Re: [oiic-formation-discuss] My perspective. display perferct?

[jose lorenzo <hozelda@yahoo.com>]

--- On Sat, 7/5/08, Peter Dolding <oiaohm@gmail.com> wrote:

> From: Peter Dolding <oiaohm@gmail.com>
> Subject: Re: [oiic-formation-discuss] My perspective. display perferct?
> To: hozelda@yahoo.com
> Cc: oiic-formation-discuss@lists.oasis-open.org
> Date: Saturday, July 5, 2008, 9:34 AM
> On Sat, Jul 5, 2008 at 9:30 PM, jose lorenzo
> <hozelda@yahoo.com> wrote:
> 
> > 2 pixels is twice as thick as 1 pixel, ie, 100% extra
> thick. So you can create a series of lines across the
...
> Ok we are nailed right off the start line.  Most parts of
> ODF don't
> use pixels.   They use relative measurements like cm pt
> inch real
> world distances.   Simply put for over 90 Percent of ODF
> this is
> unworkable.   When you are in the world of conversions you
> have to
> allow for rounding errors on scaling.
> 
> Layout Perfect or Typesetting Perfect what every you want
> to call it
> were there is tolerance for error to a small amount is
> workable.

Not all +-2 pixel cases are created equal. There is a significant error between the equivalent of .4 pixels (rounded down to 0 pixels) and 2.4 pixels (rounded down to 2 pixels). Thus a line could be off by a multiple of SIX in real measurements yet show up as only 2 pixels during a particular rendering. [I'm ignoring -2 for this argument, but if anything this likely makes the arg stronger.] In fact, it only gets worse here if the correct width of the line was to be less than .4 pixels after the transformation (vs. the actual 2.4).

As stated at the top of the original post (but not quoted here), I am not being specific to this or any example about pixel perfection. Context matters, but I wanted to show that, should it become desirable to test near a few pixels like a 2 pixel difference, this might be very achievable by finding a way to adjusting the scale (eg, through repetition in close proximity). We can probably find a way to test 2 pixels, even perhaps quite easily automatically. Context matters.

As an aside, I don't know if ODF talks about rounding, but in some scenarios you may want anything greater than 0.0 + delta pixels to round up to 1 pixel. The argument being that you don't want the FPU error to mess things up, but, otherwise, showing a pixel when something exists might be preferable to showing nothing. This might be the case for very thin lines intended to exist to separate items so that the user can see that something is in fact there (for non-graphical cases, pixelization would be much less relevant).