St: Fix blur radius computation to correspond to current CSS draft

The next draft of the CSS Backgrounds and Borders module will actually
define when the blur radius means. Fix our code to use that definition
(2 * standard deviation) rather than using the 1.9 * that we extracted
from what Mozilla was doing.

https://bugzilla.gnome.org/show_bug.cgi?id=632506
This commit is contained in:
Owen W. Taylor 2010-10-18 17:30:52 -04:00
parent 5437629e89
commit 281b2e9b0e

View File

@ -435,11 +435,12 @@ blur_pixels (guchar *pixels_in,
guchar *pixels_out; guchar *pixels_out;
float sigma; float sigma;
/* we use an approximation of the sigma - blur radius relationship used /* The CSS specification defines (or will define) the blur radius as twice
in Firefox for doing SVG blurs; see * the Gaussian standard deviation. See:
http://mxr.mozilla.org/mozilla-central/source/gfx/thebes/src/gfxBlur.cpp#280 *
*/ * http://lists.w3.org/Archives/Public/www-style/2010Sep/0002.html
sigma = blur / 1.9; */
sigma = blur / 2.;
if ((guint) blur == 0) if ((guint) blur == 0)
{ {