- From: Alan Gresley <alan@css-class.com>
- Date: Tue, 05 Feb 2013 23:27:44 +1100
- To: Brad Kemper <brad.kemper@gmail.com>
- CC: Simon Fraser <smfr@me.com>, Rik Cabanier <cabanier@gmail.com>, fantasai <fantasai.lists@inkedblade.net>, "www-style@w3.org" <www-style@w3.org>
On 5/02/2013 3:52 PM, Brad Kemper wrote: >> Wrong and correction. A pre-multiplied gradient of yellow to >> transparent to blue compiste of a whitye background is identical to >> a gradient of yellow to white to blue (fully opaque). >> >> What do you want to achieve with a gradient that has alpha >> transparency and have you tested any of this by observing the >> difference between pre-multiplied colorspace and non pre-multiplied >> colorspace? > > As I recall, last time I had a problem with the way Safari does > gradients, it was a solid color to transparent, and the stuff > underneath it was variable, some white, some other colors. I just > wanted the color to fade to transparent over the varied background, > but instead it looked dirtier as it faded out. Was this for a gradient with two color stops or three color stops? For a gradient with two color stops, you can avoid the dirtier composite color (really just less lighter ~ HSL) by going to it transparent counterpart. Like red to transparent-red or yellow to transparent-yellow. For a gradient with two color stops (transparent at one end), a non pre-multiplied gradient going back to it transparent-color is the same as a pre-multiplied gradient going to transparent (the keyword does not have a special meaning). BTW, the way Safari does gradients is the way that Firefox does gradients prefixed and now un-prefixed (since FF16). The gradients are done in non pre-multiplied colorspace. -- Alan Gresley http://css-3d.org/ http://css-class.com/
Received on Tuesday, 5 February 2013 12:28:14 UTC