Forcing pixel boundaries

**bcire68** · 29 October 2007, 03:45 PM

I read this post this morning and I was just thinking that it would be a big help to have an option to have the outline be wholy contained within or wholy outside a given shape, as well as the current method. IMHO, this would take away a lot of the aggrevation of half pixels and anti-aliasing, etc. This added feature would also eleminate the need to "work around" a limitation in the current functionality.

What does the community think?

Eric

**Egg Bramhill** · 29 October 2007, 11:50 PM

I don't know the historical reason for putting a stroke half in and half out of a shape. It could be something to do with avoiding bleeds in anti-aliasing if the 2 shapes aren't on exact pixel units, so by placing the line half in and half out it avoids this, but that's only a guess. It's probably more to do with the way the vectors rendered. The same vector points can be used for both the shape and the line but if the line was all out or all in then new vector points would need to be used.

Personally I don't see it as a huge issue, but if there was an option to do things differently I'd suggest that the line should be inside the shape, thus the shapes dimensions wouldn't alter regardless of line width.

**ss-kalm** · 30 October 2007, 01:06 AM

I think as you mention that it means only one set of vectors define both line and shape - thus making things faster. All CAD programs work the same as all dimensions are measured to the centre of lines. Maybe that's where your "historical" reason comes from

I really like the idea of the line half in and half out of a shape. I often (as you can see from my avatar) use bevelled text with a black border. With the line settings as they are cloning the text without a bevel, increasing line width and sending to back makes an effective black border without the need for further adjustment. IMHO it doesn't need to be fixed ..... it aint broke.

**Xhris** · 31 October 2007, 07:15 PM

Originally Posted by james_frost

...after using Xara on and off since 2000 I still didn't understand the basics

...

I often noticed this was the case amongst people (including myself), and it was for this reason why I wrote some tutorials (link in my name signature below). You might want to give "Grid, Guides, Snapping and Scale Line Widths" a read; it's quite replete.

FYI, the line is half in and half out of the parent shape because Xara's rendering engine and file structure is based on the Adobe Postscript rendering model, which defines it this way.

**accessD** · 01 November 2007, 07:04 PM

Originally Posted by Egg Bramhill

I don't know the historical reason for putting a stroke half in and half out of a shape.

Charles said once this is because of using PostScript standard for printing in Xara. There is no "full in" or "full out" stroke in this standard. Corel also emulates this by adding fake shapes little bigger or little smaller.