The read-only fontBoundingBoxDescent
property of the TextMetrics
interface returns the distance from the horizontal line indicated by the CanvasRenderingContext2D.textBaseline
attribute to the bottom of the bounding rectangle of all the fonts used to render the text, in CSS pixels.
The code below shows how you can get the fontBoundingBoxDescent
for text in a particular font.
const canvas = document.createElement("canvas");
const ctx = canvas.getContext("2d");
ctx.font = "25px serif";
const text = "Foo";
const textMetrics = ctx.measureText("foo");
const descentCssPixels = textMetrics.fontBoundingBoxDescent;
The descent in CSS pixels for the text "Foo" in a 25px serif font is shown below.