[webkit-dev] Can someone explain tx/ty?

2010-08-23 Thread Eric Seidel
I believe int tx, int ty -- which we see sprinkled around the rendering tree -- are the offset from the top left corner of the current renderer's parent to the containing block. Is that correct? In SVG we use IntSize containingBlockOffset in the rare places we have to deal with this

Re: [webkit-dev] Can someone explain tx/ty?

2010-08-23 Thread Maciej Stachowiak
On Aug 23, 2010, at 12:51 AM, Eric Seidel wrote: I believe int tx, int ty -- which we see sprinkled around the rendering tree -- are the offset from the top left corner of the current renderer's parent to the containing block. Is that correct? In SVG we use IntSize containingBlockOffset

Re: [webkit-dev] Can someone explain tx/ty?

2010-08-23 Thread David Hyatt
On Aug 23, 2010, at 4:33 AM, Maciej Stachowiak wrote: - tx, ty are the origin of the parent's coordinate system relative to the origin for its layer. When a layer paints, it establishes a CTM such that its own origin is 0, 0 (I think). They are relative to a painting root, which will

Re: [webkit-dev] Can someone explain tx/ty?

2010-08-23 Thread David Hyatt
On Aug 23, 2010, at 12:11 PM, David Hyatt wrote: (hopefully less verbose, but you get the idea). tx, ty could be named parentOffsetFromLayerCoordinates or something. This seems to be the intent of the names - that x,y is a point and tx, ty is a translation. But this doesn't work in