Re: Shadows vs. layout

David Hyatt wrote:
> 
> Having two types of overflow means that when it comes time to calculate 
> scroll dimensions, you have to omit the shadow information.  This means 
> that overflow information that is propagated to containers now has to 
> come in two flavors...  the overflow information *has* to be cached for 
> efficient dirty rect intersection testing on repaints, so you're left 
> with the choice of either caching two sets of propagated numbers or just 
> not using the cached numbers when computing scroll information.   The 
> first solution will impact memory.  The second solution will impact 
> performance.  Neither solution makes me very happy as an implementor.

Usually both sets will coincide. If you've got free state bits, you can
store the more unusual data in a property-table and only look it up when
needed. Gecko does this for certain types of overflow data.

~fantasai

Received on Monday, 3 August 2009 22:58:39 UTC