[metapost] defaultcolormodel

[luigi scarso]

On Fri, Jul 8, 2011 at 12:31 PM, Stephan Hennig <mailing_list at arcor.de> wrote:
> There must be some colour to output anything even if no withcolor
> statement is given (including drawoptions).
yes, of course. Probably in the default format, or in metapost itself
there is a default color (0,0,0)


> Think about MetaFont that
> has no notion of colours, yet it has to distinguish between pixels that
> have been touched by a pen and those that haven't in the output.  This
> 'implicit' black is what defaultcolormodel refers to (and what I meant
> by 'black ink').
Almost.
In Metafont each pixel has 7 weights:  -3,-2,-1,0,1,2,3, hence
it's a kind of gray color space.
It's useful to ensure that a pixel is black.


-- 
luigi