- From: Rik Cabanier <cabanier@gmail.com>
- Date: Thu, 17 Apr 2014 10:58:19 -0700
- To: www-style list <www-style@w3.org>
- Message-ID: <CAGN7qDD-Y2cE6QL2ODn_OqgD9FbLbi0v_Xr=iMSCGVcP7CQs0A@mail.gmail.com>
At the CSS F2F in Seattle, we decided to use exponential interpolation function to calculate the color ramps when there is a gradient midpoint. [1] Right now the spec [2] states: Similarly, the color of a color stop can be omitted. The causes the color to be automatically computed to halfway between the two surrounding stops, so that the "midpoint" of a transition can be easily adjusted. which specifies linear interpolation that results in banding. Could we add the right formula here? To calculate a color C between: - C0 = color stop on the left - C1 = color stop on the right - N = value between 0 and 1 describing the distance of the midpoint between C0 and C1 - X = value between 0 and 1 describing the distance of the C between C0 and C1 The formula is: C = C0 + pow(x, log(.5)/log(X)) * (C1 - C0) The spec also has this wording: If multiple stops in a row lack a color, they space themselves out equally in "color space", giving more control over the smoothness of the transition. Is this to add multiple midpoints? 1: http://lists.w3.org/Archives/Public/www-style/2014Feb/0609.html 2: http://dev.w3.org/csswg/css-images-4/#color-stop-syntax
Received on Thursday, 17 April 2014 17:58:47 UTC