Re: gEDA-user: coordinate systems [was: pcb crooked traces]

[Levente Kovacs <leventelist@xxxxxxxxx>]

On Sun, 17 Oct 2010 11:02:03 -0400
Phillip Jones <pjones13@xxxxxxxxx> wrote:

> Mainly because that has been the standard at least since Televisions
> were invented. The beam in a CRT scans from left-to-right,
> top-to-bottom. It's codified in the NTSC standard. So (x,y)=(0,0) is
> the upper left corner. Why are CRT's like this? Probably because words
> in books are also oriented left-to-right, top-to-bottom. Maybe if the
> television had been invented in the middle-east it would be different.
> I've got several digital image processing books on my shelf, the
> oldest is from 1972. Every one of them defines (x,y)=(0,0) as the
> upper left corner of an image. y as positive down, and x as positive
> right is simply the de-facto standard in digital image processing.

I think that is why X11 has its coordinate system as is; and that is why PCB
developers went that way. But a CAD tool is not about CRT display or image
processing. I think we should change it; it looks very awkward for a new user,
who doesn't know the story.

Just my EUR0.02

Levente

-- 
Levente Kovacs
http://levente.logonex.eu




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