Function baseBitmaps

docs/app/js/sanddance-app.js:138623–138630

($, data)

const INSIDE_OPACITY_IN_ALPHA = 0x10000000;
const INSIDE_OPACITY = 0.0625;
function baseBitmaps($, data) {
    const bitmap = $.bitmap(); // when there is no base mark but data points are to be avoided
    (data || []).forEach((d)=>bitmap.set($(d.boundary[0]), $(d.boundary[3])));
    return [
        bitmap,
        undefined
    ];
}
function markBitmaps($, avoidMarks, labelInside, isGroupArea) {
    // create canvas
    const width = $.width, height = $.height, border = labelInside || isGroupArea, context = (0, _vegaCanvas.canvas)(width, height).getContext("2d"); // render all marks to be avoided into canvas