tree fcfe0409f595e24a33c014c1266ff50317d6ef3c
parent 884616d4466f7d9873a67b95b95ae3882f27a5dd
author commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> 1377263592 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> 1377263592 +0000

Add luminance mask transfer modes.

This adds kSrcInLum_Mode and kDstInLum_Mode, to support CSS and SVG luminance masks (http://www.w3.org/TR/css-masking/#MaskValues , http://www.w3.org/TR/SVG/masking.html#Masking ).

The transfer coefficient is computed according to http://www.w3.org/TR/2011/REC-SVG11-20110816/filters.html#feColorMatrixElement "luminance-to-alpha":

  luma = 0.2125 * r + 0.7154 * g + 0.0721 * b


R=bsalomon@google.com, reed@google.com, robertphillips@google.com, vandebo@chromium.org

Author: fmalita@chromium.org

Review URL: https://chromiumcodereview.appspot.com/22918012

git-svn-id: http://skia.googlecode.com/svn/trunk/src@10887 2bbb7eff-a529-9590-31e7-b0007b416f81