayer's getFeatures
This commit is contained in:
MoonE
2021-02-09 19:59:05 +01:00
committed by GitHub
parent 56cea5f880 8bd081d992
commit 261bba8359
2 changed files with 61 additions and 2 deletions
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8
src/ol/render/canvas/hitdetect.js
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@@ -6,6 +6,7 @@ import CanvasImmediateRenderer from './Immediate.js';
import GeometryType from '../../geom/GeometryType.js';
import IconAnchorUnits from '../../style/IconAnchorUnits.js';
import {Icon} from '../../style.js';
import {clamp} from '../../math.js';
import {createCanvasContext2D} from '../../dom.js';
import {intersects} from '../../extent.js';
import {numberSafeCompareFunction} from '../../array.js';
@@ -162,8 +163,13 @@ export function createHitDetectionImageData(
export function hitDetect(pixel, features, imageData) {
const resultFeatures = [];
if (imageData) {
// The pixel coordinate is clamped down to the hit-detect canvas' size to account
// for browsers returning coordinates slightly larger than the actual canvas size
// due to a non-integer pixel ratio.
const index =
(Math.round(pixel[0] / 2) + Math.round(pixel[1] / 2) * imageData.width) *
(clamp(Math.floor(Math.round(pixel[0]) / 2), 0, imageData.width - 1) +
clamp(Math.floor(Math.round(pixel[1]) / 2), 0, imageData.height - 1) *
imageData.width) *
4;
const r = imageData.data[index];
const g = imageData.data[index + 1];