topics/css-masking: created

Author: dirkschulze

topics/css-masking.txt

@@ -0,0 +1,39 @@
+====== Proposal CSS Masking ======
+
+---- dataentry ----
+Spec_tags     : css-masking        # in alpha order; or "none"
+Owner_tags    : dschulze          # Who's driving the discussion?
+Status_tags   : Open            # [ Open | Resolved | Closed | Pending ] [, Urgent]?
+Added_dt      : 2012-08-28        # Date added as WG discussion request
+
+Action        : Resolve to continue on ED # Or, if Pending, pending what?
+                # Some Examples:
+# Action        : Pick A, B, or C?
+# Action        : Approve the proposal?
+# Action        : Discuss problem and provide direction?
+# Action        : Help research needed info!
+# Action        : Help write proposals!
+# Action        : Give feedback!
+# Action        : Publish FPWD/WD/LC/CR/PR/REC!
+
+Issue_urls    : http://dvcs.w3.org/hg/FXTF/raw-file/tip/masking/index.html
+Proposal_urls : 
+Agenda_urls   : # If this is part of an ordered series of related topics, e.g. LC issues, use this to link to the supertopic agenda
+----
+
+=== Background ===
+
+The CSS WG and the SVG WG decided to work on a CSS Masking specification in the FXTF. The CSS WG did not decide if the specification should specify the current behavior of browsers:
+   * 'mask' as a shorthand for 'mask-image' and other properties deriving from 'background' and 'mask-box-image' as shorthand for properties deriving from 'border-image' (WebKit)
+   * 'mask' that takes a <funcIRI> to a 'mask' element to mask arbitrary HTML and SVG content (Firefox)
+   * 'clip-path' that takes a <funcIRI> to a 'clipPath' element to clip arbitrary HTML and SVG content (Firefox)
+
+Further more the new specification unifies both implementations and extends 'clip-path' to take <shape>s from CSS Exclusions as shorthand for clipping beside <funcIRI>.
+
+The CSS WG needs to decide if we continue with the current specification.
+
+=== Problem Statement ===
+
+  * Are all properties needed? In question: 'mask-origin', 'mask-attachment' and 'mask-clip'.
+  * Masking/Clipping on Firefox operates on 'bounding client rect', 'mask-image' on WebKit operate on 'border-box', 'content-box' and 'padding-box'. Both behaviors are reasonable.
+  * select() and child are new functions/keywords requested by the SVG WG. The sense in the HTML world depends on the definition.