- From: Glenn Adams via GitHub <sysbot+gh@w3.org>
- Date: Sun, 26 Aug 2018 05:38:13 +0000
- To: public-tt@w3.org
skynavga has just created a new issue for https://github.com/w3c/ttml2: == Remove #textOrientation-sideways-LR == The semantics of `sidewaysLeft`, specifically, a 90 degree counter-clockwise rotation, is not well defined in the context of vertical, top-to-bottom inline progression line layout. For example, rotating latin text 90 degrees counter-clockwise would effectively make it a bottom-to-top inline progression layout, which is not supported by any (currently) defined writing mode in TTML. Reviewing both [UTR50](http://www.unicode.org/reports/tr50/tr50-17.html#vo_values) and [CSS Writing Modes Level 3](https://www.w3.org/TR/css-writing-modes-3/#text-orientation) reveals that in all cases, only 90 degree clockwise rotation is sanctioned. Since we have marked `#textOrientation-sideways-LR` as at-risk, I suggest we remove this feature, including the semantics of `sidewaysLeft` which appears to sanction a less than well-defined CCW rotation. Although this is a substantive change, it is permitted prior to PR without triggering a new CR since it has been marked at risk. Please view or discuss this issue at https://github.com/w3c/ttml2/issues/980 using your GitHub account
Received on Sunday, 26 August 2018 05:38:15 UTC