Thanks for the reply David. I may end up taking the approach you describe down the road. My first experiment was to add a seed to the FontCache objects, and have them check it when a width was requested, and clear their cache if the seed was out of date. I didn't follow that too far, and now I'm doing the simplest approach (to get going), which is to force all measures and draws through the "complex" case: drawComplexText and floatWidthForComplexText. I know this means I have to handle the linquistic processing on my side, but it does solve my spacing problems (and I draw just as fast or faster here than via drawGlyphs).
I'm not very excited about taking on the unicode-processing burden, so I will continue to look for other ways to make zooming look good (including your archirectural fix to reference counting the cache.) mike On 1/11/07, David Hyatt <[EMAIL PROTECTED]> wrote:
This is an architectural flaw right now. I broke the ability to flush the cache when porting the code from Obj-C to C++, because I lost the reference counting aspect of the font cache. You basically want the ability to flush the cache. My suggested approach would be to re-architect things so that FontData and FontPlatformData are actually reference-counted objects. Right now font lookup is a 2-step process primarily just for Mac. You go from: FontDescription -> FontPlatformData and then from FontPlatformData -> FontData On the Mac, FontPlatformData doesn't need to be reference-counted, since it wraps an NSFont, which is already reference-counted and canonical (so that the same font will yield the same NSFont*). Because it's canonicalized, you can actually easily go from NSFont -> FontData. In order to flush the cache easily, you need FontData to be reference- counted so that the cache can drop references, and then the individual RenderStyles can drop references as they go away. FontPlatformData is the sticky bit though. FontPlatformData will have to properly reference-count its internal object on all platforms. The easiest way to guarantee this works on all platforms would probably be to just make FontPlatformData reference-counted too. If this is done, the retains and releases of the NSFont on Mac could be dropped from FontPlatformData's constructors and destructors on Mac. I don't really have plans to get to this soon, so this would definitely be an area in which you could help out. :) dave ([EMAIL PROTECTED]) On Jan 11, 2007, at 1:26 PM, Mike Reed wrote: > In the (nearly) latest version, webkit is caching glyph metrics based > on font+pointSize. If my device characteristics change (e.g. screen > res), I think I need to invalidate those widths (or spawn a new set), > so that measuring and drawing reflect the new values. > > Any pointers to help me with my port? > _______________________________________________ > webkit-dev mailing list > [email protected] > http://lists.webkit.org/mailman/listinfo/webkit-dev
_______________________________________________ webkit-dev mailing list [email protected] http://lists.webkit.org/mailman/listinfo/webkit-dev
