javascript - Letter spacing in canvas element

Question

The question says it all pretty much. I've been searching around and starting to worry that it's impossible.

I've got this canvas element that I'm drawing text to. I want to set the letter spacing similar to the CSS letter-spacing attribute. By that I mean increasing the amount of pixels between letters when a string is drawn.

My code for drawing the text is like so, ctx is the canvas context variable.

ctx.font = "3em sheepsans";
ctx.textBaseline = "middle";
ctx.textAlign = "center";
ctx.fillStyle = "rgb(255, 255, 255)";
ctx.fillText("Blah blah text", 1024 / 2, 768 / 2);

I've tried adding ctx.letterSpacing = "2px"; before the drawing but with no avail. Is there a way to do this just with a simple setting, or will I have to make a function to individually draw each character with the spacing in mind?

Answer 1

You can't set the letter spacing property, but you you can accomplish wider letter spacing in canvas by inserting one of the various white spaces in between every letter in the string. For instance

ctx.font = "3em sheepsans";
ctx.textBaseline = "middle";
ctx.textAlign = "center";
ctx.fillStyle = "rgb(255, 255, 255)";
var ctext = "Blah blah text".split("").join(String.fromCharCode(8202))
ctx.fillText(ctext, 1024 / 2, 768 / 2);

This will insert a hair space between every letter.

Using 8201 (instead of 8202) will insert the slightly wider thin space

For more white space options, see this list of Unicode Spaces

This method will help you to preserve the font's kerning much more easily than manually positioning each letter, however you wont be able to tighten your letter spacing this way.