[whatwg] Canvas v5 API additions

[Jonas Sicking]

On Tue, Apr 10, 2012 at 6:29 PM, Charles Pritchard <chuck at jumis.com> wrote:
> On 3/28/2012 2:41 PM, Ian Hickson wrote:
>>
>> I just added a bunch of things to the<canvas>  2D API:
>
> About three or four years ago we talked about adding addition blend modes
> and/or filters to the Canvas API.
> Is there still room for discussion on that?
>
> There seems to be a consensus about some blend modes that'd be useful:
> https://dvcs.w3.org/hg/FXTF/rawfile/tip/compositing/index.html
>
> They're useful for rendering PSDs, for drawing applications, and for high
> quality generation of graphics that normally are pre-rendered using graphics
> applications.

I recently was shown an canvas based game which had been forced to use
WebGL purely for the reason of needing blending modes. I believe the
use-case in that example was when the game character was shot at, the
background of the game should be rendered with a varying red tint. I
unfortunately forget the specifics of why rendering a partially
transparent red square over the background produced the wrong colors,
but if needed I can try to find the specifics.

In summary: I've also heard requests for more blending modes.

/ Jonas