@jbrowse/plugin-wiggle/esm/drawDensity.js

JBrowse 2 wiggle adapters, tracks, etc.

import { readConfObject } from '@jbrowse/core/configuration';
import { featureSpanPx } from '@jbrowse/core/util';
import { checkStopToken } from '@jbrowse/core/util/stopToken';
import { fillRectCtx, getScale } from './util';
const fudgeFactor = 0.3;
const clipHeight = 2;
export function drawDensity(ctx, props) {
    const { stopToken, features, regions, bpPerPx, scaleOpts, height, config } = props;
    const region = regions[0];
    const pivot = readConfObject(config, 'bicolorPivot');
    const pivotValue = readConfObject(config, 'bicolorPivotValue');
    const negColor = readConfObject(config, 'negColor');
    const posColor = readConfObject(config, 'posColor');
    const color = readConfObject(config, 'color');
    const clipColor = readConfObject(config, 'clipColor');
    const crossing = pivot !== 'none' && scaleOpts.scaleType !== 'log';
    const scale = getScale({
        ...scaleOpts,
        pivotValue: crossing ? pivotValue : undefined,
        range: crossing ? [negColor, '#eee', posColor] : ['#eee', posColor],
    });
    const scale2 = getScale({ ...scaleOpts, range: [0, height] });
    const cb = color === '#f0f'
        ? (_, score) => scale(score)
        : (feature, score) => readConfObject(config, 'color', { feature, score });
    const domain = scale2.domain();
    const niceMin = domain[0];
    const niceMax = domain[1];
    let prevLeftPx = Number.NEGATIVE_INFINITY;
    let hasClipping = false;
    const reducedFeatures = [];
    let start = performance.now();
    for (const feature of features.values()) {
        if (performance.now() - start > 400) {
            checkStopToken(stopToken);
            start = performance.now();
        }
        const [leftPx, rightPx] = featureSpanPx(feature, region, bpPerPx);
        if (Math.floor(leftPx) !== Math.floor(prevLeftPx) || rightPx - leftPx > 1) {
            reducedFeatures.push(feature);
            prevLeftPx = leftPx;
        }
        const score = feature.get('score');
        hasClipping = hasClipping || score > niceMax || score < niceMin;
        const w = rightPx - leftPx + fudgeFactor;
        if (score >= scaleOpts.domain[0]) {
            ctx.fillStyle = cb(feature, score);
            ctx.fillRect(leftPx, 0, w, height);
        }
        else {
            ctx.fillStyle = '#eee';
            ctx.fillRect(leftPx, 0, w, height);
        }
    }
    ctx.save();
    if (hasClipping) {
        ctx.fillStyle = clipColor;
        for (const feature of features.values()) {
            if (performance.now() - start > 400) {
                checkStopToken(stopToken);
                start = performance.now();
            }
            const [leftPx, rightPx] = featureSpanPx(feature, region, bpPerPx);
            const w = rightPx - leftPx + fudgeFactor;
            const score = feature.get('score');
            if (score > niceMax) {
                fillRectCtx(leftPx, 0, w, clipHeight, ctx);
            }
            else if (score < niceMin && scaleOpts.scaleType !== 'log') {
                fillRectCtx(leftPx, 0, w, clipHeight, ctx);
            }
        }
    }
    ctx.restore();
    return {
        reducedFeatures,
    };
}