[whatwg] Clipping text in in canvas

Ian Hickson ian at hixie.ch
Mon Sep 16 10:40:22 PDT 2013

On Sun, 15 Sep 2013, Jasper St. Pierre wrote:
> The canvas specification maintains:
>     These shapes are painted without affecting the current path, and are 
> subject to shadow effects, global alpha, the clipping region, and global 
> composition operators. [0]
> But no browsers I tested actually implement the "clipping region" part. 
> Should this be removed for backwards compatibility reasons? Should we 
> introduce a new method of clipping text be introduced, or should we just 
> require users who want to draw clipped text to draw to a scratch canvas 
> and use drawImage to copy the pixels? [0] 
> http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#drawing-text-to-the-bitmap

Do you have a test case demonstrating the problem you describe?

(Note that browsers not following the spec is usually not resolved by 
adding another feature that does the same thing, since there's no reason 
to believe they're any more likely to follow that spec either.)

Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'

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