Changes between Version 11 and Version 12 of LayoutUnit

Timestamp:

Apr 18, 2012 1:13:26 PM (12 years ago)

Author:

leviw@chromium.org

Comment:

--

LayoutUnit

@@ -89 +89 @@
 When attempting to determine the proper unit and conversion for a new variable, here are some common types to help you decide:
 
-||A value passed in or out of the embedding layer.||Pixels: the embedding layer has no knowledge of WebKit’s subpixel units. This includes things in the render tree that are rendered outside of WebKit (like Widgets) or pass out of WebKit before being drawn (like SVG Foreign Objects). Values originating in subpixel units should be pixel snapped.||
+||A value passed in or out of the embedding layer.||Pixels: the embedding layer has no knowledge of WebKit’s subpixel units. This includes things in the render tree that are rendered outside of WebKit (like Widgets) or pass out of WebKit before being drawn (like SVG Foreign Objects). Values originating in subpixel units should be pixel snapped. Padding and margin rendered inside of objects rendered by platform code are truncated to integers.||
 ||A value passed to the graphics context.||Float for text, otherwise pixels: LayoutUnits should always be pixel snapped before being drawn. This avoids painting off pixel boundaries, which causes the graphics system to use unwanted antialiasing.||
 ||A point (or offset) in the render tree.||Subpixel, rounded if needed: Points in the render tree are often converted between absolute and relative coordinates, and need to accumulate sub-pixels. Points are ultimately rounded when passed into the embedding layer or to the graphics context.||