RE: [css3-images] July F2F minutes comment regarding SVG and non-opaque colors

I have no idea what post-multiplied means in the context of colors.  :(

> -----Original Message-----
> From: Alan Gresley [mailto:alan@css-class.com]
> Sent: Friday, August 19, 2011 7:00 PM
> To: Tab Atkins Jr.
> Cc: Cameron McCormack; Brian Manthos; www-style@w3.org
> Subject: Re: [css3-images] July F2F minutes comment regarding SVG and
> non-opaque colors
> 
> On 20/08/2011 12:34 AM, Tab Atkins Jr. wrote:
> > On Fri, Aug 19, 2011 at 2:58 AM, Alan Gresley<alan@css-class.com>
> wrote:
> >> Correction. Both Chrome and Safari 5.1 has no transparency of the
> color.
> >> rgba(255,0,255,0) is treated like rgb(255,0,255). Chrome and Safari
> 5.1 only
> >> works the same as the other UAs with stop-opacity:0 (as seen the the
> code
> >> below).
> >
> > Yes, transitioning the opacity separately from the color is separate
> > from the pre/post decision.
> >
> > ~TJ
> 
> 
> No, the gradients are interpolated in post multiplied space (copy the
> code below and view in Chrome). There is no pre/post decision. The
> adding of the stop-opacity causes the gradient to interpolate the color
> in post multiplied space in WebKit (like what is seen with some CSS
> gradients in certain UAs).
> 
> 
> <?xml version="1.0" encoding="utf-8"?>
> 
> <svg version="1.1" xmlns="http://www.w3.org/2000/svg" width="200"
> height="200">
> <g>
> <linearGradient id="dummy" gradientUnits="userSpaceOnUse" x1="0"
> y1="200" x2="200" y2="0">
>  <stop offset="0" style="stop-color:yellow;"/>
>  <stop offset="1" style="stop-color:black"/>
> </linearGradient>
> <path fill="url(#dummy)" d="M0,0v200h200V0H0z" />
> </g>
> 
> </svg>
> 
> 
> --
> Alan Gresley
> http://css-3d.org/

> http://css-class.com/

Received on Saturday, 20 August 2011 02:07:07 UTC