in Hands-on lab/lab-files/starter-project/NorthwindMVC/wwwroot/lib/Chart.js/chart.js [7702:7751]
_calculateBarValuePixels(index) {
const me = this;
const {_cachedMeta: {vScale, _stacked}, options: {base: baseValue, minBarLength}} = me;
const actualBase = baseValue || 0;
const parsed = me.getParsed(index);
const custom = parsed._custom;
const floating = isFloatBar(custom);
let value = parsed[vScale.axis];
let start = 0;
let length = _stacked ? me.applyStack(vScale, parsed, _stacked) : value;
let head, size;
if (length !== value) {
start = length - value;
length = value;
}
if (floating) {
value = custom.barStart;
length = custom.barEnd - custom.barStart;
if (value !== 0 && sign(value) !== sign(custom.barEnd)) {
start = 0;
}
start += value;
}
const startValue = !isNullOrUndef(baseValue) && !floating ? baseValue : start;
let base = vScale.getPixelForValue(startValue);
if (me.chart.getDataVisibility(index)) {
head = vScale.getPixelForValue(start + length);
} else {
head = base;
}
size = head - base;
if (Math.abs(size) < minBarLength) {
size = barSign(size, vScale, actualBase) * minBarLength;
if (value === actualBase) {
base -= size / 2;
}
head = base + size;
}
if (base === vScale.getPixelForValue(actualBase)) {
const halfGrid = sign(size) * vScale.getLineWidthForValue(actualBase) / 2;
base += halfGrid;
size -= halfGrid;
}
return {
size,
base,
head,
center: head + size / 2
};
}