Re: volunteers to fix some minor bugs in the lua/tikz terminal?

[Christoph B. <us...@be...>]

Hi,

Am 02.09.2014 22:18, schrieb Ethan A Merritt:
>
> (2)
> The linetype LT_NODRAW (defined as -3 in term_api.h) is supposed
> to indicate that this line is not drawn at all.  When applied to a fill area
> it is supposed to indicate that no fill is present (i.e. 100% transparent).
> The lua code is treating this the same as LT_BACKGROUND, which is
> suppoed to mean "draw this line in the background color".
> It is true that if you are drawing directly onto the background these both
> come out the same.   But if you draw a new line on top of a dark area,
> say a previous filled area, then they most certainly are not the same.

the more I look through the code, the more confused I get concerning the 
handling of LT_BACKGROUND, LT_NODRAW and FS_EMPTY:

* According to comments in many terminal drivers, FS_EMPTY is handled as 
if it should be filled with background color. However, I didn't manage 
to get any plot command which actually delivers the FS_EMPTY style to 
the terminal driver. Do you have an example?

I would expect the FS_EMPTY call to be handled like LT_NODRAW, i.e. no 
fillarea should be drawn at all.

* Based on your description above (LT_NODRAW applied to a fill area), I 
constructed the following script:

set object rectangle from graph 0,0 to graph 1,1 fc rgb 'red' fs solid
set object polygon from graph 0.2,0.2 to graph 0.5,0.2 to graph 0.6, 0.7 
fs solid fc lt -3

plot x

That however fails on all terminals I tested and always draws a white 
polygon (tested cairo terminals, qt, svg, lua).

Best,
Christoph