[whatwg] [canvas] matrix based changes on bitmaps

[Rob Manson]

+1 

Having matrix manipulation functions on ArrayBuffers that were
implemented at a lower, more optimised level would be awesome and would
open up all sorts of app opportunities.

roBman

On Thu, 20 Sep 2012 22:45:29 +0000 (UTC)
Ian Hickson <ian at hixie.ch> wrote:

> On Mon, 23 Apr 2012, Tyler Larson wrote:
> >
> > Looping over every pixel in JavaScript is slow. Many cool things
> > could be taken care of much faster if the canvas had some form of
> > matrix manipulations built in.
> >
> > All of the pixels could have one transformation operation defined
> > and all of the pixels could be operated on at once in something
> > lower level.
> > 
> > It could look like this...
> > 
> > context.transformMatrix([0.5,0.5,0.5,0,0,
> > 					0.5,0.5,0.5,0,0,
> > 					0.5,0.5,0.5,0,0,
> > 					0,0,0,1,0,
> > 					0,0,0,0,1]);
> > 
> > It's far simpler than looping over an array of pixels and picking
> > out the values of each color.
> >
> > Other graphics systems have ways of doing this already. You can
> > easily find sample tutorials on how to create and transform
> > matrixes.
> >
> > In some languages they have matrix objects that have methods for
> > even easier manipulation of these transformations but I'm cool
> > without this if it is easier.
> 
> It seems like a reasonable suggestion, but since the pixel data is 
> available as an ArrayBuffer, it seems like the more reasonable thing
> to do is to provide generic ArrayBuffer manipulation routines.
> 
> I recommend raising this as feedback on the ArrayBuffer spec.
>